AGAR COMPOSITE
##GENERAL INFORMATION
A light composite of textile and agar foil. The composite feels less flexible and less rubbery than the agar foil. It makes a crackling sound like paper.
Physical form
Solids
Color without additives: color of the textile used
Fabrication time
Preparation time: 1 Hour
Processing time: 7 days
Need attention: N/A, let dry in place with lots of airflow
Final form achieved after: 10 days
Estimated cost (consumables)
0,50 Euros, for a yield of approx. 200 ml (enough to make a small composite and a sheet, or larger or multiple composites)
##RECIPE
###Ingredients
- Agar - 5 g polymer (makes it hard)
- Glycerine - 15 g plasticizer (makes it flexible)
- Water - 250 ml/g solvent, to dissolve and heat the agar
- A piece of textile large enough to fit over the mold
- A mold for example a bowl, or other 2.5D or 3D surface
###Tools
- Spoon
- Scale
- Bowls to weigh ingredients
- Cooker (ideally temperature controlled)
- Thermometer (optional) if you don't have a temperature controlled cooker
- Small molds - 2x such as two glass bowls of about 8 cm diameter (or equivalent) that slide into one another.
###Yield
Before processing/drying/curing: approx. 200 ml this is enough to make a small 15x15cm composite and the agar foil found in this recipe
###Method
-
Preparation
- Weigh your ingredients
- Prepare the casting surface and find a place where you can leave it for a while, ideally near an open window where there's air flow.
-
Mixing and dissolving the ingredients
- bring the water to the boil
- optional: substitute part of the water with natural dye if you wish to use color
- add the glycerine
- add the agar
- bring the mixture to the boil while stirring gently, to dissolve the agar.
-
Cooking the ingredients
- when the agar is dissolved completely, lower the temperature to 60-80 degrees (make sure it doesn't bubble), and let it simmer and evaporate water for 40 mins while stirring slowly and continuously.
- the agar should have the consistency of a light syrup, you should be able to leave a "trace" with you trace your spoon across the pot.
- If your mixture is thicker it will spread slowly resulting in a thicker foil, if it's more liquid, it will spread wider, resulting in a thinner foil.
-
Casting and molding
- Dip the textile(s) into the hot liquid
- Take it out and position on the mold, press it down with the second bowl.
- After an hour, take off the second bowl and let the composite airdry on top of the mold
###Drying/curing/growth process
Allow the foil to dry for a week for best results (or 3 days minimum).
- Mold diameter: 8 cm
- Shrinkage thickness 0-10 %
- Shrinkage width/length 0-10 %
Shrinkage and deformation control
When used in a composite with textile fibres, the foil shrinks a lot less. The fibers prevent the shrinking.
Curing agents and release agents
None
Minimum wait time before releasing from mold
3 days
Post-processing
N/A
Further research needed on drying/curing/growth?
Not sure
###Process pictures
Waiting for the agar to dissolve, consistency of syrup, Loes Bogers, 2020
it's done when you can leave a trace with the spoon, consistency of syrup, Loes Bogers, 2020
You can really soak up the cotton by dipping it into the pan, Loes Bogers, 2020
The composite inside the "two-piece" mold of the two glass bowls, Loes Bogers, 2020
###Variations
- Substitute part of the water with a dye
- Try or design different molds to create big spatial structures and objects
- Use different fibres as enforcement. Other natural fibres may be continuous/discontinuous (long fibres like yarns, strings or hair. Or they can be short fibres that are chopped like wood chips, egg shells, leather leftovers), particles or even braided and woven fibres like the cotton used here. Collagen, cellulose, silks, and chitin are the types found in nature.
- Use a different matrix: biomaterials like beeswax or animal glue for example are thermoformable matrices (the ones you can form with the help of heat). And setting matrixes like bio epoxies, white glue (made of flour), alginate, gelatin and starch-based plastics, mycelium and kombucha.
- Textiles can be used as scaffold in many other ways too: by growing mineral crystals on it, in concrete form work, leather moulding (cuir bouilli), and in combination with lasercut wood patterns.
##ORIGINS AND REFERENCES
Cultural origins of this recipe
See also the recipe for agar foil.
On composites: a composite can be any combination of two or more dissimilar materials which together make for a material with different properties, but without merging into one new compound (they continue to be discernable). Very familiar examples is paper mache (paper and glue modelled for example around a balloon). It is one of the earliest human technologies. Early on composites were created by adding straw to mud bricks for building, or the Egyptian practice of soaking cloth tape in resin used for mummification of the dead. The technical temrs for the materials used in a composite are constituent materials with three type: the matrix, preform and the enforcement. The matrix is a pattern that distributes the load (e.g. bioresin), the preform are yarns, net wovens, whereas other reinforcement (such as fibres) contribute to the mechanical properties of the materials.
All composites (even simple ones) are engineered materials. One of the great benefits is that it can result in large but strong and lightweight spatial objects (e.g. carbon fibre enforced plastic) with relatively few resources. It also gives more options to create varying degrees of stiffness and strength. The use of textile composites in the construction industry is less common than traditional building materials, but its popularity is growing.
On open-source bioplastics: open-source documenting of how to make bioplastics with simple tools and locally available materials can be attributed to Miriam Ribul and her publication on Material Activism from 2014. Promoting collaborative production of alternatives for petroleum-based plastic, she demonstrated 20(!) known processes for material production using only 4 simple recipes. Juliette Pépin's visual research book on bioplastics (also from 2014), goes in depth into the sensory and visual aspects of simple recipes with many variations. Although bioplastics production is certainly a craft that is dispersed across many locations and times, leaving traces of many similar recipes behind, this type of cataloguing and sharing work is certainly indebted to these two pioneers.
Needs further research? Not sure
###Key sources