SeaPigs Drifters July update - things are hotting up


The design of the drifter was altered to produce Prototype 22 design. Prototype 22 design was designed around a size 9 (to suit Amanda), the tread pattern was reversed to protrude as the final design will be and the straps were altered so that they were only fixed 1 side and loose the other side – to allow easier assembly. From prototype 22 design a mould design for the sole layer was created and then was 3D printed. 

  During the process of re-design and mould creation we had discussions with Braskem, an EVA manufacturer, during which it was decided that the construction of the Drifter would be altered. Originally the Drifter was to have a natural rubber sole layer, an EVA second layer, a natural rubber third layer and a natural cork top layer. After the discussions with Braskem the base layer is to be constructed using a natural rubber/EVA mix for the sole layer, the second layer will be EVA, the third layer will be a natural rubber/EVA mix and the top layer will remain cork. 

  To move the drifter design forward, and to help us produce Prototype 23, we enlisted the help of Sunderland University’s SAM project. SAM are going to be used to produce some high quality 3D prints of the sole layer and the second layer which they will be using to produce Silicone moulds for us to use with liquid foam to produce Prototype 23. The liquid foam which will be used is going to be as close to the final materials as possible and will give us the best prototype yet. 

  At the same time SeaPigs also teamed up with Newcastle University’s Arrow program to bring on board an expert in Biomechanics. This expert is going to look at the design of the drifter to make sure it is as good as it can be and does what we want it to do as well as giving us design input from a medical perspective. 

  The input from the people we have spoken to and brought on board has now given us direction and plan for Prototype 23, which is as follows: 

4-Layer Sole Technology

Layer 1 – Under Sole Support

The changes for this layer have come from the conversations with Braskem, SAM and Arrow. The first change to this layer is, as mentioned earlier, the material is going to be changed from natural rubber to a natural rubber/EVA mix which is going to facilitate the biggest change to the design. The straps are now going to be incorporated into this layer and are going to be made from the same material. More thought and design is going to go into the design of the straps and integrating them into the sole. Alongside this change the front of the sole is also going to be raised which will make them easier to walk in, better for fit and reduce the risk of tripping. 

  To produce this layer we will be using a 3D print of the sole layer to produce a silicone mould which then will be used to produce the prototype part using liquid foam which is similar to the material which will be used in the final product. The silicone mould should be better than a 3D printed mould as the quality will be better, it will be easier to remove the part from it and it should be more durable. Braskem are going to send us some samples of the materials that we are hoping to use which we will also try and use the silicone moulds with.

Layer 2 – EVA 

Layer 2 is going to have the straps removed from the design. This layer will then be altered to suit the sole layer with the integrated straps. 

  This layer will then be produced in the same way as the sole layer using a liquid foam which is similar to the final product. Again we are hoping to use the mould produce with the Braskem material samples. 

Layer 3 – Natural Rubber/EVA mix and Layer 4 – Cork are as prototype 22. 

Prototype 23 should be ready for testing by the end of August.