Vacuum Forming

Vacuum forming is a technique that is used to shape a variety of different plastics. You need to have a mould for the first stage of vacuum forming. In my instance I have a teddy bear. The mould then needs to be placed into the vacuum former. A piece of plastic (we are using thermosetting plastic) is then heated so it can become soft, flexible and formed properly. Once the plastic is warm enough it is put on top of the mould and  the air underneath the mould is pumped out (like a vacuum) using a pump so that the plastic can take shape of the mould. The plastic and mould is then taken out of the vacuum form and separated. Battery, toothbrush and razor packaging are all products made by vacuum forming.

'Vacuum' process

Finished product after being vacuum formed

Vacuum forming process

Vacuum former



29/5/12
This lesson was only my second lesson in the workshop working on my clock so I tried to work very hard so I could get a lot of work done and catch up to the other girls. Everybody was at different stages so we put on our aprons and goggles and then began to work. Once I got out my clock's first wooden layer I made the edges smooth by using sandpaper and a file. The first wooden layer is called MDF (medium density fireboard). After I had done this I glued my other paper layers onto cardboard using normal glue and cut them out using scissors. It is pretty hard to cut out layers because the cardboard is thick. I took my clock home today because I had a couple of other small layers that needed to be cut out that I would do for homework. Some people, including Amy and Hope, have got up to vacuum forming today and their clocks look very good. Mr Andrews showed us the process of vacuum forming so we would know how to do it as a few people might be ready to vacuum form next lesson. Next lesson I will hopefully have all of my layers cut out and so I may be able to use the hot glue gun to glue my layers together. I am enjoying design futures a lot and cannot wait to see what my clock will look like after I have vacuum formed it and finished.

Sandpaper

17/5/12
Today I was very excited as it was the first day I could go into the workshop. Last lesson I wasn't there because I was sick and the lesson before that I didn't have my layers so I was a bit behind everybody else. As we went into the workshop we put on aprons and safety goggles for safety. Today I got my first layer of my teddy bear clock done. I first had to find a piece of wood that fit my first layer. Once I did that, I stuck the first paper layer onto the piece of wood with some of glue. I couldn't use too much glue otherwise I wouldn't be able to take the paper off later on. Mr Andrews then cut out my first layer of wood using a band saw. Everyone also learnt how to use a hot glue gun because some people were up to using it. You should never put it down on it's side because otherwise glue can get stuck and the glue won't come out. I didn't have enough time to smoothen the edges of my wood but that is what I will do next week.                                                                                

Band saw

Polymers

Polymers are plastics and they fall into two main groups. These groups are thermo and thermosetting plastics.

Thermo plastics can be made malleable (bendy) at high temperatures of between 65 degrees C and 200 degrees C. In this state they can be moulded in different ways for various uses. For example, toys, car dash boards, plastic water bottles and packaging can be made. These thermo plastics can be re-heated and re-moulded.

Thermoset plastics are not re-mouldable if reheated like thermo plastics are. This is because the molecules of thermoset plastics are cross linked in three dimensions. Thermoset plastic is not recyclable either. There is a strong bond between the molecules.They have a stable structure, are more brittle and are used for stronger things such as electrical fittings, handles and knobs. An example of a thermoset plastic is an electrical plug or socket.

Final clock decision

Today we finalised our design and printed it off. I found this clock on the internet and I have decided that it is what I am going to make except I will make the mouth happy and separated from the nose. I will also add a piece of wood to the middle of the ears to get some more level. Where there are holes in the eyes, nose, mouth and foot paws, I will make higher levels not have holes. The clock and numbers will go on his tummy. There is a good amount of area to fit the clock mechanism in the back.

Last week I finished all of the on guard tests so next week I am able to go into the workshop and start working on my clock.

Clock ideas

I have been thinking about what design I should use for my clock and these are some of the ideas I came up with.