High Quality Virgin LLDPE Linear Low Density Polyethylene-LLDPE-Dfda-9047

The rheological properties of LLDPE can be summarized as "rigid in shear" and "soft in extension". When LLDPE is used to replace LDPE, the film extrusion equipment and conditions must be modified. The high viscosity of LLDPE requires the extruder to have higher power and provide higher melt temperature and pressure. The die gap must be widened to avoid production reduction due to high back pressure and melt fracture.

Both LDPE and LLDPE have excellent rheology or melt fluidity. LLDPE has less shear sensitivity because of its narrow molecular weight distribution and short branched chains. LLDPE maintains a higher viscosity during shearing, so it is more difficult to process than LDPE with the same melt index. In extrusion, the lower shear sensitivity of LLDPE makes the stress relaxation of polymer molecular chain faster, and thus the sensitivity of physical properties to the change of blow up ratio decreases. In melt elongation, LLDPE usually has lower viscosity at various strain rates. That is to say, it will not produce strain hardening in tension like LDPE.