Menetelmä ja laitteisto muovikalvon valmistamiseksi

摘要

A film ( 5 ) is extruded from plastic material by means of an extruder. Material is mixed into the plastic ( 5 a) of the plastic film ( 5 ) before the extrusion so that cavitation bubbles are formed in the material particles mixed into the plastic ( 5 a) when the plastic film is stretched. The film ( 5 ) is orientated by stretching. After the extrusion the plastic film ( 5 ) is cooled slowly below the crystallization point of the plastic material before the orientation.