PP-H · reinforced grade · default condition
PP-H-UNF
Properties of the UNF condition, compared with the other PP-H grades.
Standard choice for general injection molding, sheet, pipe and chemical tanks where stiffness and chemical resistance matter more than low-temperature impact.
What is PP-H-UNF?
PP-H-UNF is PP-H in the UNF grade — standard choice for general injection molding, sheet, pipe and chemical tanks where stiffness and chemical resistance matter more than low-temperature impact. PP-H-UNF has a yield strength of 34 MPa (4.93 ksi) and a tensile strength of 35 MPa (5.08 ksi) — weaker than 70% of polymer grades. Elongation at break is 300% and the elastic modulus is 1.5 GPa (0.218 Msi). PP-H-UNF has a density of 0.91 g/cm³ (0.0327 lb/in³), lighter than 80% of polymer grades. Its glass-transition temperature is -10°C (14 °F).
Advantages
- Low moisture uptake — 0.01%, better than 97% of polymer grades
- Low embodied carbon — 2 kg CO₂/kg, better than 96% of polymer grades
- Readily welded — 90/100, better than 94% of polymer grades
- Ductile — tolerates forming and impact — 300%, better than 81% of polymer grades
- Good corrosion resistance — 90/100, better than 81% of polymer grades
Limitations
- Degrades in UV without stabilisers — 20/100, worse than 88% of polymer grades
- Hard to polish — 30/100, worse than 80% of polymer grades
PP-H-UNF properties
Typical room-temperature values for PP-H-UNF — 21 properties are specific to this condition; the rest are grade-level values shared by every PP-H grade. Each bar shows where the value sits among the polymer grades in FabDigit's library — further right is higher.
Physical6
PP-H-UNF has a density of 0.91 g/cm³ (0.0327 lb/in³), lighter than 80% of polymer grades. Its glass-transition temperature is -10°C (14 °F).
Mechanical17
PP-H-UNF has a yield strength of 34 MPa (4.93 ksi) and a tensile strength of 35 MPa (5.08 ksi) — weaker than 70% of polymer grades. Elongation at break is 300% and the elastic modulus is 1.5 GPa (0.218 Msi).
Thermal11
PP-H-UNF is rated for continuous service to 100°C (212 °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
PP-H-UNF is an electrical insulator with a dielectric strength of 28 kV/mm (711.2 V/mil) and a resistivity of 1×10¹⁵ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), better than 81% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of PP-H-UNF takes about 78 MJ of energy and emits 2 kg of CO₂ — less than 88% of polymer grades. Typical recycled content is 3%.
Manufacturability8
PP-H-UNF's machinability is good (65/100, better than 66% of polymer grades); weldability excellent (90/100); formability good (65/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other PP-H grades and fills
PP-H is also supplied in 11 other conditions. The full side-by-side table is on the PP-H overview.
- UNFDefaultStandard choice for general injection molding, sheet, pipe and chemical tanks where stiffness and chemical resistance matter more than low-temperature impact.34 MPa yield · 72 Shore D
- GF40Highest stiffness/strength PP compound for semi-structural brackets, pump housings and under-hood parts replacing low-end nylon.105 MPa tensile
- GF20Pick when about double the stiffness and much better heat distortion resistance are needed while keeping moderate cost and moldability.75 MPa tensile
- HCPPNucleated high-crystallinity homopolymer for thin-wall packaging and high-modulus unfilled parts with faster cycle times.40 MPa yield
- EXTR-SHEETSemi-finished sheet, rod and tube for machined chemical-plant tanks, ducts and fixtures; stress-relieved grades minimize machining distortion.32 MPa yield
- TALC40Low-cost stiffening and dimensional-stability filler for appliance and automotive interior parts where glass fiber's anisotropy and surface roughness are unacceptable.30 MPa yield
- FR-V0Halogen-free or brominated FR compound for electrical housings and battery components requiring V-0 at 1.6 mm.26 MPa tensile
- IMUse where PP-H's notch and sub-zero brittleness is the limiting factor but homopolymer stiffness/cost is still wanted.25 MPa yield · 64 Shore D
Working with PP-H-UNF
Is PP-H easy to machine?
Machines easily with sharp, high-rake tools, high speed and low feed; use coolant/air blast to avoid gumming and allow for springback and post-machining relaxation.
Can PP-H be welded?
Excellent hot-gas, butt-fusion, socket-fusion, hot-plate and ultrasonic welding; adhesive bonding requires plasma/flame/corona pretreatment or PP-specific primers.
Can PP-H be formed, bent or molded?
Injection molds at 200–260 °C melt, 20–60 °C tool, 1.0–2.5 % shrinkage (glass grades 0.3–0.8 %); sheet thermoforms and cold-bends only over a heated line due to a narrow rubbery plateau.
What surface finishes work on PP-H?
Not paintable or platable as-molded; needs flame/corona/plasma activation or adhesion promoter; textured mold surfaces are preferred since high-gloss polish scratches easily.
PP-H 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 |
|---|---|---|
| stabilizer/additive packagephenolic/phosphite antioxidants, acid scavenger, nucleator, slip/antistat | 0.05 – 1 | 0.3 |
| glass fiber0 for default; 20 or 40 wt % in GF20/GF40 variants, with maleic-anhydride-PP coupling agent | 0 – 40 | 0 |
| talc / mineral filleronly in mineral-filled variants | 0 – 40 | 0 |
| propylene (homopolymer chain)isotactic polypropylene, no comonomer; base resin | balance | — |
PP-H-UNF — frequently asked
What is PP-H-UNF used for?
PP-H-UNF is typically used for pipes and fittings, woven sacks and raffia tape, battery cases, fibers and nonwovens, rigid packaging containers and chemical tanks. In short: stiffest PP variant; weldable chemical-resistant polyolefin; low-cost commodity resin.
What is the yield strength of PP-H-UNF?
PP-H-UNF has a typical yield strength of 34 MPa (4.93 ksi) and a tensile strength of 35 MPa (5.08 ksi) — weaker than 70% of polymer grades. Strength varies by condition: see the 12 listed tempers.
Is PP-H-UNF easy to machine?
Reasonably — machinability is rated good (65/100, better than 66% of polymer grades). Machines easily with sharp, high-rake tools, high speed and low feed; use coolant/air blast to avoid gumming and allow for springback and post-machining relaxation.
Can PP-H-UNF be welded?
Yes — weldability is rated excellent (90/100). Excellent hot-gas, butt-fusion, socket-fusion, hot-plate and ultrasonic welding; adhesive bonding requires plasma/flame/corona pretreatment or PP-specific primers.
What surface finishes work on PP-H-UNF?
Not paintable or platable as-molded; needs flame/corona/plasma activation or adhesion promoter; textured mold surfaces are preferred since high-gloss polish scratches easily.
Can PP-H-UNF be formed, bent or molded?
Injection molds at 200–260 °C melt, 20–60 °C tool, 1.0–2.5 % shrinkage (glass grades 0.3–0.8 %); sheet thermoforms and cold-bends only over a heated line due to a narrow rubbery plateau.
What is the maximum service temperature of PP-H-UNF?
PP-H-UNF is rated for continuous use to about 100°C (212 °F), and briefly to 130°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between PP-H-UNF and PP-H-IM?
UNF is the default condition — standard choice for general injection molding, sheet, pipe and chemical tanks where stiffness and chemical resistance matter more than low-temperature impact. IM: use where PP-H's notch and sub-zero brittleness is the limiting factor but homopolymer stiffness/cost is still wanted. Yield strength is 34 MPa in UNF versus 25 MPa in IM.
Sources
- ASTM D4101 — Standard Specification for Polypropylene Injection and Extrusion Materials — ASTM International (2023)
- ISO 19069-1/-2 — Plastics, Polypropylene (PP) moulding and extrusion materials — ISO (2019)
- GB/T 12670 (PP) (2008)
- DIN 8078 — Polypropylene (PP) pipes, general quality requirements and testing — DIN (2018)
- ASM Engineered Materials Handbook Vol. 2 — Engineering Plastics — ASM International (1988)
- CAMPUS plastics database — PP homopolymer and PP-GF datasheets — CWFG/CAMPUS (2024)
- Polypropylene homopolymer and glass-reinforced PP compound datasheets — LyondellBasell / Borealis / SABIC / Ensinger (2024)
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.