Preparation of natural dye: This should be made before you start the bioplastic making and can be stored up to 72 hours before you would like to cook the recipe.
Create the natural dye recipe of your choice. This recipe uses sage as the core ingredient. See the recipe here.
Preparation of mixture: This can be done up to 24 hours before you would like to cook the recipe.
Pick the jar or container you would like to prepare the mixture in. It is best if it has a lid. Mix the 15g ‘carrageenan iota’ powder with 100 ml of water. Then add 500ml of natural dye.
Stir the powder and liquid mixture to break up any big lumps (en castellano: grumos). You can also try to shake the jar or container, holding the lid on tightly.
Important: The prep stage is important as the mixture will clump and be very hard to stir if this is done directly into the pan.
Tip: to create a thinner biomaterial, add more water/dye; to create a thinner material, add more liquid.
After 12-24 hours the powder and dye mixture should be suffiently connected. The texture will be gloopy and thick. Pour the mixture into the saucepan and turn the stove on to a low heat and begin to stir. This recipe requires lots of stirring at a medium to fast pace so do not stop stirring until all the lumps have been removed, which could be 5-10 minutes depending on your stove and consistency of stirring.
Tip: Use 50ml extra water to clean out the jar so as not to waste any of the mixture.
Note: You should trust that the mixture will become more viscous and consistent as it heats and you stir.
After around 5 minutes or when the mixture has become smoother and more liquid, you can begin to add the glycerol into the mixture. Turn up the heat from low to medium.
Note: Aim to break up all the lumps and to try and avoid bubbles, you can stir a little slower. Whisking might seem like a good idea, but it will increase the bubbles.
Prepare your mould so taht it is clean and dry. Place your mould on a level and flat surface that is close to the stove as possible. This is because the mixture surprisingly will set very fast (unlike agar, whcih is also derived from red seaweed or Rhodophyta ), so you need to pour it fast. It is best to leave the mixture to set before moving.
Tip: If needed, you can also use a sieve to pour the mixture through to make sure lumps dont go into your mould.
As with most seaweed based bioplastics, the drying period depends on the size and shape of the mould. This will mean the final product drying time varies and you can explore this in your own research by making variations of the recipe and using various kinds of moulds. Once the biomaterial is fully dry it can be removed from the mould carefully using blunt knife. Do not use a sharp utensil as this can accidentally cut into the mould.
Note 1: Drying time also depends on room temperature and humidity and it can take up to several days until a sample is dry
Note 2: This recipe creates a very pliable biomaterial. It can create a sheet which you can fold, lasercut, sew, reheat and even reform when wet again.
Tip: By useing an oven or food dehydrator on a low heat (30-40C) this can speed up the drying process, other wise airdrying in a dry prart of your home or workshop will also work well.