Linear low density polyethylene
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Linear low density polyethylene (LLDPE) is a substantially linear polymer, with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins.
LLDPE has higher tensile strength and higher impact and puncture resistance than LDPE. It is very flexible and elongates under stress. It can be used to make thinner films, with better environmental stress cracking resistance. It has good resistance to chemicals and to ultraviolet radiation. It has good electrical properties. However it is not as easy to process as LDPE, has lower gloss, and narrower range for heat sealing.
It is used for plastic bags and sheets (where it allows using lower thickness than comparable LDPE), plastic wrap, pouches, toys, lids, pipes, buckets and containers, covering of cables, geomembranes, and mainly for flexible tubing.
LLDPE manufactured using metallocene catalysts is labeled mLLDPE.
[edit] Physical Properties
| Property | Value |
|---|---|
| Density | 0.92 g/cm³ |
| Surface hardness | SD48 |
| Tensile strength | 20 MPa |
| Flexural modulus | 0.35 GPa |
| Notched izod | 1.06+ kJ/m |
| Linear expansion | 20×10−5/°C |
| Elongation at break | 500% |
| Strain at yield | 20% |
| Max. operating temp. | 50 °C |
| Water absorption | 0.01% |
| Oxygen index | 17% |
| Flammability UL94 | HB |
| Volume resistivity | log(16) Ω·cm |
| Dielectric strength | 25 MV/m |
| Dissipation factor 1kHz | 909090 |
| Dielectric constant 1kHz | 2.3 |
| HDT @ 0.45 MPa | 45 °C |
| HDT @ 1.80 MPa | 37 °C |
| Material drying | NA |
| Melting Temp. Range | 120 to 160 °C |
| Mould Shrinkage | 3% |
| Mould temp. range | 20 to 60 °C |
See also:
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