by Green Plastics
Dina, a product design student, wants to use bioplastics for a school project that involves making two products a fruit bowl and a wastebasket. She asks:
How heat resistant is the bioplastic? If I use the gelatin recipe or the algae one, can I make the product dishwasher safe?
First of all, thank you very much for your question! I think home-made bioplastics are exactly the right kind of material for projects like this. However, I also think that you might have more success using bioplastics for a wastebasket than a fruit bowl. I will explain why.
Bioplastics cast from water solutions are not water resistant and if the water is hot, they are even more vulnerable. Heat resistance is limited. Products made with this method would not be dishwasher safe, both because of the temperature but also because of the water.
Water-proofing coatings have been used to improve water resistance. Shellac, for instance, has been used. But the coating would have to be tested for good bonding to the particular material.
Although a bowl made from home-made bioplastic would probably not be safe to put in a dishwasher, it might survive careful hand-washing in warm water, especially if it has a coating. You would have to test it out, depending on what you used for the base plastic and what kind of coating (e.g. shellac) you used.
Good luck, and happy experimenting!