ForMatter/Materials/polymer/High-Density Polyethylene (HDPE)
mat_polyethylene_hdpe

High-Density Polyethylene (HDPE)

semi-crystalline thermoplastic, polyolefin, commodity · HDPE, PE-HD, high-density polyethylene

The polyethylene milk jugs, detergent bottles, traffic bollards, drinking-water pipes, kayaks, and outdoor playground equipment are made of. Cheap, tough, chemical-resistant, and recyclable as #2 in nearly every municipal stream. The most-produced thermoplastic on Earth by mass — about 60 million tons a year.

Semi-crystalline polyethylene with low branching, density 0.94–0.97 g/cm³. Tm 130–135 °C, Tg -120 °C. Tensile 25 MPa, elongation 600%. Excellent chemical resistance — survives nearly every common acid, base, and solvent at room temperature. Surface energy low; joins by ultrasonic welding or hot-plate welding. UV-degrades without carbon-black or HALS stabilization.

mechanical

  • tensile_strength_mpa25
  • yield_strength_mpa23
  • elastic_modulus_gpa1.0
  • elongation_pct_at_break600
  • density_kg_m3950
source: MakeItFrom; LyondellBasell HDPE datasheet

thermal

  • melting_point_c132
  • service_max_c80
source: LyondellBasell datasheet

Sustainability

  • embodied carbon kg co2e per kg1.85
  • sourceEditorial estimate from ICE / Granta CES EduPack class databases — industry mean, with cradle-to-gate boundary unless otherwise noted. Embodied carbon for any specific product depends on supplier mix, recycled content, and energy grid; verify against a primary source before using these numbers in a sustainability claim.
  • embodied carbon recycled kg co2e per kg0.45
  • recyclabilityvery high — RIC #2 stream, mainstream curbside collection in most municipalities
  • biodegradableFalse
  • certificationsFDA 21 CFR 177.1520 (food contact)
visual
natural translucent white; pigments universally; characteristic waxy semi-gloss on blow-molded surfaces
tactile
warm to the touch, smooth, slightly waxy
Ed Conway (living — quote)

The vast majority of hydrocarbons still end up in the tanks of vehicles, and most natural gas is used to generate power and heat. Yet the remaining 10 per cent — the by-product of refining oil and gas — plays a disproportionate role in our lives. These products clothe us and feed us. They help keep us clean and healthy, and are embedded in the vast majority of items available for purchase today. They are among the newest human creations we know, yet it is impossible to imagine the world without them. They help us conserve energy but they are produced from a fossil fuel.

Conway, *Material World: The Six Raw Materials That Shape Modern Civilization* (Knopf, 2023), Part Five: Oil, Chapter 15 'The Everything Thing,' on the petrochemical sector — the 10 percent of refinery output that becomes plastics, fertilisers, pharmaceuticals, packaging, paints, adhesives, dyes, flavourings. HDPE / PET / PP / PVC / nylon and the rest are all by-products of fuel refining; the fuel economics drive the polymer economics. Ed Conway verified living 2026-04-28.

PBR starter values

finish · matte — open for table, JSON, host snippets, downloads

Principled BSDF defaults derived from the sphere matte finish. Reasonable seed for Blender, Substance, Keyshot, Rhino — tune per material. Or grab the whole library at once: ForMaterials library →

# finish:                   matte
albedo                      #e0e2e4
metallic                    0.00
roughness                   0.75
ior                         1.45
transmission                0.00
clearcoat                   0.00
sheen                       0.00
anisotropic                 0.00
copy as JSON
{
  "albedo": "#e0e2e4",
  "metallic": 0.0,
  "roughness": 0.75,
  "ior": 1.45,
  "transmission": 0.0,
  "clearcoat": 0.0,
  "sheen": 0.0,
  "anisotropic": 0.0
}
Blender 4.x Python
# Blender 4.x — Principled BSDF
# High-Density Polyethylene (HDPE) · finish: matte
import bpy
mat = bpy.data.materials.new(name="mat_polyethylene_hdpe")
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
bsdf.inputs["Base Color"].default_value         = (0.7454, 0.7605, 0.7758, 1.0)
bsdf.inputs["Metallic"].default_value           = 0.000
bsdf.inputs["Roughness"].default_value          = 0.750
bsdf.inputs["IOR"].default_value                = 1.450
bsdf.inputs["Transmission Weight"].default_value = 0.000
bsdf.inputs["Coat Weight"].default_value        = 0.000
bsdf.inputs["Sheen Weight"].default_value       = 0.000
bsdf.inputs["Anisotropic"].default_value        = 0.000
KeyShot Python (lux)
# KeyShot 11+ — lux Python API, Generic material
# High-Density Polyethylene (HDPE) · finish: matte
# Run from Window → Scripting Console
import lux
mat = lux.createMaterial(name="mat_polyethylene_hdpe", materialType="Generic")
mat.setProperty("diffuse",      (224, 226, 228))   # 8-bit sRGB
mat.setProperty("metallic",     0.000)
mat.setProperty("roughness",    0.750)
mat.setProperty("indexOfRefraction", 1.450)
mat.setProperty("transparency", 0.000)
mat.setProperty("coatingWeight", 0.000)
Substance pbrMetalRough
{
  "_format": "Substance Designer / Painter \u2014 pbrMetalRough constants",
  "_about": "High-Density Polyethylene (HDPE) \u00b7 finish: matte",
  "baseColor": {
    "r": 0.7454,
    "g": 0.7605,
    "b": 0.7758
  },
  "metallic": 0.0,
  "roughness": 0.75,
  "ior": 1.45,
  "opacity": 1.0,
  "anisotropyLevel": 0.0,
  "_notes": "Channels listed are the standard Substance pbrMetalRough output. Drop into a Uniform Color node per channel, or as the constant input on a layered stack."
}
glTF 2.0 Metallic-Roughness
{
  "asset": {
    "version": "2.0",
    "generator": "ForMatter"
  },
  "materials": [
    {
      "name": "mat_polyethylene_hdpe",
      "pbrMetallicRoughness": {
        "baseColorFactor": [
          0.7454,
          0.7605,
          0.7758,
          1.0
        ],
        "metallicFactor": 0.0,
        "roughnessFactor": 0.75
      },
      "extensions": {
        "KHR_materials_ior": {
          "ior": 1.45
        }
      }
    }
  ]
}
USD Preview Surface
# USD Preview Surface — UsdShade.MaterialLook prim attributes
# High-Density Polyethylene (HDPE) · finish: matte
def Material "mat_polyethylene_hdpe" {
    token outputs:surface.connect = </mat_polyethylene_hdpe/PreviewSurface.outputs:surface>

    def Shader "PreviewSurface" {
        uniform token info:id = "UsdPreviewSurface"
        color3f inputs:diffuseColor = (0.7454, 0.7605, 0.7758)
        float   inputs:metallic     = 0.000
        float   inputs:roughness    = 0.750
        float   inputs:ior          = 1.450
        float   inputs:opacity      = 1.000
        float   inputs:clearcoat    = 0.000
        token   outputs:surface
    }
}
↓ download glTF material

CNC milling on swarf

surface speed (carbide)1000–2500 (HDPE machines fast — soft polymer, low thermal mass)
chipload per tooth8–15 (1/4-inch O-flute endmill — single flute non-negotiable for chip evacuation)
coolantair blast required to evacuate gummy ribbons of chip; flood acceptable
swarf-compatible toolsend 1/8end 1/4end 3/8drill 1/8drill 1/4

The cutting-board polymer. Soft, gummy, chips long and stringy — O-flute endmills mandatory. Climb-mill for clean edges; conventional-mill leaves a fuzz. Doesn't take adhesives well (low surface energy) — design mechanical fasteners. Use the swarf 'pocket' op for relief features, 'outline' for profile.

Onsrud Cutter plastic feeds & speeds (HDPE table); Curbell Plastics HDPE machining notes.

→ try this material in swarf

Second life

repairabilitymoderate — thermally weldable (extrusion-welded HDPE pipe is canonical); not solvent-bondable (low surface energy); mechanical fasteners common.
recyclabilitygood — RIC code 2, accepted curbside in most US programs; closed-loop in milk-jug-to-park-bench programs.
disposal pathcurbside recycling.
typical longevity50 years (typical)
failure modes
  • environmental stress cracking under sustained load + detergent contact (the canonical HDPE failure)
  • UV degradation without carbon-black additive
  • creep deformation under sustained load

SPI / PLASTICS recycling guide (RIC 2); ASTM D3350 HDPE pipe specifications.

Citations