What is the reason for the dark bubbles and pores in pu self crust? How to solve it?

What is the reason for the dark bubbles and pores in pu self crust? How to solve it?

PU is the abbreviation of polyurethane in English, and its Chinese chemical name is “polyurethane”. PU leather is the skin of polyurethane. It is widely used for decoration of bags, clothing, shoes, vehicles and furniture. It has been increasingly recognized by the market. It has a wide range of applications. What is the reason why there are dark blisters and pores in pu self skinning? How to solve it?

Dark blister: It is the most common defect of self skinning. From the appearance, there is a layer of skin, and there are air holes under the skin, large and small, which will bulge through extrusion. Usually, the dark bubbles cannot be seen directly. They can only be seen by touching or tearing the foam directly. Self skinning, PU, polyurethane

Solution: 1. If the peel is smooth, the air bubble is not completely discharged, or the discharge gun head of the foaming machine is not smoothly wrapped in air, which can be eliminated by relying on the exhaust body.

2. If the subcutaneous cavity is rough, it may be caused by fine dust particles in the material, which causes the foam to burst and bubble. It is necessary to eliminate pollution sources and find out the conditions that may lead to small particles. The small wood chips of ordinary wooden inserts are the source of pollution. Self skinning, PU, polyurethane

3. This also happens when the mold temperature is lower than 35 ℃ in some products with high density and high gel speed. After PVC artificial leather, PU synthetic leather, as an ideal substitute for natural leather, has achieved breakthrough technological progress after more than 30 years of dedicated research and development by scientific and technological experts.