PE-HD (low/medium molecular weight, LMWPE/MMWPE)

Designation

High density polyethylene / HDPE (Low/Medium Molecular Weight)

Tradenames

Accucomp, Alathon, Alcudia, Arak, Asrene, Axeleron, Bapolene, Borcell, Borcoat, Borealis, Bormed, Borpex, Borsafe, Borstar, Bretene, Certene, Colorrx, Continuum, Daelim, Delta, Dow Health+, Dowlex, Egyptene, Eleme, El-Lene, Eltex, Eraclene, Etilinas, Evalene, Evolue-H, Exelene, Formolene, G-Lene, G-Lex, Halene, Hanwha, Hiplex, Hival, Hivorex, Hi-Zex, Hostalen, Hypel, Icorene, Indothene, Ineos, Innoplus, J-Rex, Kazan, Kemcor, Lanufene, Lumicene, Lupolen, Lutene, Marflex, Marlex, Marpol, Midilena, Mtegrity, Neftekhim, Nexus, Novapol, Novatec, Paxon, Petilen, Petrothene, Plexar, Polimaxx, Polycompo, Ponacom, Primatop, Prixene, Purell, Qenos, Quadrant, Ravago, Relene, Rigidex, Sabic Vestolen, Safrene, Samsung Total, Sclair, Seetec, Snolen, Surespec, Surpass, Taborex, Taisox, Tipelin, Titanex, Titanvene, Titanzex, Toler, Total, Unilex, Unithene, Unival, Venelene, Vestolen, Yanshan, Yuclair, Yuhwa, Yuzex

Typical uses

Pipes, toys, bowls, buckets, milk bottles, crates, tanks, containers, film for packaging, blown bottles for food.

Compositional summary

(CH2-CH2)n

Material family	Plastic (thermoplastic, semi-crystalline)
Base material	PE-HD (Polyethylene, high density)
Polymer code	PE-HD

Composition detail

Polymer

100

%

Physical properties

Density

0.939

–

0.960

g/cm3

Mechanical properties

Young’s modulus	0.621	–	0.896	GPa
Specific stiffness	0.654	–	0.944	MN.m/kg
Yield strength (elastic limit)	17.9	–	29	MPa
Tensile strength	20.7	–	44.8	MPa
Specific strength	18.8	–	30.5	kN.m/kg
Elongation	1.21e3	–	1.4e3	% strain
Compressive modulus	0.621	–	0.896	GPa
Compressive strength	18.6	–	24.8	MPa
Flexural modulus	0.825	–	1.24	GPa
Flexural strength (modulus of rupture)	29	–	62.7	MPa
Shear modulus	0.218	–	0.314	GPa
Bulk modulus	1.64	–	1.72	GPa
Poisson’s ratio	0.418	–	0.434
Shape factor	4.3
Hardness – Vickers	5	–	9	HV
Hardness – Rockwell M	31	–	35
Hardness – Rockwell R	45	–	55
Elastic stored energy (springs)	220	–	550	kJ/m3
Fatigue strength at 10^7 cycles	21	–	23	MPa

Impact & fracture properties

Fracture toughness	1.44	–	1.72	MPa.m0.5
Toughness (G)	2.6	–	4.24	kJ/m2
Impact strength, notched 23 °C	6.14	–	18.6	kJ/m2
Impact strength, notched -30 °C	3.33	–	16.3	kJ/m2
Impact strength, unnotched 23 °C	590	–	600	kJ/m2
Impact strength, unnotched -30 °C	590	–	600	kJ/m2

Thermal properties

Melting point	125	–	132	°C
Glass temperature	-125	–	-90	°C
Heat deflection temperature 0.45MPa	65	–	80	°C
Heat deflection temperature 1.8MPa	32	–	64	°C
Maximum service temperature	90	–	110	°C
Minimum service temperature	-82	–	-72	°C
Thermal conductivity	0.403	–	0.435	W/m.°C
Specific heat capacity	1.75e3	–	1.81e3	J/kg.°C
Thermal expansion coefficient	126	–	198	µstrain/°C
Thermal shock resistance	136	–	275	°C
Thermal distortion resistance	0.00211	–	0.00333	MW/m

Electrical properties

Electrical resistivity	3.3e24	–	3e25	µohm.cm
Electrical conductivity	5.75e-24	–	5.22e-23	%IACS
Dielectric constant (relative permittivity)	2.2	–	2.4
Dissipation factor (dielectric loss tangent)	4e-4	–	6e-4
Dielectric strength (dielectric breakdown)	17.7	–	19.7	MV/m
Comparative tracking index	600			V

Magnetic properties

Magnetic type

Non-magnetic

Optical, aesthetic and acoustic properties

Refractive index	1.53	–	1.55
Transparency	Translucent
Acoustic velocity	805	–	976	m/s
Mechanical loss coefficient (tan delta)	0.0446	–	0.0644

Absorption & permeability

Water absorption @ 24 hrs	0.005	–	0.01	%
Water vapor transmission	0.0283	–	0.0425	g.mm/m².day
Permeability (O2)	49.8	–	69.4	cm³.mm/m².day.atm

Processing properties

Polymer injection molding	Excellent
Polymer extrusion	Excellent
Polymer thermoforming	Acceptable
Linear mold shrinkage	1.2	–	4	%
Melt temperature	149	–	260	°C
Mold temperature	30	–	50	°C
Molding pressure range	34.4	–	138	MPa

Durability

Water (fresh)	Excellent
Water (salt)	Excellent
Weak acids	Excellent
Strong acids	Acceptable
Weak alkalis	Excellent
Strong alkalis	Excellent
Organic solvents	Limited use
Oxidation at 500C	Unacceptable
UV radiation (sunlight)	Fair
Flammability	Highly flammable