Professional Plastic Packaging Machine Manufacturer - Bonada Machinery
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Professional Plastic Packaging Machine Manufacturer - Bonada Machinery
While the film blowing machine to blow the film, it is easy to result in some problems, when it happens, we shall find the best solution, the following items are the problems which are easy to occur during film blowing:
1. The film wrinkling
Film wrinkling, The root reason is the uneven lateral film thickness, even if it is very small, after accumulation can also result in more obvious wrinkles, fat drop impact test, tear film experiments, film friction coefficient measurement data.
(1) reduce the melt temperature, can effectively reduce the melt flow, relatively strong during the extrusion die, not because of cooling air bubble film skew caused by uneven cooling.
(2) reduce the amount of cooling air or cooling air conciliation uneven situation.
(3) the angle A-form plate is too large, so that the film bubble is pressed in a short time, thus wrinkling problems, should be appropriately reduced angle between the A-form board. (4) The mould lip squeeze film material is uneven, mediation should die to make it in the upright position.
(5) take-up reel tension over a lot of film to pull pleats. It should be appropriate to reduce the take-up reel tension.
2. Film transparency is bad.
The key is a crystalline polyolefin polymer, to improve transparency is to reduce the degree of crystallinity and a small crystal ball, the main factor is the resin material. Blown technology to improve the transparency of the film is only to some extent.
(1) low temperature extrusion, melt plastics poor, should increase the melt temperature. Poor.
(2) cooling effect, the impact of transparency, should be appropriate to increase the amount of cooling air.
(3) resin particles containing large amounts of water should be fully dried particles.
3. Film fisheye is more.
The main raw material of fish eyes in the additive, low molecular weight resins and dust, etc., in the condensation process in the die, the film continues to accumulate a certain number taken away, so as to form fish eyes in the film. Because it is resin precipitates and is therefore not eliminate the underlying process is mainly on mediation methods are:
(1) a certain time, increase the screw speed, increase the melt extrusion pressure, remove precipitates.
(2) clean the die-head regularly.
(3) an appropriate increase in the melt temperature, fully plasticized.
4 Lateral film thickness unevenness
Transverse uneven film thickness, the root cause of the die-blown film quantity uneven, solutions such as:
(1) die lip gap mediation inappropriate, you need to adjust the partial or all re-adjusted.
(2) there is debris in the mold cavity, causing disorder logistics, the material is uneven, it should be cleaned regularly die.
(3) Melt pressure or temperature is too high or too volatile, so unstable resulting in extrusion melt flow, impact of uneven thickness, can mediate temperature, extrusion speed improvements.
5. The film goes two sides while rewinding:
If the film goes to two sides, it will cause a much waste and loss, should be avoided.
(1) take-up reel tension is too small, the film roll too loose.
(2) unstable winding tension.
(3) the axis of each roller is not parallel to the guide.
(4) the lateral film thickness uneven.
Above items are the commonest problem during film blowing, hope most customers could see and solve the problems and increase the film quality during film production.
