Thermoplastics are fabrics that can be manipulated and shaped using heat and pleating, crushing or moulding techniques. When heated, the polyester organza will soften and take the shape of the mould or object and will retain this shape when it cools. The organza can be reshaped when heated once more to an even higher temperature.
100% polyester organza (no nylon!)
Objects to mould the organza with e.g. marbles, stones, glass beads etc
Aluminium foil to pleat the organza and wrap the sample
Large pot of water and stove
Heat set thermoplastics are sometimes used in decorative cushions or lamp shades due to their semi-transparent nature.
Here are some interesting samples which we saw in class:
Mould, fold or manipulate the polyester organza using objects (e.g. marbles, stones) and secure with elastic bands. Alternatively, pleat and fold the polyester organza between sheets of plastic, paper or aluminium foil. Fold the organza into multiple layers to get a repeated pattern over a larger area of fabric. The sample below is folded into 4 layers.
Wrap up the object in aluminium foil before boiling and steaming in hot water.
Unwrap the foil and let the organza cool down in the desired shape. Do not hang the fabric or remove the rubber bands or marbles when still warm, as this will loosen its shape.
Remove the rubber bands and mould objects when dry.
For my final project, I imitated the shape of the pine cone petal using thermoplastics. I wrapped organza around different sizes of disposable spoons to simulate the different petal sizes.
This technique of manipulating thermoplastics with heat is very interesting and enjoyable! It allows us to create organic shapes and mould a soft fabric into a rigid semi-translucent form. There are endless possibilities!
PVC plastic sheet
Objects to form around
Cut out an appropriate size of PVC sheet. The vacuum forming machine has 2 default sizes. Use objects with a concave shape so that they can be removed after forming such as domes (Spheres can’t be removed!). Vacuum forming can be used to create moulds for other materials such as latex and resin.
This week, we learnt to print with thermochromic inks!
Developed in the 1970s, thermochromic inks have numerous applications and can be found in everyday items, art and design:
Silkscreen and squeegee
Light-coloured fabric to print on (A different type of ink is needed to print on dark fabrics)
Thermochromic pigment (powder form)
Acrylic medium and paint (optional)
Heat source e.g. hair dryer or iron
Mix the thermochromic pigment with the medium. Caution: wear masks while doing this as inhaling the fine powder can be harmful!
Mix well to achieve a paint-like consistency.
The printing process is similar to the basic silkscreen printing process. Put some ink along the top of the silk screen.
Drag the squeegee downwards, applying pressure evenly. Move the squeegee up and down several times to ensure even coverage.
When I initially printed them, the inks were very bright and saturated. Strangely, when I brought my prints home later that day, I discovered that the colours (especially the blue) had faded substantially to a light pastel blue. I suspect this may be due to the type of fabric I used.
I printed another sample with yellow thermochromic pigment mixed with green acrylic paint. When heat is applied, the yellow disappears, leaving a cooler and darker shade of green.
‘The Original Wearable-Tech’
I like how fabrics with thermochromic ink are highly interactive. We can consider them to be the predecessor of wearable technology which is becoming increasingly popular. Instead of including electrical components such as LEDs and temperature sensors which add to the bulk of the clothing, fabric printed with thermochromic inks are lightweight and create a more seamless interaction. They are playful and can create surprising effects, reacting to human touch as well as the environment.
Ever make a hot cuppa tea to accompany a night of work, get too engrossed with the task at hand, only to later come back to lukewarm soggy tea?
Tealight is an interactive device prototype made using an Arduino, temperature sensor and adafruit LED strip as feedback. It measures the cup’s external temperature and gives real time visual feedback of how hot the drink is. The speed of the lights also mimics the behaviour of molecules at different levels of heat (i.e. high heat = high molecular speed).
When the tea is at its hottest, the LED lights will shine at maximum brightness and redness, and circulate around the cup at a high speed. As the drink cools down, the lights will slow down and shine less intensely. Past a specified temperature (whatever the user considers too cold for satisfactory consumption), the lights will change from dim red to dim blue, alerting the viewer that more hot water should be added to heat up the tea. The blue light intensifies and moves even slower as the drink gets colder.