If it is the skinning phenomenon in the foaming process, it can be divided into many kinds. Here I will first talk about how to make soft and hard foam foaming and skinning and self-skinning.
To make the hard foam foam skin thicker, the methods are as follows:
1. Appropriately use the amount of water, or increase the amount of skin conditioner;
2. The use of excessive filling method can obviously improve the surface;
3. The use of better polyether can also thicken the skin, mainly to choose polyether with moderate viscosity, because the excessive viscosity of polyether will lead to thin skinning of rigid foam;
4. To increase the surface hardness, adding an appropriate amount of low molecular polyether can also improve the thickness of the skin.
It is also a polyether. For soft foam, the molecular weight of the soft foam is low, and the choice of polyether with a higher molecular weight will improve.
If it is self-skin foam, there are some solutions:
1. Reduce the mold temperature and increase the mold pressure appropriately, but it will bring about the problem of difficult demoulding.
2. Increase the amount of physical foaming agent, reduce the amount of water, and slow down the foaming time. However, in winter, the product will be more fragile and the shortcomings will be more obvious, so you can reduce the density or add more material.
3. Use silicone oil with strong foam stabilization ability.
4. Add a small amount of catalysts that accelerate skin aging, such as glycerin, potassium acetate, castor oil, triethylenediamine, into the formula.
