Insulating glass integrates excellent characteristics such as heat insulation, sound insulation and lighting, and is an effective energy-saving means of modern buildings, which not only simplifies the structural design of ventilation and warm facilities such as air conditioning, reduces the cost of building decoration, but also increases the effective indoor space of the building. With the rapid rise of glass curtain wall in China in the 90s, the development of the insulating glass industry has been accelerated. The application range of insulating glass is expanding, in addition to being widely used in glass curtain walls, automobiles, transportation, aircraft, etc., has entered a large number of new buildings and ordinary people's homes, and people's quality requirements for insulating glass are getting higher and higher. Insulating glass with long sealing life has better economic benefits and stronger market competitiveness. Therefore, the production of excellent and reliable insulating glass has become a key issue pursued and researched by insulating glass manufacturers. At present, the production process of insulating glass is not perfect. Mastering and implementing the correct manufacturing process is the guarantee and prerequisite for the quality of insulating glass.
The coating of butyl sealant is the first and key link in the production of insulating glass, which determines the comprehensive quality performance of insulating glass products (whether it meets the five indicators of the national standard for insulating glass). Non-drying sealant composed of butyl rubber with a small amount of polyisobutylene, will not dry out in the production of insulating glass, can be mechanically glued, suitable for assembly line assembly, after coating the rubber layer does not dry to maintain a long viscosity, while having excellent heat resistance, water resistance, in the sun and rain will not flow, and maintain the airtightness of the insulating glass, and the second sealant together constitute an excellent moisture resistance system
In order to ensure the appearance and quality of insulating glass, the butyl sealant used has the following technical requirements, Senping butyl tape manufacturers will talk about it below:
1. Select suitable guaranteed butyl sealant products;
2. Good initial adhesion and adhesion to glass;
3. Good sealing performance;
4. The coating should be uniform and the coating section should be consistent;
The following is a brief discussion of the problems and solutions or suggestions that butyl sealants are prone to occur in use:
1. Phenomenon: The butyl rubber strip coated on the aluminum spacer has burrs and is not neat.
Reason: There may be impurities at the outlet of the two nozzles or the nozzle mouth is not smooth.
Solution or suggestion: Check whether there are impurities at the outlet of the two nozzles or whether the nozzle mouth is smooth.
2. Phenomenon: There is a gap (white line) between the butyl strip after joining the sheet and the first sealant.
Cause: The first sealant was not applied correctly.
Solution measures or suggestions: When applying the first sealant, it should be applied with appropriate force and in one direction to prevent air from being wrapped in the glue and reducing the sealing performance of the insulating glass.
3. Phenomenon: the extrusion is not smooth after heating, and it is easy to break the glue (broken wire).
Reason: The key to the use of butyl sealant lies in extrusion, temperature control is very important in the extrusion process, whether the temperature control is appropriate, directly affect the rheological state of butyl sealant in the entire processing process, affect the intrinsic quality and beauty of the product, should pay special attention to temperature. If the temperature is too high, the sealant will melt too large, and it will not be able to form at all without strength or even at all (flow phenomenon); The temperature is too low, the fluidity of the glue is poor, and the machine cannot squeeze out the glue, which affects the construction progress, which is the main reason for the unsmooth extrusion. Another reason may be that butyl sealants are mixed with air bubbles in the manufacture and cause breakage during the extrusion process.
Solution measures or suggestions: The selection of temperature is generally speaking, the extrusion temperature range provided by the manufacturer is appropriate, and the temperature of the extruder is generally set between 110-130 °C, and the machine head is between 112-132 °C. In order to make the host generate a certain pressure and make the melt evenly extruded, the temperature of the machine head is required to be higher than the barrel temperature. The temperature has a certain hysteresis, the adjustment should pay attention to the heating and cooling should be carried out gradually, before the start of coating, should be properly exhausted to reduce internal bubbles and voids, to prevent bubbles during extrusion caused by rubber breakage.
4. Phenomenon: the extrusion temperature control is suitable, but the aluminum spacer and butyl sealant are not adhesion or poor adhesion.
Cause:
(1) The aluminum partition or conveyor belt is not clean and has oil and dust.
(2) The belt is conveyed too quickly, and the aluminum spacer does not have time to apply glue.
(3) The aluminum partition frame is deflected, and the glue nozzle is not easy to pass or the glue position is incorrect.
(4) The initial tack of the sealant itself is poor.
Workaround or recommendation:
(1) Clean and calibrate the aluminum spacer and the conveyor belt, and adjust the speed of the conveyor belt
(2) Adjust the gap between the two nozzles proportionally.
(3) When coating, the aluminum spacer should be placed vertically to prevent the aluminum spacer from not sticking caused by the glue nozzle being difficult to pass or the gluing position is incorrect.
(4) Butyl sealant is both elastic and viscous elastomer, through the appropriate temperature and pressure extrusion adsorbed on the clean aluminum strip, molten butyl glue to the surface of the adhesive diffuse, gradually wetting the surface of the adhesive and deep into the surface micropores, this is a physical process, in this process butyl glue and the adhesive (aluminum strip) is only the line contact between the surface, only after pressing can the surface contact with the adhesive. Therefore, suitable construction pressure and temperature facilitate this process. It is worth noting that the adsorption of the glue to the aluminum strip takes a period of time (3~5min) to play a good bonding effect.
Let's specifically explain the precautions for using butyl sealants:
1. Open the original packaging and check for obvious particles and debris.
2. Do not apply too fast to prevent the application from reaching the head.
3. The coating does not reach the head or the pressure wheel is lifted, and the pressing time is too short, the pressure wheel time can be readjusted.
4. The coated aluminum partition frame is not easy to be placed for too long, otherwise it will affect the effect of bonding and sealing.
5. If the conveyor belt deviates should be corrected in time, if the conveyor belt has too much adhesive, it should be cleaned up in time, and a small amount of paraffin wax can be applied if necessary to prevent sticking to the belt.
6. After coating the first sealant, try to press it in a short time to avoid the influence of ambient temperature on the product bonding, and the insulating glass that has not been coated with the second sealant after rolling should be placed horizontally, and can be placed vertically in a short time, but can not collide to avoid unnecessary misalignment.
7. Before making double-channel insulating glass, the necessary compatibility test must be carried out on the double-channel sealant to prevent the two sealants from being compatible.
