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Plastic core materials: PVC, PP, HDPE, PS and ABS compared
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Overview: three families, seven variants
Almost all plastic cores for industrial rolls in Europe are made from three polymers: rigid PVC (also called PVC-U, unplasticised), polypropylene (PP) and high-density polyethylene (HDPE, also written PE-HD). Each comes in virgin and recycled versions and, for PP, filled with calcium carbonate (CaCO₃). Two materials appear in niches: ABS and polystyrene (PS), mostly for small cores for tapes, labels and technical films.
A warning before the numbers. The properties of a core depend on the compound (formulation, fillers, stabilisers, recycled share) and on the process (extrusion, cooling, sizing). The values below are typical ranges for base polymers: they help you understand the differences, not sign off a specification. For that you need the supplier’s data sheet and a test.
Polymer properties compared
| Property (typical values) | Rigid PVC | PP homopolymer | HDPE | GPPS | ABS |
|---|---|---|---|---|---|
| Density (g/cm³) | 1.35–1.45 | 0.90–0.91 | 0.94–0.97 | 1.04–1.05 | 1.03–1.07 |
| Short-term modulus, 23 °C (GPa) | 2.5–3.5 | 1.3–1.8 | 0.8–1.4 | 3.0–3.5 | 2.0–2.6 |
| HDT at 0.46 MPa (°C) | 57–80 | 100–120 | 60–90 | 75–100 | 68–100 |
| HDT at 1.8 MPa (°C) | 54–75 | 50–60 | 45–60 | 70–90 | 88–100 |
| Glass transition (°C) | about 80 | about −10 / 0 | about −110 | about 100 | about 105 |
| Two-year creep ratio (EN 13476 pipe requirement) | ≤ 2.5 | ≤ 4 | ≤ 4 | n/a | n/a |
| Behaviour in the cold | brittle on impact below 0 °C | brittle around 0 °C (copolymer less so) | tough down to −30 °C and below | brittle | good down to about −20 °C |
| Identification code | 3 PVC | 5 PP | 2 HDPE | 6 PS | ABS (codes 7–19 “other”) |
Sources: HDT from SpecialChem (ranges per polymer family); creep ratio from the EN 13476-2 requirements according to EN ISO 9967; densities, moduli and glass transitions from technical literature on polymers. ROLL Lab analysis.
Two useful readings. First: PVC has roughly twice the modulus of PP and HDPE. For the same wall a PVC core is therefore much stiffer, and stiffness is what resists wall buckling. Second: the two HDT values tell different stories. Under a light load (0.46 MPa) PP holds above 100 °C; under a high load (1.8 MPa) it drops to 50–60 °C. A core under a heavy roll works closer to the second case.
How to read a data sheet
Values from two data sheets can only be compared if they come from the same tests, on specimens conditioned at 23 °C. There are only a few standards to look for:
- density: ISO 1183, in g/cm³;
- tensile modulus: ISO 527; flexural modulus: ISO 178, in MPa or GPa. This is the figure that matters most against wall buckling;
- heat deflection temperature (HDT): ISO 75, at 1.8 MPa (method A) or 0.45 MPa (method B). For a core under a heavy roll the 1.8 MPa value is the most realistic;
- Vicat softening temperature: ISO 306;
- Charpy impact strength: ISO 179, useful if also measured at −20 °C for cold applications;
- tensile creep: ISO 899-1. Few suppliers give it, but it is the closest figure to how the core behaves over time.
A data sheet without test methods does not allow comparisons: ask for the complete version.
Finished cores compared: the Fiaptech documentation
Polymer properties are not enough: the finished core is what counts. The only public comparison of same-size cores we found is in Fiaptech technical documentation (a company with corporate ties to ROLL). Values are ratios against a cardboard core of the same size, set at 1.
| Core (same size) | Weight | Strength at 3% deflection | Maximum load | Minimum cycles reported by customers | NIAS risk indicated |
|---|---|---|---|---|---|
| Cardboard | 1 | 1 | 1 | 1 | medium |
| Virgin PVC | 1.76 | 1.58 | 3.5 | more than 35 | none |
| Recycled PVC | 1.85 | 1.23 | 2.7 | more than 25 | medium |
| Plain PP | 1.13 | 1.15 | 2.54 | more than 10 | none |
| Filled PP | 1.23 | 1.51 | 3.33 | more than 15 | none |
| Plain HDPE | 1.14 | 1.08 | 2.38 | more than 3 | none |
| Recycled HDPE | 1.16 | 1.01 | 2.22 | more than 5 | low |
How to read the table:
- The 3% strength for plastic follows the ISO 9969 criterion; cardboard is usually tested to ISO 11093-9, at first failure. The tests run at different speeds (2–5 mm/min against 50–65 mm/min): the ratio is indicative, not a like-for-like measurement.
- Cycles are minimums from customer experience, not limits. The figure for virgin HDPE (more than 3) being lower than recycled (more than 5) is reported that way in the source.
- These are short tests: they do not include creep over weeks, which penalises PP and HDPE more.
Use the calculator below, or open the plastic core weight calculator full page, with method and sources.
Plastic core weightTell me material, diameter and wall: I’ll tell you the weight per metre, per piece and how many pieces make a tonne.
Typical density of the chosen material. Formula: π/4 × (OD² − ID²) × density.
ROLL Lab estimate, not a test certificate. Prepare your enquiry for the manufacturer →
Temperature: the dividing line
Heat is the first filter. The same Fiaptech documentation reports that at 50 °C the strength of a virgin PVC core drops by about 20% compared with 25 °C, and that of a recycled PVC core by about 30%. PVC has its glass transition around 80 °C: as it gets closer, stiffness collapses. PP, being semi-crystalline, loses stiffness more gradually but starts from a lower value. HDPE is the most sensitive of the three at the same load.
A ROLL Lab rule of thumb, to be checked case by case: up to 35–40 °C in service all three polymers can be handled with the right wall margin; between 40 and 60 °C PP or a PVC with a generous margin is better; above 60 °C continuous you leave the field of standard plastic cores.
Heat deformation is visible to the naked eye: long cores stored with one side in the sun bend like a banana. In the Fiaptech documentation the sun effect is described as stronger for recycled PVC and recycled HDPE.
Creep: strength that fades over time
Under constant load a plastic keeps deforming slowly. For a core, that means the bore closes in the days and weeks after winding. The thermoplastic pipe standards give a useful reference: EN 13476-2 requires a two-year creep ratio (EN ISO 9967) of up to 2.5 for PVC-U and up to 4 for PP and PE. In plain terms: after two years the effective stiffness of PVC can fall to 40% of the initial value, and that of PP and PE to 25%.
For a roll that stays in storage for weeks rather than years the drop is smaller, but not negligible. In the calculations in this guide the ROLL Lab uses a long-term factor of about 0.65 for PVC and 0.45 for PP and HDPE at 23 °C, lower in the heat. These are prudent assumptions, to be calibrated with constant-load tests. Strength and creep in detail.
Cold and UV
In the cold, polymers get stiffer but more brittle on impact. Homopolymer PP has its glass transition near 0 °C: a roll loaded onto a lorry in winter can split the core if dropped. Copolymer PP and HDPE are far tougher. Rigid PVC becomes notch-sensitive below freezing.
In the sun, UV radiation breaks polymer chains. Unstabilised PP is the most exposed; HDPE with carbon black (the same principle as water pipes) is the most resistant; stabilised PVC tends to fade and lose surface impact strength. Cores for outdoor use.
Virgin, recycled and filled
Post-industrial and post-consumer recycled. Many PVC and HDPE cores are made wholly or partly from recycled material. Ask two things: where it comes from (production scrap or collected waste) and how consistent it is. For the PPWR only post-consumer recyclate counts. For food contact, recycled plastic is allowed only from processes compliant with Regulation (EU) 2022/1616.
Performance. According to the Fiaptech documentation, at the same size recycled PVC has about a quarter less 3% strength than virgin (1.23 against 1.58 relative to cardboard) and loses more in the heat. That is not a defect if the wall is sized accordingly.
Fillers. Calcium carbonate-filled PP is stiffer and cheaper than plain PP, but heavier, and it behaves differently in recycling: with about 15% carbonate its density already exceeds that of water, and in the sink-float tank the core sinks with the heavy materials (ROLL Lab analysis based on densities).
PS and ABS: small, precise cores
Polystyrene (PS, also high-impact HIPS) is stiff, light and easy to mould or extrude to tight tolerances. It is used for small cores for tapes, labels and thin films, and for plugs and end walls. Its limit is brittleness on impact and in the cold.
ABS combines stiffness, dimensional precision and good toughness even at low temperature. It is used for precision reusable cores, for example in electronics and technical films, and wherever a neat finish matters. It costs more than the other plastics and is recycled in less common streams.
Additives and substances to know
- PVC stabilisers: today calcium-zinc or tin based. Recycled PVC may contain traces of lead stabilisers used in the past; REACH (Regulation (EU) 2023/923) restricts lead in PVC with time-limited derogations for recovered PVC. Ask for the supplier’s declaration.
- Heavy metals in packaging: the PPWR sets a limit of 100 mg/kg for the sum of lead, cadmium, mercury and hexavalent chromium (Art. 5).
- Colourants and carbon black: black makes the core more UV resistant but hard to identify with optical sorters at sorting plants.
- NIAS: non-intentionally added substances, found mainly in recyclates. They matter for food contact.
Which material for which use
| Use | First choice | Alternative | Avoid |
|---|---|---|---|
| Returnable packaging film, temperate storage | virgin PVC | filled PP, recycled PVC with a thicker wall | HDPE with thin walls |
| Food, pharmaceutical, cleanroom film | virgin PP | virgin PVC with declaration, ABS | unauthorised post-consumer recyclates |
| Agricultural film, outdoor storage | black HDPE | UV-stabilised copolymer PP | homopolymer PP in frost |
| Containers to hot climates | PP with wall margin | PVC with a thicker wall | marginal HDPE |
| Tapes, labels, small cores | PS, ABS | PP | — |
| Maximum recycled content | post-consumer recycled PVC or HDPE | recycled PP | untraced recyclate |
Try it with your own data below; method, assumptions and sources are on the dedicated page: the PVC, PP or HDPE selector.
Which plastic for your core?Three questions on heat, food and priorities, and I’ll tell you which plastic to start from. Then you run the test, on the real roll.
Indicative ROLL Lab choice: 10 °C margin on the material’s continuous service temperature. Always check the compound data sheet.
ROLL Lab estimate, not a test certificate. Prepare your enquiry for the manufacturer →
Material by material: PVC cores, PP cores, HDPE cores.
Frequently asked questions
Which is the stiffest plastic for cores?
Among the common materials, rigid PVC: its modulus is about 2.5–3.5 GPa, roughly twice that of PP and HDPE. PS and ABS are as stiff as PVC or stiffer, but they are used mainly for small cores.
What temperature can a plastic core take?
It depends on polymer and load. As an order of magnitude, HDT at 1.8 MPa is 54–75 °C for rigid PVC, 50–60 °C for PP and 45–60 °C for HDPE. In continuous service under a roll, stay well below that, with a wall margin.
Is recycled PVC as strong as virgin?
At the same size it is usually a little weaker: according to Fiaptech technical documentation (a company with corporate ties to ROLL) its 3% strength is about a quarter lower and its loss at 50 °C is larger (about 30% against 20%). With an adequate wall it works well.
What is filled PP?
It is polypropylene with a mineral filler, usually calcium carbonate. It is stiffer and cheaper than plain PP, but heavier. With about 15% filler it becomes denser than water and ends up with the heavy materials in recycling.
When are ABS and polystyrene used?
For small, precise cores for tapes, labels and technical films, and for plugs and end walls. ABS stays tough in the cold; polystyrene is stiff and cheap but brittle.
Further reading
PVC cores
Rigid PVC cores, virgin or recycled: stiffness, weight, temperature, reuse, cutting, food contact, separate recycling and PPWR. With data, ratios and sources.
PP cores
Plain and CaCO₃-filled polypropylene cores: low weight, temperature, creep, cold, UV, food contact, steam sterilisation, lathe cutting and recycling.
HDPE cores
Virgin and recycled HDPE cores: toughness in the cold, UV resistance with carbon black, stiffness, creep, reuse, cutting and recycling with the polyolefins.
Strength
Radial strength of plastic cores: roll pressure, Lamé, buckling, creep, temperature, the ISO 9969 test and how plastic differs from cardboard under load.
How to choose
How to choose a plastic core: roll, bore and shaft, length, temperature, environment, hygiene and reuse. A decision tree, common mistakes and calculators.
Sources
- SpecialChem, Heat Deflection Temperature of Plastics, specialchem.com
- EN 13476-2, creep ratio according to EN ISO 9967 (PVC-U ≤ 2.5; PP and PE ≤ 4 at 2 years)
- ISO 9969:2007, ring stiffness of thermoplastic pipes
- Fiaptech technical documentation, Smart Book “Which core?” (a company with corporate ties to ROLL): weight, strength, cycles, NIAS, temperature ratios
- Regulation (EU) 2025/40 (PPWR), Arts. 5 and 7, EUR-Lex
- Regulation (EU) 2022/1616 on recycled plastic materials and articles intended to come into contact with foods
- Regulation (EU) 2023/923 (REACH, Annex XVII: lead in PVC)
- Decision 97/129/EC, identification system for packaging materials
- ROLL Lab analysis (long-term factors, densities of filled compounds, use table)
- ISO 1183, ISO 527, ISO 178, ISO 75, ISO 306, ISO 179, ISO 899-1 (test methods for plastics)
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