Molded Fiber Packaging: From Egg Trays to ABB Robots

Molded fiber packaging is the grey pulp of egg trays and wine shippers, now pressed smooth enough for coffee lids and food trays that used to be plastic. It is made by drawing a watery pulp onto a mesh mold with a vacuum, then drying the shape or pressing it in heated molds. This post traces the trade from the first pulp plates and egg cartons to the transfer molding machines that still make most of it. Then it looks at this autumn's news, from Europe's new packaging rules to dry forming lines and a startup in trouble, and at where ABB robots could fit.

A stand built from molded pulp trays by Eskay Molded Paper Pulp at the Print and Pack Tech Expo in Bangalore, 2025. Photo: Gpkp / Wikimedia Commons (CC BY-SA 4.0)

Pulp plates, egg cartons and four ways to mold fiber

The first egg boxes were cardboard. Thomas Peter Bethell of Liverpool sold the Raylite Egg Box in 1906, with interlocking cardboard frames packed into larger boxes. In 1911 Joseph Coyle, a newspaper editor in Smithers, British Columbia, is credited with inventing the egg carton, reportedly to stop eggs arriving broken. Morris Koppelman patented a cut, folded and glued cardboard carton in 1921 that worked much like today's. Then in 1931 Francis H. Sherman of Palmer, Massachusetts, patented a carton made of pressed paper pulp, which Wikipedia calls recognizable as the modern carton.

A stack of pulp egg cartons, the descendants of Francis Sherman's 1931 pressed pulp carton. Photo: Edward Betts / Wikimedia Commons (public domain)

Pulp plates were already being made by machine. Martin L. Keyes, born in Lempster, New Hampshire, in 1850, patented a paper plate making machine, described in his patent as an apparatus for making pulp articles, and founded the Keyes Fibre Company in 1903. Its plates were later sold under the Chinet brand, and the business now belongs to Huhtamäki. Wikipedia calls the way pulp cartons are made from recycled paper a mechanized papier-mâché process: the pulp is mixed into a watery slurry, formed on a mold and then dried.

A drink carrier of transfer molded wood fiber pulp made by Huhtamaki, the company that now owns the Keyes Fibre business. Photo: Dale Mahalko / Wikimedia Commons (public domain)

Four kinds of molded pulp grew out of this. Thick wall parts are also called slush molded. Transfer molded parts are thin walled, 1/16 to 3/16 of an inch, and are the most common type today: a vacuum draws the slurry tight against a mesh mold, a take-off mold transfers the wet part out, and it moves on to drying. Egg cartons, egg trays and wine shippers are made this way. Thermoformed fiber goes further. The wet part is captured in heated molds that press and densify it, so it leaves the machine finished instead of going through a drying oven. Processed parts get coating, printing, hot pressing or trimming afterwards.

Molded pulp packaging shaped to hold a faucet in its box. Photo: Rlsheehan / Wikimedia Commons (CC BY-SA 3.0)

New rules, dry forming lines and robots at the press

The rules around the material are changing. The International Molded Fiber Association noted in September that the EU's Packaging and Packaging Waste Regulation began applying on 12 August 2026, with requirements phasing in over several years, and that the EU Deforestation Regulation reaches many operators on 30 December 2026. Its new tracker follows 46 regulations across the EU and 11 countries. Suppliers are also widening the fiber mix. On 21 October Packaging Europe reported that Z1RO had finished industrial trials at Kiefel in Germany, running bamboo, hemp and fallen leaves through automated wet molded fiber equipment to make coffee lids and trays.

Eggs in a green molded pulp egg carton, the most familiar molded fiber product in most kitchens. Photo: Krzysztof Golik / Wikimedia Commons (CC BY-SA 4.0)

Machine builders want to move fiber into high volume production. On 14 October Optima announced FiberOne Pro, ahead of PACK EXPO International in Chicago. The platform forms dry molded fiber or formable paper, applies a barrier, cuts and stacks in one machine, with a three second cycle and up to 1,900 portion packs a minute. "The next challenge is industrialization," said chief executive Stefan König. Some companies have found that step hard. PulPac, the Swedish company known for its patented dry molded fiber technology, filed for restructuring in September and gave layoff notices to 50 of its 70 employees, saying the shift to fiber packaging was slower than expected. In 2024 it lost SEK 168 million on revenue of just under SEK 56 million.

Dry molded fiber products of the kind PulPac developed: a tray, lids, a plate and cutlery made of regular pulp. Photo: Suss Tainable / Wikimedia Commons (CC BY-SA 4.0)

Robots already work inside some of these lines. A US patent granted in 2024 to Shurcon Manufacturing, with a Chinese priority date of 2019, says the robotic arm on a pulp molding line usually carries a transfer jig that moves the wet blank into the forming mold or takes out the pressed product, one action at a time; its design does both at once with vacuum suction cups. After the press, the work looks like any packing line, and that is where ABB robots could fit. We found no published ABB molded fiber project, but ABB's IRB 360 FlexPicker tracks fast conveyors with payloads of 1 to 8 kg, and its IRB 460 palletizer reaches up to 2,190 cycles an hour with a 60 kg load.

ABB IRB 360 FlexPicker robots packing small items into cases at high speed. Photo: ABB

What molded fiber lines need next

In factories, the next gains are likely to come after the press, where finished parts are stacked, counted, packed into cases and put on pallets. Those are standard robot jobs, and ABB says its RobotStudio Palletizing PowerPac lets people with no robot programming experience configure palletizing systems on a PC. Tool changes could become another robot task if converters run more shapes and fibers on one machine, as Optima's note that output depends on application, material and tooling suggests. Thin trays and lids are light, which suits fast delta robots like the FlexPicker.

ABB four axis palletizing robots with layer grippers in a packaging line cell. Photo: ABB

Trade will also shape where the new plants go. In the United States, the American Molded Fiber Coalition welcomed interim action by Customs and Border Protection in a case opened on 9 September over alleged evasion of duties on thermoformed molded fiber products from China through Malaysia. The allegations are still under investigation, with a final decision due by 30 March 2027. Mark Ushpol, chief executive of US producer Genera, said trade remedies only help when duties are enforced. Plants that compete with imports have a reason to automate, and non-wood fibers like Z1RO's could let them use biomass that grows nearby.

Stacks of empty pint sized molded pulp produce baskets. Photo: Kayaker / Wikimedia Commons (CC BY-SA 4.0)

For households the change shows up as fiber trays and lids where plastic used to be, and the open problems are cost and performance. PulPac's losses show how expensive the switch can be, and barriers against water, grease and oxygen add steps to every line. Robots bring their own costs and need staff who can program and maintain them, and forming happens in a wet slurry next to heated molds, a harsh place for any machine. Cells like these are usually laid out and tested first in RobotStudio, and our post on egg handling covers ABB robots stacking egg trays onto pallets.

An operator watches an ABB FlexPicker packing cell at the Delicato bakery. Photo: ABB

Innovation

AI solutions for effortless ABB robot control.

Automation

Robotics

ceojohntran@chatwithrobot.net

+84905311611

© 2025. All rights reserved.

qtran1215@gmail.com