Dynamic die surface coating. Applied to making the perfect plastic film.
More demanding needs in industrial applications have led to new and improved plastic resins and production processes. Films are one of the largest applications in polymer processing. Those made from polyolefin resins like LDPE, LLDPE or mLLDPE are used in several industries, such as packaging, agriculture, medical and automotive.
Avoid Processing Defects
The resin and the production method used can lead to product defects that are a result of melt fracture, die build-up, interfacial instability and gel formation. You can eliminate or reduce the risk using 3M™ Dynamar™ Polymer Processing Additives (PPAs). A PPA creates a dynamic, temporary fluoropolymer coating on the die surface. This gives a low surface energy interface between the metal wall and the molten polymer stream, preventing drag and allowing the melt to slip through the die more easily. Stresses are reduced in the die and consequently melt fracture is eliminated. In addition, the lowered apparent viscosity allows the polymer melt to flow more freely through the die with reduced pressure.
Eliminate Surface Fractures
Adding a PPA to an LLDPE extrusion process eliminates surface melt fracture. Die pressure and extrusion motor torque are reduced. The processing window is expanded, leading to a potential reduction in extrusion process temperatures, an increase in extrusion output, a delay to the onset of die build-up at the die lip, increased flexibility in die geometry, and enables the use of higher viscosity polymers.
When producing multilayer films for applications like meat barrier packaging, interfacial instability needs to be avoided. Using 3M Dynamar polymer processing additives (PPAs) keeps them transparent.
Many continuous extrusion processes can be optimized by using PPA. Typical benefits, depending on resin, formulation and process, are:
Our technical specialists will work with you on process and output improvement. The following applications may benefit from PPA:
Plastic has largely replaced metal, concrete and clay composites in pipe production. Selecting a polymer – HDPE, MDPE, LLDPE, PP or PVC – will depend on whether the pipe will be used for high pressure water or gas, underfloor heating, drainage, irrigation or sewage, but each can suffer from defects during the manufacturing process. Problems relate to overall pipe dimensions, rheological behavior of the polymer, and the presence of additives such as carbon black and pigments. Process issues include head pressure, die deposits and surface defects. All can be eliminated or reduced by adding PPA at levels from 100 ppm up to 1000 ppm.