# Substitution of plastic (PE, PP, PET) by paper in flexible packaging applications.

Topic radar · 230 documents · 2021-01-01–2026-11-03 · updated 2026-10-31

Canonical: https://slate.greyb.com/radar/substitution-of-plastic-pe-pp-pet-by-paper-in-flexible-packaging-applications/innovations

## In one minute

### The closure is a synthetic film, whatever the pack is called
No document here shows paper sealing to itself at commercial speed. The seal is a polymer film formed on the sheet, and the filings describe it explicitly. Double Will Packaging builds a cellulose core with a heat-seal layer of biodegradable copolyester on each face, made by condensing terephthalic acid, adipic acid, 1,4-butanediol and dimethylolpropionic acid to a weight-average molecular weight of 70,000–200,000 g/mol, then crosslinking the cellulose interface with an aziridine agent at 2% of cellulose solids and thermosetting it [1]. Dongguan Ruize splits the job across the two faces instead: water-based ethylene acrylic acid for water and oil resistance on one side, a heat-seal coating on the other, on either thin or thick base paper [2].

Worth reading the first one carefully, because its "paper" is regenerated cellulose rather than a fibre web. That matters downstream: a cellulose film disperses in a pulper differently from a coated sheet, so its recyclability case cannot be assumed from the paper pack next to it on the shelf.

The commercial version of the same arrangement is sold as a three-party package, with UPM's barrier base paper, Siegwerk's coating and Uteco's application line quoted at up to 90% paper content [3]. What is being substituted is not the polymer but its thickness and its form: a 20 to 40 micron film becomes a few grams per square metre of dried dispersion.

1. [CN122684108A](/?paper=CN122684108A&utm_source=radar&utm_medium=dashboard)
2. [CN215164174U](/?paper=CN215164174U&utm_source=radar&utm_medium=dashboard)
3. [thepackman.in](https://thepackman.in/upm-uteco-and-siegwerk-introduce-a-paper-based-solution-for-secondary-packaging/)

### The headline number is paper content, and the sellers say what it leaves out
The figure brands are being sold is renewable share, not plastic avoided. UPM, Siegwerk and Uteco launched their paper for secondary packaging on the claim that paper content can reach up to 90%, and in the same breath positioned it as "a practical entry point", with the primary packaging continuing to safeguard product integrity. That is an unusually candid piece of product marketing: the seller states the application where the claim is safe and the layer that still does the protecting.


### The committed capital is in coaters and base sheet, not in new chemistry
Read the capacity announcements as a set and they all spend on the same step: getting a thin layer onto a moving web, or preparing a web to receive one. Mondi's €16 million line at Solec exists to make a barrier grade it reports at under 0.5 for both oxygen and water vapour. Walki rebuilt a site around what it calls The Bridge, an extruder joined to glue lamination and dispersion coating, and named the European legal framework as the reason. Ahlstrom's LamiBak Flex is sold as a surface for someone else's coating, metallisation or extrusion, with primer demand reduced.


### Three ways to get the layer onto the web, with different capital behind them
The dominant route is wet coating at the paper machine, dried inline. Mondi's €16 million line at Solec is the clearest case: the product runs on existing horizontal and vertical form-fill-seal equipment without speed loss, which is the claim that decides whether a converter has to buy anything at all.


### What is actually documented is regulatory status, not performance
Across the launches, the attributes that come with evidence are compliance attributes. Michelman's Nuvita grades are sold as microplastic-free, SUPD compliant, 100% bio-based in dry film, and designed for dual end-of-life outcomes across recycling and composting. Koehler's NexPlus OGR is presented on a high grease and oil barrier achieved without PFAS. Mitsubishi Chemical markets its SoarnoL coating as much for oil resistance as a PFAS substitute as for gas barrier. Lactips' original launch paired plastic- and PFAS-free wording with recyclability work done alongside CITEO.


### The largest single cheque is written against aluminium foil, in a format that already gets collected
Tetra Pak is putting €60 million into a pilot plant in Lund for a barrier that replaces the foil layer in aseptic cartons, with production from the first quarter of 2027. The company's own description of the structure matters more than the headline: the paper-based barrier carries an ultra-thin metallised coating, takes paper content to roughly 80%, and lifts renewable content to 92% with plant-based polymers. A first commercial use with white milk in a one-litre carton ran in Italy in April 2026, and the company frames roughly €100 million a year of packaging investment through 2030.


### The barrier is a stack, and each layer buys exactly one property
Nobody in this record tries to make fibre hold out oxygen on its own. The structures are layered and each layer has a job. Huhtamaki laminates at least five layers, 20 to 150 micrometres total, of aliphatic polyester — PHBH, PBS, PLA or PHA — onto moulded or fluff pulp, then heats the assembly to 145–195 °C to crosslink the polyester and lift grease resistance and the water barrier together. Mitsubishi Chemical coats paper with an ethylene vinyl alcohol solution, marketed as much for oil resistance as a PFAS substitute as for gas barrier.


### Where performance is claimed, it is claimed as a list of products
Rapids Paper + Packaging expanded Ecova Barrier by naming the categories it suits: cereals, rice, grains and pasta; dry mixes and powders; frozen fruit and vegetables; chocolate, chips, crackers, granola bars and fruit snacks. Koehler's Interpack display ran the same way, showing tea and pasta through to cosmetics on a stand built with a food manufacturer.


## Overview


The substitution is real, and it thins the plastic rather than removing it. Every document here that reaches a shelf or a specification describes the same architecture: fibre web, barrier layer, seal layer. The seal layer is a synthetic polymer formed from a dispersion, and the filings state how much. UPM claims heat-sealable polymer at 40% or more of the barrier coating's dry weight, and 45% in a sibling application. Koehler mills polyethylene to sub-three-micron particles and film-forms it from water onto the sheet, leaving the polymer chemically unchanged. What changes is form and thickness: a 20 to 40 micron film becomes a few grams per square metre of dried coating. That is a genuine reduction per pack and a genuinely different waste-stream problem for a paper mill, because the plastic no longer sits as a discrete layer anyone can screen out. It is not the removal of polymer that the market's vocabulary implies; outside analysis of these exact structures concludes that functionalised paper of this kind currently qualifies as single-use plastic under the EU directive.


## What's new


On 20 October UPM Specialty Materials began joint development with Ingredion and Paramelt on plant-based starch grease barriers with bio-based heat-seal coatings, trialled on two base grades, UPM Solide Lucent 78 gsm and UPM Asendo 65 gsm. A day later, with Siegwerk and Uteco, it presented a secondary packaging structure running up to 90% paper, on a UPM barrier base paper with a Siegwerk coating applied flexographically in one pass.


## Research

### One grade publishes a number, and it is the ceiling of what this record can defend
Mondi's FunctionalBarrier Paper Ultimate reports oxygen transmission below 0.5 cm³/m²/day and water vapour transmission below 0.5 g/m²/day, at 90% paper content and 60 or 90 gsm, tested to the Cepi laboratory method and the 4evergreen protocol. Those are real barrier figures and they open instant coffee sticks, tea sachets, bouillon and seasoning packs. They are not metallised-film figures, and 0.5 is the sort of threshold that sells into dry goods before it sells into anything with a water activity.


### The binding constraint at the sealing jaw is temperature, not polymer identity
The starch work is the most instructive engineering in this record. A study of modified starches for home-compostable seals found that pure sodium starch octenyl succinate sealed paper while pure maltodextrin did not, and that which plasticizer was added — sorbitol or glycerol — moved both the seal initiation temperature and the fibre tear temperature in different directions. Longer dwell times lowered both temperatures through better molecular interaction, except at the highest pressure tested, where extra pressure stopped helping.


### Liquids have been held, which is the harder half of the claim
Refill shampoo, body wash and detergent went onto eleven packaging lines across more than 130 stores using Hansol Paper's Protego, described as blocking oxygen, moisture and odour without a plastic coating, and the same grade later carried a US matcha brand's packs. Kelpi's seaweed-derived coating is reported at roughly 0.01 mm and is being evaluated inside Amcor's fibre portfolio, with a paper sachet holding liquid hand wash already on the record. A surfactant-heavy liquid in a sealed paper sachet is a more demanding demonstration than a dry-goods wrapper, and it exists.


### The route that would remove the coating entirely has no published outcome
Papure, run across four Fraunhofer institutes, uses a carbon monoxide laser to convert lignin, hemicellulose and cellulose at the paper surface into short-chain compounds that act as the adhesive, so two sheets bond under heat and pressure with nothing added. The work started from surface analysis — electron microscopy and X-ray photoelectron spectroscopy — to decide which papers could be joined without an additive at all.


### Where the format is three-dimensional, the process changes family
Huhtamaki's answer to cups and trays is pulp moulding plus a polyester laminate, not a coated web, and a review of three-dimensional cellulosic packaging makes the reason plain: existing cellulose packaging is roll-to-roll sheet or plied board and is not suited to substituting plastic in three-dimensional shapes, which is why moulded cellulose is where the development effort has moved. A converter weighing a paper switch should know which of the two businesses it is entering, because the equipment, the barrier strategy and the recycling route are all different.


## Market

### Each step down the chain sheds a technical claim
The messages are shaped by who is being sold to. Ahlstrom sells LamiBak Flex to converters on reduced primer demand and suitability for later coating, metallisation or extrusion, with barrier described as something the customer will add. UPM sells the triad to brand owners on renewable content and PPWR readiness. By the time the pack reaches a shopper, the claim is recyclability and the chemistry has disappeared from the copy.


## Strategy

### One paper maker is convening the chemistry on its own base grades
UPM appears with a different partner against each barrier function: Siegwerk's coating and Uteco's application line for secondary packaging at up to 90% paper content, Michelman's bio-based coatings on Bobst equipment, Eastman's BioPBS and Solus additives for grease and oxygen, and Ingredion's starch grease barrier with Paramelt's heat seal on two named grades, Solide Lucent 78 gsm and Asendo 65 gsm.


### The bio-based route is committing to launches and evaluations, not to capacity
The pattern runs the same way across the feedstock contenders. Lactips launched a casein coating with oxygen, fat and mineral oil claims and recyclability work alongside CITEO. Michelman put two plastic-free grades on the market, bio-based in dry film and designed for recyclability or compostability. Kelpi's seaweed coating, at roughly 0.01 mm, is inside an evaluation by Amcor against its fibre portfolio. Reflex and INNOVENT got a biopolymer-and-wax water vapour barrier to work on a transparent barrier paper and name flexographic scale-up as the unsolved step.


### The filings commit to architecture, and one commits to leaving the web behind
Where companies do file in their own name, the claim is the arrangement rather than the polymer. Double Will protects a regenerated cellulose core with copolyester seals bonded through an aziridine crosslink at the interface. Dongguan Ruize splits resistance and sealing across the two faces of a sheet. Hongxi claims the application route, transferring a water-based resin from a release film on a laminator so the paper is never wetted. The one filing that abandons the web entirely is Huhtamaki's, which builds a pulp body with a five-layer polyester laminate for cups, cases and trays and crosslinks it at 145 to 195 °C — consistent with the review finding that existing cellulose stock is flat and three-dimensional formats are where moulded material takes over.


## Areas

- Market & Regulatory Context · 102 documents
- Midstream Conversion & R&D · 42 documents
- Upstream Materials & Coatings · 41 documents
- Downstream Brand Adoption · 32 documents
- Commercialization & Deals · 10 documents