Plastic cores for rolls: the technical guide

What a plastic core is

The core is the heart of the roll. Film, paper, aluminium foil, fabric, nonwoven, geotextile or adhesive tape is wound on top of it. The winder or unwinder shaft goes inside it. A plastic core is a tube in a rigid thermoplastic, usually extruded and less often injection moulded: rigid PVC, polypropylene (PP), high-density polyethylene (HDPE) and sometimes ABS or polystyrene (PS).

Quotes use different names for the same thing: plastic tubes for reels, plastic film cores, small cores when the diameter is small (for example in thermal paper rolls for tills and card terminals, or in labels) and custom cores when diameter, wall and length follow the customer’s drawing. Small, very precise cores are also injection moulded; cores for film, textiles and geosynthetics are almost always extruded.

The process is easy to describe. Pellets or regrind melt in an extruder, pass through an annular die, are sized on the outside diameter, cooled in a water bath and cut to length. The result is a tube with a uniform wall, with no plies and no glue. That uniformity explains almost everything about how a plastic core behaves: it does not delaminate, it does not absorb water and it can be washed. But it is also a material that creeps under load and loses stiffness when hot.

Plastic cores are a niche next to cardboard. On the vast majority of industrial rolls the core is still spiral-wound board, because it costs less, weighs less and is recycled with paper. Plastic comes in where cardboard struggles: return loops, clean areas, moisture and long journeys.

Core, tube or mandrel: what we are talking about

On the shop floor the same object goes by several names: core, tube and sometimes mandrel. In this guide they all mean the tube the material is wound on. Watch out for three common mix-ups:

• Air shaft (expanding shaft): the machine part that goes inside the core and grips it. Some people call it a “mandrel”, but it stays on the machine.
• Postal tube: plastic tubes for posting drawings or samples are a different product with different rules.
• Stretch film dispenser: the hand tool for wrapping pallets. It is not the core, even if it is often sold with it.

Other languages have the same ambiguities: anima in Italian, mandrin in French, mandril in Spanish, Wickelhülse in German.

Three reasons for plastic

1. Reuse: the core comes back and goes out again

After one roll, a cardboard core usually has a marked bore, damaged ends and a little more moisture. It can be reused, but with care. A plastic core makes many trips if returns are organised. The best-documented published case we found reached 50 reuses in a trial, with a core that cost about 4 times the cardboard one. Fiaptech technical documentation (a company with corporate ties to ROLL) reports minimum cycles from customer experience ranging from more than 3 (virgin HDPE) to more than 35 (virgin PVC). These are minimums, not upper limits. How reuse is organised and when it pays.

2. Hygiene: no fibres, no dust

Cardboard sheds fibres when cut and when rubbed. In a food film, pharmaceutical or medical plant, or in an electronics cleanroom, those fibres are contaminants. Plastic has a closed, smooth surface: it sheds no fibres, it can be washed and sanitised, and it does not go mouldy. Hygiene, food contact and cleanrooms.

3. Moisture: no swelling, no collapse

Cardboard is hygroscopic: it follows the humidity of the air, swells and loses radial strength. Plastic absorbs no significant water. For rolls stored outdoors, wet areas, agricultural film and containers bound for tropical climates it is the safer choice. Moisture, outdoor storage, UV and cold.

A fourth reason is quoted less often: maximum load. Crushed plastic does not snap suddenly like cardboard: it goes oval and keeps carrying load. According to Fiaptech technical documentation, at the same size the maximum load of a plastic core is about 2.2 to 3.5 times that of a cardboard core.

Limits to know before you switch

An honest guide must also say where plastic loses.

• Price: at the same size a plastic core costs 2 to 5 times a cardboard core. It pays only if it comes back, or if cardboard fails in that application.
• Weight: PVC weighs about 1.8 times cardboard at the same size; PP and HDPE about 1.1–1.2 times (Fiaptech technical documentation). That affects freight and manual handling.
• Heat: plastics lose stiffness as temperature rises. According to Fiaptech technical documentation, at 50 °C a virgin PVC core loses about 20% of the strength measured at 25 °C, and a recycled PVC core about 30%.
• Creep: under constant load plastic flows slowly and the bore closes over time. A test lasting a few minutes does not show it. Strength and creep explained.
• End of life: in 2024 the EU recycled 42.4% of plastic packaging against 85.3% of paper and board packaging (Eurostat, estimates). A plastic core is recycled well only if the polymer is collected separately.
• Rules: from 2030 a plastic core that counts as packaging must contain a minimum share of post-consumer recycled plastic (PPWR, Art. 7). In the UK, plastic packaging with less than 30% recycled content already pays Plastic Packaging Tax.

Materials at a glance

Four families cover almost the whole European market. Each has one strength and one weakness.

Source of densities: typical literature values for base polymers; real compounds can fall outside these ranges. The full comparison of materials, with temperatures and moduli.

Use the calculator below, or open the PVC, PP or HDPE selector full page, with method and sources.

Sizes and finishes

The most common inside diameters are 76 mm (3") and 152 mm (6"), with many sizes in between: from about 25 mm to over 300 mm. Walls range from 1–2 mm for tape cores to 12–15 mm for heavy rolls. The bore can be smooth or ribbed: longitudinal ribs grip the air shaft better and help with slippery materials or high torque. Catalogues also call a ribbed bore grooved, serrated or knurled, depending on how many ribs it has and how fine they are. Ends can be left as cut, deburred, or notched for drive dogs.

There is no ISO standard specifically for plastic core tolerances. In practice ISO 13542, written for paper reel cores, is used as the reference: plus-only tolerances on the inside diameter (for example +1.2 mm on 76 mm) and a maximum difference of 1.5 mm between two perpendicular diameters from 70 mm upwards. Extruded and sized plastic cores can sit well within these limits. Diameters, tolerances, ovality and shafts.

Try it with your own data below; method, assumptions and sources are on the dedicated page: the plastic core weight calculator.

Strength: plastic does not break, it deforms

A cardboard core under crush reaches a peak and then fails: ISO 11093-9 measures exactly that peak. A plastic core has no clear peak. It goes oval, the bore closes and the force keeps rising. That is why plastic is measured with a different criterion: the force that deflects the diameter by 3%, as in ISO 9969 for thermoplastic pipes. The two tests also run at different speeds: 50–65 mm/min for paper, 2–5 mm/min for plastic. The numbers cannot be compared lightly.

The real enemy of plastic is not the peak but time. A roll squeezes its core for weeks or months, and plastic under constant load creeps. The European standard for structured-wall thermoplastic pipes (EN 13476) allows a two-year creep ratio of up to 2.5 for PVC-U and up to 4 for PP and PE: in other words, after two years the effective stiffness of a PP pipe can be a quarter of the value measured in the test. Heat speeds everything up. How it is calculated and tested.

Reuse: the sum that decides

Plastic pays when its cost per use falls below that of cardboard. Cost per use depends on four numbers: the price of the plastic core, the price of the cardboard core, the cost of one return trip, and the share of cores that actually come back. A ROLL Lab example: with a core costing 3.5 times cardboard and a return costing 20% of the cardboard price, plastic breaks even if at least 76% of cores come back, meaning each core makes about 4 trips on average. Below that, one-way cardboard is cheaper.

The calculation is below. For the full version, with the formulas explained, open the reuse break-even calculator.

Returns are not free: collection, packing, transport, inspection, washing and scrapping damaged cores. How to run a return loop.

Standards, PPWR and UK tax: what changes

Regulation (EU) 2025/40 on packaging and packaging waste (PPWR) applies from 12 August 2026. Among the packaging examples in Annex I it explicitly lists rolls, tubes and cylinders around which flexible material is wound, except those intended to be part of production machinery and not used to present a product as a sales unit. A plastic core that leaves the plant with the roll therefore has three main obligations:

• Recycled content (Art. 7): 35% post-consumer recycled plastic from 2030 and 65% from 2040 for “other plastic packaging”, as an average per manufacturing plant and year (10% and 25% if the core were contact-sensitive packaging made of a plastic other than PET). Recycled industrial scrap does not count.
• Recyclability (Art. 6): grade A, B or C from 2030; at least grade B from 2038.
• Reuse (Arts. 11 and 12): a core declared reusable must meet the requirements of Art. 11 and, from 12 February 2029 (or 30 months after the implementing act, if later), carry a label and a QR code.

Cores are not among the formats with mandatory reuse targets in Art. 29: today, reusing them is a voluntary choice. PPWR and plastic cores, article by article.

In the UK the PPWR does not apply in Great Britain, but plastic cores meet another rule first: the Plastic Packaging Tax. Since April 2022 plastic packaging components made in or imported into the UK with less than 30% recycled plastic are taxed per tonne (£228.82 per tonne from 1 April 2026), once a business passes 10 tonnes in 12 months. A core that protects and carries the roll through the supply chain is normally a packaging component. UK Plastic Packaging Tax and EPR for cores.

Plastic or cardboard in 3 questions

1. Does the core come back? If yes, and most of them come back, plastic can cost less per use. If not, start from cardboard.
2. Does the area ban fibres and dust? If yes (food, pharma, cleanrooms), plastic is often a requirement, not a cost choice.
3. Will the roll see water or high humidity? If yes (outdoors, wet areas, container export), plastic removes the risk of moisture failure.

If you answer no to all three, a well-specified cardboard core is almost always the cheapest and easiest to recycle. If you answer yes to at least one, check temperature as well: above 40–50 °C the choice of polymer matters a lot. The full plastic vs cardboard comparison.

Use the calculator below, or open the cardboard or plastic check for your case full page, with method and sources.

Where to start

• You need to choose a new core: the 7 data points to define and the decision tree.
• You already have a material in mind: PVC, PP, HDPE.
• You work in a specific sector: applications, from packaging film to geosynthetics.
• You need to write a specification or find a supplier: how to choose a manufacturer.
• You need the right words: the glossary and the FAQ.

This guide is a project by ROLL · ROLL Lab. The calculations are ROLL Lab estimates, to be confirmed by a test on the real core. About us, method and sources.

Frequently asked questions

Further reading

Sources

1. Regulation (EU) 2025/40 (PPWR), EUR-Lex: Annex I, Arts. 6, 7, 11, 12, 29
2. ISO 13542:2006, Paper and board — Specification for internal diameters of cores for reels
3. ISO 11093-9, Paper and board — Testing of cores — Determination of flat crush resistance
4. ISO 9969:2007, Thermoplastics pipes — Determination of ring stiffness
5. EN 13476-2, creep ratio requirement according to EN ISO 9967 (PVC-U ≤ 2.5; PP and PE ≤ 4 at 2 years)
6. Eurostat, dataset env_waspac (packaging recycling rates 2024, estimates)
7. Fiaptech technical documentation, Smart Book “Which core?” (a company with corporate ties to ROLL): weight, strength, cycle and temperature ratios
8. NS Packaging, case of plastic cores reused up to 50 times in a trial (2009), nspackaging.com
9. HM Revenue & Customs, Plastic Packaging Tax guidance, GOV.UK
10. ROLL Lab analysis (cost per use, materials comparison)