Dyneon 3M has developed an additive, simplifying high-quality LLDPE films production even using outdated equipment
Manufacturers of polyethylene films in Russia are facing a challenge: the increasing demand of packagers for films based LLDPE polymers and blends often cannot be met by older equipment.
Dyneon, a 3M company, is one of the world’s leading fluoropolymer producers with operations or representation in more than 50 countries. Headquartered in Oakdale, Minn., the company employs more than 800 people worldwide.
Especially older extrusion lines designed to process the commonly used LD polymers and blends may need new and more complex screw designs to accommodate the increased melt viscosity of LL. In addition, manufacturers may have to change the die geometry to reduce the high die pressure associated with processing LL. An alternative to capital intensive investments by upgrading existing extrusion machines or even buying new equipment, is the use of the Polymer Processing Additive (PPA) FX 5920A developed by specialists of Dyneon 3M, one of the world leading fluoropolymer and specialty additives supplier. The additive is forming a fluoropolymer coating on the die surface, which provides a low energy surface layer at the polymer melt-metal interface. Establishing a slip velocity reduces the resistance of the polymer melt to flow from the extrusion die. The shear stress at the polymer melt-metal interface is also reduced. Dynamar™ FX 5920A enables manufacturers in quite a number of cases to process polymer composites on existing equipment. Scientific test rows under realistic production circumstances show that already the addition of 500 to 1000 ppm Dynamar™ FX 5920A improves or even eliminates melt fracture, present in the manufacturing of control resins without PPA. These improvements offer manufacturers the opportunity to use their not really suited machinery to extrude high-end films. The additive reduces the die pressure up to 19 per cent for a 100 per cent LL composition. This effect allows higher outputs at equivalent die pressures on the same machine. It also enables manufacturer to use higher LLDPE ratios in LDPE/LLDPE resin blends. Additionally it allows lower melt temperatures at equivalent die pressures. Using Dynamar™ FX 5920A also reduces the resistance to flow. The tests show a possible 30 to 35 per cent increase in output if the melt temperature and die pressure are held constant. Even in most modern equipment, such productivity increases, are a convincing temptation. Again, using PPA reduces the energy consumption of the extrusion motor, decreasing the production costs.
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