Plastic and heat

When talking to my tutor at Morley College about my experiments with knitted plarn, she suggested putting the finished sample in the heat press. Unfortunately, the heat press at the college wasn’t working at the time. So I tried ironing another knitted piece between sheets of baking parchment at home (picture below).

Knitted plastic sample after ironing
Knitted plastic sample after ironing

I didn’t really know what to expect – I suppose I thought that the plastic would melt so that all the colours would run into each other in a kind of marbling effect. What actually happened (though the photo doesn’t show this very well) is that the sample simply became flatter, highlighting the texture of the stitches more, and also became stiffer, losing its elasticity and stretchiness – which for me was part of its appeal. Possible function: Coaster or place mat, as long as the plates aren’t too hot!

On our course, we’d moved on to learning about embroidery, both hand and machine. As a scuba diver, I was inspired by the colours and patterns of many tropical fish I’d seen, and I wondered how to create background with the texture of fish scales for embroidery stitches. The solution? Back to plastic – bubble wrap!

Again between sheets of baking parchment, I ironed layers of plastic bags and bubble wrap. The results were interesting. The bubble wrap collapsed and fused to the plastic bags, creating a honeycomb effect. Thinner, cheaper plastic often blistered, leaving clear holes and adding to the texture, while thicker, classier bags created a smoother, glossier effect. Putting the iron on the hottest setting and moving it more slowly could also cause thinner plastic to shrink, leading to a crinkled 3D effect.

Pink and blue plastic experiment
Thin plastic shrinks and crinkles under high heat

However, I soon encountered  problems when trying to embroider on top of this material. Because the bubble wrap was so thin and brittle, piercing it with a needle often left large holes. When it was fused with thicker plastic, it was robust enough, but with thinner plastic it was too delicate.

The answer was to add a layer of Vilene to the other side of the bubble wrap. This three-layer fused sandwich of Vilene, bubble wrap and plastic is sturdy but flexible enough to cut and embroider on. And by lining it with felt, I’ve produced several small items like spectacle cases, purses and iPhone/iPod covers. You can see some examples below – there are more on Flickr.

Spectacle cases
Spectacle (eyeglass) cases
phone and card cases
Smartphone and card cases

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Flextiles uses shibori, ecoprinting and felting to create original, one-off upcycled pieces. Extending the life of a garment by an extra nine months reduces its environmental impact by 20-30%.

4 thoughts on “Plastic and heat”

  1. I love your glasses cases! I’m experimenting with fused plastic at the moment…
    I was curious as to what paint or media you use for the patterns? Also I’ve been using a sewing machine for my peices but it looks like your hand sewing yours with blanket stitch is it easy enough to get the needle throught the plastic?
    Thanks great blog…

    1. Hello Sarah,

      I haven’t used any paint or media – it’s all plastic or embroidery! I cut out shapes from different coloured plastic bags and put them on top of the Vilene, bubble wrap and background plastic, then iron them all together to fuse, before embroidering on top.

      I do the hand embroidery before adding a layer of felt and sewing it all together with blanket stitch. I don’t have any problems with this, as the fused Vilene/bubble wrap/plastic is quite thin (though it depends on the plastic you use – some plastic bags work better than others).

      Good luck!

  2. Thanks for the quick reply!
    I’m so impressed you did all those patterns with pastic and embroidery I just presumed it was painted on because of the detail. The photos obviously don’t give it enough credit. I’m going to try and make a shopping bag with it. I’ve tried a small wallet but doesn’t look nearly as good as yours.
    Practice make perfect…
    Do you know of any other website I could get inspiration from?

    1. Practice definitely helps, as with most things!

      Actually even when people see the glasses cases in person they often ask what I use to paint the designs, so it’s not just my bad photos! 😉

      It’s been a while since I worked with fused plastic, so I’m not up to date with any info that’s out there, but I think there are a couple of sites about working with upcycled plastic bags and other materials in the Blogroll.

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