Smart Housing Småland

Smart Housing Småland bygger en internationellt ledande innovationsmiljö som, med användaren i centrum, skapar smart boende och hållbar byggd miljö med bas i glas och trä.

Sustainable geometries: wood fibre-reinforced biocomposites optimised for 3D printing

This pilot study has worked on enhancing understanding of 3D printer technology, biocomposites and fibre reinforcement, and which applications can be implemented when they work together.

BLB industries in Värnamo has a large-format proprietary 3D printer that may be the biggest in the world. Its objective was to devise a renewable composite material and a furniture design optimised for BLB’s unique 3D printer, and to examine what kinds of furniture design would be appropriate for printing.

Composite materials
Two biocomposites were formulated. However, such enormous problems were encountered during manufacture that it was not possible to resolve them within the scope of this pilot study.

Instead, two biocomposite pellets were ordered that had not been used for 3D printing previously. As the print head is unique, theoretically defining the specifications for the biocomposite presented a challenge. Two candidates with promising specifications were evaluated.

The composite score made up of two different polymers, PP (polypropylene) and HDPE (High Density Polyethylene), with a 50 per cent wood fibre fraction in both.

Initial print tests were executed with these composites. Examples of the challenges faced included:

  • achieving sufficiently low thermal expansion (a few per cent at most)
  • achieving a sufficiently short time in the nozzles of the 3D printer (relating to viscosity and other factors).

However, the print tests failed and resulted in smoke. That said, this did provide an indication of the upper limits for a number of design parameters

Furniture design for 3D printing
During the project, a chair was identified with a design that is well suited to 3D printing; Innovation C, produced by Blåstation, a TMF member company. This was printed using a different material, ABS (Acrylonitrile Butadiene Styrene).

This gave TMF and their members a better insight into what is possible and what should be taken into consideration when designing 3D printing.

The most important results
Discussion and knowledge transfer. Participants found out more about:

  1. the peculiarities, opportunities and limitations of 3D printing in relation to new fields of application, in this case wooden furniture manufacture. The process parameters appear to be crucial to the strength and surface structure of the printout.
  2. Biocomposites made from renewable resources.
  3. The interests, desires and requirements of potential customers for BLB’s 3D printers.

Material properties affect (to an extent) which geometries can be printed. The process in the printer makes demands of the properties of the biocomposite. The design and use of the final product makes demands of the properties that the material must have. The designer needs to know the opportunities and limitations of the print process and the material.

Production and initial print tests of two biocomposites, one in a polyethylene matrix (HDPE) and the other with a polypropylene matrix (PP), were a first step towards optimisation of a biocomposite for BLB’s 3D printers. The process of determining a composition, as well as the results of the print tests, provided information on what would be interesting to pursue.

Printing the Innovation C chair indicated which designs are appropriate. It also indicated the role of the designer in finding applications where 3D printing adds something that would otherwise not have been possible, or where 3D printing is an effective production method in terms of cost and/or time.

Partnership: RISE, TMF Trä- och Möbelföretagen (Swedish Federation of Wood and Furniture Industry), BLB Industries and Sveaskog.

Contact: Parisa Sehati, RISE Glass, parisa.sehati@ri.se, +46 (0) 10 516 63 58