Call Us Today!

Stretch Film FAQ

1、Heat seal bad

Phenomenon: After the upper and lower films are heat-sealed board or sterilized, there is separation and delamination between the upper and lower.
Causes.
(1) low heat sealing temperature, can not reach the inner heat sealing temperature needs.
(2) one or both of the upper and lower film inside and outside the heat seal cover error.
Solution.
(1) Raise the heat sealing temperature to reach the required temperature of the inner heat sealing material, but not too high, otherwise the phenomenon of sticky heat sealing plate and the problem of deformation of the upper and lower film will appear.
(2) Adjust the heat cover of one or both of the upper and lower films to ensure that the heat cover of the upper and lower films correspond to each other.

2、Lower film dropping film

Phenomenon: The lower film falls off from the chain and cannot move synchronously with the chain, resulting in not being able to stretch and package products normally.
Causes.
(1) The width of the lower film is narrow.
(2)The chain is not clamped tightly.
(3) The direction of the film is deviated.
Solution.
(1) Make the slitting width of the lower film wider to ensure that it matches the width of the chain.
(2) Repair the chain clamp.
(3) Adjust the position of the lower film, so that the center of the lower film coincides with the center of the chain.

3、Folding problem

Phenomenon: Folding on the film after product packaging.
Reason: (1) High heat sealing temperature, too much heat on the film, shrinkage of the upper film.
(2) When stopping, the upper film stays longer in the heat sealing plate, the film is subject to most heat and the film shrinks.
(3)There is crease on the film before heat sealing.
(4)There are foreign objects on the heat sealing plate or the heat sealing plate is scarred.
(5) The heat sealing gasket is not flat.

Solution:

(1) Reduce the heat sealing temperature, reduce the heat on the film and reduce the shrinkage of the film.
(2) In ensure the film has been running production, reduce the number of times of opening and closing to reduce the problem of too much heat on the film during the shutdown, and avoid the wrinkles formed by more shrinkage and deformation of the upper film by heat.
(3) there are creases on the film before the unheat seal, if it is the upper film, require the production process to control the quality of the product to avoid having creases; if it is the lower film, there are creases before stretching, require the production process to control the quality of the product to avoid having creases; if the lower film has creases in the stretching process, it means that the lower film is heated too much in the stretching process, reduce the stretching temperature, stretching preheating time, stretching forming time; or the lower film is stretching There are foreign objects on the heating plate, plate injury, remove foreign objects, repair the heating plate.
(4) Remove the foreign matter on the heat sealing plate and trim the heat sealing plate.
(5)Trim the heat sealing gasket to ensure that the heat sealing gasket is flat and at the same time there should be no gap.

4、Poor stretching and forming effect

Phenomenon: Stretched film is pulled or poorly formed
Cause.
(1) The heating plate is not heated enough.
(2) heating temperature mismatch, excessive high, the film sticks to the heat sealing plate, increasing the film haze, stretching molding will appear partial thinning. When the heating temperature is excessively low, the membrane heating temperature is low and cannot reach the stretching temperature of the membrane, and more broken after stretching.
(3) Stretching depth is too deep.

Solution.
(1) Repair the heating plate to make it heat normally and ensure the adequate supply of heat.
(2) Lower or raise the temperature of the heating plate and adjust it to the proper temperature range.
(3) Correct use in the effective stretching range of the film, deep stretching of the film using a thicker film for stretching, shallow stretching of the film using a thinner film for stretching, both to ensure the quality of the product and to reduce production costs.

5、Gas in the product packaging

Phenomenon: There is air inside the film after coming out of the heat sealing plate.
Cause.
(1)The width size of the upper film is larger than the width of the heat sealing plate, which will block the vacuum air hole of the heat sealing plate and extract the air between the upper and lower film.
(2)The vacuum extractor is malfunctioning and the vacuum extraction effect is poor.
(3)The vacuum extraction air holes in the heat sealing plate are blocked by foreign substances.
(4) Poor heat sealing effect, with partial air leakage.
(5) When the upper and lower films are sealed together, the upper film deviates from the lower film, and there is a part of bad heat sealing.
(6) The lower film has small holes that are pulled out when stretching, and there is air leakage.
(7) The upper film has small holes and air leakage.
(8) The heat sealing temperature is too high, and the upper film is burnt with small holes and has air leakage problem.
(9) There is a gap in the heat sealing gasket.

Solution.
(1)Adjust the width of the upper film to the right width, matching with the heat sealing plate.
(2)Repair the vacuum machine.
(3)Repair the heat sealing plate, take out the foreign matter and ensure the air hole is smooth.
(4) Increase the heat sealing temperature and compressed air pressure to ensure the heat sealing is intact.
(5)Adjust the upper film well and cooperate with the lower film well, no deviation of the upper and lower film, to ensure that the upper and lowe


Post time: Oct-13-2022