Käsittelyaineita

Käsittelyaineita, also known as processing aids, are substances added to plastics during manufacturing to improve their processing characteristics. They are not intended to remain in the final product in significant amounts or to impart permanent properties. Their primary function is to facilitate the transformation of raw plastic resin into a desired shape, such as films, molded parts, or fibers.

Common types of käsittelyaineita include lubricants, plasticizers, mold release agents, and flow enhancers. Lubricants reduce friction between polymer chains and between the polymer and processing equipment, preventing sticking and improving melt flow. Plasticizers increase flexibility and reduce the glass transition temperature of the polymer. Mold release agents ensure that the plastic part can be easily removed from the mold after processing. Flow enhancers improve the viscosity and flow properties of the molten plastic, allowing for faster processing cycles and the creation of more intricate shapes.

These additives are typically used in very small quantities, often less than one percent by weight of the polymer. Their effectiveness is highly dependent on the specific polymer being processed, the processing method, and the desired outcome. The selection of an appropriate käsittelyaine is crucial for efficient and high-quality plastic manufacturing. While they are primarily functional during processing, their potential migration from the final product is a consideration for certain applications, especially those involving food contact or medical devices. Regulatory bodies often provide guidelines on the use and acceptable levels of these substances.