FEEDBLOCK TECHNOLOGIES FOR FOAM CORE PRODUCTS

摘要

For production of foam core products coextrusion tooling or feedblock technology are used. The feedblock technology has more market importance than the coextrusion tooling. The products are mainly pipe and sheet made of PVC. Foam core pipes are used as sewer pipes in house and outside under ground to replace compact (high filled) PVC pipes. The reason is cost and weight saving which is well known but the benefit depends on the reliability of the feedblock system and the formulation. A new developed system will be explained which has significant advantages compared to the systems which are in use to improve productivity and saving. Foaming has also for Sheet products a long history and an wide range of Sheet products are on the market. Foam core sheets can combine Advantages of free foamed sheets with advantages of integral foam sheets. For this production a sophisticated feedblock system has to be used which is installed between extruders and the sheet die. It will be shown the mechanical design and criteria's to be able to produce Foam core sheets of PVC with excellent layer distribution over all width.