Multifilament extrusion installation to produce fibrous web from plastic material - has layers of woven wire sieve to provide plastic gauze used for filters, masks and nappies

摘要

The installation consists of a container with heating arrangement, and a build up of pressure on the fluid plastic. The heated molten plastic is drawn out finely through an extrusion arrangement into an airstream, then laid flat as a web on a conveyor band. The extruded threads have a very small dia. The airflow is created by a pump with connections below the conveyor band. The extrusion chamber is approximately 1.8 m wide and has a central container for the plastic. The supports hold layers of woven wire sieve. The plastic is kept at 250 deg.C to enable it to flow under pressure. The layers of sieve are arranged to filter impurities, and to provide very fine passages which do not easily become blocked. The finest gauge is placed on the top. This provides a multijet extrusion unit, the full width of the container. ADVANTAGE - The design is an economical soln. to the problems associated with prodn. of filter gauze for air filters, masks and nappies.