The combination of slip- and antiblocking agents is mainly used within films. The slip agent secures smooth sliding of the film against metal rollers during production and also film against film. The antiblocking agent secures that is possible to open a bag that is squeezed flat.
Typical slip agents are unsaturated primary fatty acid amides like erucamide and oleamide. They will have a controlled migration to the surface of polyolefin films. Coefficient of Friction (CoF) is measured as function of time after film production.
Typical antiblocking agents (AB) are inorganic substances such as talc and silica. Specific particle size of such additives is selected to give a topography at the film surface; if the particles are too big, they puncture the film and if too fine they will not give the desired surface effect. Blocking force is measured after contact of 2 films at elevated temperature for a given time.
Aniblocking agents will contribute to haze and haze measurements are important to find the optimum AB candidate.