PVC foaming regulator can help us bring good properties during the production and processing of PVC, enabling our reactions to proceed better and produce the products we want. However, we also need to pay attention to several key industrial control points when producing it, so that our reactions can proceed better.
The plastic foaming molding of PVC foaming regulator is divided into three processes: formation of bubble core, expansion of bubble core, and solidification of foam body. For PVC foam sheets with added chemical foaming agents, the expansion of bubble nuclei has a decisive impact on the quality of the foam sheet. PVC belongs to straight chain molecules with short molecular chains and low melt strength. During the process of bubble core expansion into bubbles, the melt is not enough to cover the bubbles, and the gas is prone to overflow and merge into large bubbles, reducing the product quality of foam sheets.
The key factor in improving the quality of PVC foaming modifiers is to enhance the melt strength of PVC. From the analysis of the processing characteristics of polymer materials, there are various methods to improve the melt strength of PVC, but the best way is to add additives that enhance the melt strength and reduce the processing temperature. PVC belongs to amorphous materials, and its melt strength decreases with increasing melt temperature. Conversely, its melt strength increases with decreasing melt temperature, but the cooling effect is limited and only serves as an auxiliary function. ACR processing agents all have the effect of improving melt strength, which increases with the increase of foaming regulator content. Generally speaking, as long as the screw has sufficient dispersing and mixing ability, adding high viscosity foaming modifiers has a more significant effect on improving the strength of the melt.
The above is a brief introduction to the key points of foam process control for PVC foam modifiers. When producing them, we should pay attention to the formation, expansion, and curing of their bubble nuclei and strictly control them.
Post time: Sep-07-2024
