LLDPE

Linear Low-Density Polyethylene (LLDPE) is a type of copolymer created through the polymerization of ethylene and various olefins, such as 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. The incorporation of these olefins during the polymerization process enhances the strength and impact resistance of the final LLDPE product. This process, known as free radical polymerization, results in LLDPE resins that appear as odourless white granules, which can be processed through methods such as extrusion, injection moulding, and blow or cast film techniques.

In recent years, there has been a notable shift in the market from Low-Density Polyethylene (LDPE) to LLDPE, primarily due to the latter’s easier processing capabilities and superior properties. However, LLDPE poses environmental concerns as it is inert to degradation, despite its potential for recycling into products like lumber, floor tiles, trash bins, liners, landscaping ties, and shipping envelopes.

While LDPE and LLDPE have similar densities, LLDPE offers enhanced impact and crack resistance compared to LDPE. The linear structure of LLDPE contributes to improved appearance, yielding a higher gloss finish, although it typically has poorer clarity or transparency in its natural state. This characteristic allows for the production of thinner sheets without compromising strength and resistance properties.

LLDPE is known for its flexibility, higher tensile strength, and ability to elongate under stress. It also exhibits excellent chemical resistance, puncture resistance, and good electrical properties. However, it has a lower capacity for heat sealing, making it somewhat more challenging to process than LDPE.

To optimize both appearance and strength, manufacturers sometimes blend granules of LDPE and LLDPE when creating finished products.