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    • 专利摘要:
    A method for heat strengthening or curing glass sheets in a glass loading containing several glass sheets (G1, G2), where the glass sheets are heated in an oven (1) to a curing temperature and moved with a glass loading flow rate (W) out of the oven (1). curing unit (2), where the actual curing cooling is performed by blowing cooling air on both surfaces of the glass sheets (G1, G2). With a pre-blowing unit (8) located between the furnace (1) and the cure cooling unit (2), which is divided in transverse direction with respect to the movement of the glass in the pre-blowing zones (6.1 - 6.i, 6b.1 - 6b.i), pressurized air is blown on the front and rear ends of the glass plate (G1, G2), where the end is desired to be aligned with the normal surface to reduce end bending.
    公开号:FI20185513A1
    申请号:FI20185513
    申请日:2018-06-05
    公开日:2019-12-06
    发明作者:Pekka Lyytikäinen；Jukka Vehmas
    申请人:Glaston Finland Oy；
    IPC主号:
    专利说明:

    Method for tempering glass sheets
    The invention relates to a method for tempering glass sheets, in which the glass sheet is heated to a tempering temperature and quenching is performed by blowing 5 bars of cooling air as jets towards the glass sheet.
    Glass-plate tempering furnaces in which the glass sheets move in one direction or reciprocally over rotating ceramic rolls and from which they pass successively, side by side or in mixed glass loads at the tempering temperature to a 10-furnace tempering and cooling unit. A furnace with a roller track is known in the art as, for example, a roller furnace. The oven typically has a temperature of 700 ° C and typically the temperature of the air used for cooling is approximately the same as that of the outside or in the factory. The cooling air 15 is supplied by a fan or a compressor. In air-supported furnaces and quenching units, the glass sheet floats supported by a thin air mattress and contacts only one side edge of the conveyor track rollers or other conveying means. Air-supported glass sheet tempering machines are clearly less common than track roll tempering machines. An air-supported kiln-based furnace is referred to in the art as, for example, an air-supported furnace.
    The aim of the tempering process is the same regardless of the type of glass support. The support plate of the glass sheet does not eliminate the end deflection problem which will be described later which the invention solves.
    The typical tempering temperature of a 4 mm thick glass plate, i.e. the temperature at which the glass moves from the oven to the tempering unit, is 640 ° C. The glass tempering temperature can be slightly decreased as the glass thickness increases. Raising the tempering temperature allows the glass to become thinner and decreases the cooling power required for tempering cooling. On the other hand, simply raising the kar30 roll temperature from, for example, 640 ° C to 670 ° C brings a significantly higher degree of reinforcement, i.e. the surface of the glass, to 4 mm thick glass.
    20185513 prh 05 -06- 2018 Compression tension increases. For example, with a thin 2 mm thick glass, the tempering temperature should be raised to at least 660 ° C for successful tempering. Decreasing the thickness of the glass and raising the tempering temperature both add to the end deflection problem which the invention solves.
    The tempering process of the incoming glass is excellent in straightness and optical properties. Therein, the compression stress of the glass surface is typically 1-4 MPa. In the solution process, a sufficient strength increase is sought for the glass sheet, while minimizing its straightness and optical properties. In addition to strength 10, another desirable feature of tempered glass is its safety in the event of breakage. Untreated glass breaks into large pieces that are dangerous to the cut. Tempered glass breaks into almost harmless crumbs.
    The stress on the surface of the glass during tempering (degree of hardening) 15 is dependent on the temperature profile of the glass as the glass cools through the glass transition zone (about 600-500 ° C).
    The thinner glass requires more cooling power to achieve the same temperature difference. For example, for a 4 mm thick sheet of glass, a tempering of about 100 MPa is desired with a tensile stress of about 46 MPa in the middle of the glass thickness. Such a glass sheet breaks into crumbs that meet the requirements of safety glass standards. For so-called FRG (fire resistant glass) tempering, a much higher surface tension is sought. The so-called heat-reinforced glass does not seek a safe method of breaking, nor is it as high strength (about 50 MPa surface compression is sufficient) as for tempered glass. Heat 25 reinforcement is achieved when the cooling power of the air jets in the quench unit is clearly reduced in proportion to the quench. Otherwise, as a process, the heat reinforcement and hardening are similar. The present invention solves the same problem in both. The quenching temperatures mentioned above are also suitable as examples for thermal reinforcement, i.e. the quenching temperature also means 30 thermoforming temperatures. The end deflection problem does not depend very much on whether the surface is pressed for 50, 100 MPa or more
    20185513 prh 05 -06- 2018 tension if the tempering temperature remains the same. In practice, especially when thin glasses less than 2.5 mm thick are tempered, the tempering temperature is increased as the target is raised.
    The formation of a downward-facing end puma begins to flow downward during heating due to gravity of the glass end. The end creeps in as the glass is heated to above 500 ° C in the oven, whereupon the mechanical properties of the glass begin to change relatively sharply. At the same time the glass begins to change from elastic to plastic. The mechanical stiffness of the glass is thus greatly reduced, that is, it is easier to bend. The creep rate is still slow at 600 ° C with respect to heating time, but at 650 ° C it is already quite fast. The deformation of the glass is reversed as the plasticity increases. The end of the glass would not bend and creep if the glass were evenly supported in the oven. However, in the roller oven, the glass support points (lines) are only spaced between the roller spacers (typically 100-150 mm). In an air support furnace, a pressurized air mattress (relative to the pressure in the furnace air space) supports the edges of the glass more weakly than the rest of the glass area because the static overpressure supporting the glass in the air mattress is smaller. This is because, at the edges of the glass, the air mattress air can escape from the air support table, not only from the openings under the glass, but also between the glass and the plane surface of the air support table. In the oven, the bent end glass does not spontaneously straighten through the quenching process, which solidifies the glass within seconds in its final elastic form. The downward (towards the lower pre-cooling air housings) end deflection typically begins at about 50 to 200 mm from the ends of the glass, e.g. depending on the thickness of the glass, the pitch and the type of tempering machine. The length of the end deflection is the distance between its origin and the end. In the pattern glass (1095 mm in length), the front end deflection starts at 80 mm (= end deflection length) at a distance from the front end of the glass and is 0.415 mm deep. The rear end deflection starts at a distance of 70 mm from the rear end of the glass and is 0.326 mm deep. The most common starting point for the end deflection is 60 to 150 mm from the end of the glass. Note that the above values are read in the shape of the glass
    20185513 prh 05 -06- 2018 data instead of measuring the end deflection of Figure 3. The depth of the fin end read was the vertical distance between the beginning of the end deflection and the end, which does not fully correspond to the end deflection of the measuring method shown in Figure 3. However, the correspondence is very good.
    Generally, the downward bending of the glass ends due to the aforementioned creep is called the end bump.
    Some top-coated glasses may also have an upwardly curved portion at the end of the downwardly bent end. This upward (toward the upper pre-cooling air casing) end deflection occurs with certain types of coatings (e.g., pyrolytic low emissivity coating) on the upper surface of tempered (or heat-reinforced) glasses. Its formation is likely to be related to the thermal expansion difference between the glass and the coating, that is, when renewed and / or quenched, the coating tends to expand or shrink to a different extent than the glass, resulting in the tempered glass ends turning typically about 10-50 mm. In such a glass, the end deflection usually begins first downward (about where the said downward deflection begins) and then turns upwards at said distance from the end, as in the glass of Figure 2. In the glass of Fig. 2 (1505 mm in length), the front end deflection downwards begins at a distance of 130 mm from the front end of the glass, and turns upward to deflect at a distance of 35 mm from the front end. At this point it rises 0.115 mm. At the rear end, the corresponding values are 93, 28 and 0.04 mm. Further, in such a glass, in addition to the front and rear ends, the sides of the glass are often upwardly bent about 10-50 mm from the side edge.
    The corrugated shapes of glass inside the ends of Figures 1 and 2 are so-called. roller waves generated in glass tempered furnaces (not generated in air support furnace). The method of the invention only improves the straightness of the glass ends, i.e. it does not affect the roll waves. Figure 1 Shape
    20185513 prh 05 -06- 2018 The variation in the magnitude of the wave peaks and the coordinates of the troughs of Figure 2 is due to the indirectness of the support level of the measuring device.
    Figure 3 illustrates a method for measuring the end or puma of a glass according to EN 12150-1. Here, the top surface of the glass is opposite to the direction of the end deflection. The glass is placed on the measuring platform so that its end exceeds the plane by 50 mm. Place a straight ruler of 300-400 mm on top of the glass so that the gauge at the other end of the ruler is at the measurable end of the glass. The dial reads the end deflection of the glass, or the depth of the puma. Em. according to the standard, for example, for glass of 4 mm thickness the permissible deflection is 0.4 mm. In practice, the requirements for end-bending glass producers for tempered glass are somewhat tighter than standard. The ever higher quality values of glass are a competitive advantage for the tempering machine manufacturer, and for the producer of still tempered glass.
    The end deflection problem grows as the thickness of the glass decreases, and is particularly great with glasses 4 mm thick and thinner. With glasses over 8 mm thick, the problem of end bending is minor. The length of the glass in the direction of motion of the furnace does not contribute much to the end deflection problem, but for glass less than 300 mm long it is difficult to measure according to the above standard. The invention can be said to be limited to glasses having a length greater than four times the downward inclination of the end. For example, with the typical lower limit of the end bend length mentioned above, the minimum length of the glass is 4 x 50 mm = 200 mm.
    The end deflection described above is a quality problem for tempered glass commonly known in the art. The end deflection is practically problematic e.g. because it distorts the reflection of the glass. A distortion, for example, the reflection of a building window is aesthetic disadvantage. In addition, the end deflection makes it more difficult to minimize the la30 glass (two glasses are bonded together by means of a laminating film between them), which requires special measures and / or thickness.
    20185513 prh 05 -06- 2018 man (more expensive) la m i n i n d also ivon. The tightness of the edges of the laminated glass is particularly important to prevent moisture from entering the outside air.
    In practice, it has been found that the method of the invention can reduce end or Puma values. To reduce the end deflection, it is essential that the pre-blast is applied to the upper surface of the glass end when the expected end deflection is downward, i.e. toward the lower cooling air housings. Thus, it is generally applied to the upper surface because creep bends the glass end downwards. As a result of the pre-blasting, the top surface of the glass end cools, thereby tending to contract relative to the underside. The loose plastic underside is unable to resist the tendency of the upper surface to contract. Thus, pre-blowing raises the end of the glass upwards, i.e. the end deflection is rectified. The quenching, which begins immediately after the pre-blast, solidifies the glass on both sides of the glass.
    Em. in the case of pyrolytic low emissivity in the case of glass, the pre-blast is initially applied to the underside because the end has an upward deflection. After the upwardly deflected portion (10-50mm), the pre-blowing stops or shifts to the upper surface, where it continues to approximately the point of assumed downward deflection.
    In general, the preblowing according to the invention is applied to a side window surface, which end up in the normal direction to be corrected. Thus, pre-blowing in the pre-blowing zone is applied to the upper surface of the glass when the direction of the assumed end deflection in the glass sheet is towards the lower pre-cooling air shells, and pre-blowing in the pre blowing zone.
    GB 1 071 555 discloses a method and apparatus for manufacturing bent tempered glass sheet 30 utilizing various stresses created at various regions and opposing surfaces of the glass sheet during bending.
    20185513 prh 05 -06- 2018
    In the precooling section, only the upper surfaces of the side edges of the glass sheet are cooled to provide a temporary upward curvature of these areas, which is multiplied as the entire glass moves to both sides of the cooling. The side edges are cooled in the precooling section along the entire length of the glass 5, with no middle strips at all. With the device described in the publication, it is not possible to apply pre-cooling to the middle strip of the glass sheet, nor to apply it only to the front and rear ends of the glass. Thus, the publication does not attempt to solve the problem of flat glass plate end deflection, which is solved by the invention of this patent application.
    In FI 20155730A, the tempering of the side edges of a glass sheet begins to cool slightly earlier than the middle strips. The lateral edge bands are cooled at the beginning of the quench cooling along the entire length of the glass, with no central bands at all. Thus, the publication does not solve the flat deflection of a flat glass sheet of 15 gels.
    US 3,923,488 discloses a technique for reducing upward deflection of a glass front end. In it, pre-cooling air is blown onto the underside of the glass on the outside of the front end before the actual quenching. Blowing begins at the front of the 20 glass ends at 305-610mm (1-2 feet) and continues to the rear. The front end of the glass thus remains 305-610mm in length without pre-freezing the underside. The rear end deflection of the glass does not reveal the problem at all and cannot even be affected by the blowing described above. Not at the same time with the front end problem. Thus, the publication does not solve the downward deflection problem of the glass end resulting from creep ai25, which occurs at both ends of the glass and which is solved by the method of claim 1.
    US 4 261 723 solves the same problem as US 3 923 488, but there is a clear difference in technology. In US 4 261 723, only the upper surface 30 of the glass sheet front end (i.e., the portion not pre-cooled in US 3 923 488) is pre-cooled before the tempering unit for the glass sheet
    20185513 prh 05 -06- 2018 to correct the upward bend in the front end. Thus, the deflection is in the opposite direction to the problem solved by the method of claim 1. Further, with respect to the direction of the end deflection, the pre-blowing is applied to the opposite surface than is essential for the patentable process. 5 preblowing not, therefore, on the side of the window surface having a normal direction of the end to be adjusted. The teaching of the publication thus clearly contradicts the patentable method. The blowing direction in the teachings of the publication would add to the problem of end deflection which the patentable method reduces. In the publication, pre-cooling is applied to the first 305 mm (1 foot) of the front end, and the need for a shorter blowing distance is not stated. The rear end of the glass is not pre-cooled at all and the rear end deflection does not exemplify the problem at all. Thus, the publication does not solve the creep downward bending problem of the glass end which occurs at both ends of the glass and which is solved by the method of claim 1. In the publication, the pre-cooling blast current15 ma is weaker in the side edge bands of the glass than in the middle band of the glass because of the larger openings in the pre-cooling air box at the middle of the glass and the same blowing pressure. As the width of the glass pane changes, the pre-cooling air housing would need to be replaced to maintain the side and middle band widths of the glass pane relative to the width of the glass pane, or to completely eliminate blasting on any glass pane. The duration of the pre-blast and the length of the pre-blasting trip are the same across the entire width of the glass. With the publication device, it is not possible to pre-cool the glass from its underside.
    In practice, efforts have also been made to reduce the above-mentioned downward inclination problem e.g. aiming to use the lowest tempering temperatures and the densest roller distribution in the roller oven and tempering unit.
    In US 6,410,887, the above-described upwardly directed end flap 30 in pyrolytically-coated tempered glass has been reduced by using a higher upper than lower convection at the beginning of the furnace and vice versa at the end of the heating.
    It is an object of the invention to provide a method for making front and rear ends of thin, heat-toughened and tempered glass sheets (thickness less than 9 mm, in particular less than 5 mm). It is therefore an object of the invention to improve the quality of glass by reducing its end deflection (e.g. measured according to EN12150-1).
    This object is achieved by the process according to the invention on the basis of the features set forth in the appended claim 1. Preferred embodiments of the invention are disclosed in the dependent claims. In the specification, tempering generally refers to the significant heat treatment reinforcement of glass.
    The invention will now be described in more detail with reference to the accompanying drawings, in which
    20185513 prh 05 -06- 2018
    Figure 1 shows the measured shape of the glass with the downwardly facing end faces 20 deflections appear at both ends of the glass. Figure 2 shows the measured shape of its pyrolithically coated glass on its upper surface. 25 Figure 3 describes the method for measuring the end deflection of glass in EN12150-1. Figure 4 shows schematically, from the side, the compartments of the device required in the method.
    Figure 5 schematically shows the pre-cooling air housings of the device required in the method, with blowing openings viewed from below the glass.
    20185513 prh 05 -06- 2018
    Figure 6 shows schematically the equipment required for controlling the pre-blast zones of the pre-cooling zones.
    Fig. 7 shows the pre-blowing effect area of the method in two successive glasses according to the simplest embodiment of the method.
    Figure 8 shows the zones of pre-blown effect in all single glass loading glasses.
    Figure 9 shows the end deflections measured at the front and rear ends of the glass and the pre-blowing effect areas for straightening the end deflections measured at the glass when zone-specific adjustment is performed with the blowing time.
    Figure 10 shows the end deflections measured at the front and rear ends of the glass and the pre-blast blowing pressures to straighten the measured end deflections in the glass when the zone-specific adjustment is performed at the blowing pressure.
    Fig. 11 shows examples (a-d) of the method of possible pre-blowing effects on the glass to straighten its end deflections.
    The apparatus comprises an oven 1 and a quench cooling unit 2, which are in the order of running of the glass sheet in the order shown in Fig. 4, one after the other. The furnace 1 is typically provided with horizontal rollers 5 or an air support table with conveyor means. These form the glass sheet conveyor track. The heated glass sheet G is conveyed continuously in the furnace at a constant speed 30 in the same direction or back and forth over the heating time. Tempered glass plate moves from oven to 1 tempering unit
    20185513 prh 05 -06- 2018 kitchen with 2 transfer speeds W, which is typically higher than glass motion in oven 1. Typically, transfer rate W is 200 - 800 mm / s.
    The quenching unit 2 is typically provided with horizontal rolls 5 and cooling air housings 3 above and below the rolls, as shown in Figure 2. With the furnace 1 being an air support furnace, the rolls 5 or air support table with conveyor means are typically parallel to the direction of movement of the glass. The ice cooling air housings 3 are provided with blow openings 4, from which cooling air is discharged as jets of glass G. The blow openings 4 are typically circular holes and are typically arranged in series in rows, as in Figure 5. The blow openings 4 may also be of other shapes, e.g. For example, every point of a 3 mm thick glass should wait at least about 3 seconds for quench cooling. For example, at a transfer rate of 600 mm / s, this would require at least about 1800 mm of a Pass-through tempering cooling unit
    2. In a pass-through tempering unit, the glasses move in only one direction at a transfer rate W. The so-called oscillating tempering unit is generally about 1 m longer than the longest allowed glass loading length. The glass loading is then shifted entirely at the transfer rate W to the tempering unit, and reversed when the front of the loading reaches the end of the tempering unit. The glass loading then moves back and forth within the quench unit until the quench and generally the final quench are over.
    At the beginning of the quenching unit 2, immediately after the furnace 1, there is a pre-cooling unit 8 in which pressurized air is blown towards the upper and / or lower surface of the glass sheet. The air pressure device 13 (Fig. 6) is, for example, a fan or a compressed air compressor. In a preferred embodiment, the air used for pre-cooling is pressurized with a compressed air compressor. The precooling unit 8 consists of a precooler distributed in the width direction (= horizontal transverse direction of motion of the glass) of the tempering line 30 (above 6.1-6.Ϊ and below 6b.l-6b.i).
    20185513 prh 05 -06- 2018 on both sides of the glass plate (above 6 and below 6b). The pre-cooling air housings 6 and 6b typically have circular blow openings, and the blow openings in the different zones are preferably the same (same layout and diameter). Typical widths of one pre-blasting zone are 20 to 250 mm, and preferred widths are 30 to 130 mm. The length of the blowing area of the pre-cooling unit 8 in the direction of motion of the glass sheet is preferably one diameter of the nozzle orifice, i.e., it consists of a single transverse row of nozzle orifices for movement of the glass. Preferably, the pre-cooling unit 8 is comprised of 1 to 3 consecutive nozzle orifice rows, and typically 1 to 6 nozzle orifice rows or nozzle orifice regions having a length in the direction of movement of the glass between one nozzle orifice diameter and 100 mm. Preferably, the said length is less than 50 mm. The distance between the lips in one row of nozzle orifices is typically less than 20 mm and preferably less than 10 mm. The distance (blow distance) between the vent opening and the surface of the glass in the pre-cooling unit is typically 5 to 70 mm, and preferably 10
    - 40 mm. Preferably, the air jets discharged from the tapes of the pre-cooling air housing strike the glass perpendicularly or at an angle of less than 10 degrees. The vent opening diameter in the pre-cooling air housings 6 and 6b is typically 0.5 to 3 mm, and preferably 0.8 to 2 mm. The blowing pressure in the pre-cooling unit is typically 0.1 to 8 bar, and preferably 0.5 to 4 bar. The pressure can be adjusted, for example, as the glass thickness changes. In a preferred embodiment, the zone-specific valves 7 are of two positions, i.e. of the open / closed type. The upstream and downstream pre-blast zones have their own valves 7. The blast pressure is controlled by a pressure control valve 14 in the air ducts prior to branching into the zones, between the end of the pre-blast and the quench cooling blade 25, preferably 8 cm. Typically, the aforementioned distance is 1 to 25 cm.
    Figure 5 illustrates a sheet of glass moving to a pre-cooler unit 8 according to the invention. The glasses may also be multiple side by side, of different sizes, and their leading edges may arrive at the pre-cooler unit at different times, such as
    20185513 prh 05 -06- 2018 Figure 8. Blowing into the glass entering the pre-cooling unit 8 begins as accurately as possible as soon as the leading edge of the glass enters there.
    In one embodiment of the method, the blowing pressures and blowing times to the front and rear ends of the glass are the same in all pre-blower pre-blowing zones 6.1-6J, and pre-blowing to below pre-blowing zones 6b.l-6b.i is prevented by zone-specific lower vents. In this case, if the (assumed) end deflection is shorter in length and / or depth at the rear end of the glass, shortening the blowing time (i.e. blasting the distance 10 to the glass end) at the rear W moving glass prevents the blowing too much from the rear. Such an embodiment of the method is successful without pre-blast zone division when the glasses arrive at the pre-blast in a row. Figure 7 shows the blowing patterns in this case. In Fig. 7, pre-blowing to the downstream glass pane G2 begins at At = AS / W later than to the forward end glass pane G1, where AS is the glass moving distance between the front ends of the glasses G1 and G2, which (AS) is greater than the downward glass pane G1. the direction of movement. The case of Figure 7 is the simplest embodiment of the method. ME20 the simplest embodiment of the method is characterized in that the beginning of the chilling of the glass sheet preblowing the front and the rear end of the side surface of which end up in the normal direction to be corrected is blown pressurized air esipuhalluspaineeseen only one zone covering the entire width of the glass blower. Thus, the pre-blowing distance from the leading edge of the glass sheet toward the rear edge of the glass sheet, (Sh = Wtn), is typically 10 to 250 mm and preferably 50 to 150 mm. Also, the pre-blowing distance from the rear edge of the glass sheet toward the leading edge of the glass sheet, (Sr, = WtRi), is typically 10 to 250 mm and preferably 50 to 150 mm. The pre-blowing distance selected and the pre-blowing pressure are dependent on the estimated end deflection in the glass sheet without pre-blowing and / or previous substantially similar deflection on the glass sheet. The pre-blowing distance depends in particular on the estimated time of end deflection14
    20185513 prh 05 -06- 2018 from the point (length) and the pre-blast pressure from the estimated decision value (depth).
    The zone division of the pre-blowing device of Figure 6 provides increasingly advantageous control modes 5, which will be described below.
    In a more advanced embodiment of the method, the blowing time in the pre-blowing zones 6.1-6.Ϊ above the pre-cooling unit 8 within the width of the glass is dependent on the estimated local end deflection in the glass sheet without pre-blowing and / or end deflections measured from previous substantially similar glass sheets. Thus, the blowing time varies between the pre-blowing zones 6.1-6... If the estimated end deflection in the band of glass sheet in the area of influence of the pre-blast zone is deeper and / or longer, then the blowing time is greater. Typically, in particular for air-heated glass 15, the blowing time of the glass strip in the center band blowing pre-blast zone is shorter than that of the glass sheet blowing in the side blast because it is common for end bends to be slightly larger at glass corners. It is also typical that the end deflections are larger at the front than at the rear of the glass sheet. Typically, therefore, the blowing time is greater when blown to the front ends of the glass than when blowing to the rear ends. There are also glasses that have a greater rear-end deflection than the front-end deflection.
    Instead of or in addition to the blowing time, the blowing pressure in the pre-blowing zones 6.1-6.Ϊ above the pre-cooling unit 8 within the width of the glass may depend on the estimated local end deflection in the glass sheet without pre-blowing and / or end deflection from substantially similar glass sheets. In this case, the blowing pressure increases, especially as the depth of the end deflection increases, but sometimes also as its length increases. Increasing the blowing pressure increases the cooling effect of the pre-blast, which increases the end-correcting effect of the pre-blast 30 on the glass. This type of control requires that the zone-specific valves 7 be open / closed pressure control valves 15
    20185513 prh 05 -06- 2018 instead of valves. The pressure control valves are not as reliable as the open / close valves, and there are differences between valves, even though the control pressures are all the same. Also, the timing of their (fully) open / close adjustment is inaccurate, which is improved when valve 7 consists of both a pressure control and an open / close valve. Pressure control valves are also more expensive than open / close valves.
    A third way of adjusting the pre-blast with a different zone effect is to blow to the ends of the glass, both in the upper and lower zones. Then all zone-specific valves 7 are open / close valves. Above, the pre-blast pressure is the same in all pre-blast zones 6.1-6.Ϊ, but the end lanes with a lower end deflection are also blown in the lower blast zones 6b.l-6b.i. The downward blowing time (blowing distance) is shorter and / or the blowing pressure is lower than above, so that the cooling effect of the pre-blast and further its glass-correcting effect is lower. The lower pre-blowing pressure is reduced by the auxiliary valve 15. In this case, the downstream pre-blast compensates for the effect of the overhead pre-blast, whereby the upstream effect of the pre-blast glass is less corrected.
    Above, various ways of adjusting zone-specific pre-blowing to correct the normal downward deflection are described. In the case of pyrolytically coated glass, the end end tendency of the end of the glass is directed upwards, whereby the pre-blast (in the case of the third mode of adjustment, a more powerful pre-blast) is applied to the lower surface of the glass end.
    Bottom pre-blowing means are only necessary, in the case of the third mode of adjustment described above, and in the case of pyrolytically coated glass, when the end deflection of the beginning of the glass end 30 is directed upwards. Thus, only the above pre-blowing means are obligatory for the extensive method of the invention
    20185513 prh 05 -06- 2018 to improve the quality of glass. Bottom instruments can be considered as an additional option sold with instruments above.
    The zone-adjustable pre-blowing equipment enables the ends of the parallel glass to be blown even though the glass ends arrive at the pre-blowing area at different times. The glass loading of Figure 8 has several glasses and the size of the glasses varies. In Fig. 8, the pre-blowing is directed to the front and back ends of each glass for the same length, i.e., the pre-blowing distances Sh and Sr are the same for each glass and each zone i. However, the zone blending of the pre-blowing device is necessary since the glass loading glasses under. In Figure 8, the front ends of the glass sheets G1 and G2 arrive at the pre-blast region at different times, and the pre-blast to the downstream glass sheet G2 begins at At = AS / W later than the forward end glass sheet G1, where AS is the motion distance between the glass ) is smaller than the length of the downwardly facing glass plate G1 in the direction of motion of the glass. With a full blast area wide, i.e., zoneless, pre-blast device, the entire glass loading preload would not succeed. In contrast to Fig. 8, the glass blowing surfaces 20 of the glass end blows may vary from zone to zone to glass to end.
    Fig. 6 schematically illustrates devices associated with the control of the pre-cooling unit 8. With the method, it is necessary to obtain information on the position of the leading edges of the glass sheets in the control device 10 so that it opens the valves 7 from the pre-blast zones 6.1-6.Ϊ at the right time. The valves 7 are closed after the blowing time required to complete the pre-blowing distance. The control device 10 also needs information about the position of the rear edges of the glass sheets in order to properly pre-blow the rear end of the glass. Information is also needed to determine which bands in the direction of movement of the glass sheet30 where the localized end deflection is predicted or measured from previous substantially similar sheets of glass are obtained
    20185513 prh 05 -06- 2018 movement in the transverse direction correctly positioned with respect to pre-blast zones 6.1-6.Ϊ 0a 6b.l-6b.i). Apparatus for such positioning of the glass, that is, for automatically determining and feeding the size and position information of the glass sheets to the control device 10, during tempering, are already well known. However, there are significant differences in accuracy between different hardware solutions. In Figure 6, arrow 9 illustrates the information required for positioning the glass provided by the automatic glass positioning apparatus. The information related to the dimensions of the glass sheets can also be manually entered on the keypad 11 to the control device 10. Such a manual solution is mainly relevant only in production, whereby similar glass sheets and one glass sheet at a time are annealed (in long series).
    Suitable blowing lengths and blowing pressures for straightening the estimated endplates of the glass sheet are manually entered by the keyboard 11 to the control device 10. The control device 10 is accelerated if the control device 10 is provided with an extensive menu of 15 different recipes for end blowing. The control device 10 may also select the recipe most suitable for the size, type and thickness of the glass from the menus itself, or form it based on the equations provided and the dimensions of the glass. It is advantageous for the method that the deflections of the tempered glass plate ends are measured, for example, by an end deflection automatic measuring device 12 located immediately after the quenching unit 2 or after the final cooling unit 20 which supplies data to the control device 10. The control device 10 controls the valves 7 and Thus, the zone-specific blowing times of the pre-blast zones are automatically adjusted based on the measurement data of the previous similar glass end deflections. The operation of the measuring device 12 is based, for example, on a change in direction of the laser beam reflected from the glass or a distortion of the pattern due to the end deflection. Devices such as measuring device 12 for rapid measurement of glass sheet end deflection exist but are not yet used for automatic up-regulation of glass end deflection.
    20185513 prh 05 -06- 2018
    The air required for pre-blasting is routed to both sides of the glass, for example, by means of two separate air supply ducts from the air pressure device 13. The air supply can also be branched to different sides of the glass even after the pressure control valve 14, for example by means of an auxiliary valve which directs air only to the desired glass side.
    Figure 9 shows an example of the measured local end deflections of glass (numbers at the ends of the glass sheet, unit in mm) and relative blowing lengths to reduce the measured local end deflections of the glass. The end or bottom of the image is facing downwards, i.e. toward the lower pre-cooling air housings. The control system, which senses the position of the front and rear edges of the glasses and the speed of the glasses, starts and stops pre-blowing into the front glass zone of the glass by blowing the top surface of the glass tn = Sh / W. Above, W is the transmission speed of the 15 glasses, and Sh is the pre-blowing distance given to the control system, determined on the basis of empirical information and / or information measured by the control system from the previous glass. At the rear end of the glass, the pre-blowing zone blows the glass at a time t R, = Sr, / W, which begins to wear as the rear edge of the glass approaches a distance Sr, from the beginning of the blowing area of the pre-cooling unit.
    The pre-cooling zones of the pre-cooling unit located in the transverse direction of the glass loading movement do not blow at all. The pre-blowing distance in the pre-blowing zone to the end of the glass is preferably the longest (at the point of the glass having the greatest end deflection) the predetermined zone-specific length, i.e. 50-150 mm. Typically, the pre-blowing distance in the pre-blowing zone 25 to the end of the glass is 0 to 250 mm, i.e. a glass zone may also be completely devoid of pre-blowing (such as the central bands of the glass a in Figure 11). Thus, at the above typical transfer rate (200 to 800 mm / s), the blowing time at the glass end is 0 to 1.25 s. Blowing times, and further pre-blowing distances, are specific to the pre-blowing zone and decrease as the estimated end bumps decrease.
    20185513 prh 05 -06- 2018
    Fig. 10 is the same glass as Fig. 9, but now the zone-specific adjustment of the local end deflections is done by adjusting the blowing pressures instead of the blowing time (blowing distance). In Figure 10, the zone-specific pre-blowing pressure given to the control system is indicated adjacent to the zone. The selection of the inflation pressure values is based on empirical and / or control system measurement from the previous glass.
    Figure 11 illustrates various blowing patterns that can be formed on the glass sheet by pre-blowing zones. In the blowing pattern a, the pre-blowing only touches the angles of the 10 glass, which means that the ends of the middle bands of the glass are not pre-cooled at all.
    In blowing pattern b, the pre-blowing distances at the rear end of the glass are constant and at the front end they are longer in the center bands than in the edge bands. In blowing pattern c, the pre-blowing distances are constant at the front and back ends of the glass, but at the front end they are longer. Such a blowing pattern can be formed on 15 individual glasses with no other glass alongside it, even without pre-blast zone division. In the most common types of glass tempering lines, tempered glasses are mixed loads, whereby the blowing pattern c cannot be achieved for glass loading glasses without pre-blast zone division. The blow pattern d covers not only the ends but also the side edges of the glass. Such a blowing pattern is possible in the case of the aforementioned coated glass quality. The blowing patterns a-d of Figure 6 may be formed on the upper and / or lower surfaces of the glass. The pre-blast in the pre-blast zone is applied to the opposite surface of the glass with respect to the direction of the assumed end deflection. That is, for example, to the upper surface when the direction of the assumed end deflection in the glass sheet is downward, i.e. towards the lower pre-cooling air casing. The pre-blowing patterns of Figure 11 may be performed differently or similarly on each glass of the glass loading of Figure 8.
    Preferred or alternative embodiments of the invention not mentioned above which apply, mutatis mutandis, to all the embodiments described above will now be described.
    20185513 prh 05 -06- 2018
    The pre-blowing glass end need not be continuous throughout the pre-blowing distance (Sh, Sr,) but can be interrupted and restarted (pulsed). Preferably, the pre-blowing edge of the glass sheet edge starts again earlier than the middle sheet glass sheet. Typically, pre-blasting in the middle band is completely terminated when the pre-blasting distance is filled, and at least its intensity is substantially reduced so that the region of the pre-blasting distance at the glass end has a significantly stronger cooling effect than outside.
    The cooling capacity required for tempering (unit W / m 2 ) varies greatly depending on the thickness of the glass pane and the degree of tempering desired. For this reason, the invention contemplates relative cooling power in different areas of the quench cooling unit. Thus, since they are not absolute but relative cooling powers, it is equally possible to speak of the cooling effects in different regions of the glass 15 plate. Thus, when referring to cooling power, cooling efficiency and cooling effect are also meant. The heat transfer coefficient is obtained by dividing the cooling power by the temperature difference between the glass and the air. Increasing the blowing pressure and shortening the blowing distance, for example, increase the heat transfer coefficient, which increases the cooling effect. The blowing pressure of the pre-blast depends relatively little on the thickness of the toughened glass as the transfer rate W decreases as the thickness increases normally. Normally, the transmission speed of e.g. 8 mm thick glass is about 200 mm / s and 3 mm thick glass about 500 mm / s. As the transfer rate decreases, the residence time of the pre-blown end in the pre-blast is increased, which increases the cooling effect of the ground on the glass. The ratio of the heat transfer coefficients of the pre-blast to the actual quenching can be as follows. The average heat transfer coefficient produced by the pre-blasting in the tempering of thick glass over 5 mm in the area of contact of the pre-blowing jets on the surface of the glass sheet is higher than after the pre-blasting area in the actual quenching operation. The heat transfer coefficient of the quench cooler increases with the glass, whereby
    20185513 prh 05 -06- 2018 heat transfer coefficient ratio, quench heat transfer coefficient / pre-blast heat transfer coefficient, increases.
    In this disclosure, the longitudinal direction of the quench unit or the glass sheet is the direction parallel to the movement of the glass sheet. The start of the pre-cooling unit is the part of the pre-cooling unit where the glass sheet first enters. The width direction of the glass sheet or pre-cooling unit is transverse to the direction of motion of the glass sheet. Above, the center band of a glass sheet refers to a portion of the middle region perpendicular to the end of the glass sheet and the edge band to the side edge of the glass sheet. The front edge of a sheet of glass refers to the area of movement of the glass of defined length starting from the front of the glass. The rear end of a sheet of glass refers to the area of movement of the glass of defined length starting from the rear of the glass.
    The above and the claims have used e.g. words pre-blast, pre-blast15 zone and pre-blast. The words are shortened versions of the words pre-cooling blast, pre-blowing blast zone and pre-cooling blasting distance. Thus, the abbreviated words also refer to the cooling of the glass.
    For purposes of the claims, end bending is defined as the downward bending of the ends of the glass from the creep, which is 50 to 250 mm (usually 50 to 150 mm), whose formation is described in more detail in the specification and measured in the EN12150-1 standard.
    In the case of a glass having a pyrolytic coating on its upper surface, the end deflection in the claims refers to the upward bending of the front and rear ends of the coating (e.g., pyrolytic low emissivity coating) and glass over a distance of about 10-50 mm.
    权利要求:
    Claims (15)
    [1]
    The claims
    1. A method of thermally reinforcing or tempering glass panes comprising multiple sheets of glass comprising at least two sheets of glass loaded on a sheet of glass.
    5 in parallel, and in which method glass sheets are heated in a furnace to a tempering temperature and transferred to glass load transfer speed (W) is removed from the oven karkaisujäähdytysyksikköön of performing the actual tempering by blowing cooling air to the glass sheets on both surfaces, and wherein an area between the furnace and karkaisujäähdytysyksikön window for movement in the transverse suun10 direction separately to the adjustable esipuhallusvyöhykkeisiin shared esipuhallusyksiköllä preblowing a glass plate front and rear ends of the blowing of compressed air, characterized in that the preblowing applied to a glass plate of the side surface having the normal direction of the end is desired to reduce the päätytaipuman corrected, and that esipuhallusmatkat glass sheets etureu15 those including a glass sheet rear edges (Sh = Wtn), and the glass sheet trailing edges including towards the leading edges of the glass sheets, (Sr, = WtR 1), are 10 to 250 mm.
    [2]
    2. A method according to claim 1, characterized in that
    The front ends of the jets arrive at the pre-blasting area at different times, and the pre-blowing to the downstream glass sheet begins at At = AS / W later than the downstream glass sheet, where AS is the movement distance of the glass between the front glass faces which is smaller the direction of movement.
    [3]
    3. A method according to claim 1, characterized in that, as a pre-blow to the upper surface of the front and rear ends of the glass sheets, pressurized air is blown to reduce the end deflection downwards, i.e. towards the lower pre-cooling air housings, and
    The distance between the leading edges of the glass sheets including toward the rear edges of the glass sheets, (Sh = Wtn), and from the rear edges of the glass sheets toward the leading edges of the glass sheets, (Sr, = Wt R i), is 50 to 250 mm.
    20185513 prh 05 -06- 2018
    [4]
    The method of claim 3, wherein the pre-blowing trips from the leading edges of the glass sheets toward the rear edges of the glass sheets, (Sh = Wtn), and from the rear edges of the glass sheets toward toward the leading edges of the glass sheets, (Sr, = WtRi),
    [5]
    5 are 50-150 mm.
    Method according to claims 1 and 3, characterized in that the width of one of the pre-blowing zones is 30 to 130 mm.
    10
    [6]
    Method according to claims 1 and 3, characterized in that the pre-blowing distance at the rear end of the glass is shorter than at the front end of the glass.
    [7]
    Method according to claims 1 and 3, characterized in that the pre-blowing pressure at the rear end of the glass is lower than at the front end of the glass.
    [8]
    Method according to claims 1 and 3, characterized in that the pre-blowing pressure increases as the end deflection deepens and the pre-blowing distance increases as the end deflection is maintained.
    20
    [9]
    Method according to Claims 1 and 3, characterized in that pressurized air is also blown on the lower end of the glass rear end, the cooling effect of which on the lower surface of the glass is lower and / or the pre-blowing distance is shorter than on the upper surface of the glass.
    25
    [10]
    Method according to Claims 1 and 3, characterized in that the duration (tn, t ^) of the pre-blow to the glass sheet at the front and back ends is adjusted locally in the transverse direction by at least three pre-blow zones such that the pre-blow distance from the front of the glass sheet Wtn), and / or the rear edge of the glass sheet toward the leading edge of the glass sheet (Sr, = Wt ^) varies between the pre-blowing zones.
    20185513 prh 05 -06- 2018
    [11]
    Method according to Claim 10, characterized in that the pre-blowing distances are longer in the direction of glass movement near the side edges of the glass sheet than in the middle of the glass width.
    5 in the summer zones.
    [12]
    A method according to claim 10, characterized in that the duration of the pre-blowing of the glass sheet is adjusted locally in the transverse direction of movement of the glass by at least five pre-blowing zones.
    [13]
    Method according to Claim 10, characterized in that the shape of the tempered glass sheet ends is measured on-line by an automatic measuring device, and the zone-specific blowing times of the pre-blasting zones are automatically adjusted based on this measurement data.
    [14]
    Method according to Claim 1, characterized in that, as a pre-blow to the underside of the front and rear ends of the glass panes coated on its upper surface, pressurized air is blown upwards, i.e. towards the upper pre-cooling air housings,
    20, and the pre-blowing distances from the leading edges of the glass sheets including toward the rear edges of the glass sheets, (Sh = Wtn), and from the rear edges of the glass sheets including toward the leading edges of the glass sheets, (Sr, = WtRi).
    [15]
    The method of claim 14, wherein the pre-blowing glass
    The zone of 25 edges extends over the entire length of the glass to a zone 10 to 50 mm wide.
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    同族专利:
    公开号 | 公开日
    FI128669B|2020-09-30|
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    EP18824578.1A| EP3645473B1|2017-06-27|2018-06-13|Method for tempering glass sheets|
    US16/606,472| US20200131070A1|2017-06-27|2018-06-13|Method for tempering glass sheets|
    PCT/FI2018/050459| WO2019002672A1|2017-06-27|2018-06-13|Method for tempering glass sheets|
    CN201880038576.3A| CN110730764A|2017-06-27|2018-06-13|Method for tempering glass sheets|
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