Originally I wanted to make a combination of banana fibres and tussle and latex.
But the laminating process would prove to be problematic and long in this time frame. So I stumbled upon a made sheet material called Cocolok. This is coconut fibres and latex. I found it on a blog called Hello Materials http://hellomaterialsblog.ddc.dk/2012/06/11/a-design-boost-for-natural-fibre-composites/
This material is used for a number of things but main application is for mattresses. The company informed me as footwear company called Po-Zu has been using the material for insoles http://po-zu.com/uk/coconut.
The material is coconut layered up and strayed with latex then compressed through rollers. It comes in differing densities. In speaking with the representative of the company we thought there would be a density suitable for wedges. They very kindly sent samples thin to thick of 80-120 density. I believe it goes up to 200 density.
As a student you have to work with what is on hand. Please remember this investigation in natural fibres in application to footwear primarily exploring how a natural material can evolve in arrangement and binding to have the same potential properties of rapid prototyping processes.
So we found that the cocolok wedge “blocks” while pleasurable under the feet were too unstable. So we bio resined the side walls with a brush, spatula and because the resin ran through the open cocolock a “wall” of bio resin which was structural foamed and then the centre stayed soft. We then put on a top layer cocolok insole “mattress”.
below is an image of the crude test mock. A felt sock mule would be attached to the top. The bioresin would be polished.
The rational behind using Crochet as one of the materials is that it is not only non-woven but is a structure which adds, or builds in a very direct manner. So the choice to to keep the crochet stitch was a purposeful one. The aim was to keep the unit (the stitch) the same but repeat and then make the knit denser as the material moved from the upper to the heel. This is very important, this repetition, as this is modernism…
A few months ago Jess the Materials Librarian at CSM and LCF suggested I contact the people at Sodra to possibly use this mouldable paper pulp material. She showed me a sample of the finished material. It was like a plastic styrene with a velvety surface finish. The material is really strong and was used for furniture. When I first approached Sodra the company were concerned the water wear would prevent the application in footwear. After a couple months being urged again by Jess I contact the company again explaining that these shoes were prototypes which could be applied to further research and development in which the water wear issue could be investigated further at a later stage.
They agreed and sent the material. Fantastic!
The pulp is paper so cellulose with a biopolymer. Water is added and then the material is poured or put into a mould which needs to compress and heated once the water is removed. In manufacturing a metal tool would be used with heat compression for best surface quality.
But we will have to rig up a workshop method to recreate this process as close as we can get. I am sure the surface quality will suffer a but these things go in stages!
Above is a link to the Sodra Labs website. In it the material is explained. We are using Durapulp as the pulp comes in three strengths.
In the workshop at the college I tried playing with the material initially as I do not have the moulds yet. This play was also to help inform what might be needed in the moulds.
I mixed the pulp with water…
Tested it under flat compression and let air dry.
The result was very dense and tough but really the material needs to be baked soon after or as it is compressed.
The toe was wrapped with pulp and gauze and let to air dry. I tried putting the material in the footwear flash oven and some densifying of the material happened but again this needs to happen as compressed or close to this stage.
Now in theory this material could work as it has been used on furniture as below…
(all from the Sodra website…)
So the chair is a “bucket shape” with nice draft angles…
I am hoping to create a “up-side-down” bucket with the side ledges that the felt sock with the stiffened sole can sit on – be glued in?
Originally, was going to try to laminate up the flax fibres into the mould similar to the hemp fibres. But as the hemp proved to not be working I had to think in other ways. Like the hemp, flax is used in composites for surfboards and bicycles.
Jess the CSM and LCF materials librarian showed me a bag made of flax. The company Norafin produces the flax sheets in various thicknesses in either 100% flax or a combination of 65% flax and 35% viscous.
So Norafin kindly send me a selection of weight sheets to test.
Acrodur was tested on the flax and flash heat in the oven several times…Again this was too high heat too fast and the result whilst strong was brittle. The 100% flax absorbs the binder better and would need to be layered up and dried slowly over a period of time. The reaction again of passersby was that they wanted to touch the the moulded materials.
Originally, I thought about using raw hemp stick which is the long, tough, coarse fiber of the cannabis plant, used to make cordage.
I through a bunch into my crude plaster test mould and added point shoe shellac and came up with a promising potential. But the feedback I go was the hemp looked a bit messy all tangled. The problem was the messy tangles were what gave the hemp it’s strength.
I wanted to layer the hemp up in one direction and then cross the direction. I layered up the hemp wet and let it dry around the one side of the last. However, this whilst potential beautiful and a bit subversive was propbematic in the sense that the fibres even if place and proper moulds were hard to control. Gravity pull these fibres down in clumps. I tried holding it with PU glue but I was worried this would interfere with the resin application.
I also tried with dry hemp resined but found whilst strong it could thin in areas and these areas were weak.
I revisited the information and realised I missed the matte suppliers of hemp. These are the mattes Werner Aisslinger used with his hemp chair. The company J. DITTRICH & SÖHNE sent me a selection of hemp mattes, some pre preg with the acrodur. This meant the mattes only needed to be moistened once delivered, however these mattes usually come with moisture still in and waterproof sealed.
So we created a rig to test the material of clay and ply
Then clapped the material through and pressed around the last
The result was a surprisingly strong form
The design is to use the hemp shrouded around the felt sock
But this was just the start. This matte is a combination of hemp and kenaf another natural fibre. So I tested the 100% hemp and it moulded really nice.
See I want to mould in this way so working with the material is a challenge. J. DITTRICH & SÖHNE the material supply have been great, a designers dream. These people are so helpful. They contacted BASAF the acrodur suppliers and sought further advice for me. I emailed images of my test and they were not put off by the fact I am trying to recreate compression moulding and resin transfer moulding in a workshop, non industrial environment. They picked up that my wall thickness should be less on the upper so suggested I use the 600 gsm weigh sheets but realised I will need thicker in the heel area and double checked I could fuse the two sheets together via heat and compression. They suggested with the consultation of BASAF to use a glove iron the heat thus curing the acrodur whilst on the form.
So the mould is for compression and once open and the material still around the last and the heel, insole blank I can run the iron over it. Brilliant! They are so cleaver!
Then once pat cured I can further cure in the oven at anywhere over 160-200 degrees. The lower the tempature the longer curing time.
But that is not all…They recognised I will need to potentially add binder to stiffen the heel areas of stress and I can either spray or brush on the acrodur BEFORE it cures in stress areas.
In my test using the flash oven I realised two things…if any water is still in the fabric the binder bubbles and becomes brittle. It really is using the sensitivity of a chef in these workshop conditions.
Thing I realised in this process were that for some reason people respond more to the 100% hemp moulding. The kenaf hemp combo is apparently 90% with a 10% polyester fibre. I am not sure if it is that 10% which is somewhat of a deterrent, or the 100% of a natural material which seduces us with it’s elegance or if the thinness of the material moulded over the last is so seductive, but something is happening which makes this material notable for a passer by.