High slip performance
Polyolefin films tend to adhere to themselves and metal surfaces due to their high coefficient of friction (COF). For processing ease, films need a COF near 0.2. Slip additives can modify the surface properties of a film and thus lower the friction between film layers and other surfaces. To be effective the slip needs to migrate out of the polymer to the surface and therefore it must have a degree of incompatibility with the polymer. Fatty acid amides are often used as slip additives. During processing, they are solubilized in the amorphous melt, but as the polymer cools and crystallizes the fatty acid amide is "squeezed" out forming a lubricating layer at the polymer surface. The addition of a slip additive can prevent film sticking and pulling helping to increase throughput.
Types of Slip Additive
The most commonly used slip additives are erucamide (C 22-) and oleamide (C 18-). Oleamjde migrates quicker than erucamide and is often called "fast blooming". However, after a certain time, the slower erucamide will provide films with a lower COF than oleamide. Erucamide, with its lower vapor pressure and volatility, is used in higher temperature processing applications and it also stays at the surface longer, not venting off as smoke. Oleamide is used where a low COF is needed in a short period of time, while the slower migration of erucamide can be advantageous in roll stock applications and online corona treatment. Another fatty acid amide is Streamside. This is often used together with erucamide or oleamide to provide an anti-blocking effect when film transparency is very important. The concentration of slip present affects performance. Initially, the COF is sensitive to small variations in concentration until a critical level of slip is reached, after which further slip has little effect on the COF. The amount of slip required depends upon film thickness, the slip additive being used, and the presence of other additives such as anti-blocks
Antislip: - Packaging & stackable items,
where this product to be used in increase the coefficient of friction between films or sheet of polyethylene.
Coefficient of friction reduction of films also provides anti-block & mold release improvement. Blow Moulding& Injection Moulding Slip additives are added to reduce the surface coefficient of friction of polymers and are used to enhance either processing or end applications. High- and low-level slip additives are available and immediate and slow-acting performance can be engineered into the masterbatch. Food contact approved grades are available. Combinations with antistatic and antiblock products for use in the film industry offer cost-effective, multi-use masterbatches. Application Examples Film, sheet, injection molding, and others.
Slip & Antiblock Products
• Full range of products for the extrusion industry
• Grades formulated for high transparency applications
• Cost-effective, highly concentrated systems available.