IOTA CORPORATION LTD.
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One-component silicone sealant operating process guide And common problem solutions Deketoxime-type products will corrode copper and hard PC in a closed environment, so be careful when selecting. First, the use of technology 1. When bonding new materials, it is necessary to do a suitability test to determine if it can be bonded. 2. Before sizing, be sure to clean the bonded substrate. 3. When using the machine to automatically dispense, short-term stop dispensing requires water vapor isolation of the glue outlet. 4. The curing speed of the glue has a great relationship with the ambient temperature. If it is necessary to speed up the curing speed, it can be properly heated and humidified according to its own conditions. Second, the matters needing attention 1. Disposable unused glue should be tightened and squeezed out a proper amount of glue to protect the air. 2. Before the glue is not fully cured, it can not be operated in a high temperature environment, and it also causes bubbles and no adhesion. 3. When it is necessary to dilute the glue, the solvent product must be selected according to the product description, and the operation should be carried out in a good ventilation environment. 4. Due to the limited storage period of the product, the principle of first-in-first-out is recommended. Third, common problems and solutions 1. How do one-component products achieve optimum curing performance? One-component condensation-cured silicone rubber products are cured using moisture in the air. When cured, the condensation-cured silicone rubber can be cured for 3 hours in the table and inside, usually at 25 ° C and 50 % R.H.; it takes 7 days to reach the inherent physical properties. 2. Why is there a difference in dry time between winter and summer? The surface dryness and curing speed of one-component condensation-cured silicone rubber products have a great relationship with the ambient temperature. The humidity and temperature in winter are low, the glue surface is dry and the curing speed is slow, the humidity is high in summer, the temperature is high, and the glue surface is dry and solidified quickly. 3. Why is the viscosity different in winter and summer? The viscosity of the glue changes with temperature, and the high viscosity in summer is reduced. In winter, the opposite is true, but it will be within the acceptable range. 4. How to increase the curing speed? When the curing thickness is greater than 6mm, it is recommended to use 2 times of filling; increasing the temperature and humidity can accelerate the curing speed of the product, but the temperature should not exceed 50 °C, and the effect of increasing the humidity is better than increasing the temperature. 5. Why is white silica gel yellowing? The ketone oxime type silica gel contains a ketone oxime crosslinker, an amino silane type tackifier and a catalyst. Under long-term ultraviolet light irradiation or a high temperature environment of 80 ° C or higher, the surface may be surface due to oxidation of an amino group or some chemical reaction of the catalyst. Yellowing occurs. To improve the yellowing phenomenon, special formulas such as solar silica gel have good anti-yellowing properties. The common 737, KE45W, etc. on the market have relatively serious yellowing. In the case where the dealcoholized silica gel is not completely cured, the titanate catalyst which does not participate in the reaction is displayed under heating conditions due to its own yellow color, which causes the colloid to turn yellow. 6. What is the temperature resistance of silica gel? Generally, the temperature of silica gel is in the range of -40 ° C - 200 ° C, the long-term use temperature does not exceed 150 ° C, the special high temperature resistant glue such as iron red silica gel temperature range is - 40 ° C -250 ° C, the long-term use temperature does not exceed 180 ° C. The temperature resistance is greatly related to whether the gel is completely cured. When the uncured temperature is completely heated, bubbles, cracks, smoke and other undesirable phenomena may occur. 7. How is the "aerosol" phenomenon of the ketoxime-type silica gel in a closed system? Deketoxime silica gel is used in closed systems. For example, in lighting, lamp and other industries, it sometimes produces a similar "aerosol" on the inner surface of the glass, which greatly reduces the transparency of the glass and affects the transmittance and aesthetics of the glass. degree. This is due to the fact that in the closed system sizing, the butanone oxime released during the curing of the deodorized silica gel cannot be discharged into the atmosphere in time and accumulates and adheres to the surface of the glass; it is easier to avoid such aerosols by using the dealcoholized silica gel. Phenomenon, because the product released by curing is an alcohol substance, which is a gas at normal temperature and does not aggregate and adhere to the surface of the glass. 8. How to remove silica gel? Before the silicone gel is cured: the uncured paste is scraped off with a putty knife and then the residue is washed with petroleum ether (120# gasoline). After curing the silica gel: First, mechanically scrape as much silica as possible with a knife or razor, then use a solvent (120# gasoline, toluene, xylene or acetone) to remove various oil residue or silica gel, soak the silica gel. Allow it to swell overnight in this solvent and then clean it |
