Production of plates and mouldings from popcorn granules

Newly developed processes for the production of popcorn granulate boards and mouldings. They now make it possible to produce boards or mouldings from renewable resources with improved water resistance and flexural strength. The boards and mouldings are particularly suitable for packaging, furniture, automotive (including caravans) and housing applications.

csm BioC 2138 SUG IMG 5858 eec75e0354Source: C. Pertsch

Challenge

In the packaging, automotive and house construction sectors, moulded parts are still made from conventional plastics. These polymers have some positive properties such as low density, hydrophobic surfaces or low thermal conductivity. However, they also have numerous negative properties, including lower stiffness and strength compared to some traditional materials. In addition, the long degradation time and the problem of microplastics pose major social challenges. In addition, these plastics are made from finite fossil raw materials, and these technical and social problems mean that alternative solutions are urgently needed, particularly those made from renewable raw materials.

Our Solution

In order to meet this demand, the scientists have developed new processes for producing panels and mouldings from expanded popcorn granules. In a special process, the granules used can be coated with a polymer before being pressed, making them easier to store before further processing and reducing their water absorption. Another innovative process has now been developed to reduce water absorption even further. This involves increasing the degree of crystallisation of the starch in the popcorn granules by raising the temperature and humidity (retrogradation). Another production process has been optimised for the special renewable raw material, using radio wave technology to make it faster, more efficient and therefore more cost-effective.

Production process using radio wave technology (hν): the moulding compound (polymer-coated or retrograted popcorn granules) is pre-compressed pneumatically and then filled into the mould. Temperature and pressure are used to heat the moulding compound. The use of radio wave technology enables a faster and more efficient moulding process. Following the successful bonding of the popcorn particles, the final step involves the removal of the part from the mould.

Advantages

  • Production of panels and moulded parts from renewable raw materials,
  • Increased moisture resistance,
  • Improved transverse tensile strength,
  • Enhanced compressive strength,
  • Increased flexural strength,
  • Good storability and pourability of the granulate,
  • Fast and efficient compression moulding process.

For the manufacture of flexurally rigid sandwich panels, retrogradation offers the possibility of producing very compressive core layers, allowing the potential of very rigid face layers such as HDF, HPL etc. to be utilised in sandwich panels. Additionally, the process allows for the production of sandwich panels with a fibreboard or chipboard face layer in a single operation, enhancing efficiency and consistency in the manufacturing process.

BioC 2543 SUG VergleichsgraphTransverse tensile strength (QZ) of the test specimens before and after retrogadation (climate chamber). The strength increased by almost four times (binder: haemoglobin) or nine times (binder: UF resin). For comparison: A chipboard with a similar density of about 650 kg/m³ has a minimum tensile strength of 0.35 N/mm² according to EN 312.

Applications

  • Packaging materials (e.g. cool boxes, protective packaging, food packaging, cooking boxes, plates, etc.)
  • Automotive parts (including parts for caravans)
  • Construction industry: insulation materials (sound or heat insulation), dry construction, partition walls (incl. exhibition stands), sustainable construction

Development Status

Various boards and molded parts (prototypes) were successfully manufactured and tested.

Patent Status

A broad IP portfolio is available (applicant: Georg-August-Universität Göttingen Stiftung Öffentlichen Rechts).

References

EP2961580B1
EP3897196B1
US12070912B1
WO2021170676A1
DE102024129183.4

Contact

Dr. Stefan Uhle
Patent & Innovation Manager Life Science
E-Mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Tel: +49 551 30724 154
Referenz: BioC-2138+2232+2543-SUG

Tags: Wood technology and forest, Wood and Agrotechnology

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