PVB film production

Product introduction

A process and parameters of production folder glass products recommended Huakai PVB film:

(1) glass washing

In order to eliminate the dirt, the dirt on the surface of glass, and greasy dirt, should be carefully washed glass. Glass cleaning machine using water must be clean processing,according to the strict requirements is the use of ion softened water. After being washed awayin the special dirt and so on, in order to prevent detergent solution residue on the glass surface, finally must rinse clean, in order to avoid adhesion caused by low waste. The finalrinse water has a great influence on the bond strength of laminated glass, especially thecleaning water salinity influence the final quality of bonding between glass and PVB. Af. After cleaning the glass drying and kept at room temperature before use.

The production of curved laminated glass, glass washing must be completed before bending.

(2) PVB film preparation

Must be treated shrinkage reasonably cut film according to the glass specification, marginsize and film, film compensation by hot pressing process of shrinking in size. In the use of low temperature storage film, shrinkage rate charged depends on the film itself and the film layingthe size of the stress.

(3) the technical index and key operation piece chamber:

Environment conditions is the key of the sandwich glass press. Operate strictly in accordance with the technical standard temperature, humidity and dust free workshop, equipped with air conditioning system, air filter, air dehumidification equipment, general quality requirementscan reach grade 300000 is preferred. Adjusting room temperature and humidity should bebefore laminating, relative humidity control in general between 25%-40%, control temperature between 18-22 ℃. The room requires: exit and entrance are double doors; the use of air conditioning, with filtered air the room always at positive pressure; at the entrance of theground, place the carpet or doormat, to avoid the dirt into the interior; the operator before entering the lamination room to replace the cleaning slippers, at the same time must be equipped with: (1). Masks: prevent spoke slobber splash on the PVB surface, in order to reduce the speckle small bubbles in glass. (2) the medical latex gloves. Gloves: gloves or lint free of chemical products. More important for the summer, because the human body is easy to sweat from hands, resulting in the operation easily infected with dirt indirect PVB infectiondirt, lead to the occurrence of nematode (Caenorhabditis elegans bubble bubble productsgenerally out of the autoclave 2-5 genius apparent). (3) with a hat and wearing clothes withelastic cuffs, preferably anti-static clothing is more ideal, mainly to prevent the hair and armpithair loss between the clip into glass causing unnecessary losses.

Press two to align the glass, film in the glass edge leaving around 5mm. Press, the glass surface slightly heated, making certain adhesion between glass and PVB, can ensure the filmposition in laminated glass, so as to ensure the piece after the glass in the production linewithout sliding. When the film thickness is used for 0.76mm, the production of laminated glassglass temperature is generally between 21-41OC. If the glass temperature higher than 41OC,press it will appear to shrink film, resulting in wrinkling or adhesive shrinkage film. The glasstemperature is too high will cause premature or re positioning the edge sealing film difficult.Edge premature seal will cause internal bubbles sandwich glass.

Double tempered laminated glass must be strictly matching (matching is completed, in thesteel production line of each glass should be divided into two furnace, positioning, pairproduction).

Then the glass after trimming, pull the middle film to avoid the intermediate film deformation should not be pruned, PVB in the glass edge should stay beyond the glass about 3mm is better, when the sharp blade to trimming and with less than 45 degree angle gently cut edge,prevent the pull glue phenomenon, caused by the edge edge small bubbles. At the same time, trimming knife must not be in contact with glass, glass particles so as not to cause theprocessed back caused the bubble.

(4) pre pressure exhaust

Semi finished piece after going through pre pressing process. Preloading aims to remove the glass and film between the air, so that the steam pressure, don't make the air in the middle,the formation of air bubbles; the glass and film preliminary glued together, steam pressurebetween each layer will not have the dislocation, and water will not penetrate the barrier sheetglass, laminated glass is a good foundation for high quality lay, pre pressure exhaust is divided into two methods: a roll exhaust method: a good glass by preheating, enter the first line of roller press, roller extrusion, into the oven, then by second roll extrusion, exhaust,edge to complete this process. Out of second roll, sandwiched glass should be around a circle of transparent tape will edge sealed, avoid the gas inside the autoclave recirculationbubble. Other parts can be opaque parts evenly distributed, this single thermostat / doubletelescoping process requirements of glass surface temperature must be controlled strictly,neither can the temperature is too high, so that the edge of premature, internal gas can not be discharged; nor can the temperature is too low, the edge is not complete, the recirculation bubble. Suggestion: Glass preheated surface temperature 25-40 ℃, the first roller gap thansandwiched glass small total thickness of about 1mm, pressure 0.2-0.5MPa. Second rollergap than clamping glass small total thickness of about 2mm, pressure is 0.3-0.5MPa. Thesecond roll surface temperature of glass must be strictly controlled at 60-80 ℃. First preparethe required production of glass, as far as possible, uninterrupted, consecutive, avoid long time interval Heng Wenxiang temperature series, caused by the glass surface temperaturecan not accurately control.

B. thermal vacuum preloading exhaust method: will the glass into the vacuum bag in or around a vacuum rubber ring, the cold smoke, heat pump, using the interface of glass /PVB film from the air and sealing pressure difference. Suggestion: vacuum is above 650mmHg,cold drawing temperature is 25 ℃, cold time is over 15 minutes; heat pumping glass surface temperature required to reach 70-120 ℃, time in more than 30 minutes.

(5) high pressure molding

Sandwiched glass vertically on the support pre pressure exhaust good, the adjacent clampglass interval greater than 5mm. The glass into the kettle, sealed the cauldron gate, the firstheating, the reactor temperature reached 45 degrees, and heating and pressurizing. The heating speed control in 5 ℃ / min, pressure speed control in 0.06MPa/ minutes. When the temperature reaches 120-140, the pressure of 1.0---1.5MPa, began to pressure and temperature holding 30 - 60 minutes. Then the pressure down to 45 ℃, pressure up toatmospheric pressure, high pressure molding process is completed, to get the final need toclamp glass products. Pressure, pressure relief when the temperature must be controlled strictly, to avoid clamping glass edge bubble.

Effect of two, the thickness of the glass and PVB thickness of the basic requirements and thestress of glass.

1 when laminated glass is broken, the glass is thicker on the PVB film tension is greater, somust according to the glass thickness using the appropriate thickness of PVB, the phenomenon of degumming, rational use of PVB can reduce the bubble glass rebound. For PVB film plates and other special purpose can be customized.

2 basic requirements of glass thickness and thickness with PVB.

1) suitable for 0.38mmPVB (3+3), (5+5), (6+6) of ordinary float glass.

2) 0.76mmPVB applied to (6+6) below the double tempered glass and float glass (8+8).

3) 1.14mmPVB for (8+8) double tempered glass and float glass (10+10).

4) 1.52mmPVB for (10+10) double tempered glass and float glass (12+12).

5) 1.90mmPVB for (12+12) double tempered glass and float glass (15+15).

6) where the use of hot bending process of laminated glass using at least 0.76mm PVB.

Three, autoclave molding: the autoclave working temperature, pressure, time curve shown in Figure

Heating, cooling, autoclave pressure, pressure are usually equipped with automaticprocedures do not adjust. If no automatic control manual, from a closed autoclave door after the first open filling, heating switch, when the temperature reaches to 70 ℃ before 0.6Mpa,pressure switch of the heating switch, and then open the heating switch until the heat preservation, packing the required temperature and pressure for pressure is 0.6Mpa,temperature 135 ℃ General requirements, the pressure 1.3Mpa, time 45-60 minutes. This can increase the stability and weather resistance of laminated glass. When the heat preservation, packing time to start to cool between 135 ℃ -70 ℃ cooling speed is not too fast,to take measures to keep the pressure in the kettle air does not decline during this period,after at least 50 minutes. Better put into the reactor cooling water 50%, all open cooling waterat 70 ℃. Kettle temperature dropped to 40 ℃ after pressure relief, pressure relief time canslow down a bit, not because of rapid relief appear quality problem.

Four, PVB storage standard

1, good packaging of the product can be stored for 24 months at room temperatureenvironment clean, to avoid direct sunlight, Yu Lin, water and corrosive gas.

2, the aluminum foil packing damage or is open, must be placed on the lamination room ormeet the storage requirements of space, no longer than 60 days, should be placed in the ground more than 300 mm.

3, lamination room storage room to keep constant temperature, constant temperature,temperature was 18-22 ℃, humidity is between 25%-40%, the air quality in the 300000 level and above.

4, lamination room, storage room floor requires use of wood floor, thermal insulation, moisture resistance is better, if the conditions Limited customers also can use brush floor paint,prevent ground water caused by excessive humidity.