Technique 7: Thermochromic ink printing and vacuum forming

THERMOCHROMIC INK PRINTING:

Thermochromic ink (also called thermochromic ink) is a type of dye that changes colour when temperatures increase or decrease. Often used in the manufacture of many toys or product packaging, as well as thermometers.

Materials used:

  • Fabric- with a lighter background
  • Silkscreen
  • Thermochromic Pigment
  • Cups for mixing
  • Spoons for mixing
  • Plastic bags to lay the table before silkscreen printing
  • Silkscreen Printing Clear Base
  • Squeegee

Steps:

1) Mix the thermochromic pigment powder with clear base in the ratio of 1:3 in a paper cup. Be careful not to inhale the powder during the process. (Avoid talking/ laughing)

2) Lay the table with plastic sheets to avoid any transfer of the mixture onto the table.

3) Lay 1-2 layers of tissue onto the plastic sheets before placing your fabric on top.

4) Put down the silkscreen on top of the fabric.

5) Scoop the mixture with the spoon and spread the desired amount along the edge on the silkscreen (blue area).

6) Make sure the silkscreen prepared is secured and ideally have someone to hold the silkscreen frame for you.

7)  Hold the squeegee along the edge with the mixture and tilt it to 30 degrees.

8)  Swipe it evenly to the other end of the silkscreen forward and backwards to make sure that the colour spread throughout the silkscreen.

9) Hold the fabric down and lift the silkscreen slowly.

10) Remove your fabric and let the ink dry.

11) Put the silkscreen and the squeegee propped up on a cup for the next person to use.

My outcomes:

Trial #1:

I tried the grey colour first.

Trial #2:

Followed by the red.

Trial #3:

And eventually, trying out a gradient colour scheme of yellow and red.

Trial #4:

For the 4th attempt, I tried the wooden block printing method where we had to place some mixture on the plastic sheet and spread it out evenly before placing the wooden block on the mixture.

For my very first stamp on the upper right, I forgot that we had to stamp on the tissue laden area and hence resulted in this uneven thickness of prints. Subsequently, I printed on the soft area and the prints turned out better.

HEAT TEST: 

I used the hot air gun to do a heat test for the piece with red ink and this is the result.

Overall, I think thermochromic printing is very interesting and yields satisfying results. It could be very useful in making “smart fabric” that reacts according to one’s body heats or their surroundings.

PART 2: VACUUM FORMING

Materials used:

  • Vacuum forming machine
  • Scissors to cut the PVC sheet to your desired size
  • Mould or object

Steps:

Cut the PVC sheet to the desired size according to the shape and size of the chosen object.

Secure the metal plate and place the object in the middle of the vacuum forming machine is an upright manner.

 

Lower down the object into the machine using the handle.

Place the PVC sheet in the designated area of the vacuum forming machine.

Pull the overhead lid over and cover the PVC entirely.

Wait for 30 to 45 seconds for the PVC to get heated up.

When the PVC sheet is ready for moulding, push the lid back. Pull the handle down and switch on the air pump simultaneously.

Once the mould is successfully formed, remove the PVC and the object.

My attempt:

For the first attempt, I didn’t grasp the pulling of the handle and the suction well enough, resulting in the mould having very blunt edges.

For the second attempt, it was slightly better and you could see that the edges became more defined.

Overall, I think vacuum forming is a fast and efficient process to get the desired mould done up, especially for resin or silicone moulding purposes. However, I think it is advised not to stay around the vacuum machine for a long time as the fumes emitted made me a bit nauseous after a while.

Applications: 

The wrapper on chocolates to know if the chocolate may be melted or not.

Vacuum forming: 

Vacuumed formed chopping board.

Plastic dividing drawer.

 

 

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