At One Place

LDPE

Density of LDPE
920 kg/m³ (910–930)
0.92 g/cm³ · 57.4 lb/ft³

Chemically the same polymer as HDPE, but the chains are branched so they pack badly — that is the whole difference, and it produces a material four times less stiff, much clearer, and far easier to tear. Branching is why LDPE film clings and stretches while HDPE film crackles. It melts around 110 °C, low enough that a carrier bag left on a hot lamp will pool.

Properties

Density
920 kg/m³ (910–930) — 0.92 g/cm³
Melting range
105–115 °C
Tensile strength
8–20 MPa
Young's modulus
0.25 GPa
Thermal conductivity
0.33 W/(m·K)
Thermal expansion
180 µm/(m·K)
Floats in water
Yes
Magnetic
No

What it is used for

  • Carrier bags and cling film
  • Squeeze bottles
  • Wire and cable insulation
  • Damp-proof membrane sheeting

How it compares

Water is 1,000 kg/m³. Anything with a shorter bar than water floats in it.

air 1.2 kg/m³
expanded polystyrene foam 20 kg/m³
rigid polyurethane foam 40 kg/m³
LDPE 920 kg/m³
Water — the float line 1,000 kg/m³
tungsten 19,250 kg/m³
gold 19,300 kg/m³
platinum 21,450 kg/m³
Water is 1,000 kg/m³. Anything below that floats.
Material Density Relative to water
rigid polyurethane foam 40 kg/m³ 0.04×
expanded polystyrene foam 20 kg/m³ 0.02×
air 1.2 kg/m³ 0.00×
LDPE ← 920 kg/m³ 0.92×
platinum 21,450 kg/m³ 21.45×
gold 19,300 kg/m³ 19.30×
tungsten 19,250 kg/m³ 19.25×

Does it rust?

LDPE contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.

Is it magnetic?

LDPE is not a metal and has no ferromagnetic response.

Common questions

What is the density of LDPE?
920 kg/m³ (910–930), or 0.92 g/cm³.
Does LDPE float?
Yes. At 920 kg/m³ it is less dense than water's 1,000.
Is LDPE magnetic?
LDPE is not a metal and has no ferromagnetic response.

Related pages

Sources

  1. Typical range compiled from manufacturer specifications — At One Place

How these figures are compiled and checked