Linear-Low density Polyethylene (LLDPE)

Brief Overview

Linear low-density polyethylene is a substantially linear polymer with significant numbers of short branches, commonly made by copolymerizing ethylene with longer-chain olefins. It looks similar to HDPE but has lower crystallinity due to a more substantial number of short-chain branches. Therefore, it also has a lower density (typically lower than 940 kg/m3). LLDPE is produced by polymerizing ethylene (or ethane monomer) with 1-butene and smaller amounts of 1-hexene and 1-octene, using Ziegler-Natta or metallocene catalysts. The structure of LLDPE has a linear backbone with short, uniform branches (unlike longer branches of LDPE). These short branches are able to slide against each other upon elongation without becoming entangled like LPDE. In the present-day scenario, Linear low-density polyethylene (LLDPE) has successfully replaced Low-Density Polyethylene. LLDPE is used to make flexible as well as rigid products. LLDPE is very tough and keeps its shape. These properties are helpful for the manufacture of larger objects like lids.
Available grade : Film, Injection, Rotomolding

Manufacturing Process

The manufacturing process is similar to that of LDPE using the Ziegler-Natta catalyst, but an additional raw material, 1-butene or 1-hexene is added to the feedstock. This results in the formation of small side chains of one or two carbon atoms. The structure of the polymer is linear, but the density is lower due to the presence of such short branches and gives more shear strength and flexibility.

Flexible applications
Flexible films are often used for packaging, but they are used for many non-packaging applications, as well, such as:   
Pouches 
Stretch wrap 
Cable jacketing 
Flexible tubing 
Geomembranes 
Sheeting  

Rigid applications
LLDPE resins could use for many rigid applications including:
Caps and closures 
Buckets  
Containers 
Covers and lidding 
Pipes