TL;DR: The wall construction decision for a paper tube or composite can is a materials engineering call — get it wrong and you’re either over-specifying at unnecessary cost or under-specifying and watching product fail in transit or on shelf.
TL;DR: A composite can destined for powdered food contact must meet FDA 21 CFR 176.170 for wet-strength adhesives and typically requires a minimum 18 gsm polyethylene liner to achieve a water vapor transmission rate below 10 g/m²/day.
When the Brief Says “Paper Tube” but the Product Needs More Than That #
A brand partner came to us late in 2023 with a brief for a premium loose-leaf tea range. The packaging direction was clear: cylindrical, kraft aesthetic, resealable metal overcap. What was not in the brief: the tea was a high-aromatics blend, shelf life target was 18 months, and the distribution channel included humid Southeast Asian retail. We flagged it at our M-02 material intake review — the standard spiral-wound kraft tube they had been using for their domestic market would not hold up. Moisture vapor was going to migrate through the body wall long before month 18.
The problem with generic material selection for paper tubes and composite cans is that the format looks deceptively simple. It is a cylinder. But the cylinder has to carry compressive load during palletisation, resist moisture ingress at varying ambient humidity, survive a die-cut or scored end-cap fitment without delaminating, and — if it is food or cosmetics contact — comply with applicable food safety regulations. Every one of those requirements pulls the material specification in a different direction.
The root cause of most material failures we see in this category is not choosing the wrong base material outright. It is applying a standard tube grade to a product load that requires a composite can grade, or specifying a composite can construction when a simpler two-ply spiral wound tube would have served the product and reduced unit cost by 20–35%.
The Parameters That Actually Drive the Material Decision #
Six parameters determine whether a paper tube or composite can will perform. Work through each one before committing to a construction type.
Wall caliper and ply count. Spiral-wound tubes in our standard production range from 3-ply to 7-ply construction, yielding wall thicknesses of 3.0 mm to 9.0 mm depending on the body paper grade. Convolute-wound tubes are typically thicker per ply because the body paper wraps parallel to the tube axis — we usually see wall caliper starting at 5.0 mm for convolute. For composite cans, the body wall is thinner: a typical 3-ply composite can body runs 1.8–2.5 mm, using a high-density paperboard ply (280–350 gsm) bonded to a kraft outer and an inner barrier film or foil.
Burst strength requirement. For tubes handling product weights above 400 g or exposed to stacking loads in transit, we reference TAPPI T 810 radial crush test as the baseline qualification. Our standard production targets a minimum flat crush resistance of 600 N for tubes in the 75–100 mm diameter range. Below that, we flag the job for a wall thickness review.
Barrier performance. This is the most commonly overlooked parameter at brief stage. If your product is moisture-sensitive — powders, coffee, confectionery, botanical ingredients — you need a specified WVTR (water vapor transmission rate) for the can body, not just “food-grade liner.” A PE liner at 18 gsm achieves approximately 8–12 g/m²/day WVTR at 38°C/90% RH tested to ASTM E96. A foil laminate liner drops that to below 1 g/m²/day. Specify which you need before we quote. The material cost delta between PE and foil laminate inner is real — roughly 15–25% on liner cost alone.
Food contact compliance. For any composite can with direct food contact, we require documented compliance with FDA 21 CFR 176.170 (adhesives) and, where the product ships to the EU, compliance with EU Regulation 10/2011 on plastic materials in food contact. The inner liner specification and the adhesive used to bond it both fall under this scope. Non-food applications do not carry this requirement, which changes the material options considerably.
End-cap fitment tolerance. Metal overcaps, press-fit plastic closures, and membrane seals each impose different dimensional tolerances on the tube body. Metal overcaps require a tube OD tolerance of ±0.3 mm to guarantee consistent fitment across a production run. We hold ±0.2 mm on our CNC-wound composite can lines. Exceed that tolerance band and you get caps that jam at assembly or fall off in retail.
Print surface and outer ply specification. If you are printing directly onto the tube body (as opposed to applying a wraparound label), the outer ply grade matters. A 90 gsm coated woodfree outer gives you a print surface capable of 133 lpi halftone reproduction. An uncoated kraft outer at the same weight tops out at around 100 lpi before dot gain becomes visible. For brand colours with tight Pantone matching requirements, we recommend coated outer plies — we typically pull delta-E checks at ΔE < 1.5 for brand-critical spot colours on composite cans.
| Construction Type | Typical Wall Thickness | WVTR Range (PE liner) | Suitable Product Weight |
|---|---|---|---|
| 3-ply spiral wound kraft | 3.0–4.5 mm | 25–40 g/m²/day | Up to 300 g |
| 5-ply spiral wound composite | 5.0–7.0 mm | 8–15 g/m²/day | 300–800 g |
| 3-ply composite can (foil liner) | 1.8–2.5 mm | < 1 g/m²/day | Up to 600 g |
| Convolute wound tube | 5.0–9.0 mm | 20–35 g/m²/day (unlined) | 500 g–2 kg |
Choosing the Construction — Conditional Logic for Real Briefs #
If the product has a shelf life requirement of 12 months or more and contains any moisture-sensitive ingredient, the construction needs a foil or metallised film inner liner. A PE liner alone will not hold WVTR below 5 g/m²/day, and for products like instant coffee or fine botanical powder, that is the threshold that matters. Composite can with foil laminate inner is the right call. The tube body wall does not need to be heavy — 1.8 mm is sufficient if the foil liner is doing the barrier work.
If the product is non-food, ambient-stable, and primarily requires structural performance (e.g., hardware, candles, premium spirits accessories), the approach changes. Here you can specify a 5-ply or 7-ply spiral wound tube with unlined interior. You gain wall rigidity, better crush resistance, and you eliminate liner cost. For a candle tube in the 80 mm diameter range with a 250 g product, we typically quote 5-ply spiral wound at 5.5 mm wall — that clears 800 N flat crush resistance with comfortable margin.
If the brief specifies sustainable materials and reduced plastic content — which has become common across EU-facing brands since the EU Packaging and Packaging Waste Regulation (PPWR) came into force — the foil inner becomes a design challenge. A recyclable alternative is a wax or aqueous dispersion barrier coating applied directly to the inner kraft ply, achieving WVTR around 15–20 g/m²/day at 38°C/90% RH. That is not sufficient for coffee or powder, but for dry botanical sachets or tea with a 9-month shelf life target, it is viable. The paper tube with aqueous barrier inner is FSC-certifiable and, depending on your end market, claimable as curbside recyclable.
One non-obvious recommendation: do not let outer diameter drive wall thickness unless you have a hard dimensional constraint. We see briefs where the brand has fixed the OD at 80 mm because it matches a display tray, then specified a 4-ply body that leaves insufficient wall for the burst strength the product needs. If OD is fixed and you need more wall, the inner diameter shrinks — check that your product volume still fits before locking the spec. We have caught this at sample stage on at least four jobs in the last two years, and it always costs a sampling iteration.
Specification Notes for Brand Partners #
When you brief us on a paper tube or composite can project, the three items we need before we can develop an accurate quote are: the product type and weight (not just dimensions), the intended shelf life and storage conditions, and whether the product is food, cosmetics, or non-regulated contact. Without those three, we are quoting a generic construction that may not fit your actual performance requirement.
The most common gap in incoming briefs is the absence of a barrier specification. Brands will write “food-grade inner” without specifying whether they mean PE-lined, foil-laminated, or aqueous-coated. Those three options have different costs, different WVTR performance, and different recyclability profiles. A clear brief here saves one sample iteration almost every time.
Our standard sampling timeline for composite can construction is 18–22 working days for first structural sample, assuming outer artwork is supplied as a print-ready PDF in CMYK with embedded ICC profile. If you need functional testing (drop test per ISTA 2A, leak test, humidity cycling), add 7–10 working days. MOQ for composite can production starts at 5,000 units for standard diameters (65 mm, 73 mm, 99 mm); custom diameters require a minimum of 10,000 units to offset tooling.
What do you need from me to get the wall thickness right?
The product weight, the fill density if it is a powder, and the intended stacking configuration in transit. Those three inputs let us calculate the required flat crush resistance and back-calculate the ply count and body paper grade. Diameter alone is not sufficient.
Can a paper tube meet the same barrier performance as a composite can?
It depends on the liner. A spiral-wound tube with a foil laminate inner ply can achieve WVTR below 2 g/m²/day — comparable to a composite can with foil liner. The structural profiles differ (tube wall is thicker, composite can body thinner), but barrier performance is primarily a liner decision, not a format decision.
What is the minimum order for a custom diameter?
Custom diameters outside our standard tooling range (65 mm, 73 mm, 99 mm, 127 mm) require new winding mandrels, which we amortise over a minimum of 10,000 units. Standard diameters start at 5,000 units. Tooling cost for a new mandrel is a one-time charge, typically in the range of USD 400–800 depending on diameter.
Are PE-lined composite cans recyclable?
In most municipal recycling streams, no — the bonded PE-paper laminate is not separable at sorting facilities. The FSC-certifiable, curbside-recyclable option is an aqueous dispersion barrier coating on the inner ply. The tradeoff is WVTR: aqueous barrier inner gives you 15–20 g/m²/day versus under 1 g/m²/day for foil. For products that can tolerate that, it is a viable sustainability move.
What print process do you use on composite can outer plies?
For print runs above 50,000 units, we use offset litho on the outer wrap before winding, which gives us 133–150 lpi halftone capability and tight spot colour control. Below 50,000 units, digital print on the label wrap is more cost-effective. Our delta-E threshold for brand colour approval is ΔE < 2.0 on production press checks — tighter than many converters hold as standard.
Planning a packaging project? Contact our team to request a complimentary specification review and sample quote.
