1. Choose 2 machines that you used in the fabrication of your desk tidy. With these machines in mind, outline WPH&S (work, place, health & safety) considerations that must be adhered to when using these machines. Include photographs of your chosen machines (OnGuard may be an excellent resource for this question).
| BAND SAW |
* DO NOT use this machine unless a teacher has instructed you in its safe use and operation and has given permission.
Safety glasses mush be worn at all times in work areas.
Sturdy footwear must be worn at all times in work areas.
Rings and jewellery mush not be worm.
Long and loose hair must be contained.
Close fitting/protective clothing must be worn.
Hearing protection may be required for some operations.
PRE - OPERATIONAL SAFETY CHECKS
1. Ensure no slip/trip hazards are present in work spaces and walkways.
2. Locate and ensure you are familiar with the operation of the ON/OFF starter and E-Stop (if fitted).
3. Check that all guards are in position.
4. Ensure push stick is available.
5. Lower the blade guide and guard to full effect.
6. Start the dust extraction unit before using the saw.
7. Faulty equipment must not be used. Immediately report suspect machinery.
OPERATIONAL SAFETY CHECKS
2. Locate and ensure you are familiar with the operation of the ON/OFF starter and E-Stop (if fitted).
3. Check that all guards are in position.
4. Ensure push stick is available.
5. Lower the blade guide and guard to full effect.
6. Start the dust extraction unit before using the saw.
7. Faulty equipment must not be used. Immediately report suspect machinery.
OPERATIONAL SAFETY CHECKS
*Keep fingers off the line of the cut at all times
1. Never leave the machinge rinning unattended.
2. The workpieve should be fed forward evenly and held firmly on the table to ensure effective control during cutting whilst keeping hads in a safe position
3. Use a push stick when feeding material past the blade.
4. Do not force a wide blade on a cut of small radius. Use relief cuts when cutting sharp curves.
5. Before making adjustments switch off the saw and bring the machine to a complete standstill.
6. Stop the machine before attempting to back the work away from the blade.
4. Do not force a wide blade on a cut of small radius. Use relief cuts when cutting sharp curves.
5. Before making adjustments switch off the saw and bring the machine to a complete standstill.
6. Stop the machine before attempting to back the work away from the blade.
HOUSEKEEPING
1. Switch off the saw and rest all guards to fully closed position
2. Leave the maching in a safe, clean and tidy state
FORBIDDEN
Attempting to cut very small items
cutting cylindrical or irregular stock
Attempting to cut very small items
cutting cylindrical or irregular stock
Disc sander:
The Disk Sander is used to smooth materials such as woods and plastics. It is also used to remove small amounts of waste material. It is a dangerous machine if safety is ignored.
Goggles must be worn at all times. Hands and fingers must be kept as far away from the rotating disk as possible. A guard, making it impossible to use the wrong portion of the rotating disk must be in permanent position. If the right hand side of the disk were to be used the material would be quickly lifted upwards. This would be very dangerous. A Dust extraction unit should be connected to this type of machine. This is very important as it will extract dust particles produced when the machine is in use. The disk rotates in an anti-clockwise direction which means only the left portion of the disk should be used. The rotation of the disk holds the work down on the table. Lose clothing must be held back by an apron. Long hair must be tied back for personal safety. The machine operator carefully using the disk sander. The material is carefully and lightly pushed against the rotating disk and at the same time moved from left to right. Only the exposed part of the disk can be used because of the position of the guard.
Goggles must be worn at all times. Hands and fingers must be kept as far away from the rotating disk as possible. A guard, making it impossible to use the wrong portion of the rotating disk must be in permanent position. If the right hand side of the disk were to be used the material would be quickly lifted upwards. This would be very dangerous. A Dust extraction unit should be connected to this type of machine. This is very important as it will extract dust particles produced when the machine is in use. The disk rotates in an anti-clockwise direction which means only the left portion of the disk should be used. The rotation of the disk holds the work down on the table. Lose clothing must be held back by an apron. Long hair must be tied back for personal safety. The machine operator carefully using the disk sander. The material is carefully and lightly pushed against the rotating disk and at the same time moved from left to right. Only the exposed part of the disk can be used because of the position of the guard.
# Bend saw # Sander
2. The material you are using for your desk tidy is called Polymethylmethacrylate (ACRYLIC). It has specific properties and uses. Choose 2 other common polymers and in table form give their industrial name, common name, properties and uses.
POLYTHENE AND POLY STYRENE
Monomers can join together to form polymers. Addition polymers are formed from alkenes. For example:
- ethene can polymerise to form polyethene, which is also called polythene
- styrene can polymerise to form polystyrene
Ethene makes polyethene
- a typical use of polythene is for a plastic shopping bag or plastic bottle
- a typical use of polystyrene is for insulation and protective packaging
Nylon
Nylon is a synthetic fabric made from petroleum products. It was developed in 1930s as alternative to silk, although it quickly became unavailable to civilian consumers. Nylon, like many synthetics, was developed by Wallace Carothers at the Dupont Chemical Company, which continues to manufacture it today. Nylon is valued for its light weight incredible tensile strength, durability, and resistance to damage. It also takes dye easily, making nylon fabrics available in a wide array of colors for consumers.
Nylon is very sensitive to heat and should be washed and dried on cool settings. Nylon can also be hung dry, and it is favored by campers because it dries very rapidly. Nylon is a flexible textile, and as a result, it appears in a wide range of applications, from clothing to climbing equipment. Depending on how it is processed, nylon can be formed into the gossamer like threads used in stockings or into think toothbrush bristles.
3. Extrusion, injection moulding, compression moulding, vacuum forming and laminating are examples of common manufacturing processes used with polymers (Plastics). Choose one process and with the use of diagrams and bullet points outline the process.
Compression moulding is the process by which thermosetting polymers are usually formed (Figure 3).
The compression moulding process involves placing the polymer ‘dough’ into the die cavity. This ‘dough’ is carefully measured to avoid waste and minimise the amount of ‘flashing’ (fine, thin webs attached to the moulding) around the finished article.
Figure 3a. With the dies apart, the prepared polymer ‘dough’ is placed into the cavity.
Figure 3b. With the die closed, the article is formed and the small amount of flashing on each side will be removed later.
When the die is closed, heat and pressure is maintained until the condensation polymerisation process is completed.
The hot compression moulding process is used to form components from phenolic, urea and melamine thermosetting polymers, as well as alkyd resins.
Transfer moulding is different to compression moulding because the plastic is not fed directly into the die cavity. Instead it is fed into a chamber outside the die. Here it is preheated before a piston forces it through a system of runners and gates that allow it into the die cavity. When the polymer is cured through heat and pressure it is ejected from the mould. The advantage of this process is that the runner system allows the simultaneous production of many small, intricate parts and there is no ‘flashing’ around the finished article.
Rotational moulding is a unique process for manufacturing thermosoftening polymers as it produces hollow items eg. Lawnmower grass-catchers, balls and some types of children’s toys. A split mould is filled with exactly the right quantity of polymer which is then tumbled in the mould once it is bolted together. The die is rotated in a heated chamber until the polymer is completely melted. The die is removed from the chamber and continues to rotate until the polymer is set. The die halves are separated and the article removed.
4. Extension Work - Using processes acquired from your maths lessons, calculate the amount of acrylic sheet that your FINAL desk tidy represents. Show all calculations; answer needs to be in square metres.
1) Red
Lenght: (280 x 2) + (120 x 2) + 200 +1.5
Width: 80 mm
= 560 + 240 + 200 + 1.5 x 80
= 901 x 80
= 72080 mm2 (7208cm2)
2) White
leght: 200 mm
width: 60 mm
200 x 60 = 1200
1200- (3.14 x 1.9 = 5.966)
= 1194.034 mm2 (119.4034 cm2)
1200- (3.14 x 1.9 = 5.966)
= 1194.034 mm2 (119.4034 cm2)
3) Black
2(200 x 80) + (170 x 80) + 2(60 x 80) + (200 x 60)
= 32000 + 13600 + 9600 + 12000
= 67200 mm2 (6720 cm2)
4) Clear
80 x 200
= 16000 mm2 (1600 cm2)
TOTAL: 72080 + 1200 + 6720 + 1600
= 81600mm2 ( 8160 cm2 / 81.60 m2)
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