What is it?
A mixture of plant-based polymers and at least 40% spent grain, a very abundant waste product from the beer brewing industry. The material is home-compostable, while most other biodegradable plastics can be composted only in industrial composting facilities. The company is currently in the process of obtaining home compostability certification.
Tensile strength (MPa): 16,1 (ISO 527 standard)
Tensile modulus (MPa): 1136 (ISO 527 standard)
Impact strength (kJ/m2): 9,2 (ISO 179 standard)
MFI (g/10 min): 4,7 (ISO 1133 standard)
The fibres from the spent grain reinforce the material and thereby improve the strength and stiffness of the moulded product. The mechanical properties of the material are close to those of polypropylene. The flow rate when moulding is good for a reinforced material, and the material has been used for mouldings with a wall thickness of just 0.8 mm.
Look and feel
The material has a natural look and the grain within the material is very visible on the surface. The grain within the material also gives it a slight odour of malt. The colour is a natural dark brown, which can be pigmented to other dark shades. The moulded sample is soft and smooth to the touch with a degree of flexibility.
Granulous materials are bio-based, which leads to a reduction in the CO2 emission of up to 80 percent compared with fossil-based plastics with similar mechanical properties. The material breaks down without releasing any microplastics or toxic substances when exposed to moisture and living organisms within the soil. The spent grain is currently collected from breweries in Finland.
This general-purpose grade is designed for injection moulding with visual fibres that give products a natural look and warm haptics. It is best suited for non-technical short life products. Because of its natural look and verifiable low environmental impact, it is well suited for consumer products such as toothbrushes, pens, razor handles, phone cases, and durable packaging.
The material will slowly break down if exposed to the outdoor environment and it is therefore best suited for indoor applications unless used outdoors for applications in which biodegradability is desirable.
Why we chose this material
We like that this material is bio-based, has a low environmental impact, and consists of 40% spent grain that would otherwise have been incinerated. It is also rare to find a plastic material that can be home composted or broken down reasonably fast if left in nature.
Why you should consider this material
You want a bio-based material.
You want an injection-mouldable material with a distinctly bio-based look.
You need a biodegradable material that can be home composted or will break down in nature.
About the manufacturer
Granulous Biocomposites is a material developer based in Finland. The company has developed the proprietary plant-based polymer matrix material used to create this bio-composite with spent grain.
The company is partnering with manufacturers, moulders, and product designers for sample testing in 2022 with full production set for 2023.