VACUUM FORMING KEY STAGE 3 GCSE A LEVEL For more information CLICK ON Vacuum Forming Machine Below KEY STAGE 3 GCSE A LEVEL VACUUM FORMING

Advantages and Disadvantages HOME Exam Questions ELECTRONICS The Process June 05 Former VACUUM FORMING GRAPHICS June 03 Advantages and Disadvantages RESISTANT MATERIALS June 04 Materials

HOME Overview In a nutshell, vacuum forming is where a thin thermoplastic sheet is heated until it is in its plastic state (i.e. flexible) and then it is stretched over a former and allowed to cool. When cool it becomes rigid again and so keeps the shape of the former. Animation Previous Next

The Process HOME FORMER PLACED ON PLATEN PRACTICAL NOTE: BEFORE PLACING THE FORMER ON THE PLATEN LIGHTLY DUST IT WITH TALCUM POWDER. THIS MAKES IT MUCH EASIER TO RELEASE THE FORMER FROM THE FORMING PLASTIC CLAMPED SECURELY ONTO MACHINE PLASTIC HEATED TRIMMING PLATEN RASIED Once the forming is removed it needs to be cut out of the plastic sheet using a Gerbil Cutter VACUUM APPLIED LEFT TO COOL PLATEN LOWERED FORMING REMOVED Previous Next

Products HOME Bath (Acrylic) Blister Packaging (PET) Chocolate Box Tray (PVC) Previous

HOME Former Design 1 To produce a successful vacuum forming the former needs to be carefully designed the sides must have a 5-10° taper SO that the forming can be easily separated from the former any corners must be radiused (NOT ON BASE) SO the plastic does not split when formed over them any cavities must have vent holes SO no air is trapped in the cavity preventing the correct shape being formed the surface of the former must be smooth SO that a high quality surface finish on forming the former material must be stable when heated SO it keeps its shape when hot Previous Next

HOME Former Design 2 there must be no undercuts OR the forming cannot be separated from the former PRACTICAL NOTE: WHEN MAKING A FORMER KEEP THE WIDTH TO DEPTH RATIO 2:1 TO AVOID THINING OF THE PLASTIC SHEET WHILE FORMIMNG Previous Next

Former Materials (school) HOME Former Materials (school) In school MDF is usually the material used for making formers. The benefits of using MDF are: it has no grain THEREFORE it is quick and easy to shape it is dense THEREFORE it is possible to get a very smooth surface finish it is stable when heated THEREFORE it will not distort under the heat of the vacuum former it is quite tough THEREFORE it can be used over and over again Other Materials Pine could also be used but as it has a grain it is more difficult to shape and also it may warp under the heat of the vacuum former. It is also more difficult than mdf to get a smooth surface finish on it. Clay (wet) can also be used but only once as the former is destroyed removing it from the forming. Fired clay is too brittle to be used. Previous Next

Former Materials (industry) HOME Former Materials (industry) In industry an aluminium or epoxy resin former would be used because these materials are harder and tougher than mdf so the former can be reused many more times than an mdf one. Previous

Advantages BECAUSE the same former is used again and again HOME Advantages STATE/GIVE (B/C) DESCRIBE/EXPLAIN (A*/A) all objects produced are exactly the same BECAUSE the same former is used again and again it is a highly automated process WHICH means lower cost low tooling costs WHICH means lower cost high production technique WHICH means that it will be able to meet the high demand for the product Previous Next

Disadvantages SO that it can be released from the former HOME Disadvantages STATE/GIVE (B/C) DESCRIBE/EXPLAIN (A*/A) forming must have sloped sides SO that it can be released from the former designs must be simple BECAUSE complex shapes and fine detail are not possible Previous

SCT June 05 Q1(d) HOME QUESTION The drawings below show the bulb reflector cone. It is made of a thermoplastic using the vacuum forming process. outside view sectional drawing Explain two reasons why vacuum forming is a suitable process to manufacture the reflector cone. (4 marks) POSSIBLE ANSWERS it is a simple shape (1) MAKING the former simple (1) the shape has sloped edges (1) MAKING it easy to remove (1) the high quality former (1) MAKES the inside surface finish excellent (1)

GP June 03 Q1(d) HOME QUESTION CUT PLASTIC SHEET TO SIZE Complete the block diagram opposite to show, in the correct sequence, five more main stages in vacuum forming trays. PUT MOULD IN (1 mark) CLAMP PLASTIC (1 mark) Some stages have been done for you. HEAT (1 mark) (6 marks) VACUUM FORM (SUCK DOWN OVER MOULD) ANSWERS COOL (1 mark) Correct Sequence (1 mark) REMOVE/TRIM (1 mark) FINISHED TRAY

RMT June 04 Q4(b) HOME QUESTION When vacuum forming, a mould or former is required. The manufacturer of the egg box uses a mould made form MDF State two properties of MDF that make it suitable for making the mould to be used for vacuum forming. For each property give a reason why it is suitable. (4 marks) POSSIBLE ANSWERS it has no grain (1) THEREFORE it is quick and easy to shape (1) it is dense (1) THEREFORE it is possible to get a very smooth surface finish (1) it is stable when heated (1) THEREFORE it will not distort under the heat of the vacuum former (1) it is quite tough (1) THEREFORE it can be used over and over again (1)

HIPS easy to mould BECAUSE of its low melting point HOME HIPS easy to mould BECAUSE of its low melting point electrical insulator WHICH prevents short circuits waterproof WHICH keeps the contents away from the weather tough WHICH means the product can withstand knocks lightweight WHICH means that products will not be too heavy available in a wide range of colours WHICH means that products will appeal to wide market rigid WHICH means that contents are protected scratches easily WHICH means that products looks will deteriorate Next

ACRYLIC BECAUSE of its low melting point easy to mould HOME ACRYLIC easy to mould BECAUSE of its low melting point electrical insulator WHICH prevents short circuits waterproof WHICH keeps the contents away from the weather available in a wide range of colours WHICH means that products will appeal to wide market durable WHICH means that it will last a long time outside available in clear and translucent WHICH means that light can shine through products/contents visible brittle WHICH means that product will shatter if dropped scratches easily WHICH means that products looks will deteriorate

FURTHER INFORMATION GCSE Resistant Materials Text Book, Pgs HOME FURTHER INFORMATION GCSE Resistant Materials Text Book, Pgs GCSE Graphic Products Text Book, Pgs Focus on Plastics (Subjects/Technology/Focus Educational Software) TEP Materials Selection (TEP Materials Selection) http://www.technologystudent.com/equip1/vacform1.htm http://www.design-technology.org/CDT10vacuumforming.htm http://en.wikipedia.org/wiki/Vacuum_forming