How does eva foam cotton harden?

  EVA foam cotton is widely used in various fields because of its soft texture and good cushioning performance.However, sometimes we need to adjust its hardness to meet specific needs.This article will discuss how to harden EVA foam cotton through process adjustment.

EVA foam

 Increase the content of EVA resin

  In the formulation of EVA foam cotton, the content of EVA resin directly affects its hardness.Increasing the content of EVA resin can increase the intermolecular force, thus making foam cotton hard.However, it should be noted that too high EVA resin content may cause the foam cotton to be too hard and lose elasticity.

 Increase foaming temperature

  Foaming temperature is another key factor affecting the hardness of EVA foam cotton.Increasing the foaming temperature can accelerate the diffusion and formation of gas in the material, resulting in a more dense bubble structure.This results in increased interaction between bubbles, which hardens the foam cotton.However, too high temperature may lead to too large bubbles, which will make foam cotton soft.Therefore, choosing the appropriate foaming temperature is the key.

 Increase the amount of crosslinking agent

  Crosslinking agent plays an important role in the manufacturing process of EVA foam cotton. It can make resin molecules form a network structure and increase the hardness and stability of materials.Increasing the amount of crosslinking agent can enhance the degree of crosslinking between molecules, thus making foam cotton hard.However, excessive use of crosslinking agents may lead to material brittleness, affecting its elasticity and cushioning properties.

 extend the cooling time

  After the foaming is completed, extending the cooling time can make the bubbles have enough time to stabilize and crystallize, thus making the foam cotton hard.Properly extending the cooling time can improve the compactness of the bubble structure, increasing the hardness and elastic modulus.However, too long a cooling time may make the material too hard and lose its elasticity.

  To sum up, the hardness of EVA foam cotton can be effectively changed by adjusting its manufacturing process parameters, such as increasing the EVA resin content, increasing the foaming temperature, increasing the amount of crosslinking agent and extending the cooling time.In practical production, process adjustments should be made according to specific needs and product performance requirements to achieve the desired hardness level.At the same time, it is also necessary to pay attention to the mutual influence and balance between various process parameters to obtain the optimal hardness and comprehensive performance.

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