EVA Foam

In the easter holiday i ordered a big block of EVA foam, so that i could carve into it and make the sole of a shoe, the block cost around £40 and it was ordered from ebay. when it arrived i realised that it wasnt dense enough and was more like the cussioning you find in a sofa. I didnt want to use this because i have found a different type of foam called closed cell EVA which is basically the same thing however all the small air pockets are mostly filled up and is more dense.

My brother uses it to make the insoles of shoes for people who have sporting injuries, etc. He is going to get hold of a few sheets for me so that i can carve the sole.

Casting

The other day I finally finished my last and decided it was ready to be casted, we melted down this latex like material, made a box to fit the plaster last into and poured the liquid into the box. When it had set properly I realised that there was some air bubbles in the cast that would rip because they were to close to the plaster and so i had to melt some more  down and fill the holes. When we came to take the plaster out of the cast, there must have been a crack init and the plaster broke, however the cast works and i have produced several more casts.

PMC-790

PMC is typically used for industrial parts such as rubber belts, belt scrapers, industrial rollers and so on. However, some of the features of this material can be useful to making the sole of a shoe, it is high impact resistant and doesn’t rip or show any signs of wear.

I don’t think it would be very comfy because although I need a material that is strong I think this will be too hard and uncomfortable. it is relatively cheap in comparison with others and is a lot easier to get hold of.

http://www.benam.co.uk/products/urethane/pmc-790/

Thermoplastic molding

“The most common way to produce plastic parts is the plastic injection molding process. When the process uses materials that can be heated to soften or melt, it is called thermoplastic injection molding. Most plastic parts today are made from thermoplastic materials such as nylon, and ABS. When the process uses materials that permanently solidify by a chemical reaction, it is called thermoset molding. Thermoplastic injection molding, which relies on the rapid cooling of the plastic melt in the mold, typically results in a much faster process cycle than thermoset molding. The principal thermoset materials molded by Rebling are DAP, phenolic polyester and epoxy.”

this was taken from- http://rebling.com/custom-molding/molding-processes/ to me it is relevant because want to cast the plaster last I have carved and use some of the materials mentioned such as Nylon and phenolic polyester to fill the cast. the reason I want to do this is so that I have a functional last that can be used to make the upper if a trainer.

15/03/2017

Today in the morning we were in a lecture talking about the examination criteria which was quite helpful because now i feel like i have a better idea of what work i need to do, how to record the process and ultimately i feel more confident with my ideas and the reasons for the ideas.

After the lecture, I did a bit of research on different materials and innovations used throughout the history of the sneaker industry, for example, polyurethane (used for outsoles). A process called blow rubble molding (used to make the air bubbles in certain running shoes).

In the afternoon i worked in the clay room carving a foot shaped last out of plaster, this is the second day i have work on it and im glad to say its looking more like the shape i want then yesterday, however, I think it still needs more work. It was harder to work with yesterday because the plaster hadn’t fully dried out, but now its more brittle and easier to carve.  Hopefully, if it turns out alright, i was to cast the plaster and fill the cast with a material that is stronger and won’t break if hit with a hammer or if dropped. this should leave me room to develop another idea of making my own usable last and design the upper of a shoe.

Last Types

http://www.fagus.com/en/services/shoe-lasts/traditional-lasts-plastic

looking at the different types of lasts.

Classic Hinged Lasts- Classic hinged lasts are primarily used in the production of men’s shoes. Here, the toe end of the last is hinged downwards after the last has been placed on the pin. This model is designed for lasted shoes.

Sliding Hinged Lasts- Sliding hinge lasts (parallel sliding hinged lasts) are often used for moccasins and strobel uppers. The mechanism is incorporated in such a way as to achieve optimal shortening when the toe end is pushed up. One can both relast and delast. This design is used even for lasted ladies’ shoes.  The last partition II has been approved for delasting of strobel uppers. A relasting and delasting machine is required for opening the lasts.

Solid Last- Solid lasts are used for production of sandals and sports shoes. They do not have any mechanisms. This is the one that i will be using.