1. The film appear fold
Membrane fold, its basic reason is that film transverse thickness uneven, even a very small, also can cause obvious fold after accumulation, become thin to experimental film, film tear test, friction coefficient and other measurement data. Can solve from the following aspects:
(1) lower melt temperature, can effectively reduce the melt liquid, when die extrusion is strong, is not caused by cooling wind and skew of membrane bubble film cooling.
(2) reduce the cooling air cooling air volume or mediation not divide evenly.
(3) the herringbone plate Angle is too large, makes the film get squashed in a short time, so fold problems, should be properly reduce the herringbone plate Angle.
(4) membrane mouth crowded is uneven, should be mediation module, in a vertical state.
(5) winding roller tension is too large to pull the membrane folds. Should be properly reduce the tension of the winding roller.
2 film transparency is poor
Polyolefin as the crystalline polymer, improve the transparency is the key to reduce the degree of crystallinity and make spherulite small, the main influence factors is resin raw materials. Blown film process is only to a certain extent, improve the transparency of film.
(1) extrusion temperature is low, the melt plasticization, should be appropriately increase the melt temperature.
(2) the poor cooling effect, influence the transparency, should be appropriately increasing the cooling air volume.
(3) the resin particles contains a lot of water, should be fully dry particles.
More than three film fisheye
Fisheye mainly is the additive in the raw material and low molecular weight resin and dust, condensed in the processing on the mouth mould, accumulated a certain amount by the membrane continuously, thus form fisheye on film. Because it is caused by deposition of resin, so can not fundamentally eliminate, craft main conciliation way:
(1) after a certain time, increasing the screw speed, improving melt extrusion pressure, take away the exudates.
(2) clean mouth mould on a regular basis.
(3) increasing the melt temperature, plasticizing adequately.
4 film transverse uneven thickness
Lateral film thickness is not uniform, fundamental reason for the mouth of the blown film tools and the rate of uneven, solutions such as:
(1) the die lip clearance mediation is undeserved, partial adjustment or all again.
(2) the cavity of sundry, thus cause logistics disorders, discharging, shall regularly clean mouth mold.
(3) the melt pressure or temperature is too high or too volatile, so cause extrusion melt flow instability, uneven thickness, can mediate temperature, extrusion speed improvement.
5 when winding run volume
Run when the winding volume could do a lot of waste and losses, should be avoided whenever possible.
(1) the winding roller tension is too small, roller is too loose.
(2) the winding tension instability.
(3) the guide roller's axis is not parallel.
(4) thin film transverse thickness uneven.
