TPO HS
Additive grade
GB PP-EPDM, GB/T 22012
HS = heat-stabilized / high-heat TPO
Extra antioxidant/heat-stabilizer package for under-hood ducting and parts seeing prolonged 100–120 °C air.
Values for the HS condition
Other TPO grades and fills
TPO is listed in 12 conditions; see the grade overview at TPO.
Compare all 12 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
TPO foam / foamed skin | Chemically or physically foamed TPO sheet used as a cushion layer behind slush skins and in roofing/insulation composites. | 2 | 4 | 160 | 12 Shore D |
Shore A 70 | Very soft, rubber-like grade for grips, seals, boots and soft-touch overmolding onto PP. | — | 6 | 600 | 22 Shore D |
Shore A 85 | Mid-hardness flexible grade for gaskets, bellows, wire jacketing and skin/slush layers. | 7 | 10 | 550 | 32 Shore D |
FR V-0 | Metal-hydroxide/intumescent FR package for cable jacketing, EV battery-pack trim and rail interior parts needing UL 94 V-0. | 11 | 12 | 150 | 52 Shore D |
HSThis page Heat-stabilized / high-heat TPO | Extra antioxidant/heat-stabilizer package for under-hood ducting and parts seeing prolonged 100–120 °C air. | 14 | 17 | 300 | 50 Shore D |
10 % talc-filled TPO | Light mineral loading for a stiffness/impact balance in soft fascia and cladding with modest CTE reduction. | 15 | 17 | 300 | 52 Shore D |
High-flow thin-wall injection grade | MFR 25–45 grade for long-flow, thin-wall fascias and large interior panels with lower pack pressure. | 15 | 16 | 200 | 55 Shore D |
20 % talc-filled TPO | The classic exterior bumper/fascia compound: stiff enough for large panels, still tough at -30 °C, low CTE for paint fit. | 17 | 19 | 180 | 60 Shore D |
Paintable / adhesion-promoter-free exterior grade | Surface-modified TPO formulated for direct 2K paint adhesion on bumpers without a chlorinated-polyolefin primer. | 17 | 18 | 200 | 60 Shore D |
Conductive / e-paintable TPO | Conductive-filler grade allowing electrostatic painting of large fascias in-line with steel bodies. | 17 | 18 | 120 | 62 Shore D |
30–40 % mineral-filled TPO | Choose when panel stiffness, dimensional stability and low CTE matter more than elongation — IP carriers, door modules. | — | 22 | 45 | 66 Shore D |
20 % glass-fiber reinforced TPO | Niche grade when a semi-rigid, impact-tolerant polyolefin bracket or under-hood part needs real load capacity. | — | 45 | 6 | — |
What is TPO HS?
TPO HS is TPO in the HS grade — extra antioxidant/heat-stabilizer package for under-hood ducting and parts seeing prolonged 100–120 °C air. TPO HS has a yield strength of 14 MPa (2.03 ksi) and a tensile strength of 17 MPa (2.47 ksi) — weaker than 84% of polymer grades. Elongation at break is 300% and the elastic modulus is 0.9 GPa (0.131 Msi). TPO HS has a density of 0.89 g/cm³ (0.0322 lb/in³), lighter than 83% of polymer grades. Its glass-transition temperature is -50°C (-58 °F).
Advantages
- Low embodied carbon — 2.2 kg CO₂/kg, better than 93% of polymer grades
- Low moisture uptake — 0.02%, better than 92% of polymer grades
- Readily welded — 80/100, better than 86% of polymer grades
- Lightweight — 0.89 g/cm³ (0.0322 lb/in³), better than 83% of polymer grades
- Good corrosion resistance — 90/100, better than 82% of polymer grades
Limitations
- Hard to polish — 25/100, worse than 90% of polymer grades
- Low strength — 14 MPa (2.03 ksi), worse than 84% of polymer grades
TPO HS properties
Typical room-temperature values for TPO HS; 28 are specific to this condition. Other listed values are TPO reference data and may not represent this condition. Bars are the position among polymer grades.
Physical5
TPO HS has a density of 0.89 g/cm³ (0.0322 lb/in³), lighter than 83% of polymer grades. Its glass-transition temperature is -50°C (-58 °F).
Mechanical16
TPO HS has a yield strength of 14 MPa (2.03 ksi) and a tensile strength of 17 MPa (2.47 ksi) — weaker than 84% of polymer grades. Elongation at break is 300% and the elastic modulus is 0.9 GPa (0.131 Msi).
Thermal11
TPO HS is rated for continuous service to 110°C (230 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 60% of polymer grades. Thermal expansion is 110 µm/m·K (61.1 µin/in·°F).
Electrical7
TPO HS is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), better than 82% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of TPO HS takes about 82 MJ of energy and emits 2.2 kg of CO₂ — less than 83% of polymer grades. Typical recycled content is 10%.
Manufacturability8
TPO HS's machinability is fair (50/100, worse than 73% of polymer grades); weldability very good (80/100); formability very good (70/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with TPO HS
Is TPO easy to machine?
Machines like soft PP — sharp, high-rake, well-polished tools, high speed with low feed and air cooling; the rubber phase smears and grabs, so avoid dull cutters and use climb milling for clean edges.
Can TPO be welded?
Excellent for hot-plate, vibration, ultrasonic (near-field), IR and hot-gas welding to itself and to PP; not solvent- or adhesive-bondable without flame/plasma/corona treatment or a chlorinated-polyolefin primer.
Can TPO be formed, bent or molded?
Easy injection molding at 195–240 °C melt / 20–60 °C mold; dry is unnecessary (non-hygroscopic) but pellets must be surface-dry; expect 0.8–2.0 % shrinkage with strong flow-direction anisotropy in talc grades, and thermoforms/extrudes well for sheet and skins.
What surface finishes work on TPO?
Grained or textured tool surfaces are standard; painting requires flame or plasma pretreatment (or a primerless paintable grade), and molded-in-color UV grades avoid finishing altogether — no plating, and the soft surface scratches so a mar-resistant additive or hard clearcoat is common.
TPO chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| EPDM / EPR elastomerdispersed rubber phase; may be reactor-made (in-reactor TPO) or melt-blended | 15 – 45 | 30 |
| talc (mineral filler)0 % in unfilled grades; 10–20 % typical for bumper fascia | 0 – 40 | 15 |
| POE / plastomer (C2-C8 octene copolymer)alternative impact modifier in modern TPO | 0 – 25 | 0 |
| carbon black + UV/heat stabilizersHALS + UVA + phenolic/phosphite AO package | 0.2 – 3 | 1.5 |
| polypropylene (homo/copolymer matrix)continuous phase; copolymer PP used for cold impact | ≥ 45 (balance) | — |
TPO HS — frequently asked
What is TPO HS used for?
TPO HS is typically used for automotive bumper fascias, roofing membranes, soft-touch interior skins, weatherstripping and flexible exterior trim. In short: flexible thermoplastic PP blend; paintable exterior trim material; recyclable EPDM alternative.
What is the yield strength of TPO HS?
TPO HS has a typical yield strength of 14 MPa (2.03 ksi) and a tensile strength of 17 MPa (2.47 ksi) — weaker than 84% of polymer grades. Strength varies by condition: see the 12 listed tempers.
Is TPO HS easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 73% of polymer grades). Machines like soft PP — sharp, high-rake, well-polished tools, high speed with low feed and air cooling; the rubber phase smears and grabs, so avoid dull cutters and use climb milling for clean edges.
Can TPO HS be welded?
Yes — weldability is rated very good (80/100). Excellent for hot-plate, vibration, ultrasonic (near-field), IR and hot-gas welding to itself and to PP; not solvent- or adhesive-bondable without flame/plasma/corona treatment or a chlorinated-polyolefin primer.
What surface finishes work on TPO HS?
Grained or textured tool surfaces are standard; painting requires flame or plasma pretreatment (or a primerless paintable grade), and molded-in-color UV grades avoid finishing altogether — no plating, and the soft surface scratches so a mar-resistant additive or hard clearcoat is common.
Can TPO HS be formed, bent or molded?
Easy injection molding at 195–240 °C melt / 20–60 °C mold; dry is unnecessary (non-hygroscopic) but pellets must be surface-dry; expect 0.8–2.0 % shrinkage with strong flow-direction anisotropy in talc grades, and thermoforms/extrudes well for sheet and skins.
What is the maximum service temperature of TPO HS?
TPO HS is rated for continuous use to about 110°C (230 °F), and briefly to 140°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D6162 / D4000 classification practice for thermoplastic elastomer and automotive plastics — ASTM International (2021)
- ASTM D6878 – Standard Specification for Thermoplastic Polyolefin Based Sheet Roofing — ASTM International (2021)
- ISO 527 / ISO 178 / ISO 75 / ISO 1133 test methods — ISO (2019)
- Engineered Materials Handbook Vol. 2 – Engineering Plastics — ASM International (1988)
- Hifax / Adflex TPO compound datasheets — LyondellBasell (2023)
- ExxonMobil Exxtral / Vistamaxx-modified TPO datasheets — ExxonMobil Chemical (2023)
- CAMPUS plastics database – PP+EPDM compound entries — CWFG / CAMPUS consortium (2024)
- GB/T 30923 (automotive modified PP) (2014)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.