Biomaterials for making: plaster, wood chips

After collecting three different levels of wood shavings, wood chips, and small wood shavings, I followed the following steps to make the bioplastic:

1. Proportioning: Firstly, I mixed the proportion of wood chips and gypsum according to the desired physical properties, such as hardness and flexibility. In general, the higher the proportion of wood chips, the harder the bioplastic made, but it may also reduce its flexibility.

2. Mix the materials: Mix the wood chips, flakes, and small wood shavings evenly with the gypsum to ensure that the wood particles are evenly distributed in the gypsum so that a homogeneous structure is formed during the curing process.

3. Adjustment by adding water: Gradually add an appropriate amount of water to the mixture and mix by hand or with a mixing tool until a slurry is formed. The amount of water added critically affects the consistency and structural strength of the final product.

4. Moulding: Pour the mixed mixture into the pre-prepared mould. Before pouring into the mould, a small amount of vegetable oil can be applied to the inside of the mould to facilitate mould release.

5. Drying and curing: Dry naturally in a well ventilated environment or use a dryer for accelerated drying. The drying time depends on the thickness of the mixture and the ambient humidity.

6. Post-processing: After curing, the bioplastics are removed from the mould, sanded and trimmed to achieve the desired appearance and dimensional accuracy.

During the fabrication process, although the wood shavings increased the stability and sturdiness of the bioplastic, making it closer to the wooden theme and suitable for functional furniture making, some shortcomings were revealed:

1. Uniformity problem: The mixture of wood chips and gypsum may suffer from delamination during the drying process, which affects the structural uniformity of the final product. This may be due to the different specific gravity of wood chips and gypsum or inadequate mixing.

2. Drying Cracks: If too much moisture is added or if the drying process is too fast, the bioplastic is prone to cracks during drying, which can reduce the aesthetics and practicality of the product.

3. Environmental adaptability: Wood chip-reinforced bioplastics may be sensitive to environmental humidity, and overly wet or dry environments may affect their performance and longevity.

4. Sustainability considerations: Although biomaterials such as wood chips are used, the sustainability and environmental impact of gypsum should also be considered. The use of more environmentally friendly adhesives or other bio-based materials could be explored as an alternative to gypsum in the future.

Through this fabrication experiment, I have realised that in the development of bioplastics it is important to consider not only the physical properties of the material, but also the environmental factors and sustainability issues. Future research will continue to optimise material formulations and explore new environmentally friendly materials.