alginatenet.md

ALGINATE NET

Tactility & sound impression

Description

a cotton and alginate-based composite with open structure, molded onto a half dome shape

Physical form

Solids

Color without additives: color of the yarn used

Fabrication time

Preparation time: 1 hour (plus resting overnight)

Processing time: 5-7 days

Need attention: None, just leave it to dry in the mold with lots of airflow.

Final form achieved after: 7 days

Ingredients

• Alginate powder - 24 gr
  • the polymeer (so it becomes a solid)
• Glycerine - 40 gr
  • the plasticizer that bonds with the alginate (makes it flexible).
• Water - 800 ml/gr
  • to dissolve and mix the polymeer and plasticizer
• Yarn - cotton, 2 metres
  • to create the net
• Calcium chloride solution 10%
  • curing agent: spraying it onto the alginate plastic starts the curing process. Use 10 gr of calcium chloride in 100gr hot water (see below)

Tools

1. Scale
2. Spoon
3. Blender
4. Glass jar with lid
5. Spray bottle (150 ml contents, for the calcium chloride solution)
6. Circular loom OR: nails and a wooden board to design the net
7. Moulds for shaping the net, e.g. two identical bowls that fit inside one another
8. Acrylic sheet to catch the excess alginate mixture (can be scooped up and reused before curing)

Yield before processing/drying/curing

Approx. 300 ml (make sure to evaporate a lot of water during cooking time)

Method

1. Preparation

   • 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.

2. Mixing and dissolving the ingredients

   • bring the water to the boil
   • optional: add natural dye if you wish to use color
   • add the glycerine
   • add the gelatine
   • keep the temperature below 80 degrees celcius while stirring very very slowly and gently to avoid making bubbles. I prefer a simple spoon to do this, not a whisk.

3. 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.

4. 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.
   • 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.

Drying/curing/growth process

• Mold depth: 7 cm (filled up until 2.5cm high)
• Shrinkage thickness: 20-30 %
• Shrinkage width/length: 20-30 %

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.

Curing agents and release agents

None.

Minimum wait time before releasing from mold

Using a silicon mold: 7 days (or until it comes undone)

Post-processing

Store in a dry and ventilated room.

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.

Process

Making a net-like structure on a loom (does not have to be "proper" weaving), Loes Bogers, 2020

Preparing a 10% calcium chloride solution with hot water, Loes Bogers, 2020

The calcium chloride solution in a spray bottle, Loes Bogers, 2020

Pouring the alginate mixture onto net, Loes Bogers, 2020

You can pour a lot and scoop up the excess to use again later, Loes Bogers, 2020

Alginate evenly distributed along the yarn lines, Loes Bogers, 2020

Letting the alginate net cure and dry on top of a half-dome shape, 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.

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.

Needs further research? Not sure

References this recipe draws from

• Bioresin (gelatin) Recipe by Cecilia Raspanti (Textile Lab, Waag), Fabricademy Class "Biofabricating", 2019, link.
• The Bioplastics Cookbook: A Catalogue of Bioplastics Recipes by Margaret Dunne for Fabtextiles, 2018, link

Known concerns and contestations*

Needs further research

Gelatin is an animal-based ingredient. Some might find it problematic to use resources that requires killing an animal because of religious or animal welfare beliefs. Arguments are also made that as long as there's a meat industry, it is better to use product from the entire animal, including skin and bones. Some might consider gelatin to be a product that comes from a waste stream, but this is considered controversial by others.

Acrylic (for the mold) is a petrol based plastic but results in very shiny foils and sheets and can be reused endlessly for casting high quality bioplastic sheets.

Using renewable ingredients is not by definition petrol-free. Imagine they have to travel long distances by plane, boat or truck: it takes fuel. Also, the effects of GMO technologies and pesticides can be harmful to the environment and it's worth using knowing the source and production standards involved. If you can afford it, buying organic ingredients is a good starting point.

Sustainability tags

• Renewable ingredients: yes
• Vegan: no
• Made of by-products or waste: no
• Biocompostable final product: yes
• Reuse: yes, by melting and recasting

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.

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.

Technical and sensory properties

• Strength: strong
• Hardness: rigid
• Transparency: transparent
• Glossiness: matt
• Weight: heavy
• Structure: closed
• Texture: medium
• Temperature: medium
• Shape memory: high
• Odor: moderate in final product, high during production
• Stickiness: low
• Weather resistance: low
• 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
• Chemical resistance: needs further research
• Scratch resistance: moderate
• Surface friction: medium
• Color modifiers: none

About this entry

Maker(s) of this sample

• Name: Loes Bogers
• Affiliation: Fabricademy student at Waag Textile Lab Amsterdam
• Location: Rotterdam, the Netherlands
• Date: 06-03-2020 – 16-03-2020

Environmental conditions

• Outside temp: 5-11 degrees Celcius
• Room temp: 18 – 22 degrees Celcius
• PH tap water: 7-8

Recipe validation

Has recipe been validated? Yes

By Cecilia Raspanti, Textile Lab, Waag Amsterdam, 9 March 2020

Estimated cost (consumables) in local currency

2,56 Euros for a yield of approx 300 ml

Local supplier/sourcing info

Gelatin powder - Jacob Hooy (online retailers) Glycerine 1.23 - Orphi/Chempropack (online retailers) Molds - Houseware stores, thrift shops

Copyright information

This recipe is in the public domain (CC0)

Yes

This recipe was previously published by someone else

Yes, in: Bioresin (gelatin) Recipe by Cecilia Raspanti (Textile Lab, Waag), Fabricademy Class "Biofabricating", 2019, link.

##References

• The Secrets of Bioplastic by Clara Davis (Fabtex, IAAC, Fab Lab Barcelona), 2017, link.
• The Bioplastics Cookbook: A Catalogue of Bioplastics Recipes by Margaret Dunne for Fabtextiles, 2018, link
• Bioresin (gelatin) Recipe by Cecilia Raspanti (Textile Lab, Waag), Fabricademy Class "Biofabricating", 2019, link.

Images of final product

Bioresin slab, Loes Bogers, 2020

Bioresin slab, Loes Bogers, 2020

Bioresin slab and half dome, Loes Bogers, 2020