The Importance Of Plastic Drying Equipment

Drying raw materials (plastic granules) is an indispensable part of plastic manufacturing. The purpose of drying is to remove moisture and other volatile substances from the plastic raw materials at a temperature that allows for continuous heating without deformation. Different plastic materials have varying degrees of sensitivity to moisture; therefore, whether drying is necessary and the extent of drying depend primarily on the characteristics of the raw materials.

Polyamide (nylon) may absorb moisture during transportation and packaging, so it often requires drying before use. However, if the plastic will be used for a short period, such as no more than one hour, drying may not be necessary. On the other hand, PET and PBT are very sensitive to moisture; failure to dry them will affect the impact strength of the finished product. These resins will rapidly absorb water after drying, so special care must be taken during processing to avoid using open containers and to consider the residence time of the resin in the hopper.

Furthermore, special care is required when drying recycled materials after crushing or granules that have already absorbed water.