During the plastic sealing process, have you ever encountered this situation:
The laminating film seems to be attached, but the corners are curled up?
Don't worry, this article will tell you several common reasons why laminating film is not firmly bonded, and how you should deal with it.
1. First understand how laminating film is "attached"
Laminating film is mainly composed of two layers of materials:
PET layer: transparent, stiff, and supports
EVA glue layer: melts when heated and acts as a bond
When using a hot plastic sealing machine, the EVA layer melts when heated, and then the film is firmly bonded to the paper through pressing.
So, if it is not firmly bonded, most of the problems are caused by "temperature", "pressure" or "material".
2. 6 common reasons why laminating film is not firmly bonded
1.) The temperature is not high enough
If the temperature is not high enough, the EVA glue will not be completely melted, and it will not be firmly bonded.
How to solve it:
Check the temperature setting of your plastic sealing machine, which is generally recommended to be 100~130℃.
2.) Insufficient pressure or too fast speed
The temperature is appropriate, but if the pressure is not tight or the conveying is too fast, the glue may not have time to stick firmly.
How to solve:
Slow down the speed of the laminating machine to give the film enough time to heat.
3.) Poor quality of laminating film
Some inferior laminating films have too thin EVA layer or insufficient viscosity, and they cannot stick firmly even when heated.
How to solve:
Choose a guaranteed product, such as a laminating film with a PET+high-quality EVA structure.
4.) The laminated paper is too thick or uneven
If your laminated object is cardboard, thick cardboard, or the corners are curled, it is easy to cause loose lamination.
How to solve:
Try to use flat paper. Thick paper can increase the temperature and pressure appropriately.
5.) The laminating film is placed upside down (EVA glue side facing outward)
Some users mistakenly put the glue layer outward, resulting in no contact with the paper at all.
How to judge the front and back?
Tear off a small corner and feel which side is smoother. The smooth side is the PET side, and the slightly sticky side is the EVA adhesive layer. The adhesive layer should be attached to the paper side.
6.) The machine is not preheated enough
Many people start operating the laminator directly after it is turned on for a few minutes, and the temperature is not stable at this time.
How to solve it:
After turning on the machine, let the machine preheat for 5-10 minutes before using it to ensure that the glue can be fully melted.