The reason why polyurethane foam is easy to shrink
Why does polyurethane foam shrink?
1. There are too many materials in group A, which reduces the strength of the adhesive and leads to a large shrinkage.
2. The materials in the spray gun are not evenly mixed, resulting in too small spray or too high viscosity.
3. The curing speed is too fast, causing most of the bubbles to appear closed.
4. Working at low temperature will directly cause the styrofoam to shrink. If it encounters a high temperature, it will expand rapidly.
Why is the foaming abnormal after mixing?
1. The temperature of the material is too low, or the blowing agent and catalyst are not added.
2. The ratio of the two groups of materials is unscientific, causing the adhesive to fail to foam normally. Or there is a problem with the quality of the adhesive and it cannot be used normally.
Why is polyurethane styrofoam crispy?
1. There are too many components of B material, or too much water. When material B contains too many impurities, it will directly affect the foaming effect.
2. The temperature of the base surface is a bit low, or excessive flame retardant is added.
Why does the foam of polyurethane styrofoam collapse?
1. Excessive speed will directly affect the foaming effect. The amount of amine catalyst can be appropriately reduced to avoid foaming and crisping.
2. The catalyst does not play its due role, and the amount of catalyst can be increased appropriately.
Why are the cells of polyurethane styrofoam too large?
1. The foam stabilizer has lost its effect or contains too much water.
2. The materials are not stirred uniformly, or the purity of B material is too low.
