Case study: PMMA mould - Aliapur/Wiki GitHub Wiki

Date: 20.05.2017

Location: Techshop LM Ivry, France

Description

The aim was to use a self-made thermoformed PMMA mould to create a compressed moulded slab of rubber

Material

• PMMA mould
• Rubber powder (0-0.8 mm) from Aliapur Beta Starter Kit
• PU binder from Aliapur Beta Starter Kit
• Clamps and two wooden panel

Protocol

Rubber powder is mixed manually with approx. 10% of PU binder. A few percent of water is also added to accelerate the setting of the binder. The mixture is poured into the PMMA mould, and the surface is equalized with a flat object. THe pressure is maintained for 24 hours using two wooden panels and clamps.

Feedback

1. The major problem is that the slab was stuck to the PMMA mould after the setting. The use of a demolding agent might be useful.
2. The final slab tends to crumble. This is maybe due to:

• an insufficient quantity of binder
• a bad repartition of the binder in the mixture, which could be enhanced by gently warming up the binder during mixing to reduce its viscosity

Pictures

Mould

Compression setup

Final slab