Thinky Mixer

The Thinky mixer is used for thoroughly mixing elastomer components, which helps to achieve uniform curing and standardizes elastomer properties between batches/researchers.

Principle

The Thinky is a planetary centrifugal mixer: the cup of material rotates clockwise about its own axis, while also being revolved counterclockwise about the mixer’s central axis (image on left). This combined spinning generates very high centrifugal force (400 G!) which forces material towards the bottom of the cup, creating a vertical convection spiral. This convection causes the contents of the cup to be mixed thoroughly.

Instructions for using the Thinky mixer

  1. In a new Thinky cup, weigh out elastomer parts in the appropriate ratio
    1. Note: only use Thinky cups! Regular plastic cups cannot withstand the centrifugal force and will crack and spill everywhere inside the machine.
    2. Never fill the cup more than halfway. As it is mounted at an angle in the mixer, a full cup will spill when placed inside.
  2. Combine the cup/elastomer with the removable cupholder/adapter from inside the mixer, and weigh. Set the counterbalance dial inside the mixer to this weight.
  3. Choose the appropriate program, 30s mixing + 60s defoaming is sufficient for Ecoflex but more viscous materials may require longer time – i.e. for Elastosil, continue until all streaks are gone. For the 60 Oxford mixer, the automatic program is 30s @ 2000 rpm (mixing) followed by 30s @ 2300 rpm (defoaming). A smaller/less powerful mixer will require a longer time.
  4. Note: mixing for too long can be bad – the mixer tends to heat up with use, and your elastomer can actually cure by the time mixing is over.
  5. Run the program, then remove the cup. You may have to pry out the cup with a finger or tool because it gets stuck in the spilled material at the bottom of the cup holder