Four-company partnership trials biobased paperboard food trays

Eurobrillance, Plastigraf Trevigiana, NatureWorks and Form iQ have developed biobased paperboard structures for food packaging, combining functional barrier materials with industrial forming technology. Their CellShield Protopia collaboration has produced thermoformed tray samples and measured forming performance under defined trial conditions, including an average of 27 mould-closing cycles per minute for containers 35 mm deep.

The development uses NatureWorks’ Ingeo biopolymers within coating and lamination systems supplied by Eurobrillance and Plastigraf Trevigiana. Form iQ contributes the machinery and forming expertise required to convert the prepared paperboard into containers. The companies have evaluated two approaches: a thin-film lamination and a water-based dispersion coating applied directly to the fibre substrate.

The laminated construction combines a thin biaxially oriented polylactic acid film, known as BOPLA, with paperboard using a compostable water-based adhesive. The film is intended to provide barrier and heat-sealing functionality while retaining a predominantly fibre-based structure. The companies are investigating its use in formed trays and other food packaging applications where the material must withstand conversion into a three-dimensional shape.

The alternative approach uses a water-based coating containing Ingeo biopolymers. Applied as a dispersion, the formulation provides a functional layer without requiring a separately produced film to be laminated to the substrate. The partners identify frozen foods and products with shorter shelf lives among its potential applications, where the required barrier performance can differ from that of products intended for extended ambient storage.

Paperboard offers stiffness and can be converted into rigid or semi-rigid packaging, but its untreated surface does not necessarily resist grease or moisture sufficiently for direct exposure to food. Liquid can penetrate the fibre structure, while some applications also require the package to form a reliable heat seal. The coating or lamination must provide the required protection without preventing the material from being formed or handled on industrial equipment.

These functions are affected by the interaction between the substrate and the barrier layer. A coating must cover the material sufficiently to achieve consistent performance, while lamination depends on adequate bonding between the film and board. Both constructions must tolerate bending and deformation during forming. Cracking, delamination or excessive thinning of a functional layer could reduce its effectiveness in the finished package, even if the flat material performed well before conversion.

NatureWorks’ Ingeo polymers are derived from renewable feedstocks and can be processed into different material forms. In this collaboration, they provide part of the functional packaging structure. The renewable origin of a polymer is a material characteristic, not proof that every package containing it is recyclable or compostable under all conditions. Those properties must be assessed for the complete construction and the intended end-of-life treatment.

The companies have described CellShield Protopia as supporting the development of recyclable and compostable packaging. However, the October announcement does not identify a certification covering every finished tray produced using both proposed barrier systems. The adhesive, film, coating and paperboard must be considered together, since changing their composition or proportions can affect the behaviour of the assembled pack.

Form iQ’s trials examined whether the prepared material could be converted into three-dimensional containers at speeds relevant to industrial packaging production. The partners report forming times of approximately 0.2 seconds and an average of 27 mould-closing cycles per minute for containers with a depth of 35 mm. They describe the observed performance as comparable with conventional PET-laminated paperboard under the conditions tested.

The two measurements describe different parts of the forming process. A forming time of 0.2 seconds refers to an operation within the machinery cycle, while mould-closing cycles per minute measure the repetition of the larger process. The overall cycle can include material feeding, heating, forming, opening and removal of finished parts. Consequently, the quoted figures cannot be converted directly into the number of saleable trays produced each hour.

Actual production output also depends on the number of cavities in the tooling, the proportion of acceptable parts and the way material is transferred through the equipment. A machine operating at 27 mould-closing cycles per minute could produce different quantities depending on whether each cycle forms one container or several. The partners have not disclosed the complete tooling configuration or a measured commercial production yield.

Form iQ’s contribution allows the coated paperboard to be assessed as a material that must survive industrial processing, rather than only as a laboratory coating sample. The trials help establish whether the material can be shaped consistently without losing the characteristics required in its finished form. Additional evaluation would be needed for other tray depths, product geometries and barrier formulations.

The two coating routes also create different manufacturing requirements. Thin-film lamination involves production and application of a separate polymer film, while dispersion coating deposits the functional material from a water-based formulation. The selected method influences equipment requirements, drying conditions and the total material structure, and may therefore affect production economics as well as subsequent material recovery.

For food packaging, the finished tray must also meet the requirements of its intended contents. A frozen product, a greasy prepared meal and a chilled product with a short shelf life place different demands on moisture resistance, sealing and dimensional stability. Qualification must take account of the actual food, storage temperature and expected contact conditions rather than assuming one barrier structure is suitable for every application.

Eurobrillance and Plastigraf Trevigiana provide the converting expertise needed to apply these material systems, while NatureWorks supplies the biopolymer technology and Form iQ assesses the manufacturing process. The four companies have demonstrated formed packaging samples, but have not identified a food manufacturer using CellShield Protopia in routine production or announced a timetable for commercial adoption.

The reported trials provide specific forming measurements and show that the partners have progressed beyond testing coatings only as flat sheets. Further work will establish whether the barrier performance remains consistent after forming, whether completed packs meet food-contact requirements and how each construction performs in the intended recycling or composting system. Commercial production rates and repeatability remain to be verified for the final packaging specifications.