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When selecting materials for project, it’s important to consider the effects of density, melt index and molecular weight on polyethylene. The following chart will help you with material selection:

Property

As Density Increases Property

As Melt Index Increases Property

Tensile Strength
(at yield)

Increases

Decreases

Stiffness

Increases

Decreases slightly

Impact Strength
Decreases
Decreases
Low Temperature Brittleness
Worsens
Worsens
Abrasion Resistance
Increases
Decreases
Hardness
Increases
Decreases Slightly
Softening Point
Increases
.
Stress Crack Resistance
Decreases
Decreases
Permeability
Decreases
Increases Slightly
Chemical Resistance
Increases
Decreases
Melt Strength
.
Decreases
Gloss
Increases
Increases
Haze
Decreases
Decreases
Shrinkage
Increases
Decreases