IntheloopLesson three: Making casein

Learning objectives• To learn about casein• To learn how casein can

contribute to the circular economy

• To manufacture casein

Starter activity: Thinking about the biological cycle

Introducing casein

Casein is a polymer. A polymer is a material made on many parts and all plastic we use are in fact polymers.

There are biosphere polymers such as casein and technological cycle polymers such as acrylic & ABS.

You are going to make your own casein, use it as a mould for pewter and then return its nutrients to nature. We will simply be borrowing them, not destroying them or using them up.

We are closing the loop.

What is Casein?

Casein is curdled cow’s milk. We need to separate the curds and whey, then manufacture casein from the curds.

Casein was often used for the manufacture of buttons, often mixed with formaldehyde to prevent it from rotting (or from attempting to return it’s nutrients to nature).

Casein is still used as a coating in the paper and textiles industries.

Interestingly, casein can also be manufactured as an effective wood glue. Early aircraft were often held together with this.

Pewter and the circular economy

Why is pewter a suitable product for the circular economy?

Pewter is an alloy consisting mainly of tin, sometimes up to 99 percent, with copper and lead added to increase the hardness.

If a product using pewter is designed correctly, all the pewter can be recovered at the end of the products life to be used again.

We call this made to be made again.

Making casein: Ingredients

You are about to make casein, You will need:

Microwave or oven to heat the milkSaucepan or microwave dish to contain the milkSemi-skimmed milk to get the casein fromVinegar to curdle the milkSieve to help separate the whey & caseinRolling pin to create a perfectly flat template

Making casein: Method

Step 1: Gently heat 1 litre of milk. Do not let it boil it should be warm.

Step 2: When it is warm take it off the heat and slowly add the vinegar.

Step 3: Stir gently until the milk curdles, adding additional vinegar as required.

Step 4: Pour the mixture into a sieve to separate the curds and whey.

Step 5: Heat the casein directly without water for around 20 seconds.

At this point you should have a very pliable material. (See next step.)

Making casein: Preparing a casein sheet

1. The casein should be very pliable and able to form into

most shapes.

2. Using a rolling pin create a circular

sheet, around 3mm thick.

3. Ensure that the sheet is flat with an

even thickness throughout

4. Cut the sheet into the required size

shape, ready for the next stage.

5. Waste pieces can be used to form more sheets quite easily.

6. Compress all waste together to begin the process

again.

Creating the mould

The next slides include two different manufacture routes:

1.Predominantly CAD using a laser cutting route

2.Predominantly craft knife/scalpel route

At this point you should decide which route should be taken.

Creating the mould: Laser cutting

1. Place sheet into laser cutter. (Frozen casein is easier to

use.)

2. Laser cut the desired shape into

the casein.

3. Separate the two parts of the mould, reusing the waste.

4. Place the mould template into the mould housing.

5. Pour pewter into the mould cavity to create the desired

shape.

6. Compress all waste together to begin the process

again.

Creating the mould: Using knives

1. Place sheet onto a cutting mat or

something to protect the surface.

2. Draw your desired shape onto the

surface of the casein template.

3. Separate the two parts of the mould, reusing the waste.

4. Place the mould template into the mould housing.

5. Pour pewter into the mould cavity to create the desired

shape.

6. Compress all waste together to begin the process

again.

Making casein: Homework

Homework

Produce an information sheet on Casein

Try and include information and images about:•Casein’s history•Casein’s manufacture•Casein’s uses•Products made from casein•Products made from whey (the bi-product of casein manufacture