Plastic theory

• What are the properties of plastic?

  Brittle, durability, toughness, strength, moisture resistant, buoyant, chemical resistant, flexible, good heat insulator
• What does it mean if a plastic is described as brittle?

  It cracks or breaks easily
• What does moisture resistant mean in terms of plastic properties?

  It is the ability to repel liquids
• How does toughness relate to plastic properties?

  Toughness refers to the ability to withstand sudden blows without breaking
• What are the basic raw materials used in the manufacture of plastics?

  Oil, natural gas, and coal
• What are biopolymers?

  Plastics made from renewable resources such as starch, sugar, and cellulose
• What is the significance of biopolymers in plastic disposal?

  They can decompose and return nutrients to the soil
• What are the two main groups of plastics?

  Thermoplastics and thermosetting plastics
• What is a thermoplastic?

  A plastic that can be reheated and reshaped multiple times
• What does 'plastic memory' refer to in thermoplastics?

  It refers to the ability of thermoplastics to return to their original shape when reheated
• Give an example of a thermoplastic.

  Acrylic
• How do thermosetting plastics differ from thermoplastics?

  Thermosetting plastics become rigid and non-flexible after being formed
• What is a good analogy for thermosetting plastics?

  An egg, which becomes solid when heated and cannot return to its liquid state
• Name two examples of thermosetting plastics.

  Urea Formaldehyde and Epoxy Resin
• What forms can plastic supply come in?

  Granules, powder, synthetic, fabric, sheet, tube, rod
• What are the stages of finishing plastic?

  1. Cross Filing: Remove large bumps at a 90-degree angle.
  2. Draw Filing: Smooth along the cut line at a 90-degree angle.
  3. Wet-and-Dry Paper: Make the surface very smooth.
  4. Polish: Apply polish with a cloth and remove excess.
• What is the purpose of a steel rule in marking out tools?

  Used for measuring and marking out work
• What is the function of an engineer's square?

  Used for drawing lines across material at right angles
• What is the use of a coping saw?

  Used to cut curved shapes in plastic
• What is the purpose of a band saw?

  Used for cutting straight or curved lines
• How does a strip heater work?

  It heats acrylic to make it malleable for bending
• What is the function of a laser cutter?

  It cuts or engraves sheet plastic using a laser
• What is rapid prototyping in the context of plastic manufacturing?

  It refers to 3D printing processes to create three-dimensional objects
• What is the first stage of filing plastic?

  Cross Filing to remove large bumps
• What is the purpose of jigs and formers in plastic shaping?

  To ensure plastic is shaped exactly as desired
• What is the advantage of using plastic over other materials?

  Durable, tough, strong, and flexible
• What is a disadvantage of using plastic over other materials?

  Can snap or scratch easily
• What is the purpose of a junior hacksaw?

  Used for intricate details in plastic cutting
• What is the function of a pillar drill?

  Used to drill specifically sized holes
• What is the purpose of a belt sander?

  Used to sand flat edges or outside curves
• What is the use of odd-leg calipers?

  Used to draw lines parallel to an edge
• What is the function of dividers?

  Used to mark out circles or arcs on material
• What is the purpose of a scribe?

  Used to mark lines on material
• What is the function of a marking gauge?

  Used for marking out measurements on material
• What is the purpose of a sliding bevel?

  Used for transferring angles
• What is the function of a tenon saw?

  Used for cutting joints in wood and plastic
• What is the purpose of a sash cramp?

  Used to hold pieces of material together while they are being glued
• What is the function of a G-clamp?

  Used to hold materials together tightly
• What is the purpose of a wood vice?

  Used to hold wood securely while working on it
• What is the function of a mitre saw?

  Used for making angled cuts in wood and plastic