Making Larger Forms

The curing process

I have been experimenting with making larger moulded forms from bioplastic. It’s quite tricky at this point as the bioplastic slips down the sides of glass and metal of a mould (a bowl in this instance) and collapses on itself. The stability of the mixture seems to vary with different agar powders. But it just doesn’t harden enough with the water content to stay in situ. I want to try this in a wooden mould to see if the slightly more textured surface will provide some additional grip.

After removing the bioplastic from the mould, I will fill the cavity with fabric or place it over the bowl. If there is enough elasticity in the bioplastic (determined by the levels of he glycerine) it will cure and keeps its shape but it is quite thin. In the image below, the form at the back right is made in the same metal bowl that the form on the left (and is placed over). This clearly shows the difference it makes if the bioplastic is left to cure without that larger internal support.

At this time these, are still curing. I tried a different pouring process with the form on the left. I placed a thin skin in the mould and then dripped bioplastic down the sides to build it up. I was investigating if pouring a smaller quantity (which would cool quicker) would mean less of the bioplastic would slide to the bottom. I coloured some of this with algae based pigment, which apart from incorporating some organic colour from a body of water, it allows me to see how the dripped bioplastic flows through cooling and consequently sets after the majority of the water has evaporated.

After the works had cured I poured some clear bioplastic into the forms. The agar powder I used for this is clearer and seems to hold moisture longer. The forms appear to be holding water. The forms are the skins, that border which contains the water.