The application of butyl sealant is the key step in making the insulating glass. It determines the comprehensive quality performance of the insulating glass products (whether it meets the five indicators of the national standard for insulating glass). The non-drying sealant composed of butyl rubber and a small amount of polyisobutylene does not appear dry in the production of insulating glass. It can be mechanically coated and is suitable for assembly in the assembly line. After coating, the adhesive layer does not dry and remains sticky for a long time. At the same time, it has excellent heat resistance and water resistance. It does not flow under the sun and rain, and maintains the airtightness of the insulating glass. Together with the second sealant, it forms an excellent moisture resistance system.
In order to ensure the appearance and quality of the insulating glass, the following technical requirements are applied to the butyl sealant used:
1, must choose the appropriate guaranteed butyl sealant products;
2, has a good initial tack and adhesion to the glass;
3, has a good sealing performance;
4. The coating should be uniform and the coating cross-section should be consistent;
A theoretical study and practical problems
Let's talk about the problems and solutions or suggestions that are easy to occur in the use of butyl sealant:
1 Phenomenon: The butyl strip coated on the aluminum spacer has a burr and is not neat.
Cause: There may be impurities at the outlet of the two nozzles or the mouth of the nozzle is not smooth.
Solution or suggestion: Check for impurities at the outlet of the two nozzles or whether the mouth of the nozzle is smooth.
2 Phenomenon: A gap (white line) appears between the butyl strip after the splicing and the front sealant.
Cause: The front sealant was not properly applied.
Solution or suggestion: When applying the front sealant, apply it with force and apply it in one direction to prevent air from being wrapped in the glue and reduce the sealing performance of the insulating glass.
3 phenomenon: the extrusion is not smooth after heating, easy to break the glue (broken wire).
Reason: The key to the use of butyl sealant is extrusion. The control of temperature is very important in the extrusion process. Whether the temperature control is suitable directly affects the rheological state of the butyl sealant during the whole process, which affects the inherent product. Quality and aesthetics should pay special attention to temperature. If the temperature is too high, the sealant will melt too much, and there will be no strength or even no shape at all (flowing phenomenon); if the temperature is too low, the fluidity of the glue will be poor, and the machine will not squeeze out the glue, which will affect the construction progress, which is the main reason for the unsuccessful extrusion. . Another reason may be that the butyl sealant is trapped in the manufacture of air bubbles and causes breakage during extrusion.
Solution or suggestion: The selection of temperature Generally speaking, the extrusion temperature range provided by the manufacturer is appropriate, the extruder temperature is generally set between 110-130 °C, and the head is at 112-132 °C. between. In order to cause the host to generate a certain pressure to uniformly melt the melt, the head temperature is required to be higher than the barrel temperature. The temperature has a certain hysteresis. During the adjustment, it should be noted that the heating and cooling should be carried out gradually. Before the coating starts, it should be properly vented to reduce internal bubbles and voids, and to prevent bubbles from being generated during extrusion.
4 Phenomenon: The extrusion temperature control is suitable, but the aluminum spacer and the butyl sealant have poor adhesion or poor adhesiveness.
Reasons: (1) Aluminum spacers or conveyor belts are not clean, oily and dusty.
(2) The belt is transported too fast, and the aluminum spacer is too late to be glued.
(3) The aluminum frame is skewed, the glue mouth is not easy to pass or the glue position is not correct.
(4) The initial viscosity of the sealant itself is poor.
Printed Fabric,Animal Print Fabric,Printed Cotton Fabric,Woven Print Fabric
Shaoxing Ruby Textile Co., Ltd , https://www.sxrubytex.com