stretch film-4

stretch film-4

stretch film LLDPE and LDPE have excellent rheological properties and melt fluidity. stretch film LLDPE has smaller shear sensitivity, because the stretch film has a narrow

molecular weight distribution and short branched chain. stretch film in the cutting process (for example, stretch film LLDPE extrusion ) maintained a greater viscosity, so

stretch film than the same melt index LDPE is difficult to process. In extrusion, stretch film LLDPE lower shear sensitivity of the polymer molecular chain of the stress

relaxation is faster, and the physical properties of blow ratio change sensitivity reduction in melt extension school, stretch film LLDPE in various strain rates generally have

lower viscosity. That is to say stretch film will not like LDPE in tension generated strain hardening. With polyethylene deformation rate increases . LDPE showed a striking

increase in viscosity, which is caused by molecular chain entanglement. This phenomenon in LLDPE to be observed, as in stretch film LLDPE lack of long chain branched polymers do

not tangle. The properties of stretch film application is extremely important. Because stretch film LLDPE film while maintaining high strength and toughness called precursor

thinner films.

stretch film LLDPE rheological properties can be summarized as" stretch film shear rigidity" and" stretch film extension is soft". When stretch film is LLDPE instead of LDPE

when the film extrusion equipment and conditions must be modified. stretch film LLDPE high viscosity extruder with greater power. And provide higher melt temperature and

pressure. Die orifice gap distance must be widened in order to avoid because of the high back pressure and melt fracture and reduce yield. LDPE and stretch film LLDPE generally

die gap distance size are O 024 ~ 0.040 in. And 0 0600 . 10in.

Stretch film LLDPE" extension to soft " features in stretch film blowing process is a disadvantage. Stretch film LLDPE blown film bubble is not as stable as LDPE. General single

lip ring on LDPE stable enough to use . Stretch film LLDPE stretch film unique bubble more perfect lips wind ring to stabilize. With your lips wind ring cooling internal

membrane vesicles can increase the bubble stability, at the same time in high productivity improvement under the stretch film production capacity. In addition to the stretch

film bubble better cooling, many stretch film production plant using blended with LDPE method to enhance LLDPE soluble sense, stretch film LLDPE extrusion in the existing LDPE

film equipment to complete, when the LDPE stretch film LLDPE blends the concentration reached 50%. Processing of 100% LLDPE or in stretch film LLDPE and LDPE blend materials,

using common LDPE extruder, must improve equipment. According to the extruder life, requires improved may be widened die gap distance, improved air ring, screw extrusion

modification design to better, when necessary, to increase the motor power and torque. For injection molding applications, generally do not need to improve equipment, but the

optimal processing conditions required. Rotational molding processing requirements of LLDPE grinding into uniform particles ( 35 mesh ). Machining process includes powder LLDPE

fill the mold, heating and biaxial rotating mold making LLDPE uniform distribution. After the product is withdrawn from the mold cooling. This is to blow the stretch film for

example, of course, now many casting production of stretch film.