The Vacuum Forming Process

This is my final blog on these extra topics I am talking about that will help with the overall understanding of our clock making. Definitely in this case I have left the best until last, and will talk about Vacuum Forming - something that everyone in Grade 7 who has made a clock has seen and had the process used on their clock. 

Anyway, on with the description!

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Vacuum forming is a manufacturing technique where thin plastic, and in this case, thermo plastic is shaped by heat and force. 

1. The first stage of vacuum forming is to make an accurate die or mould. This die must be very precise as any flaws will show when shaping the thermo plastic, any sharp edges can pop the plastic or if an edge is hanging over the plastic will wrap around that then underneath it causing the die to become stuck. 

2. The die is placed in the centre of the vacuum former

3. A sheet of thermo plastic is placed above the die and clamped into position.

4. The heater is turned on. When the machine is being used from ‘cold’ it takes about five to ten minutes to warm up to the temperature needed to heat the thermo plastic sufficiently.
Once warm, thermo plastic takes only four to five minutes to heat up before the vacuum forming process can begin.

5. The thermo plastic must become flexible before it can be formed properly.

6. Once the thermo plastic is ready the "Platen" or the base the die is placed on is lifted towards the thermo plastic sheet. The air underneath the thermo plastic and the die is pumped out and the thermo plastic takes the shape of the die.

7. You then pop your die out and cut out the plastic to just around your shape. 

8. The next part is the fun part, you can paint your plastic shape or decorate it in any way you want! TIP: A good tip for painting is to paint from the inside so you can see the coloured plastic still with the shine from the plastic.

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Well, thats all from me on these Extra pieces of information and blogs! My blogs will now go back to my regular lesson reflections, unless there are any other topics to talk about or cover. Once again... Thank you very much! 

Sustainability

This is my first post (out of two) on Processes and Things We Need To Think About in the workshop during our clock making process. This first blog is based on Sustainability. Please enjoy!

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AN OVERVIEW ON PLASTIC AND SUSTAINABILITY: 

In order for a product or material to be truly described as sustainable it must be environmentally, economically and socially sustainable. These aspects have become known as the Three Pillars of Sustainability. Plastics make a positive contribution to all three pillars of sustainability.

Plastics make an immense contribution to the environmental sustainability through their energy saving potential and intrinsic recyclability and energy recovery options. Economically plastics form an important part of the UK economy and are a major export product. Socially the plastics industry is a major and inclusive employer with an attention to training and education.

ENVIRONMENTAL SUSTAINABILITY:

Plastics have a very good environmental profile.  Only 4% of the world’s oil production is used for plastics and much less energy is used to produce it compared to other materials.  Plastics are durable yet lightweight and thus save weight in cars, aircraft, packaging and pipework.

When plastics have completed their use phase, whether as a car bumper or a bottle, they can either be recycled or if this is not economic or environmentally beneficial the calorific value of the plastic can be recovered through energy from waste incineration to provide a much source of home-grown power. As a consequence plastics can be viewed as ‘borrowing’ the oil.

• Plastics provide unparalleled benefits as a packaging material. This is because plastics are lightweight, resource efficient and offer excellent barrier properties. Due to these properties packaging items in plastics significantly reduce waste and saves energy.

• Plastics have a huge role to play in sustainable construction, whether it be PVC windows, plastic foam insulation or plastic water pipes. 

• Plastics have a number of inherent properties which make them an ideal material for modern
transport systems. Plastics are lightweight, corrosion free and easily moulded into complex  shapes without the need for assembly or fastening systems.

• Plastics recycling takes place on a significant scale in the UK and there is considerable research conducted to discover the most efficient ways to recycle. Raw materials have a high value and are a precious resource, so to conserve both money and the environment the industry makes every effort to recover as much as possible.

ECONOMIC SUSTAINABILITY:

Plastics make a major contribution to the UK economy and a healthy manufacturing sector is vital to a sustainable economy.


Plastics contribution to the UK economy:

• Circa 7400 plastics companies in UK.
• The industry turnover is approximately £17 billion.
• Plastics are a much need source of export revenue with circa £4.5 billion in exports.
• For many plastics products, especially construction related products, the whole supply chain is situated within the UK.

Plastics also have a role to play at a micro-economic level:

• Plastics products are very cost effective to produce and provide the ability to make single moulded components in complex shapes. This significantly reduces costs associated with assembly and the use of fixtures.

Plastics also have a role to play at a micro-economic level:

• Plastics products are very cost effective to produce and provide the ability to make single moulded components in complex shapes. This significantly reduces costs associated with assembly and the use of fixtures.

There are also many other Economic benefits, but for now I will only stick to these (some of the most important).

SOCIAL SUSTAINABILITY:

Completing the final pillar of sustainability, plastics are also socially sustainable;

• The UK plastics industry is socially inclusive and offers a wide range of worthwhile careers with considerable room for career development, progression and training. The industry is very attentive to training and this is led by Cogent (the Sector Skills Council) and Polymer Training in Telford.

• Plastics companies are geographically widely distributed across the UK and provide jobs to some 180,000 people.

• The plastics industry has a superb industry health and safety record as demonstrated by BPF accident survey statistics.

• Plastics make a major contribution to safety, the used plastics in cars, for example, reduces weight and allows for the addition of safety features such as airbags. Furthermore, plastic foams such as EPS and EPP provide the necessary shock absorbency to be used in life saving devices such a bicycle helmets.

Essential medical applications include:

• Blood bags
• Fluid bags
• Heart and Lung bypass sets
• Blood transfusion sets
• Blood vessels in artificial kidneys
• Surgical gloves
• Catheters
• Endotracheal tubing 

Plastics are essential in modern day healthcare. Plastics products are used in surgery, healthcare products, pharmaceuticals, drug delivery systems and medical packaging.

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Thank you very much for taking the time to read about Plastic and its sustainability in the world. My final blog under these extra topics will be the Vacuum Forming Process. Stay posted!

Cellulose Nitrate (Extra)

This will be my final blog on materials we may use or encounter in the workshop...so enjoy!

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The plastic cellulose nitrate was invented in the early 19^th century, and is often thought of as the earliest synthetic polymer or plastic. The uses of cellulose nitrate range from everything including cutlery handles, toys and dolls, photographic film, and many other cosmetic, household and toiletry items. It was even used by Kodak, and other suppliers, from the late 1880s as a film base in photograph, X-ray films and motion picture films; and was known as nitrate film. After numerous fires caused by unstable nitrate films, safety film started to be used from the 1930s in the case of X-ray stock and from 1948 for motion picture film.The colour of an untouched, unprocessed cellulose nitrate plastic is transparent and colourless, and until about the 1920, the only cellular nitrate plastic available was light coloured or translucent.

An old, rusted, rolled up film reel made from Cellulose Nitrate

The stability of cellulose nitrate is strongly influenced by the amount of nitrogen present, the more nitrogen content, the more unstable the product. Therefore, products with high nitrogen content (usually more than 13%) are likely to explode on contact to heat, friction, or shock, whereas objects with a lower nitrogen content (typically less than 12%) are not explosive.

There were two main types of Cellulose Nitrate Guncotton and Nitrate Film: 

Guncotton:

In general, cotton was used as the cellulose base, and is added to concentrated sulphuric acid and 70% nitric acid cooled to 0 °C to give cellulose trinitrate (or guncotton).

While guncotton is dangerous to store, its risks can be reduced by storing it wet or in oil.

Nitrate Film:

Cellulose is treated with sulfuric acid and potassium nitrate to give cellulose mononitrate. This was used commercially as Celluloid, a highly flammable plastic used in the first half of the 20th Century for lacquers and photographic film.

However, cellulose nitrate degrades to produce acidic and oxidizing nitrogen oxide gas. In enclosed spaces with restricted ventilation, these gases can build up, causing metal to erode, and discolour organic materials, as well as accelerate the process at which objects decay. Cellulose nitrate is additionally a very flammable material and must be isolated from heat and ignition sources.

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                                  Thank you very much for reading my post on Cellulose Nitrate.

                                                 Next up, will be a post on Sustainability!

Thermosetting Plastics

This second blog on Materials and Processes we will encounter and undertake in the workshop is based on Thermosetting plastics. Now, in my previous blog based on Thermo Plastics, my last information paragraph was as follows: Sometimes, thermoplastics are confused with Thermosetting Plastics. Although they may sound the same, they actually contain very different properties. While Thermo Plastics can be melted to a liquid and cooled to a solid, Thermosetting Plastics chemically deteriorate when subjected to heat. Ironically, however, Thermosetting Plastics tend to be more durable when allowed to cool than many Thermo Plastics.

In this blog, I will go into more detail about this confusion and comparison and other aspects of Thermosetting Plastics.

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Thermosetting plastics are synthetic materials that strengthen during being heated, however, cannot be remoulded of reheated after their first heat-forming. Thermosetting plastics retain their shape and strength after heating, which makes the plastics well suited for the production of permanent components and large, solid structures.

Examples of thermosetting plastics include epoxy (as shown below), and because it has excellent chemical, thermal and electrical resistance and can be used for coatings, casting compounds, adhesives (as shown below) and encapsulating for electrical components (e.g. covering for a wire cable). Additionally, Phenolic plastic is another example of a thermosetting plastic.

Epoxy - In The form Of Clear Adhesive Glue

!!!HERE IS A FUN FACT!!!

Phenolic plastic was created by Leo Baekland. This type of plastic was solvent and water resistance, and was used in early consumer electronic items such as telephones, radios, and records. However, Phenolic plastics are used little in consumer products today due to the cost and complexity of its production and its brittle nature.

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Thank you very much for reading and keep a look out for my next blog on Cellulose Nitrate (an extension that caught my eye when I was researching information on Thermosetting Plastics).

Thermo Plastics

The next few blogs that I will be posting, will be regarding different types of plastics and different processes we will undertake in the workshop during our clock making process. This first blog is on Thermo Plastics.

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A thermoplastic is a type of plastic made from polymerresins that becomes a homogenized liquid when heated and hard when cooled. When frozen, however, a thermoplastic becomes glass-like and subject to fracture. These characteristics, which give the material its name, are reversible. That is, it can be reheated, reshaped, and frozen repeatedly, Which additionally makes thermoplastics recyclable. Heading into more detail about why Thermo Plastics can be recycled is because the weaker interactions between polymer chains break down at much lower temperatures than the chemical bonds between monomers. This allows thermoplastics to be recycled indefinitely until the polymers are broken down to the point that the material loses structural integrity.

Thermo Plastics are different from Thermosetting Plastics however, as on heating this type of plastic, it does not undergo a chemical change, whereas Thermosetting Plastics do. Additionally, Thermo Plastics cannot resist heat very well and therefore can easily be formed into other shapes, making it one of the most common materials used in the school workshop. A moulded sheet of Thermo Plastic that has been formed into a shape can be reheated and it will return to its original shape. This occurrence is referred to as plastic memory.

Examples of Thermo Plastics include Polyamides (or nylon), acrylics and Polystyrene (as shown below). As Polyamides is tough and resists abrasion, as well as being self-lubricating, makes it ideal for ropes, fishing line, gears and zips. Acrylics have good impact strength and transparency, which is why it is most often used in goggles, windows and lenses. Polystyrene is easy to use, and comes in many colours, making it an ideal material to use in packaging trays, vending cups and ceiling tiles.

Polystyrene - in this case in the form of a disposable cup.

Sometimes, thermoplastics are confused with Thermosetting Plastics. Although they may sound the same, they actually contain very different properties. While Thermo Plastics can be melted to a liquid and cooled to a solid, Thermosetting Plastics chemically deteriorate when subjected to heat. Ironically, however, Thermosetting Plastics tend to be more durable when allowed to cool than many thermoplastics.

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Thank you very much for reading and keep posted for more useful information!

Lest Lesson for Term 3

7K's last Design Futures lesson was our final lesson of the Term - and can I say, it was DEFINITELY the best and most exciting. When we first walked into the workshop, Mr Andrews was preparing a machine to cut some more MDF for the students without a square for their clock - little did I know that he would ask me next along with 3 other girls and himself to cut the MDF. We did this in front of the class so they could see the machine in action, but most were startled at the noise! The process for cutting the MDF was quite simple really;

1. Two people at either end of the long sheet of MDF pushed it onto the bench and into the saw. 
2. Myself and another girl at the opposite end then had to pull it out making sure the wood at all times   was brushing up against a metal barrier. 
3. Mr Andrews was standing on the out-wards side watching the process ready to act on any problems that may have occurred. 

...unfortunately for us there was a problem. About half way through the process, the machine started squealing (more than its usual loud sawing sound). Mr Andrews stopped the machine immediately and all pushing and pulling stopped. We were informed that we were not pushing the MDF towards the metal barrier enough, this had caused the machine to jam, the saw to lock and the woo to have sharp jagged edges. Once we realigned the wood we tried again however the saw kept jamming on the already jagged edges. Mr Andrews turned the MDF around (with the help of us extremely muscular girls...not) and we started form the other end. The saw again jammed but luckily the two ends had been met and the MDF was cut!

Mr Andrews then invited some other girls to help him cut the long strip of MDF into smaller individual squares. This was when the rest of the class (who were able to) started tracing their first clock layer onto their square for Mr Andrews to cut out. I have decided that the actual shape of a Ferris Wheel is not to be cut as a base layer, simply because the main cutting machine cannot accurately cut it out and there is not enough time to use a hand-held saw or sander. Instead, I will probably paint the gaps in when decorating my final result. As a result, my first layer is a circle.

After my first layer was cut out, I sanded the edges of my first layer with sandpaper, and then the bumps with a curved file, however the circle shape still seemed uneven - so Mr Andrews used the 'motor-operated sanding machine' to finish it off. My final result was a completely smooth circle that will be my first layer. For the rest of the working time in the lesson, which was only about five minutes in total, I started work on my second layer, which is basically my second layer traced onto a piece of grey, stiff cardboard.

Next lesson, I will definitely be finishing tracing my second layer on the cardboard, which will take longer than my first as it was not cut perfectly, and it involves a lot of painstaking and precise cutting of smaller shapes and then cutting in between them. So I will probably spend most of the lesson on my second layer - if not all. Hopefully, I will be able to finish that, I will cut it out, and then start on my third layer of Ferris Wheel detail, most likely on the grey cardboard again.
A summary for this Term would be:

• I have decided on my design.

• I have completed all blogs for all lessons and will now commence blogs for different materials and processes e.g. Thermo and Thermo-Setting Plastics, the Vacuum Forming Process etc.

• I have decided and completed all my layers - plan.

• I finished my first layer. 

• I've started on my second layer.

• And my goal and plan for next lesson will be finishing my second layer and starting on my third.

Thank you Mr Andrews for a wonderful Term and I cannot wait until Term 4 when we will really be knuckling down into the clock-making process! 

Bye for now and keep posted for my next blogs on information that will help me and possibly you in creating your own clock!

In The Workshop...

YAY! I am so excited, we are finally in the workshop. All our hard work of finding and deciding on the right clock for us, and then creating and forming our layers is all about to come together in our finalised clock. On Thursday, Mr Andrews told us that after he did a final check on our layers - making sure they were okay, he would take us on our first venture to the workshop to begin working. Luckily enough, everyone's layers must have been ready as we were taken to the workshop. This was quite a relief for me as even though I spent quite a long time on the weekend perfecting my layers, I wasn't quite sure if they were correct.

Once clock layers from our class had 'passed the test', Mr Andrews took us to the workshop. We left our books outside on some racks and walked inside making sure to stand behind the safety line (yellow marking tape) - this was to ensure everyone was in the one place at the one time and that Mr Andrew's knew that no-one could be hurt by any tools or machines. At the same time we were taken into the workshop, Mr Ward was teaching some Grade 11 students. This didn't bother me at all, and if anything I thought we were quite lucky to have them in there as 7K had the opportunity to see what a class looked like 'in action'.

After Mr Andrews instructed us on a few safety precautions - such as never cross the safety line unless instructed to, always wear an apron and goggles (goggles depend on the activity you are doing), and when the teacher says STOP everyone must  stop completely and immediately. We were allowed to go to one of the working benches and choose a piece of MDF wood square carving that would fit the shape and size of our layering images. Now, my clock fitted best to a square shaped piece of wood, however it needed to be even all the way around (e.g. 20cmx20cm not 15cmx22cm) as all my carrousels needed to be able to fit on without cutting them in half. Finding a piece of wood suitable for me was not as easy as it was for some other girls but in the end there were two pieces of wood I found that I was tossing up between to decide which one would be the most space-efficient to the size of my clock.

By the time everyone had found their piece of wood (at this point I was helping Charlotte with her layers and wood) Mr Andrews told us that the lesson was nearly over and that we needed to pack up. Everyone understood completely, took off their aprons, put their layers and piece of MDF wood into a cupboard underneath one of the working benches and reassembled behind the safety line, for Mr Andrews to do a short re-cap on the lesson and dismiss us.

I thought this would have to be the most exciting lesson we have had yet, as we were finally allowed to go into the workshop, and begin the hands-on process to our clock building and making. What I also loved was the fact that Mr Andrews told us to always meet down at the workshop now, and not in the computer room - this reinforced to us that we would definitely start to make our clocks and not go back to the computers to plan anymore.

I cannot wait until our next lesson and next Term when we are able to put all this Term's (Term 3) hard work into a finalised and practical result!

Layering Lessons

For the past few lessons 7K has been starting our layering process and now in the 9th week of Term, we are finally ready to start doing practical lessons in the workshop!

Firstly we had to find images of our chosen clock design - in my case this was a Ferris Wheel; preferably vintage. After we had found either one image that would be suitable to start designing our layers on we would print it out and highlight all the different layers. However I chose another option, none of the images on google were suitable for what I wanted my clock to be or resemble. For example:

They only show parts of the Ferris Wheel or the picture is not front on...

They do not have 12 spokes for all 12 numbers on a clock...

Or they were too plain, boring and non-realistic...

So I found two different pictures and blended them together. I found one of a ferris wheel with 12 spokes (so I have room for all 12 numbers) which also had good detail in the middle and a elegant yet sturdy looking base without being too noticeable or too blended in. Then I took my second image and cut out the carriages (as the other image didn't have any) and also cut out a cute vintage centrepiece which was also located from the second image. I then glued them together and pretended like it was already an image I found so I could continue with the following steps.

Next, we had to photocopy our photo and go around each layer in a different colour so we could tell which was the 1st, 2nd, 3rd etc. I had some trouble with this initially, however, as I thought I had 12 layers, but Mr Andrews explained to me that this was far too many and some layers could be joined together. He also said that some were too small to make and I could just paint them in. I also found and observed that everyone else in the class struggled with the layers in one way or another. For example some people would cut gaps in their layers, this was incorrect as you needed a base and to think in advance for the next layer, otherwise they would all fall into each other (into the open gaps) and you would end up with only a one-layered clock. Only Lois managed to do this properly...even I made a mistake with my first layer!

After we had decided on how many layers our clock would consist of we had to photocopy our original image one time for each layer and then another as a spare (so say if your clock had 5 layers, you would photocopy it 6 times).

These steps have been very time consuming and have occupied us for the past three to four lessons. Now, everyone's layers should be completed which now gives us all the opportunity to start the initial process of practical work in the workshop! I am really excited for next lesson, and are completely prepared for any  challenges or successes (lows or highs) my clock presents me with.