The defoaming challenges in polyurethane production mainly stem from multiple aspects, which not only affect the appearance quality of the product, but may also have adverse effects on the performance and service life of the product. The formation of polyurethane foam is mainly due to the gas generated in the production process is not discharged in time in the liquid polyurethane, thus forming bubbles in the liquid. These bubbles are fixed during the curing process of polyurethane to form foam. The gas may come from carbon dioxide generated by the reaction between moisture in the raw materials and isocyanates, or other gases generated during stirring and reaction processes.

The temperature, stirring speed, feeding sequence and other process parameters in polyurethane production process have an important impact on the formation of foam. Optimizing these parameters to reduce gas generation and foam formation requires precise process control and adjustment. Different kinds of polyurethane raw materials have different reactivity and physical properties, which increases the difficulty of controlling the formation of foam. In addition, the moisture content in raw materials is also an important factor affecting the formation of foam, which needs to be strictly controlled. The humidity and temperature of the production environment may also affect the formation of foam in polyurethane production. For example, too high humidity will lead to the raw material absorbing more water, increasing the possibility of foam formation.

Gas generation and foam formation during polyurethane production can be reduced by optimizing production process parameters, such as reducing mixing speed, adjusting temperature, controlling feeding sequence, etc. In addition, vacuum defoaming technology can effectively remove bubbles from polyurethane. Defoamer is a chemical substance that can destroy the surface tension of foam and make foam burst rapidly. Adding an appropriate amount of defoamer in the production process of polyurethane can effectively remove the generated foam. However, selecting the appropriate defoamer and determining its optimal dosage needs to be determined based on specific production processes and raw material characteristics. Strict control of moisture content in raw materials is the key to reduce the formation of foam. The moisture content in raw materials can be reduced by drying them and selecting materials with low moisture content.

Maintain stable humidity and temperature in the production environment to avoid adverse effects on polyurethane production caused by excessively high or low humidity and temperature.

In summary, the defoaming challenges in polyurethane production mainly come from multiple aspects such as process control difficulty, raw material characteristics, and environmental factors. To address these challenges, comprehensive measures need to be taken, including improving production processes, adding defoamers, controlling raw material moisture, and maintaining environmental stability.