At the other end of the polyethylene spectrum, LDPE has many crystalline branches in its composition for an end product that is softer, more flexible and less brittle than the polyethylene materials with higher density ranges. LDPE and LLDPE are often used for lower temperature injection molding applications and will not withstand the high temperatures tolerated by HDPE.

The highly-specialized processing knowledge accumulated by the staff at Majors Plastics over the years with the regard to ISO class 7 molding/packaging has been engrained into written procedures and practices. All manufacturing practices have been time-tested and proven reliably to yield very clean components for the customer. Regimented cleaning and HEPA filter replacement schedules ensure that clean components cannot be contaminated by their environment.

The characteristics of plastic injection molded polyethylene differ by the grade selected with HDPE having the greatest strength and rigidity and LDPE showing the most softness and flexibility. Polyethylene is:

High-density polyethylene injection molding results in products that are less flexible and stronger than products produced by injection molded lower-density polyethylene. With the fewest crystalline branches in its makeup, HDPE is defined with a density range of .941 to .960 g/cc. Although it has greater impact resistance, HDPE can sometimes be used in place of polypropylene, another commonly produced plastic found in commodity products.

As a group, polyethylene plastic is the most widely-used plastic in consumer goods. The range of polyethylene plastic materials is defined by density produced by crystalline branching within the material composition. The material grades include high-density polyethylene (HDPE), medium-density polyethylene plastic (MDPE) and low-density polyethylene (LDPE). Within the low-density polyethylene family, linear low-density polyethylene (LLDPE) is stronger and less flexible than LDPE.

With many years in the business of providing hyper-clean components to some of the largest medical and pharmaceutical suppliers in the field, Majors Plastics has proven processes that can be utilized for any customer requiring a clean room injection molding environment.

Majors Plastics is an award-winning, full-service injection molder and assembly and secondary service with multiple facilities in Omaha, Nebraska and Mexico. We specialize in custom injection molding, cleanroom molding, and overmolding of engineering and commodity-grade resins with extensive secondary processing and assembly capabilities.

While this material is a popular choice, under certain conditions, polyethylene can warp and suffer environmental stress fractures.

Within the broad industry of consumer goods, plastic injection molded polyethylene applications using grades from high density to low are found in many products, including:

Majors Plastics routinely provides components that are both molded and packaged in an environment compliant with ISO 14644 class 7 at 0.5 and 5.0µm. Formally classified as federal standard 209E, class 10,000. These ultra-clean environments are either highly automated, with side-entry part-removal robots at the press, or staffed by fully gowned, hooded, goggled and double-gloved operators in an adjacent packaging room. The customers of Majors Plastics can enjoy the benefits of particulate-free molded products with real-time ASTM E 2090 testing and packaging that meets or exceeds IEST-CC-1246 D, class 100.

Polyethylene plastic is the common choice for high-volume, low-cost injection molded applications. It can also be overmolded onto tubing for surface smoothness or roughness. Polyethylene is also used to produce sheeting for food wraps and plastic film. Interested in using this material for your project? Request a quote to get pricing.