Pultrusion Hollow part processes

For thermosets, the hollow part processes are filament winding and pultrusion. These processes are limited in shape and structure. There are three hollow part processes for thermoplastics (1) rotational molding, (2) twin sheet thermoforming, and (3) blow molding. 

Pultrusion is an automated process for continuous production of endless composite profiles of constant cross-section. It is the only fully continuous production method for profiles which is unreservedly regarded to be suitable for mass production. Specific chaxacteristics of the process are a fully automated process causing low labor costs, little waste, and no need for auxiliary material. Pultruded profiles are mainly stock articles with cylindrical or rectangular hollow cross-sections or L-, U-, T-, or H-shapes. The application of these profiles is widespread. Typical examples are window frames, reinforcing for concrete, stairways, fences, wires, exterior covering for railroad cars and container parts [10]. 

---