In the process of soft foam, I do not know if you will encounter such a problem, the phenomenon of half collapse bubble, and collapse bubble degree than the normal fall back to much more powerful, the normal fall back to about 1 cm to 2 cm, half collapse bubble is more than 5 cm, and the surface has a lot of large bubbles. For this phenomenon, I can only combine the views of users to say some solutions, whether the approach is useful, but also to see the process of practice, everything to the actual prevail, all methods are only theoretical knowledge.
The following to say what solutions.
First, this situation, if the assembly line foaming, it is possible that the TDI and polyether feeding time is not well coordinated, may be slow polyether out, where the slow is relative to the TDI is TDI fast. By adjusting the speed of TDI to make it slower, it may be effective. Mutual adjustment of the speed of the two, there will always be results.
Secondly, the flow rate is too fast, add some A-1. bring down the flow rate.
Third, increase the flow rate to ensure the amount.
Fourth, the problem of silicone oil, the choice of silicone oil must be appropriate, adjust the amount of silicone oil, if it still does not work, you can consider replacing the type of silicone oil.
Fifth, the temperature problem, whether it is the material temperature, or mold temperature, should be appropriate.
Sixth, it is possible that none of the above problems, but external problems, check the design of the pipeline, whether it has recently replaced the silicone oil or TDI pipeline.
Polyurethane soft foam is mostly open pore structure, with low density, good elastic response, sound absorption, breathable, thermal insulation and other properties, mainly used as furniture cushioning materials, mattresses, transportation seat cushions and other cushioning materials, industrial and civil also use soft foam as filtering materials, sound insulation materials, shockproof materials, decorative materials, packaging materials and thermal insulation materials. At present, the application of high resilience, slow resilience, self-crusting, high flame retardant foam in various fields will become more and more widespread. The wide application of polyurethane flexible foam in large quantities has driven the rapid development of polyurethane materials, thus the demand for R&D technicians has increased significantly. At the request of the majority of polyurethane industry people and information and manufacturers such as polyurethane alliance network forum, polyurethane QQ group, polyurethane WeChat channels, polyurethane alliance network continues to join hands with experts in sponge technology and molding process for more than fifteen years to create practical, professional and We will provide excellent technical talents for the development of the industry.
