What are the factors that influence the quality of PET self-adhesive die-cutting?

The main factors influencing PET self-adhesive die-cutting quality are self-adhesive facestock and adhesives.

1. Label facestock:

During the die-cutting process, the die-cutting knife must cut off the facestock and adhesive layer of the self-adhesive to complete the process. Therefore, the self-adhesive facestock is an important factor affecting the quality of die-cutting. Choose the appropriate die-cutting knife according to the self-adhesive facestock.

In general, suppliers offer two types of die-cutting knives: unhardened die-cutting knives and commercially printed die-cutting knives. When die-cutting paper self-adhesive labels, you can choose a die-cutting knife that has not been hardened; if it is a film self-adhesive label, you must choose a hardened die-cutting knife to ensure the die-cutting quality.

The design rarely causes die-cutting quality problems, but the special fillers in the paper are very abrasive to the die-cutting knife. To extend the service life of die-cutting tools, manufacturers adjust the blade angle of die-cutting tools from 75° to 90°.

Commonly used film self-adhesive facestock mainly include: PE , PP , PET , PO, PVC , PS , etc. Compared with paper, film has higher requirements in the die-cutting process.

Because the film has strong toughness, especially toughness, when PET material is cut with an ordinary die-cutting knife, the service life of the die-cutting knife will not be long because of the insufficient strength of the blade after digital printing. After the mold is cut for a period of time, the self-adhesive label part cannot be cut off, and the waste edge pulls the label from the backing paper.

Therefore, when choosing a die-cutting knife, be sure to choose a hardness-treated blade. The best hardness is above 58, and the blade angle is between 37° and 75°. The smaller the angle, the sharper the blade, and the easier die cutting.

2. Adhesive:

The adhesives used in self-adhesive materials are divided into acrylic water-based latex and rubber-based hotmelt adhesive. Because of the small cohesion of acrylic water-based latex, mold cutting is easy to evaluate. There are no special requirements for mold cutting tools and die-cutting environments, which can ensure good die-cutting quality.

However, the cohesion between hotmelt adhesive molecules is large, and the die-cutting tool and environmental requirements are strict. The die-cutting knife must completely cut off the adhesive layer to ensure that the company discards it normally; otherwise, the label will be removed from the base paper.

In addition, because hot melt adhesive has weak activity at low temperatures, it has higher requirements in the processing environment. During the discharge process, because the bonding force between the self-adhesive surface material and the backing paper is too small, it is easy to cause "flying marks".

The above are the two common factors that affect the die-cutting quality of PET self-adhesives and other types of self-adhesives.

A perfect PET self-adhesive finished product requires layers of processes and checks before it can be made. The die-cutting quality of PET self-adhesive labels is affected by many factors such as die-cutting methods, die-cutting equipment accuracy, die-cutting tools and self-adhesive materials. It is also related to the operator's proficiency, processing links, static electricity and other factors.