During the foaming process of soft foam, I wonder if you will encounter such a problem. The phenomenon of semi-collapse occurs, and the degree of foam collapse is much greater than the normal drop. The normal drop is about 1 cm to 2 cm. , the half-collapsed bubbles are more than 5 cm, and there are many large bubbles on the surface. Regarding this phenomenon, I can only give some solutions based on the opinions of netizens. Whether the method is useful depends on the practical process. Everything is based on reality. All methods are only theoretical knowledge. 
The following are some solutions:
First, if this situation is caused by assembly line foaming, it may be that the feeding time of TDI and polyether is not coordinated well. It may be that the polyether is coming out slowly. The slowness here is relative to TDI. TDI is faster. By adjusting the TDI speed and making it slower, it may have an effect. Adjust the speed of the two to each other, and there will always be results.
Second, the flow rate is too fast, add some A-1. Reduce the flow rate.
Third, increase traffic and ensure volume.
Fourth, regarding silicone oil, the choice of silicone oil must be appropriate, and the amount of silicone oil must be adjusted. If it still doesn’t work, you can consider changing the type of silicone oil.
Fifth, the temperature issue, whether it is material temperature or mold temperature, must be appropriate.
Sixth, it may not be the above problem, but an external problem. Check the design of the pipeline and whether the silicone oil or TDI pipeline has been replaced recently.
Polyurethane soft foams are mostly open-cell structures with low density, good elastic recovery, sound absorption, breathability, thermal insulation and other properties. They are mainly used as furniture cushions, mattresses, vehicle seat cushions and other cushions for industrial and civil use. Soft foam is also used as filter materials, sound insulation materials, shock-proof materials, decorative materials, packaging materials and heat insulation materials in the world. At present, foams with high rebound, slow rebound, self-skinning, and high flame retardancy will be used more and more widely in various fields. The wide application of polyurethane soft foam has led to the rapid development of polyurethane materials, which has significantly increased the demand for R&D technicians. In response to the requirements of the majority of polyurethane industry personnel and polyurethane alliance network forums, polyurethane QQ groups, polyurethane WeChat channels and other information and manufacturers, The Polyurethane Alliance Network continues to join forces with experts in sponge technology and molding technology for more than fifteen years to create practical, professional, and useful polyurethane technology training courses to provide excellent technical talents for the development of the industry.
