Causes and Solutions for Adhesive Transfer of Protective Films

Film adhesive transfer, also known as adhesive transfer residue, is a common issue that occurs when protective film adhesive sticks to the surface it was meant to protect, leaving a residue or transfer behind. This transfer can be undesirable as it can affect the appearance and functionality of the underlying material.

To prevent adhesive transfer, certain precautions should be taken. Firstly, it is crucial to choose a high-quality protective film with a compatible adhesive to ensure proper adhesion and easy removal. Additionally, proper application techniques, such as applying the film smoothly and evenly, can minimize the chances of adhesive transfer.

Regular cleaning and maintenance also play a vital role in preventing adhesive transfer. Gentle cleaning solutions and non-abrasive materials should be used to clean the protected surface. It is important to avoid harsh chemicals or abrasive cleaning agents that can damage the film or the material underneath.

In cases where adhesive transfer has already occurred, prompt action is necessary. A specialized adhesive remover or solvent can be used to gently dissolve and remove the adhesive residue. However, caution must be exercised to avoid damaging the surface finish or texture.

In conclusion, protecting against adhesive transfer involves using high-quality protective films, proper application techniques, and regular maintenance. By doing so, one can ensure that the protected surfaces remain clean, residue-free, and in optimal condition.

Adhesive transfer of protective films can be divided into the following three situations:

1. Cohesive failure: Both the profile surface and the substrate surface have pressure-sensitive adhesive, and the adhesive surface of the protective film loses its luster.

2. Adhesive failure: There is a significant amount of adhesive residue on the profile surface, and the adhesive surface of the protective film reveals the substrate.

3. Residual migration: There is a small amount of adhesive residue on the profile surface, and the adhesive surface of the protective film maintains good gloss.

Causes and protective measures:

1. Poor quality in the production process of the protective film, substrate (PET), and materials (pressure-sensitive adhesive) can lead to defects.

Solution:

- Improve the production process and establish scientific process specifications to ensure quality. The process requirements for coating production include adhesive preparation, adhesive amount, uniformity of coating, proportion of curing agents, dispersion of curing agents in the adhesive, machine speed, temperature settings, drying effects, etc.

- Improve the quality of adhesives, such as using pressure-sensitive adhesives with higher gel fractions to enhance cross-linking with the product, using long carbon chain acrylate monomers for copolymerization or grafting, adding UV absorbers to reduce UV aging, optimizing formulations and adhesive production processes to improve heat resistance and low-temperature resistance of pressure-sensitive adhesives, etc.

- Increase the surface tension of aluminum-plated PET film. PET itself is a polar material with certain tension on both sides, but over time, the tension gradually decreases. Therefore, using corona treatment equipment for online corona activation can enhance the adhesion between PET substrate and adhesive.

- Enhance the cross-linking degree of the pressure-sensitive adhesive. The cohesive strength can be improved by improving the adhesive formulation and increasing the proportion of cross-linking agents.

2. Aging of the protective film

The protective film consists of plastic substrate and pressure-sensitive adhesive, both of which are polymeric materials. Aging mainly includes thermal aging and UV aging. After aging, the polymer chains of the substrate and adhesive break, the average molecular weight decreases, the cohesive strength decreases, leading to cohesive failure and adhesive transfer.

Solution: The protective film and the profile covered with the protective film should avoid direct sunlight. After installation, the protective film should be removed in a timely manner.

Treatment for adhesive transfer: Once adhesive transfer is found, first identify the profile specifications and batch number for isolation. It is best to handle it on semi-finished profiles. Once it is fully formed into products, it becomes more challenging.

Treatment method: First, remove the protective film (the residual adhesive on the profile surface may vary with the peeling speed, so control the peeling speed). Use a cloth soaked in "tar cleaner" to repeatedly wipe, and finally use a clean cloth to wipe off the cleaning agent grease. Avoid using rough and hard fiber fabric, as it may damage the gloss of the profile surface. After the treatment, reapply the protective film.