Guidance on the use of PPA: PPA price

1. Master batch preparation

1.1 Clean the twin-screw extruder.

1.2 Stir LLDPE particles (95%) of the same brand and PPA powder (5%) evenly, then add them into the twin-screw extruder, extrude and granulate to obtain PPA master batch with 5% PPA content. The key of this step is to make PPA particles form a good dispersion in LLDPE matrix.

2. Film blowing evaluation

2.1 Clean the film blower.

2.2 Blow the film with LLDPE of the same brand. After the machine is stabilized, gradually increase the screw speed until there are defects, such as die buildup and/or shark skin. Record the process parameters at this time, such as screw speed (S0), torque, die pressure, current and power of the extruder, etc.

2.3 Do not change the screw speed (S0) at this time, add the PPA master batch for experiment. It is recommended to use a large amount of additives, such as 1000ppm, so that the coating balance of PPA can be achieved quickly and the effect can be observed. Taking 1000ppm as an example, 98% LLDPE and 2% PPA masterbatch (concentration 5%) are required. Stir them evenly, and then add them to the film blowing machine for film blowing. After a period of time, the coating of PPA is balanced, and the effect can be observed, such as the reduction or disappearance of die buildup and/or shark skin. Record the process parameters at this time and compare them with the parameters in 2.2.

2.4 It can maintain the screw speed (S0) and gradually reduce the amount of PPA added. For example, from 1000ppm → 750ppm → 500ppm......, this can determine the small amount of zui added that PPA works.