Hot melt extruders are common plastic processing equipment widely used in the production of plastic products. This article will delve into the working principle of hot melt extruders, revealing their scientific secrets in plastic processing and helping readers better understand and apply this equipment.
I. Basic Principles of Hot Melt Extruders
Hot melt extruders heat and melt plastic raw materials, then apply pressure through an extrusion screw to extrude the molten plastic into shapes. Its basic working principle can be summarized in the following key steps:
**Feeding and Melting:** Plastic granules or powder are added to the molten rubber tank. The heating system heats the plastic, melting it into a flowable melt.
**Feeding and Mixing:** The molten plastic enters the extrusion screw through the feeding device, simultaneously mixing with other additives (such as pigments, stabilizers, etc.) to form a homogeneous plastic mixture.
**Extrusion and Molding:** Under the action of the extrusion screw, the plastic mixture is propelled forward by the screw barrel and extruded under high pressure into the extrusion die (or die head) on the screw. Under the action of the mold, molten plastic is shaped into the desired cross-sectional shape through the mold's form and orifice, ultimately forming a continuous plastic product.
Cooling and Curing: The extruded plastic product is rapidly cooled by a cooling system, allowing it to solidify and stabilize within a short time to maintain the desired shape and size.
