When using butyl sealant, we must understand its usage and precautions in advance, so as to better avoid unnecessary safety hazards caused by misuse. After all, butyl tape is a chemical product. If eaten by mistake, it will cause damage to the body! Everyone must pay attention.
The coating of butyl sealant is the first and key link in the manufacture 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). The non-drying sealant composed of butyl rubber and a small amount of polyisobutylene will not dry out in the production of insulating glass. It can be mechanically coated and suitable for assembly line assembly. After coating, the adhesive layer does not dry and maintains permanent viscosity. At the same time, it has excellent heat resistance and water resistance, will not flow under the sun and rain, and maintains the air tightness of the insulating glass. Together with the second sealant, it constitutes an excellent anti-moisture system.
Butyl sealing waterproof strip
Butyl sealing waterproof strip
In order to ensure the appearance and quality of insulating glass, the following technical requirements are required for the butyl sealant used:
1. You must choose a suitable guaranteed butyl sealant product.
2. Good initial viscosity 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 introduction to the problems and solutions or suggestions that are prone to occur in the use of butyl sealant:
Performance 1: The butyl rubber strip coated on the aluminum spacer has burrs and is not neat. Reason: There may be impurities at the exits of the two nozzles or the nozzles are not smooth. Solutions or suggestions: Check whether there are impurities at the exit of the two nozzles or whether the nozzles are smooth.
Performance 2: There is a gap (white line) between the butyl rubber strip and the first sealant after lamination. Cause: The first sealant was not applied correctly. Solution or suggestion: When applying the first layer of sealant, it should be applied with appropriate force and in one direction to prevent air from being wrapped in the glue and reduce the sealing performance of the insulating glass.
Performance 3: Extrusion is not smooth after heating, and it is easy to break the glue (broken line). 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 affects the rheological state of the butyl sealant in the entire processing process and affects the inherent properties of the product. Quality and aesthetics, special attention should be paid to temperature. If the temperature is too high, it will cause the sealant to melt too much, without strength or even unable to form at all (flow phenomenon); if 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 the butyl sealant contains air bubbles in the manufacturing process, which causes the glue to break during the extrusion process. Solutions or suggestions: Generally speaking, the selection of temperature is based on the extrusion temperature range provided by the manufacturer. The temperature of the extruder is generally set between 110-130 °C for the barrel and 112-132 °C for the head. between. In order to make the main machine generate a certain pressure and extrude the melt evenly, the temperature of the head is required to be higher than the temperature of the barrel. 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 the internal air bubbles and voids and prevent the glue from being broken due to air bubbles during extrusion.
Performance 4: Extrusion temperature control is appropriate, but the adhesion between aluminum spacer and butyl sealant is not good or the adhesiveness is poor.
reason:
(1) The aluminum spacer or conveyor belt is not clean with oil and dust.
(2) The belt transmission is too fast, and the aluminum spacer is too late to apply glue.
(3) The aluminum frame is skewed, and the glue nozzle is not easy to pass or the glue application position is incorrect.
(4) The initial viscosity of the sealant itself is poor.
Solutions or suggestions:
(5) Clean and proofread aluminum spacers and conveyor belts, and adjust the speed of conveyor belts
(6) Adjust the gap between the two nozzles proportionally.
(7) The aluminum spacer should be placed vertically during coating to prevent the aluminum spacer from not sticking due to the fact that the glue nozzle is not easy to pass or the position of the glue is not correct.
(8) Butyl sealant is both elastic and viscous elastomer. It is extruded and adsorbed on the clean aluminum strip through suitable temperature and pressure. The melted butyl rubber diffuses to the surface of the adherend and gradually wets the Adhesive surface and deep into the surface pores, this is a physical process, in this process, the butyl glue and the adherend (aluminum strip) are only in line contact between the surfaces, and only after pressing can they be connected to the adherend. Make face contact. Therefore, suitable construction pressure and temperature are beneficial to the progress of this process. It is worth noting that the adsorption of the glue on the aluminum strip takes a period of time (3 ~ 5MIN) to achieve the best bonding effect.
Let's take a look at the precautions for using butyl sealant.
Open the original packaging and check for obvious particles and debris. The application speed should not be too fast, so as to avoid the end of the application. If the coating can not reach the end or the pressure roller is lifted, the pressing time is too short, and the pressure roller time can be readjusted. The coated aluminum frame should not be placed for too long, otherwise the effect of bonding and sealing will be affected. If the conveyor belt deviates, it should be corrected in time. If there is too much glue on the conveyor belt, it should be removed in time. If necessary, a small amount of paraffin can be applied to prevent the belt from sticking. After applying the first layer of sealant, try to press together in a short time to avoid the influence of ambient temperature on product adhesion. The insulating glass that has not been coated with the second layer of sealant after rolling should be placed horizontally, and can be placed vertically in a short time But not collision, to avoid unnecessary dislocation. 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 miscible.
