Assesment 1 Flashcards
Properties and definition of thermoplastics
During processing the chemical composition remains unchanged and the material can be reshaped many times
Properties and definition of Thermosetting plastics
Changes chemically during the moulding process and cannot be reshaped any further
Properties of acrylic
Good light transmitting properties, hard and ridged and is available in lots of colours. Used for display signs and jewellery
What does PVC stand for
Polyvinyl chloride
Properties of PVC
Biologically and chemically resistant, cheap, durable and easy to assemble. Water proof and used in clothing
Define electrical conductivity
Is a measure of a materials ability to conduct an electric current
Define thermo conductivity
Is the property of a material that indicates it’s ability to conduct heat
4 common forms of metal
Sheet, angle, channel, flat bar
Properties of high carbon steel
Very hard and brittle, less tough and malleable(easily formed) , difficult to cut can withstand wear and shearing. Used for cutting tools and saw blades
Properties of abs
Good shock absorbance, tough, stability under load is excellent, 2x cost of producing polystyrene although it has better hardness, gloss, toughness and electrical insulation properties. Some products- automotive body parts, head gear
Properties of polystyrene
2 forms: expanded and ridged, transparent, colours well, has impact resistance, light and buoyant, good insulator. Used for food containers, packaging and insulation
Material selection considerations (6)
•function requirements
•manufacturing demands (scale of production, sustainability)
•environment (corrosion resistance)
•Availability (common forms, sizes)
•cost
•appropriate joining methods
Properties of graphene
Made from honeycomb sheets of carbon just one atom thick, one of the lightest, thinnest, best heat and electricity conducting materials ever discovered, almost completely transparent
Applications of graphene
Could revolutionise everything from computing, car tires, solar cells to smoke detectors
Properties of ferrous metals
Contains iron, small amounts of other metals or elements added, magnetic and little resistance to corrosion
Types of ferrous metals
Cast iron, carbon steel, alloy steel
Properties of non-ferrous metals
Do not contain iron, non magnetic, usually more resistant to corrosion than ferrous metals
Types of non ferrous metal
Aluminium, zinc, lead, copper
Properties of manufactured boards
Large availability, veneers can be applied, large stable sheets and uniform thickness and quality
Applications of manufactured boards
Doors, internal panelling, skirting boards
Definition of holograms
An image that appears to be 3D which can be seen by the naked eye, a photographic recording of a light field rather than a image formed by lens
List the 3 types of hologram
Reflection, transmission, EM based
Reflection hologram definition
Illuminated by a white light source on the viewing side of the hologram. Light is reflected from the hologram to show the image
Transmission hologram definition
Views by illuminating from the rear with a laser. Advantages are that it can be a very sharp image with great detail and great depth
Embossed hologram definition
Found on credit cards. Embedded on the plastic film backed with reflective aluminium. The aluminium reflects incident light back through the hologram activating it.
How do photochromic materials work
Change colour as the temperature changes
Used for photochromic materials
Used on contacts thermometers and test strips on the side of batteries(heat comes from the resistor) also used as food packaging materials to show when food is cooked to the correct temp
