Method for manufacturing a thermoplastic plastic container and system for pulling apart a tube

专利摘要:
A method of manufacturing a thermoplastic plastic container. The method includes locally heating a middle zone of a thermoplastic plastic pipe; gripping the tube on both sides by using gripping members; pulling apart the tube narrowing a middle zone; pushing the inner wall of the middle zone together to obtain a seal; and cutting the closed center zone to obtain two separate tubing sections. The container is formed by: blow molding a pipe part; or arranging a bottom molding member and deforming a bottom portion by pressing a bottom molding member and a holding member together; or by vacuum forming the bottom portion. This combination of steps allows to make containers over a whole range of relative and absolute dimensions.
公开号:BE1026730B1
申请号:E20185937
申请日:2018-12-21
公开日:2020-06-02
发明作者:Alain Pierre Ormeggi
申请人:Valunorm Bvba；
IPC主号:

专利说明:

Werkwik® for manufacturing a thermoplastic plastic container and system for pulling apart a tube
Technical field
The present invention relates to a method of manufacturing a thermoplastic plastic container. The present invention also relates to a system for pulling apart a tube, in particular a thermoplastic plastic tube, and its use in the manufacture of a thermoplastic plastic container.
State of the art
In the prior art, thermoplastic plastic containers are used to pack various consumer goods, including detergents, food, for example in the form of liquids (such as drinks), solids (such as butter) or powder (such as Nesquik), and other objects, for example toys, kitchen utensils or parts for vehicles (eg parts of the engine). Depending on the desired application, containers are required over a whole range of different dimensions with a wide range of different materials. Correspondingly, different methods are also known for manufacturing such containers depending on the application.
In a first known application, a container is made by thermoforming. Here, a flat layer of a thermoplastic plastic is heated, for example by an infrared radiation source, until the thermoplastic plastic has reached its thermoforming temperature, which is normally between its glass transition temperature and its melting temperature. After this, the flat layer is locally deformed by an external force,
BE2018 / 5937 for example by deep drawing with a pestle, in order to obtain the desired shape of the container. Typically, but not always, the mold is also blown against the mold after deep drawing. This desired shape is then retained after the thermoplastic plastic has cooled. Materials suitable for this process include, inter alia, polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS) and polypropylene (PP). A typical example of a container made in this way is a butter dish.
A drawback of this method is that the relative dimensions of the container are limited. In particular, the depth of the container can, in practice, hardly ever exceed, or at least not significantly exceed, the length and / or the width of the container. In addition, the ratio of the length to the width is often also limited such that, typically, the length is at most about double the width.
Furthermore, the dimension of the top opening of the container depends on the size of the pestle. Namely, the top opening of the container should be large enough for the pestle to be removed.
Furthermore, deep drawing causes the side walls to be very thin and, in particular, thinner than the bottom. In other words, the container does not have a uniform thickness. These thin walls also limit the extent to which the container can still be inflated, since over-inflating the container can cause the already thin walls to become too thin, compromising the integrity of the container.
Labels can be applied to the container by applying so-called in-mold labeling or by applying the label after the container has been manufactured, or by applying a print after the container has been cooled.
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In a second known application, a container is made by injection molding. Here, a thermoplastic plastic in a liquid state is injected under high pressure into a mold, the cavity of which is the shape of the desired container. The plastic solidifies by cooling. Materials suitable for this method include, inter alia, PE and PP. A typical example of a container manufactured in this manner is a reusable container, such as a Tupperware or Rubbermaid container.
A drawback of this method is that the entire container is necessarily made from one and the same thermoplastic plastic. This makes it difficult to provide an odor and / or moisture barrier.
Also, it is practically impossible to provide undercut shapes since such dies are very expensive. Namely, it is necessary that the central part of the mold is then adjustable to a diameter smaller than the smallest diameter of the container, which is mechanically complex. In addition, the outer shape of the mold must also consist of at least two halves. Due to their high cost, such molds are not economically applicable for the production of disposable containers, for example.
Furthermore, the wall of the container should be quite thick since the plastic, in its liquid state, must flow through the mold. This also leads to a limitation of the relative dimensions of the container. In particular, the following rule of thumb applies, namely, the larger the volume of the container must be, the thicker the walls must be. However, the time required for the container to cool, i.e. harden, in the mold increases rapidly depending on the thickness of the walls. In other words, the production of large containers takes considerably more time and is therefore less economically interesting.
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In addition, although printing on the container is theoretically possible by providing the corresponding shape on the die, any change in the shape of the printing requires the die to be replaced, which is overly expensive. Applying a label during the production of the container is also very laborious and usually requires the use of a vacuum installation to prevent liquid plastic from getting between the label and the mold. Also, a new label design often results in stocks of previous labels having to be discarded and / or a new device required for manufacturing the new labels.
In a third known application, a container is made by blow molds, also known as extrusion blow molding. A thermoplastic plastic is first extruded in a preform (a so-called parison), for example a hollow tube. Immediately afterwards, the preform, which is still warm and semi-liquid, is placed in a mold and blown against the mold with the aid of a gas, for example compressed air, in order to obtain the desired shape of the container. This desired shape is then retained after the thermoplastic plastic has cooled. This type of blow molding is therefore an almost continuous process. Materials suitable for this method include, inter alia, PE and PP. A typical example of a container manufactured in this manner is a fabric softener or detergent bottle.
A drawback of this method is that the PET material is difficult to use in practical applications. In general, extrusion blow molding is very sensitive since the parison is almost liquid, which means that the preform can deform undesirably even with small air disturbances, for example opening an outside door in a production hall. Since PET is even more fluid compared to other materials (such as PE or PP), the unwanted deformation can even lead to a collapse of
BE2018 / 5937 de parison.
Furthermore, the blowing causes different parts of the preform to expand differently, so that the thicknesses of the different walls of the container are not uniform. Also, the wall should be relatively thick for the preform to be sufficiently rigid. Labels can be applied to the container by applying the so-called in-mold labeling or by applying the label after the container has been made or by printing it on the container afterwards.
The blow molding can also be used, in modified form, for the production of containers (e.g. bottles) for water and soft drinks based on PET. This is known as injection blow molding or injection stretch blow molding. For this, the preform is obtained by injection molding in the case of injection blow molding (which, as described above, makes it difficult to foresee an odor and / or moisture barrier) or with a stamper in the case of injection stretch blow molding. This type of preform is used after it has cooled and is typically completely solid and, in particular, much firmer compared to a parison, making the PET material useful. On the other hand, since the preform is the result of injection molding, it is not possible to provide relatively large undercuts, since the preform cannot be undercut. Undercuts can be provided during blow molding, but this causes local thinning of the container walls, which is undesirable.
Also, an installation for injection blow molding is relatively expensive.
Description of the invention
It is an object of the present invention to provide a method for manufacturing a thermoplastic plastic container where there is less limitation on the relative dimensions of
BE2018 / 5937 the container.
This object is achieved by a method for manufacturing a thermoplastic plastic container, the method comprising: a) providing a thermoplastic plastic tube with an inner wall, an outer wall, a longitudinal direction, a first end, a second end, a middle zone, a first zone and a second zone, the first zone extending from the middle zone to said first end and the second zone extending from the middle zone to said second end; b) gripping said first zone and said second zone; c) locally heating said middle zone to the thermoforming temperature of the thermoplastic plastic; d) pulling said first zone and said second zone apart along said longitudinal direction thereby narrowing the middle zone; e) closing a closure portion of the middle zone to obtain a closure; f) cutting the closed middle zone at the closing portion to obtain two separate pipe sections; g-ii) placing at least one of the pipe sections in a mold; h-ii) heating said tube section in the mold to the thermoforming temperature of the thermoplastic plastic; and i-ii) blow molding said tubular section against the mold to obtain said container.
In step a), a thermoplastic plastic pipe is provided with a middle zone, a first zone and a second zone. Already in this step the dimensions of the container have already been mainly determined. After all, it is the case that these have been chosen such that, during blow molding in step i), the pipe part should only deform minimally. Hence, the final base surface of the container substantially corresponds to the diameter of the tube and the depth of the container substantially corresponds to the height of the first and second zone, respectively. The dimensions of the tube can be in it
BE2018 / 5937 are chosen in such a way that they are just small enough to be placed in the mold.
The method also makes it possible to obtain relatively large absolute dimensions of the container. This is partly because there is no need for injection molding which would entail thick walls and also because there is no need for a parison which is often too liquid to manufacture sufficiently large.
Likewise, there is less restriction to making undercuts. Namely, in no step in the method is there any need for a stamper or similar element to be placed inside the tube or container for deformation. Hence, the wall thickness of the blow molding container is much thicker compared to the existing methods, leaving sufficient material for the locally high deformation required for an undercut.
Furthermore, there is also no need to use a parison such that this method is also suitable for manufacturing PET containers and other materials that are typically too sensitive to extrusion blow molding.
In addition, this method allows for printing directly on the thermoplastic plastic pipe, especially on the first and / or second zone, since deformation is minimized during blow molding as described in more detail below.
Also, the final container, at least its sidewalls, has a more uniform wall thickness compared to containers manufactured by the existing methods since the tube is initially uniform in thickness and is poorly deformed relatively little.
It has been found in practice that the above-described method, when applied to certain thermoplastic plastics, can lead to the bottom of the container being quite brittle. It is true that
BE2018 / 5937 the bottom of the container that emerges from the middle zone during the process is normally heated at least twice, namely during the extraction of the tube and during the blow molding. However, it is known that such successive heating cycles are detrimental to the integrity and / or strength of certain thermoplastic plastics.
It is an alternative object of the invention to provide a method for manufacturing a thermoplastic plastic container, where there is less limitation on the relative dimensions of the container, where there is less limitation on the choice of thermoplastic plastic.
This alternative object of the invention is achieved by an alternative method for manufacturing a thermoplastic plastic container, the method comprising: a) providing a thermoplastic plastic tube with an inner wall, an outer wall, a longitudinal direction, a first end, a second end, a middle zone, a first zone and a second zone, the first zone extending from the middle zone to said first end and the second zone extending from the middle zone to said second end; b) gripping said first zone and said second zone by means of holding members, each of said holding members having a molding surface substantially perpendicular to said longitudinal direction and located along said middle zone; c) locally heating said middle zone to the thermoforming temperature of the thermoplastic plastic; d) pulling said first zone and said second zone apart along said longitudinal direction thereby narrowing the middle zone by moving said holding members away from each other; e) closing a closure portion of the middle zone to obtain a closure; f) cutting the closed middle zone at the front closing section
BE2018 / 5937 splitting the middle zone into a first part and a second part so that said pipe is split into a first and a second pipe part, the first pipe part comprising said first zone and a first bottom part, which first bottom part is formed by said first portion of the middle zone and wherein the second tube portion comprises said second zone and a second bottom portion, said second bottom portion being formed by said second portion of the middle zone; gi) arranging, for at least the first tube part, a bottom molding member opposite a respective of said holding members so that said first bottom portion is located between the bottom molding member and the respective holding member, each bottom molding member having a counter-forming surface which is substantially perpendicular to said longitudinal direction and oriented to its respective shape surface; and h-i) deforming said first bottom portion into a bottom by pressing the bottom molding member and its respective holding member together.
The same advantages are retained in this alternative method, for example that the dimensions of the container have already been mainly determined in step a). Moreover, the dimensions of the container may even be completely determined in step a) if the container is no longer deformed after step h-i).
This alternative method has the further advantage that there is no need to reheat each tube section after blow molding for blow molding in a mold. On the contrary, after splitting, the bottom is immediately formed by the bottom parts created from the split of the middle zone.
In an embodiment of the alternative method, step h-i) comprises venting gas from a space between said mold surface and said first bottom portion, preferably each receptacle is provided with a gas vent for said venting.
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This avoids an overpressure between a holding member and a bottom portion during the pressing of the mold surface and the counterform surface together.
In an embodiment of the alternative method, steps d), e), f), g-i) and h-i) are performed without cooling said middle zone below the thermoforming temperature of the thermoplastic resin.
This alternative object is also achieved by another method of manufacturing a thermoplastic plastic container, the method comprising: a) providing a thermoplastic plastic tube with an inner wall, an outer wall, a longitudinal direction, a first end, a second end, a middle zone, a first zone and a second zone, the first zone extending from the middle zone to said first end and the second zone extending from the middle zone to said second end; b) gripping said first zone and said second zone by means of gripping members, each of said gripping members having a molding surface substantially perpendicular to said longitudinal direction and located along said middle zone; c) locally heating said middle zone to the thermoforming temperature of the thermoplastic plastic; d) pulling said first zone and said second zone apart along said longitudinal direction thereby narrowing the middle zone by moving said holding members away from each other; e) closing a closure portion of the middle zone to obtain a closure; f) cutting the closed middle zone at the closure portion to split the middle zone into a first section and a second section so that said tube is split into a first and a second tube section, the first tube section being said first zone and a first bottom portion, which first bottom portion is formed
BE2018 / 5937 is through said first portion of the middle zone and wherein the second tube portion comprises said second zone and a second bottom portion, said second bottom portion being formed by said second portion of the middle zone; and g-iii), for at least the first pipe section, drawing gas out of a space between said molding surface and said first bottom portion for deforming said first bottom portion to against said molding surface.
The same advantages are retained in this other method, for example that the dimensions of the container have already been mainly determined in step a). Moreover, the dimensions of the container may even be completely determined in step a) if the container is no longer deformed after step h-i).
This other method also has the advantage that there is no need to reheat each pipe section for blow molding in a mold after splitting the tube. On the contrary, after splitting, the bottom is immediately formed by the bottom parts arising from the splitting of the middle zone by the vacuum forming of the bottom part.
Obtaining the closure in step e) can be done in several ways.
In a first embodiment, step e) further heating at least the closing portion of said middle zone above the melting temperature of the thermoplastic plastic before pushing the inner walls together so that the inner walls pushed together fuse to obtain the seal.
In a second embodiment, step a) comprises co-extruding the tube with an inner layer formed by a low density polyethylene or a linear low density polyethylene and step e) further heating at least the closure portion of said middle zone above the melting temperature of the
BE2018 / 5937 low-density polyethylene or the linear low-density polyethylene before pushing the inner walls together so that the inner walls pushed together fuse to obtain the closure.
In a third embodiment, step a) includes applying an adhesive layer to the inner wall of said middle zone at least at said closing portion and step e), after the inner walls have been pressed together, to cure the adhesive layer to obtain of the closure.
These alternative possibilities make it possible to manufacture the closure in different ways depending on the desired application. For example, certain thermoplastic plastics are less suitable for manufacturing a seal by melting, while co-extrusion increases the cost, which is not always desirable.
Obtaining the thermoplastic plastic tube in step a) can be done in several ways.
In a first embodiment, step a) comprises extruding the tube.
In a second embodiment, step a) comprises co-extruding the tube.
In a third embodiment, step a) comprises injection molding the tube.
These alternative possibilities make it possible to manufacture the thermoplastic plastic pipe in different ways depending on the desired application. The desired thickness of the pipe can thus be taken into account before deciding which process to use.
In the second embodiment, the co-extrusion can be used to produce at least one layer that forms an odor barrier and / or a moisture barrier. Optionally, the inner layer can also be made of low-density polyethylene or linear low-density polyethylene for the closing of step e).
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The process of the invention is suitable for a wide variety of thermoplastic plastics, including polyethylene terephthalate, polypropylene, polyvinyl chloride, polystyrene, acrylonitrile butadiene styrene, polyethylene and biopolymers, especially polylactic acid.
In an advantageous embodiment, step a) comprises applying a print to an outer wall of the tube. Here, the printing preferably has a design that takes into account blow molding deformation in step i-ii).
The print can be used to convey information to the consumer, such as the brand name, container features, etc. In other words, the print can replace a label to be applied with an in-mold process or afterwards. Such prints are also difficult to remove unlike a label. In addition, such printing is also more environmentally friendly than a label since the printing is applied directly to the container, while the label may be made of a material other than the container, which complicates recycling.
In one embodiment, step g-ii) includes placing a label between the tubing and the mold.
This makes it possible to apply a label to the container via an in-mold labeling process.
In an advantageous embodiment, step a) comprises providing said tube with a protruding portion at its first end and at its second end integrally manufactured with the tube and the method further comprising step j) deforming said protruding portion into a lid for the container.
By providing an integrally manufactured protruding portion at the ends, which ends form the top of the container, these portions can be used to form the lid of the container.
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In an embodiment, step e) comprises pushing the inner wall of said closure portion together to obtain said closure.
In an alternative embodiment, step e) includes rotating said first zone and said second zone about said longitudinal direction in opposite directions relative to each other to obtain said occlusion.
These alternative embodiments allow to obtain the closure in different ways.
It is a further object of the present invention to provide a system for pulling apart a tube.
This further object is achieved by means of a system for pulling apart a tube, which tube has an inner wall, an outer wall, a longitudinal direction, a first end, a second end, a middle zone, a first zone and a second zone wherein the first zone extends from the middle zone to said first end and the second zone extends from the middle zone to said second end, the system comprising: a first holding means which is provided, via the first end, in the first 20 zone to be entered; a second receptacle adapted to be inserted, via the second end, into the second zone, each receptacle being adjustable between a first position in which the receptacle fits inside the tube and a second position in which, in use, the receptacle is pressurized exerts on the inner wall of the tube; and actuating means configured to: insert the receptacles in their first position into their respective zone of the tube; then bringing the fasteners into their second position so that they exert pressure on the inner wall of the tube to provide a temporary fixed connection between a fastener and its respective zone; and then moving the holding members apart to form the first zone and the
BE2018 / 5937 move the second zone of the pipe away from each other.
By using such a system it is possible to make a temporary fixed connection between a securing member and its respective zone so that movement of the securing members leads to the zones moving away from each other.
In one embodiment, each receptacle includes an inflatable annular element that has a deflected position in which the annular element fits within the tube and has an inflated position in which the annular element, in use, exerts pressure on the inner wall of the tube.
The released position of the annular element corresponds to the first position of the holding member and the inflated position of the ring-shaped element corresponds to the second position of the holding member. The use of inflatable means has the advantage that the pressure is exerted more uniformly on the tube, in contrast to mechanical means, so that there is less chance of damage to the tube. Also, inflatable means are relatively inexpensive compared to mechanical means.
Preferably, the annular element is located in a channel provided on the holding members. In one embodiment, the trough is formed between two plate-shaped elements, each of which has a shape corresponding to a cross-section of the tube. Advantageously, one of the plate-shaped elements, typically the outer one, is mounted on a movable arm configured to be controlled by the actuating means. In another embodiment, each holding member is manufactured integrally.
In an advantageous embodiment, the driving means are further configured to insert the first securing member in the first zone of the tube as close as possible to the middle zone and inserting the second securing member into the second zone of the tube as close as possible at the middle zone.
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This reduces the risk of deformation of the first and second zones.
The tube can be made from a variety of materials, including metal, a thermoplastic, or glass.
In an advantageous embodiment, the system further comprises heating means provided to heat said center zone and wherein the driving means are further configured to drive the heating means to heat said center zone before the holding means are actuated to move away from each other.
The heating means make it easier to move the first and second zones away from each other with a limited force.
In one embodiment, a length of the middle zone is selected in function of a desired thickness of a bottom of the container.
It is the case that stretching the middle zone locally reduces the wall thickness. By taking the middle zone sufficiently long, it is possible to minimize the local thinning of the wall during stretching, so that the bottom of the container, which is formed by a part of the middle zone, is sufficiently thick.
In one embodiment, the tube is made of a thermoplastic plastic and the system further comprises splitting means movable substantially transversely of said longitudinal direction to split the middle zone into a first section and a second section so that said tube is split into a first and a second pipe section, the first pipe section comprising said first zone and a first bottom section, said first bottom section being formed by said first section of the middle zone and the second pipe section comprising said second zone and a second bottom section, said second bottom section
BE2018 / 5937 is formed by said second part of the middle zone, and wherein the actuating means are further configured to move the splitting means transversely, in particular towards each other, after splitting means have moved away from each other, in order to split said tube in said pipe sections.
This system allows not only to pull apart the thermoplastic plastic tube, but also to divide this tube into two tube parts.
In a preferred embodiment, each of said retaining members comprises a molding surface configured to be positioned substantially perpendicular to said longitudinal direction and along said middle zone, the system further comprising: a first bottom molding means adapted to cooperate with said first retaining member about said deform the first bottom section; a second bottom former configured to cooperate with said second holding member to deform said second bottom portion, each bottom former comprising a counterform surface corresponding to its respective mold surface and configured to be substantially perpendicular to said longitudinal direction and oriented to its respective mold surface positioned, and wherein the actuating means are further configured to, after the splitting means have split the tube: to position the first bottom molding member opposite the first holding member and the second bottom molding member opposite the second holding member; and then pressing the first bottom molding member and the first holding member together to deform said first bottom portion to form a bottom and pressing the second bottom forming member and the second holding member together to deform said second bottom portion into a bottom.
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This system allows, after the pipe has been split into pipe parts, to deform the bottom part of each pipe part into a bottom without having to use an additional blow molding step.
Preferably, each receptacle having a gas vent opening is configured to vent a gas from a space formed between said mold surface and said first bottom portion. In particular, this gas discharge opening is formed by making the movable arm hollow.
As above, such a gas discharge opening prevents an overpressure from occurring between the mold surface and the bottom part of the pipe part.
In an alternative preferred embodiment, each of said capturing members comprises a molding surface configured to be positioned substantially perpendicular to said longitudinal direction and along said middle zone, each capturing means having a plurality of gas vent openings configured to form a gas from a space formed between said molding surface. and releasing said first bottom portion, which system further includes suction means configured to aspirate gas from a space between said mold surface and said first bottom portion through said gas vent openings.
This system allows, after the pipe has been split into pipe parts, to deform the bottom part of each pipe part into a bottom without having to use an additional blow molding step and without having to use one or more bottom mold members.
The object of the invention is also achieved by using a system as described above for performing steps c) and d) of the method as described above.
The alternative object of the invention is also achieved by using a system as described above for implementation
BE2018 / 5937 of steps g-i) and h-i) of the method as described above and also by using a system as described above for performing step g-iii) of the method as described above.
In a further embodiment, the invention provides a method for manufacturing a thermoplastic plastic container, the method comprising: a) providing a thermoplastic plastic tube with an inner wall, an outer wall, a longitudinal direction, a first end, a second end a middle zone, a first zone and a second zone, the first zone extending from the middle zone to said first end and the second zone extending from the middle zone to said second end; b) gripping said first zone and said second zone; c) locally heating said middle zone to the thermoforming temperature of the thermoplastic plastic; d) pulling said first zone and said second zone apart along said longitudinal direction thereby narrowing the middle zone; e) closing a closing portion of the middle zone to obtain a closure; f) cutting the closed middle zone at the closing portion to obtain two separate pipe sections; and g-iv) deforming at least one of said tube parts into a container.
Details on steps a) to f) are already described above. Step g-iv) in one embodiment comprises steps g-i) and h-i) already described above. Step g-iv) in one embodiment comprises steps g-ii), h-ii) and i-ii) already described above. Step g-iv) in one embodiment comprises steps g-i), h-i), gii), h-ii) and i-ii) which have already been described above. Step g-iv) in an embodiment comprises step g-iii) already described above. Step g-iv) in one embodiment comprises steps g-iii), g-ii), h-ii) and i-ii) already described above.
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Brief description of the drawings
The invention will be explained in more detail below with reference to the following description and the accompanying drawings.
Figure 1 shows a flow chart of a method for manufacturing a thermoplastic plastic container.
Figure 2 shows a thermoplastic plastic tube for use in the method of Figure 1.
Figure 3 shows a system for pulling apart the tube of Figure 2 for use in the method of Figure 1.
Figure 4 shows a holding member of the system of Figure 3 in more detail.
Figure 5 shows the tube of Figure 2 after pulling the first and second zones apart using the system of Figure 4.
Figure 6 shows a container blow molding system for use in the method of Figure 1 where the front part of the mold has been omitted.
Figure 7 shows an alternative thermoplastic plastic tube for use in the method of Figure 1.
Figure 8 shows a thermoplastic plastic container manufactured by the method of Figure 1.
Figure 9 shows a flow chart of an alternative method of manufacturing a thermoplastic plastic container.
Figures 10 to 12 show the successive steps for forming a bottom of the thermoplastic plastic container in the method of Figure 9.
Figure 13 shows the same view as Figure 4 for a holding member for use in the method of Figure 9.
Figure 14 shows the same view as Figure 11 with an alternative bottom molding member.
Figure 15 shows the same view as Figure 11 with alternative holding members.
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Embodiments of the Invention
The present invention will be described below with reference to certain embodiments and with reference to certain drawings, but the invention is not limited thereto and is only defined by the claims. The drawings shown here are only schematic representations and are not limitative. In the drawings, the dimensions of certain parts may be shown enlarged, which means that the parts in question are not shown to scale for illustrative purposes only. The dimensions and relative dimensions do not necessarily correspond to the actual practical embodiments of the invention.
In addition, terms such as "first", "second", "third", and the like are used in the description and in the claims to distinguish between similar elements and not necessarily to indicate a sequential or chronological order. The terms in question are interchangeable in the appropriate circumstances, and the embodiments of the invention may operate in sequences other than those described or illustrated here.
In addition, terms such as "top", "bottom", "top", "bottom", and the like are used in the description and in the claims for descriptive purposes. The terms thus used are interchangeable under appropriate conditions, and the embodiments of the invention may operate in orientations other than those described or illustrated here.
The term "comprising" and derived terms, as used in the claims, should or should not be interpreted as being limited to the means which are stated thereafter; the term does not exclude other elements or steps. The term is to be interpreted as a specification of the stated
BE2018 / 5937 referenced properties, integers, steps, or components, without, however, excluding the presence or addition of one or more additional properties, integers, steps, or components, or groups thereof. Therefore, the scope of an expression such as "a device comprising means A and B" is not limited only to devices consisting purely of components A and B. What is meant, on the other hand, is that, as far as the present invention is concerned, the are only relevant components A and B.
As used herein, the term "container" means a typically thin-walled, volume-containing object. Examples are reusable boxes for storing goods, packaging, car parts, etc.
Figure 1 shows a flow chart of a method 100 for manufacturing a thermoplastic plastic container. In step 102, a thermoplastic plastic pipe 200 is provided with an inner wall 202, an outer wall 204, a longitudinal direction 206, a first end 208, a second end 210, a middle zone 212, a first zone 214 and a second zone 216, the first zone 214 extends from the middle zone 212 to said first end 208 and the second zone 216 extends from the middle zone 212 to said second end 210 as shown in Figure 2.
Each of zones 214, 216 will be deformed into a container. As shown in Figure 8, this container 500 may be provided with a lid 508. However, the container 500 need not necessarily have a lid 508. Sufficient is that the container 500 is provided with a bottom 502, side walls 504 (only two of which are indicated by a reference number) and an open top 506. The wall of the tube 200 in zones 214, 216 forms the side walls 504 of the container 500 and the middle zone 212 will serve to produce the bottoms 502 of the containers 500, in other words the middle zone 212 will
BE2018 / 5937 for manufacturing two separate bottoms 502. The tube 200 shown in Figure 2 is not provided to form a container 500 with lid 508, but to form a container around an open top 506 (as shown in Figure 6), while the tube 200 shown in Figure 7 is provided for this by the additional portions 220 at the ends 208, 210, which additional portions 220 will form the lid 508.
In one embodiment, the tube 200 is extruded. This can be done by introducing solid pellets of the thermoplastic plastic into a mold which heats it up so that it liquefies and then presses it through the mold to produce the hollow tube 200. Suitable thermoplastic plastics are polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS), polypropylene (PP) and biopolymers, such as polylactic acid.
The extrusion process can be carried out continuously or discontinuously. In addition, a co-extrusion can also be used to obtain a multi-layer pipe 200. In this way an odor barrier and / or a moisture barrier can be formed. Also, an inner layer can be made of a low density polyethylene or a linear low density polyethylene which, as described below, is advantageous for obtaining the seal of the middle zone 212.
In another embodiment, injection molding is used to manufacture the tube 200.
The dimensions of the tube 200, in particular the cross-section, are determined by the ultimately desired shape of the container. In particular, the cross-section should ideally be chosen which corresponds as closely as possible to the ground surface of the container.
In step 104, an optional printing can be applied to the outer wall 204, for example using rollers, pads, inkjet printing, offset printing, etc. When designing the printing (i.e. the
BE2018 / 5937 effective design), preferably, the deformation should be taken into account, although it is minimal, which is still required from the wall of the tube 200 in the blow molding step (step 118). Being able to form the print directly into the tube 200 has the advantage that, after the container has been manufactured, an additional label does not have to be provided, which additional label is typically made of a material other than the container, whereby the recycling of the container is made more difficult. Preferably, the printing is applied before the tube 200 is cut into pieces, which pieces serve to produce two containers. This allows the printing to be applied in-line with the extruding of the tube.
In step 105, zones 214, 216 are gripped as described in more detail below.
In step 106, the middle zone 212 is locally heated to the thermoforming temperature of the thermoplastic plastic which is typically above the glass transition temperature and below the melting temperature. This heating can be done in various ways, including the use of infrared lamps or heated airflows. The purpose of this step is to make the center zone 212 locally deformable. To this end, care should be taken to keep the temperature, preferably, below the melting temperature of the thermoplastic plastic to avoid collapse of the middle zone 212 as a whole.
In step 108, the first and second zones 214, 216 are pulled apart along the longitudinal direction 206. One of the two zones 214, 216 may remain stationary, but both zones 214, 216 may also be translated. It will be appreciated that by stretching the center zone the wall thins locally, which thinning can be minimized by taking the center zone sufficiently long as already described above.
Preferably, step 108 is used
BE2018 / 5937 made from a system 300 according to the present invention. As shown in Figure 3, the system 300 includes a frame 310 on which two movable arms 306, 308 are provided, which arms 306, 308 are provided on their ends with retaining members 302, 304. As shown in Figure 4, the retaining members 302, 304 provided with an inflatable annular element 408 sandwiched between two plates 402, 404 and supported on a support plate 406. In other words, the plates 402, 404, 406 together form a trough in which the annular element 408 is placed. The different plates 402, 404, 406 are, in the embodiment shown, connected to each other by bolts 412, but other connecting means, for example glue, are also possible. The plates 402, 404, 406 can also be integrally manufactured and provided with a channel in which the annular element 408 is located.
As shown in Figure 3, a first holding member 302 is inserted into the first zone 214 as close as possible to the middle zone 212, which middle zone 212 may already be heated but still be cool. Positioning the fastener 302 close to the middle zone 212 reduces the risk of the first zone 20 deforming under the influence of the tensile force to be applied to the fastener 302. Analogously, a second fastener 304 is introduced into the second zone 216. This insertion is accomplished by controlling the arms 306, 308 under the control of actuators (not shown) provided as part of the system 300. Both arms 256, 308 can be inserted sequentially or simultaneously.
Preferably, the middle zone 212 is not yet tangled before the retaining members 302, 304 engage their respective zone 214, 216 so that, as described below, the annular element 408 can perform its role as an insulator.
As shown in Figure 4, it is possible to adjust the holding members
302, 304 since their annular element 408 is in the
BE2018 / 5937 abandoned position. After the retaining members 302, 304 have been inserted, the annular elements 408 are inflated. This can be done, for example, by supplying compressed air, or another gas or liquid, via opening 414. By inflating the annular elements 408, these will exert a pressure on the inner wall 202 of the tube 200. Such contact results in the tube 200 is no longer locally displaceable relative to the retaining members 302, 304 due to the friction between the annular elements 408 and the inner wall 202 of the tube 200. In other words, the retaining members 302, 304 provide a temporary fixed connection with the first, respectively , second zone 214, 216 so that these zones can be moved.
After inflation, one or both of the retaining members 302, 304 are translated so that they are pulled apart in the longitudinal direction 206. As a result, zones 214, 216 are also moved away from each other, so that the middle part 212 has a smaller diameter as shown in figure 5, i.e. narrows the middle part 212. In one embodiment, the annular element 408 is made of a rubber.
The shape of the retaining members 302, 304 (ie the shape of the cross section substantially perpendicular to the longitudinal axis 206) is typically similar to the shape of the tube 200 so that the annular element 408 should be inflated as little as possible before it contacts the inner wall 202 of the tube 200. In case the annular element 408 has to bridge a relatively large amount of space to come into contact with the inner wall 202, the compressed air must be supplied under a relatively high pressure, which may result in the wall of the tube 200 deforms by the pressure of the annular element 408. It will be appreciated that, if the tube 200 has a rectangular, triangular, or other cross section, the annular element 408 has a corresponding shape.
An additional advantage of the annular element 408 is that this
BE2018 / 5937 partly functions as an insulator, whereby the first and second zones 214, 216 remain relatively cool compared to the heated middle zone 212. This further reduces the risk of deformation of the first and / or second zone 214, 216. In addition, the annular element 408 thus prevents the heating of the center zone 212 from having an effect on the crystal structure of the first and / or second zone 214, 216.
In an alternative embodiment, it is also possible to replace the inflatable annular element 408 by mechanical means, for example one or more bars that slide outwardly to push against the wall of the tube 200. Such mechanical means are especially advantageous if the tube is made of a metal, since the mechanical means can generate a greater frictional force allowing the zones 214, 216 to be pulled apart from a metal tube, as opposed to a rubber annular member 408 that could slip.
It is clear to a person skilled in the art that the system 300 is suitable for both thermoplastic plastic pipes and metal pipes. In addition, the system 300 is also suitable for pulling apart a glass tube.
In step 110, the most central part of the middle zone 212, which will hereinafter be referred to as the closing part 218, is pushed in such that opposed inner walls 202 come into contact so that the middle zone 212 is closed. This pushing together can be done by means of two bars (not shown) which are pushed together and between which the closing part 218 is located. In certain embodiments, these bars can also be mounted on the frame 310 of the system 300 and can also be controlled by the same actuating means. In another embodiment, there is no need for bars, but the gripping members 302, 304 are rotated in opposite directions relative to each other about the longitudinal axis 206 so that the
BE2018 / 5937 middle zone 212 and, in particular, the closing part 218, rotates until the inner walls of the closing part 218 come into contact with each other. The closing of the closing part 218 can be achieved in various ways.
In a first embodiment, the closing part 218 is heated further, for example by infrared lamps or heated air or by heating the rods themselves. In particular, the temperature is raised above the melting point, causing the inner walls 202 to fuse together and thus make the seal.
In a second embodiment, the tube 200 is formed by a co-extrusion with an inner layer of a low density polyethylene or a linear low density polyethylene. Further heating of the closing part 218 is now only necessary insofar as the melting temperature of the inner layer of the tube 200 must be reached. The fusion of the inner layers ensures the sealing.
In a third embodiment, a glue layer is locally applied in the middle zone 212 at least at the location of the closing part 218. By pressing the inner walls 202 against each other, the glue layers come into contact with each other, so that they harden and form the closure.
In step 112, the first and second zones 214, 216 are separated from each other by cutting the closure. In this way, two closed pipe sections are obtained. This cutting can be done by a knife (not shown) which, if desired, can also be mounted on the frame 310 of the system 300 and which can also be controlled by the same control means. It is clear here that the middle zone 212 thus splits into a first bottom part 230 and a second bottom part 232 (shown in Figure 11). The first bottom part 230 together with the first zone 214 forms a first pipe part 400 and the second bottom part 232 together with the second zone 216 forms a second pipe part 400.
BE2018 / 5937
Each of these tube parts 400 is converted into the final desired container in the following steps. In particular, in step 114, at least one of the two tube parts 400 is placed in a mold 402. In the mold 402, the tube part 400 is heated, for example by infrared lamps 404, heated air, electric heating 404, in step 116. Since the tube part 400 already closely matches the shape of the mold 402, the required deformation is small, so that, as above described, the walls 504 have a relatively uniform thickness. In step 118, the pipe section 400 is blow-molded up to the mold 402, for example by supplying compressed air or another gas.
In this way, the final container is obtained, which, after cooling, can be removed from the mold 402.
In case the container has an undercut, it is advantageous if the mold 402 consists of two separate halves. This allows, after the container has cooled sufficiently, to move the two halves apart to remove the container from the mold 402.
It is optionally possible, before placing the tube part 400 in the mold 402, to place a label (not shown) in the mold 402 so that the final container is provided with a label. This is known as in-mold 20 applying a label.
In step 120, a lid for the container is manufactured. This lid can be manufactured in various ways, which are known to the skilled person. However, in an advantageous embodiment, the lid is manufactured integrally with the container. This embodiment 25 is described in more detail with reference to Figures 7 and 8.
Figure 7 shows a tube 200 of which, unlike the tube in Figure 2, additional portions 220 are provided at the ends 208, 210. These portions 220 form an integral part of the tube 200 and come through cutting away certain portions of the tube 200.
This cutting can be done, for example, by a knife, a laserjet, a waterjet or a jig. In the embodiment shown, each of the
BE2018 / 5937 sections 220 are a substantially flat section, but it may also be the case that these sections 220 are gutter-shaped, for instance if the tube 200 has a non-rectangular cross section but rather a circular cross section. It will be appreciated that the dimensions of the additional portions 220 are large enough to form the lid 508.
Steps 104 to 118 are identical for tube 200 with additional parts 220. In this way, after step 118, the container is obtained, with the additional part 220 still attached thereto. This part is deformed in step 120 into the lid, for example by blow molding against a mold half or by thermoforming with a stamper. Preferably, blow molding steps 118 and 120 are performed simultaneously.
A flow chart of an alternative method 900 for manufacturing a thermoplastic plastic container is shown in Figure 9. Steps 902 through 912 correspond to respective steps 102 through 112 already described above. Briefly, these steps therefore include the following: manufacturing a thermoplastic plastic container in step 902, optionally applying a print in step 904, gripping zones 214, 216 in step 905, locally heating the center zone 212 in step 906, pulling the zones 214, 216 apart in step 908, closing the most central part of the middle zone 212 in step 910 (as shown in figure 10), and separating the 25 first and second zones 214, 216 in step 912.
In step 914, at least for one pipe section 400 but preferably for both pipe sections simultaneously (as illustrated in Figures 10 to 12), a bottom molding member 320, 322 is positioned opposite each holding member 302, 304 as shown in Figure 11. Preferably, this is done placement while moving out the retaining members 302, 304 (indicated by arrows 1102) to time
BE2018 / 5937 save. In particular, each bottom molding member 320, 322 is displaced transversely so that they are slid between the separate tube parts 400. This can be done, for example, by positioning the bottom molding members 320, 322 each on a movable arm (not shown), which arm in turn is mounted on the frame 310.
A holding member 302, 304 for use in method 900 is shown in more detail in Figure 13. The main difference from the holding member of Figure 4 is that plate 404 is on its outward-facing side (ie, the side substantially perpendicular to the longitudinal direction 206 and oriented to the center zone 212) is a molding surface having a shape corresponding to the desired shape of the bottom. A further difference is that the holding member 302 of Figure 13 is provided with a gas outlet opening formed by making the arm 306 hollow so that gas, i.e. air, can escape from the hollow space between the mold surface and the bottom part 230. The bottom molding members 320, 322 are then in turn provided with a counter-forming surface which has a shape corresponding to the molding surface.
In step 916, the retaining members 302, 304 and the bottom molding members 320, 322 are moved in the longitudinal direction 206 (indicated by arrows 1204) until they exert pressure on each other causing the bottom members 230, 232 to deform to the desired shape. and thus form a bottom 240, 242. During this deformation, the gas outlet opening allows air, which would otherwise be trapped between the mold surface and the bottom part 230, 232, to be released.
Although two bottom molding members 320, 322 have been described above, namely one bottom molding member for each tubing section, it will be appreciated that, in certain embodiments, only one integrally formed bottom molding member can be provided with a counter-forming surface on both sides (as shown in Figure 14). . In such an embodiment, the bottom molding member remains
BE2018 / 5937 static while, by the movement of the holding members 302, 304 towards the static bottom molding member, the bottom parts 230, 232 of both tube parts 214, 216 are deformed.
In an alternative method (not shown), steps 914, 5 and 916 are replaced by one common step, namely vacuum forming one or both bottom parts 230, 232. Preferably, use is made of holding members 302, 304 as shown in figure 15, namely with a plurality of gas vent openings 350 connected with conduits 352 to the hollow arm 306 which in turn is connected to suction means (not shown). It will be appreciated that each of the gas vent openings 350 may also be directly connected, via lines 352, to the suction means. In this alternative method, there is no need for bottom mold members.
The suction means is configured to draw the gas located between a holding member 302, 304, in particular its molding surface, and the bottom part 230, 232 through the gas discharge openings 350. By drawing off this gas, ie making the vacuum of the space between the holding member 302, 304, in particular its molding surface, and the bottom part 230, 232, will deform the bottom part 230, 232 until it is closely sucked against its respective molding surface. In other words, the bottom part 230, 232 is vacuum formed against the molding surface of the retainer 302, 304 until they have the desired shape and thus form a bottom 240, 242.
Although the tube portion 400 formed after step 916 forms already finished container 500 in itself, it is possible to go through steps 918 and 920 corresponding to steps 118 and 120 to further customize the shape of the tube portion, if desired. Briefly, these steps include blowing the tubing 400 to 30 against the mold 402 in step 918 and forming a lid in step 920.
BE2018 / 5937
While certain aspects of the present invention have been described with respect to specific embodiments, it is understood that these aspects may be implemented in other forms within the scope of the scope of the claims.

权利要求:
Claims (15)
[1]
A method for manufacturing a thermoplastic plastic container, the method comprising:
a) providing a thermoplastic plastic tube having an inner wall, an outer wall, a longitudinal direction, a first end, a second end, a middle zone, a first zone and a second zone, the first zone extending from the middle zone to said first end and the second zone extending from the middle zone to said second end;
b) gripping said first zone and said second zone by means of holding members, each of said holding members having a molding surface substantially perpendicular to said longitudinal direction and located along said middle zone;
c) locally heating said middle zone to the thermoforming temperature of the thermoplastic plastic;
d) pulling said first zone and said second zone apart along said longitudinal direction thereby narrowing the middle zone by moving said holding members away from each other;
e) closing a closure portion of the middle zone to obtain a closure;
f) cutting the closed middle zone at the closure portion to split the middle zone into a first portion and a second portion so that said tube is split into a first and a second tube portion, the first tube portion being said first zone and a first bottom portion comprising, said first bottom portion being formed by said first portion of the middle zone and said second tube portion comprising said second zone and a second bottom portion being said second bottom portion being formed by said second portion of the middle zone;
BE2018 / 5937 gi) arranging, for at least the first tube part, a bottom molding member opposite a respective of said holding members so that said first bottom portion is located between the bottom molding member and the respective holding member, each bottom molding member having a counter-forming surface which is substantially perpendicular to said longitudinal direction and oriented to its respective molding surface; and h-i) deforming said first bottom portion into a bottom by pressing the bottom molding member and its respective holding member together.
[2]
The method of claim 1, wherein step h-i) comprises venting gas from a space between said mold surface and said first bottom portion.
[3]
A method according to claim 2, wherein each holding member is provided with a gas outlet opening and wherein the gas is released via the gas outlet opening of the respective holding member.
[4]
A method according to any of the preceding claims, wherein steps d), e), f), g-i) and h-i) are performed without allowing said middle zone to cool below the thermoforming temperature of the thermoplastic plastic.
[5]
E) closing a closing portion of the middle zone to obtain a closure;
f) cutting the closed middle zone at the closing portion to obtain two separate pipe sections; and g-iv) deforming at least one of said tube parts into a container.
The method of claim 1, 5, 6 and 38, wherein step g-iv) comprises:
- steps g-i) and h-i); and / or
5, wherein the printing has a design that takes into account blow-molding deformation in step i-ii).
The method of any one of claims 5 or 7 to 13 when dependent on claim 5, wherein step g-i) comprises: placing a label between the tubing and the mold.
The method of any of the preceding claims, wherein step a) further comprises: providing said tube with on
15 its first end and a protruding portion at its second end which is integrally manufactured with the tube and the method further comprising the following step:
j) deforming said protruding portion into a lid for the container.
A method according to any of the preceding claims, wherein step e) comprises pushing the inner wall of said closure portion together to obtain said closure.
25
The method of any one of claims 1 to 17, wherein step e) comprises rotating said first zone about said longitudinal direction in opposite directions relative to each other and said second zone to obtain said occlusion.
20. System for pulling apart a tube, which tube is a
BE2018 / 5937 has an inner wall, an outer wall, a longitudinal direction, a first end, a second end, a middle zone, a first zone and a second zone, the first zone extending from the middle zone to said first end and the second zone extending from the middle zone to said second end, the system comprising:
- a first holding member which is arranged to be introduced into the first zone via the first end;
a second holding member which is arranged to be introduced, via the second end, into the second zone, each holding member being adjustable between a first position in which the holding member fits inside the tube and a second position in which, in use, the holding member is exerts pressure on the inner wall of the tube; and
- actuators configured to:
- inserting the holding members in their first position into their respective zone of the tube;
subsequently bringing the securing members into their second position so that they exert pressure on the inner wall of the tube to obtain a temporary fixed connection between a securing member and its respective zone; and
- subsequently moving the holding members away from each other to move the first zone and the second zone of the tube away from each other.
The system of claim 20, wherein each receptacle includes an inflatable annular member having a deflected position in which the annular member fits within the tube and an inflated position in which the annular member, in use, applies pressure to the inner wall of the tube.
The system of claim 21, wherein each holding member
BE2018 / 5937 is provided with a gutter in which the annular element is positioned.
The system of claim 21, wherein each holding member comprises an inner and an outer plate-shaped element, each of which has a shape corresponding to a cross-section of the tube, said trough being formed between the plate-shaped elements.
The system of claim 21, wherein each holding member is integrally fabricated.
The system of any of claims 22 to 24, wherein each holding member is mounted on a movable arm configured to be controlled by the actuating means.
The system of any one of claims 20 to 25, wherein the actuating means are further configured to: insert the first receptacle in the first zone of the tube as close as possible to the middle zone and the second receptacle in the second zone. of the pipe as close as possible to the middle zone.
A system according to any of claims 20 to 26, wherein the system further comprises heating means provided to heat said center zone and wherein the driving means are further configured to control the heating means to heat said center zone before the sensing means. be controlled to move away from each other.
A system according to any of claims 20 to 27, wherein a length of the middle zone is selected in function of a
BE2018 / 5937 desired thickness of a bottom of the container.
The system of any one of claims 20 to 28, wherein the tube is made from one of a metal, a thermoplastic plastic and a glass.
The system of any one of claims 20 to 29, wherein the tube is made of a thermoplastic plastic, the system further comprising splitting means movable substantially transversely of said longitudinal direction about the middle zone in a first section and a second split section so that said tube is split into a first and a second tube section, the first tube section comprising said first zone and a first bottom section, said first bottom section being formed by said first section of the middle zone and wherein the second tube section comprises said second zone and a second bottom portion, said second bottom portion being formed by said second portion of the middle zone, and the actuating means further configured to move the splitting means transversely, in particular towards each other, after the gripping members have moved away from each other move to split said tube into ge called tube parts.
The method of claim 30, wherein each of said holding members comprises a molding surface configured to be positioned substantially perpendicular to said longitudinal direction and along said middle zone, the system further comprising:
- a first bottom molding member which is arranged to cooperate with said first holding member to deform said first bottom portion;
- a second bottom molding member which is designed to cooperate
BE2018 / 5937 with said second holding member for deforming said second bottom portion, each bottom forming member comprising a counter-forming surface corresponding to its respective forming surface and configured to be positioned substantially perpendicular to said longitudinal direction and oriented to its respective forming surface, and wherein the driving means further configured after the splitting means have split the tube:
positioning the first bottom molding member opposite the first holding member and the second bottom molding member opposite the second holding member; and
- then pressing the first bottom molding member and the first securing member together to deform said first bottom portion into a bottom and pressing the second bottom molding member and the second securing member together to deform said second bottom portion into a bottom.
The system of claim 31, wherein each receptacle includes a gas vent opening configured to vent a gas from a space formed between said mold surface and said first bottom portion.
The system of claim 32 when dependent on claim 25, wherein said gas vent is formed by making said movable arm hollow.
The system of claim 30, wherein each of said holding members comprises a mold surface configured to be positioned substantially perpendicular to said longitudinal direction and along said center zone, and wherein each
BE2018 / 5937 retainer includes a plurality of gas vent openings configured to vent a gas from a space formed between said molding surface and said first bottom portion, the system further comprising suction means configured to aspirate gas from a space between said molding surface and said first bottom portion through said gas vent openings.
Use of a system according to any of claims 20 to 29 for performing steps c) and d) in a method according to any of claims 1 to 18.
Use of a system according to any of claims 30 to 33 for performing steps g-i) and h-i) in a method according to any of claims 1 to 4 and 7 to 19 when dependent on claim 1.
Use of a system according to claim 34 for performing step g-iii) in a method according to any of claims 6 to 19 when dependent on claim 6.
38. A method of manufacturing a thermoplastic plastic container, the method comprising:
a) providing a thermoplastic plastic tube having an inner wall, an outer wall, a longitudinal direction, a first end, a second end, a middle zone, a first zone and a second zone, the first zone extending from the middle zone to said first end and the second zone extending from the middle zone to said second end;
b) gripping said first zone and said second zone;
(c) locally heating said middle zone to the
BE2018 / 5937 thermoforming temperature of the thermoplastic plastic;
d) pulling said first zone and said second zone apart along said longitudinal direction thereby narrowing the middle zone;
The method of claim 14 when dependent on claim
A method for manufacturing a thermoplastic plastic container, the method comprising:
a) providing a thermoplastic plastic tube having an inner wall, an outer wall, a longitudinal direction, a first end, a second end, a middle zone, a first zone and a second zone, the first zone extending from the middle zone to said first end and the second zone extends from the
BE2018 / 5937 middle zone to said second end;
b) gripping said first zone and said second zone;
c) locally heating said middle zone to the thermoforming temperature of the thermoplastic plastic;
d) pulling said first zone and said second zone apart along said longitudinal direction thereby narrowing the middle zone;
e) closing a closing portion of the middle zone to obtain a closure;
f) cutting the closed middle zone at the closing portion to obtain two separate pipe sections;
g-ii) placing at least one of the pipe sections in a mold;
h-ii) heating said tube section in the mold to the thermoforming temperature of the thermoplastic plastic; and i-ii) blow molding said tubular section against the mold to obtain said container.
[6]
6. A method of manufacturing a thermoplastic plastic container, the method comprising:
a) providing a thermoplastic plastic tube having an inner wall, an outer wall, a longitudinal direction, a first end, a second end, a middle zone, a first zone and a second zone, the first zone extending from the middle zone to
Said first end and the second zone extending from the middle zone to said second end;
b) gripping said first zone and said second zone by means of gripping members, each of said gripping members having a molding surface substantially
30 is perpendicular to said longitudinal direction and is situated along said middle zone;
BE2018 / 5937
c) locally heating said middle zone to the thermoforming temperature of the thermoplastic plastic;
d) pulling said first zone and said second zone apart along said longitudinal direction thereby narrowing the middle zone by moving said holding members away from each other;
e) closing a closure portion of the middle zone to obtain a closure;
f) cutting the closed middle zone at the closure portion to split the middle zone into a first portion and a second portion so that said tube is split into a first and a second tube portion, the first tube portion being said first zone and a first bottom portion comprising, said first bottom portion being formed by said first portion of the middle zone and said second tube portion comprising said second zone and a second bottom portion being said second bottom portion being formed by said second portion of the middle zone; and g-iii), for at least the first pipe section, drawing gas out of a space between said molding surface and said first bottom portion for deforming said first bottom portion to against said molding surface.
[7]
A method according to any of the preceding claims, wherein step e) comprises: further heating at least the closing portion of said middle zone above the melting temperature of the thermoplastic plastic before pressing the inner walls together so that the inner walls are pushed together fuse to obtain the closure.
[8]
The method of any one of claims 1 to 6, wherein step a) comprises: co-extruding the tube with an inner layer
BE2018 / 5937 formed by a low density polyethylene or a linear low density polyethylene and wherein step e) comprises: further heating at least the closing portion of said middle zone above the melting temperature of the low density polyethylene or the linear low density polyethylene before pushing the inner walls together so that the inner walls pushed together to fuse to obtain the closure.
[9]
The method of any one of claims 1 to 6, wherein step a) comprises: applying an adhesive layer to the inner wall of said middle zone at least at said closing portion and wherein step e) comprises: after the inner walls are pushed together, curing the adhesive layer to obtain the seal.
[10]
The method of any of the preceding claims, wherein step a) comprises extruding the tube.
[11]
The method of any one of claims 1 to 9, wherein step a) comprises co-extruding the tube, wherein, preferably, at least one layer of the co-extrusion forms an odor barrier and / or a moisture barrier .
[12]
The method of any one of claims 1 to 9, wherein step a) comprises injection molding the tube.
[13]
A method according to any of the preceding claims, wherein thermoplastic plastic is selected from: polyethylene terephthalate, polypropylene, polyvinyl chloride, polystyrene, acrylonitrile butadiene styrene, polyethylene and biopolymers, in particular polylactic acid.
BE2018 / 5937
[14]
The method of any of the preceding claims, wherein step a) comprises applying a print to an outer wall of the tube.
[15]
Steps g-ii), h-ii) and i-ii); and / or
- step g-iii).

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US5547364A|1994-10-19|1996-08-20|Industrial Technology Research Institute|Tipping device and method of producing medical catheters|

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US4988399A|1989-07-05|1991-01-29|Aluminum Company Of America|Process for making a three-piece container involving stretch-blow molding, severing and attaching an end panel to the open bottom|

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法律状态:
2020-08-10| FG| Patent granted|Effective date: 20200602 |

优先权:

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申请号 | 申请日 | 专利标题

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BE20185744A|BE1026734B1|2018-10-26|2018-10-26|Method for manufacturing a thermoplastic plastic container and system for pulling apart a tube|EP19784100.0A| EP3870424A1|2018-10-26|2019-10-16|Method for manufacturing a thermoplastic container and system for pulling a tube apart|

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PCT/EP2019/078065| WO2020083721A1|2018-10-26|2019-10-16|Method for manufacturing a thermoplastic container and system for pulling a tube apart|

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US17/288,058| US20210394425A1|2018-10-26|2019-10-16|Method for manufacturing a thermoplastic container and system for pulling a tube apart|