FIELD: process engineering.
SUBSTANCE: proposed method comprises tubular film extrusion, orienting the film in main orientation direction and drawing it from extruder in fused or semi-fused state. Note here that aforesaid direction is located at 0° to 45° relative to tube axis. Then, tube is cut at an angle to main orientation direction to produce web oriented for, at least 20° relative to its lengthwise direction. Said method comprises segmented film drawing for making multiple linear ledges 1 made from thicker material to be integrated by thin webs 2. Said ledges and webs extend in direction, mainly, parallel with that making acute angle with web lengthwise direction. After drawing and cutting, ledges are shifted relative to each other and reoriented in webs to increase angle of extension of both ledges and webs in direction of orientation. Ledges are spaced over 3 mm apart. Segmented rolls 5 allow said shift.
EFFECT: high lengthwise orientation and strength at increased temperatures.
61 cl, 12 dwg
