The Crack
Sometimes there is even a partial swelling hotmelta heated in the low double-glazed window. With a significant cooling of hotmelt hardens, loses elastic properties, gives the crack. Wind effect leads to the separation of glass from the plastic mass. In addition, moisture (condensation) freezes in the microcracks, the ice breaks these cracks, the cracks penetrate pollution. Repetition of the process leads to the destruction of the sealant (remember the forgotten piece of asphalt construction workers on the street). Ultimately, this negatively affects the quality of glass. Longevity of glass collected using hotmelta about twice yields glazed with other secondary sealants. The most widely used today, the secondary sealing – These are two competing technologies, using two-component polyurethanes and polysulfides.
Both types of sealants congeal in the process of mixing the two components, the reaction of polymerization. Both types of possess high strength characteristics and low rates of gaseous diffusion. Around the same time and pour sealants (2-3 hours prior freezing; about 24 hours, subject to final the correct ratio of components). And polyurethanes, and polysulfides are designed for high production. Standard packaging is a collection of drums: Part A-190 liters, a component of B – 20 liters.
And then it's time say about the practical differences between the two types of sealants. Firstly, when we talk about the engine design process, we must remember that we are dealing with a variety of chemical point of view of products. From this it follows difference in the machines to work with these products.
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