Formulation of cast film anti-blocking masterbatch

The anti-blocking masterbatch is used to prevent the films on the coil from adhering to each other. Due to temperature and time, adhesion occurs when two layers of film are pressed together. After adding the anti-blocking masterbatch, not only the adhesion is reduced, but also many properties of the film are improved. However, the addition of the anti-blocking masterbatch also leads to the degradation of the optical properties of the film. Therefore, there are still a lot of matters that need to be paid attention to when the manufacturer chooses the anti-blocking masterbatch.

The effect of an anti-blocking masterbatch is usually indicated by bond strength, and most companies have their test methods, but the ASTM standards D1893 and D3354 also describe the anti-blocking masterbatch test.

It is amorphous (i.e. aphakia), so it does not cause silicosis.

Transparent film is especially important because of its high purity, refractive index is almost the same as PP.

— It won’t wear out the screws of the extruder because it’s soft.

Because of the compact arrangement of the chain segments, they are evenly dispersed in the film.

Compared with natural silica, the concentration of the anti-blocking masterbatch used in the film can be greatly reduced.

According to the experience of the anti-blocking masterbatch manufacturers, the particle size of BOPP silica used in this field is usually between 2 and 4μm. The amount of effective anti-stick agent depends on different film thicknesses and is generally 200-1000PPM (i.e. Between 02 and 0.1%, the thinner the film, the more anti-blocking masterbatch.

Since the anti-blocking masterbatch is an inorganic product, it does not migrate and will be effective after film production.

After adding the anti-blocking masterbatch, not only the adhesive strength of the film is reduced, but also many properties of the film are improved. However, the addition of the anti-blocking masterbatch should also be limited due to the degradation of the optical properties of the film. According to the experience of functional masterbatch manufacturers, it is best to choose high-purity anti-blocking masterbatch, to reduce the amount of anti-blocking masterbatch added as much as possible, and to avoid the effect of excessive addition of film transparency.

Waterproof steam packaging must be stored in a dry area because of the high hygroscopicity of the anti-blocking masterbatch.

Before using the anti-blocking masterbatch, the water content of the anti-blocking masterbatch must be tested by increasing its weight. If the water content is too high, spots and bubbles form in the film.