@@ -18,11 +18,11 @@ Color without additives: yellow
Preparation time: 1 Hour
Processing time: 5-10 days
Processing time: 1-7 days
Need attention: None, just leave it to dry while pressed (e.g. on a roster) as long as is feasible with lots of airflow.
Final form achieved after: 10 days
Final form achieved after:7 days
## Ingredients
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@@ -35,19 +35,23 @@ Final form achieved after: 10 days
***Water - 50 ml/gr and a dash extra**
* To dissolve and mix the polymeer and plasticizer
* To dissolve and mix the corn starch before adding to the other liquid
***White vinegar - 15 ml**
* Vinegar is almost always added to starch-based biopolymers to change the molecular structure of the starch, making it stronger and more workable.
## 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.**Sheet of textured plastic for casting**
1.**Spoon**
2.**Strip of acrylic** (or spatula for even spreading)
3.**A press or a stack of heavy books** (to keep the slab pressed while drying)
## Yield before processing/drying/curing
Approx. 300 ml (make sure to evaporate a lot of water during cooking time)
Approx. 200 ml
## Method
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@@ -65,28 +69,27 @@ 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.
- dissolve the starch in a separate bowl using a few tablespoons of hot water
- when the gelatine is completely dissolved, add the starch mixture and stir for another 5-10 mins at 80 degrees
- finish with a thick but still somewhat liquid paste
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.
- The mix is a thick paste that needs to be cast (quickly!) by smearing across a the surface of the mold with a spatula.
- It cures quickly at this stage, so be fast
- 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 slab will shrink relatively quickly, then take it off the mold and let it air dry
- Alternate drying with some periods of keeping it pressed. If you have a roster you can dry and press at the same time.
### 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: N/A
- Shrinkage thickness: 5-10 %
- Shrinkage width/length: 5-10 %
**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 for a week or so to get to the final form. It will be flexible at first but will slowly harden until its totally rigid. The slab needs some attention during drying as the edges that are thinner will curl up. Trim the piece before it's completely hard. Occassionally press down the slab under a stack of books for a few hours to keep it flat.
**Curing agents and release agents**
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@@ -94,40 +97,48 @@ None.
**Minimum wait time before releasing from mold**
Using a silicon mold: 7 days (or until it comes undone)
Ready to be released after 1-2 hours.
**Post-processing**
Store in a dry and ventilated room.
Store in a dry and ventilated room. Keep pressed until fully dry.
**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.
Not sure.
### Process
*Evaporating water until the liquid is thick like honey, Loes Bogers, 2020*
*Trimming the - still flexible - slab for further curing, Loes Bogers, 2020*
*Drying the slab on a roster (pressed down with books occasionally), 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
- Add **less glycerine** for a more rigid slab (or try adding more for more flexibility)
- Reduce amount of gelatine or leave it out altogether
-**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.
### Cultural origins of this recipe
Bioplastic production is older than petrolbased 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.
Biopolymer 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.
**Needs further research?** Not sure
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@@ -152,43 +163,42 @@ Using renewable ingredients is not by definition petrol-free. Imagine they have
- Vegan: no
- Made of by-products or waste: no
- Biocompostable final product: yes
- Reuse: yes, by melting and recasting
- Reuse: further research needed
Needs further research?: not sure
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 biopolymers with PET plastics contaminates the waste stream. Compost bioplastics in a warm environment with sufficient airflow.
## Material properties
### Comparative qualities
This resin is dense and rather heavy, but not rock hard like synthetic epoxy or cold like glass. It keeps certain level of bounciness to it.
This slab feels a bit like a rubber car tyre. It's tough but resilient. It has a storng sour smell from the vinegar (this slowly fades).
### Technical and sensory properties
-**Strength**: strong
-**Hardness**: rigid
-**Transparency**: transparent
-**Glossiness**: matt
-**Weight**: heavy
-**Hardness**: resilient
-**Transparency**: translucent
-**Glossiness**: satin
-**Weight**: medium
-**Structure**: closed
-**Texture**: medium
-**Temperature**: medium
-**Texture**: smooth
-**Temperature**: cool
-**Shape memory**: high
-**Odor**: moderate in final product, high during production
-**Stickiness**: low
-**Weather resistance:**low
-**Odor**: strong
-**Stickiness**: medium
-**Weather resistance:**needs further research
-**Acoustic properties:** needs further research
-**Anti-bacterial:** needs further research
-**Non-allergenic:** needs further research
-**Electrical properties:** needs further research
-**Heat resistance:** low
-**Water resistance:**water resistant
-**Water resistance:**needs further research
-**Chemical resistance:** needs further research
-**Scratch resistance:** moderate
-**Surface friction:** medium
-**Color modifiers:** none
## About this entry
### Maker(s) of this sample
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- Name: Loes Bogers
- Affiliation: Fabricademy student at Waag Textile Lab Amsterdam
- Location: Rotterdam, the Netherlands
- Date: 06-03-2020 – 16-03-2020
- Date: 16-03-2020 – 22-03-2020
### Environmental conditions
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@@ -208,7 +218,7 @@ This resin is dense and rather heavy, but not rock hard like synthetic epoxy or
Has recipe been validated? Yes
By Cecilia Raspanti, Textile Lab, Waag Amsterdam, 9 March 2020
By Cecilia Raspanti, Textile Lab, Waag Amsterdam, 16 March 2020
### Estimated cost (consumables) in local currency
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@@ -237,6 +247,9 @@ Yes, in: ADDD HERE
-**The Secrets of Bioplastic** by Clara Davis (Fabtex, IAAC, Fab Lab Barcelona), 2017, [link](https://issuu.com/nat_arc/docs/the_secrets_of_bioplastic_).
-**The Bioplastics Cookbook: A Catalogue of Bioplastics Recipes** by Margaret Dunne for Fabtextiles, 2018, [link](https://issuu.com/nat_arc/docs/bioplastic_cook_book_3)
- Material archive sample Maria Viftrup
- "Make it and Break it: Bioplastics from Plant Starch with
incorporation of Engineering Practices", by Richard Harris, Carla Ahrenstorff
Gracye Theryo, Aaron Johnson, Jane Wissinger. Center for Sustainable Polymers at the University of Minnesota, 2017: https://csp.umn.edu/wp-content/uploads/2017/03/Make-it-and-Break-it.pdf
