A (naturally) amber-coloured hard bioresin, gelatin-based.
A tough but light, textured bioplastic. Remains some flexibility when cast as a sheet. Gelatine-based with dried and ground eggshells as filler to avoid shrinkage.
### Physical form
Solids
Solids, Surfaces
Color without additives: transparent, yellow/orange/amber colored.
Color without additives: light brown/liver color with speckles.
### Fabrication time
Preparation time: 1 Hour
Preparation time: 1 Hours (if you prepared the egg shell powder already)
Processing time: 5-10 days
Need attention: None, just leave it to dry as long as is feasible with lots of airflow.
Need attention: Every 8-16 hours to alternate between drying and presing.
Final form achieved after: 10 days
## Ingredients
***Gelatine powder - 96 gr**
***Gelatine powder - 24 gr**
* Functions as the polymeer (so it becomes a solid)
***Glycerine - 16 gr**
***Glycerine - 18 gr**
* Functions as plasticizer that bonds with the gelatine (makes it flexible).
***Water - 480 ml/gr**
***Water - 200 ml/gr**
* To dissolve and mix the polymeer and plasticizer
***Dried and ground egg shells - 55 g**
* Used as a filler that reduces shrinkage, and simultaneously adds texture and strength. Recipe for drying and grinding egg shells is [here](../files/recipes/eggshellpowder.md).
## Tools
1.**Cooker or stove** (optional: temperature controlled)
1.**Pot**
1.**Scale**
1.**Moulds** (ideally with removeable base to increase airflow). I have modular silicon walls with metal wire inside them that allow me to cast and then turn the moulds on their side for more airflow and drying from top and bottom. I use a silicon or acrylic sheet with these mould walls.
1.**Moulds** (acrylic or glass surface to cast sheets on, silicon molds for solids. Molds with removable base are very useful).
1.**Spoon**
## Yield before processing/drying/curing
Approx. 300 ml (make sure to evaporate a lot of water during cooking time)
Approx. 200 ml
## Method
1.**Preparation**
- Prepare the egg shell powder if you don't have it already (see recipe [here](../files/recipes/eggshellpowder.md)
- Weigh your ingredients
- Prepare the mold and find a place where you can leave it for a while, ideally near an open window where there's air flow.
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@@ -62,28 +67,26 @@ Approx. 300 ml (make sure to evaporate a lot of water during cooking time)
1.**Cooking the ingredients**
- Simmer and slowly stir the mixture between 60-80 degrees celcius for at least 20 minutes or up to an hour. Turn it lower when bubbles appear: you don't want the liquid to move, don't boil it. This sample has some bubbles due to vigorous mixing.
- Longer cooking time allows more water to evaporate. You will get a thicker liquid. To cast larger volumes and solids with this recipe, evaporate a lot of water, until it's very thick.
- Simmer and slowly stir the mixture between 60-80 degrees celcius for at least 20 minutes. Turn it lower when bubbles appear: you don't want the liquid to move, don't boil it. This sample has some bubbles due to vigorous mixing.
- Longer cooking time allows more water to evaporate. You will get a thicker liquid to cast with, and less shrinkage of the cast object. To cast larger volumes and solids with this recipe, evaporate a lot of water, until it's very thick.
1.**Casting**
- Let the liquid cool for a couple minutes until it gels a little but is still liquid and pourable.
- Cast into the mould slowly to avoid bubbles
- Pour from the middle and hold still, let the liquid distribute itself.
- Stir in the egg shell powder, slowly stir until the liquid gels a little. If it's very liquid the powder will sink to the bottom of the mold.
- Cast into the mould(s) slowly to avoid bubbles. Pour from the middle and hold still, let the liquid distribute itself.
- Put the mould away to dry in a cool place with lots of air flow (like near an open window). A warmer place might speed up the drying process but also allow bacteria to grow faster and can result in fungal growth.
- If the mould has a removable base, remove it after 4-8 hours and put the mould on its side to allow air flow from both sides.
- When using a flexible mould: let it dry without releasing to keep the form as much as possible. The resin will likely shrink and release itself from the mold. If it feels cold to the touch it is still drying. If you are using a rigid mold: release after 4-8 hours and dry flat.
- The compound will shrink a little. Press it under a stack of heavy books for a few hours and then dry for a few hours again, alterating the two. If you can dry the cast objects on a roster while pressed that is ideal.
### Drying/curing/growth process
- Mold depth: 7 cm (filled up until 2.5cm high)
- Shrinkage thickness: 20-30 %
- Shrinkage width/length: 20-30 %
- Mold depth: 3 cm (filled up until 2.5cm high), or cast on a sheet (3-5mm)
- Shrinkage thickness: 10-15 %
- Shrinkage width/length: 10-15 %
**Shrinkage and deformation control**
Letting it dry up to ten days to get to the final form. It will be flexible at first but will slowly harden until its totally rigid.
Letting it dry up to ten days to get to the final form. Flat sheets will remain somewhat flexible.
**Curing agents and release agents**
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@@ -91,7 +94,7 @@ None.
**Minimum wait time before releasing from mold**
Using a silicon mold: 7 days (or until it comes undone)
4 to 8 hours
**Post-processing**
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**Further research needed on drying/curing/growth?**
Casting larger volumes without growing fungus/mold, and limited warping can be challenging. Fillers like debris or egg shells can help. More research can be done on ideal conditions for drying larger volumes.
The resin does not cure evenly across the surface, some might be negotiated by shaving off some slides while it is still relatively soft and flexible.
It's worth trying to evaporate as much water as possible to reduce shrinkage even more. Adding the powder will thicken the liquid too so try to find the sweet spot where you can still pour it.
### Process
*Evaporating water until the liquid is thick like honey, Loes Bogers, 2020*
*Preparing molds for small half domes (egg cups), and a big slab (silicon mould and separate base), Loes Bogers, 2020*
*Casting the resin (I had to put a weight on top to press the mold into the base and prevent leakage, Loes Bogers, 2020*
*just casted (silicon mold is the green one, the glass mold didn't release well), Loes Bogers, 2020*
*Putting the mold on its side next to open window to allow further drying from top and bottom, Loes Bogers, 2020*
*just casted on an acrylic sheet, Loes Bogers, 2020*
## Variations on this recipe
- Add a **natural colorant** such as a vegetable dye or water-based ink (e.g. hibiscus, beetroot, madder)
- Add **less glycerine** for a more rigid foil
-**Stiffeners** such as fibres, yarn or natural debris may be added for more structure and reinforcement.
-**Fillers** such as almond or sunflower oil, can be added to prevent additional shrinkage but might affect stickyness.
- Add **more glycerine** for a more flexible material
### Cultural origins of this recipe
Bioplastic production is older than petrol based plastics. In 1500 BC, people in Egypt were already using glues based on gelatin, casein and albumin for furniture constructions. Gelatin casting as a technique has also been used in production of jelly-based foods such as aspic, jelly desserts and candy.
Text
**Needs further research?** Not sure
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- Renewable ingredients: yes
- Vegan: no
- Made of by-products or waste: no
- Made of by-products or waste: partially (only the egg shell filler)
- Biocompostable final product: yes
- Reuse: yes, by melting and recasting
- Reuse: needs further research
Needs further research?: not sure
Needs further research?: can this be remelted and reused?
Gelatine-based bioplastics can be recasted by melting them in a pot with some water. Recycling them with PET plastics contaminates the waste stream. Compost bioplastics in a warm environment with sufficient airflow.
Recycling gelatine-based bioplastics them with PET plastics contaminates the waste stream. Compost bioplastics in a warm environment with sufficient airflow.
