Features And Classification Of Polyurethane Sealant
Polyurethane sealant has the following characteristics: excellent wear resistance; low temperature flexibility; a wide range of adjustable performance; mechanical strength;Good adhesion, good elasticity, excellent recovery, can be suitable for dynamic joints; good weather resistance, the service life of up to 15 to 20 years; excellent oil resistance; resistant to aging; affordable.
Polyurethane sealant also has some drawbacks. Such as: can not be long-term heat; light-colored formulations susceptible to UV aging; single-component plastic storage stability by the packaging and the outside world is relatively large, usually slow curing; high temperature thermal environment may produce bubbles and cracks; Painted At the same time the polyurethane sealant water resistance is also poor, especially poor alkali resistance.
Polyurethane sealant is generally divided into two types of single-component and two-component basic type, one-component moisture curing type, two-component reaction curing type. One-component sealant construction is convenient, but the curing is slow; two components have fast curing, good performance characteristics, but need to use the preparation, the process is more complex. Both have their own development prospects.
According to whether there is liquidity, polyurethane sealant can be divided into non-hanging type (non-sagging) and self-leveling parallel (self-leveling). No hanging type for vertical, inclined, ceiling and other occasions, before curing due to the weight of the tape will not shift, slide or flow; and self-leveling type specifically for horizontal occasions. According to the nature of the use can also be divided into dry, semi-dry and fully cured elastic body