Can you injection mould ldpe

Various polyethylene copolymers are also available that show much different characteristics than the parent monomer. Polyethylene is available in clarity ranging from transparent to opaque and in an unlimited number of color possibilities. This plastic injection molding material possesses outstanding chemical resistance to alkalis and organic solvents but is attacked by oxidation when exposed to strong acids.

It is also subject to environmental stress cracking caused by exposure to a chemical while under an imposed stress that otherwise could be withstood almost indefinitely. The chemical resistance of polyethylene improves with increasing density; thus a high density polyethylene possesses greater chemical resistance when compared to low and medium density grades. The low cost of this versatile material makes it an ideal candidate for disposable and recyclable product applications.

Rebling design engineers have extensive experience in optimizing plastic part designs for functionality, cosmetics, cost and the plastic injection molding process. As with other thermoplastics, maintaining a uniform wall thickness throughout the part is essential in producing an aesthetically pleasing molding. Ribs, gussets and bosses incorporated in the design can result in sink marks if not properly designed.

Undercuts, which are often used for snap fits, are common in polyethylene moldings and can be readily ejected from the mold if sized correctly. Insulated hot tip runners are preferred for frequent color changes. Low density polyethylene is produced by the polymerization of ethylene at high pressure and temperature. The material is semicrystalline-crystalline. The crystallinity level is low because of chain branching. The material is tough but possesses moderate tensile properties and exhibits creep.

However, it has good impact and chemical resistance. These types are generally separated based on density. The higher the density, the better the strength, chemical resistance, and hardness, but the tradeoff is a shorter lifespan and increased low-temperature brittleness.

The most common of these types include:. All grades of polyethylene are receptive to drilling, turning, and cutting, but the higher-density variations tend to have easier machinability than lower-density grades. Because of its diversity, polyethylene is used in countless applications in injection molding.

Furthermore, in its solid form, it is a nontoxic material, making it useable with produce and safe for children.