Sizes of paper
•Sizes of paper •The paper gets smaller as the number increases. •E.g. Width and length of A1 is double of A2. •Paper thickness is measured in gsm (grams per square metre). •Card thickness is measured in microns (µm). One micron is 1/1000th of a millimetre. • The main ways to change the properties of paper and card: •Laminating: the gluing together of layers (plies) of card or paper to achieve a board that will meet the designer’s needs. A range of laminated boards is manufactured. •Coating: china clay or chalk can be sprayed onto the surface to give a smooth finish. •Sizing: the paper or card is sealed by a chemical agent to improve its ability to accept ink. The sizing can affect the whiteness (brightness) of the material surface.
Properties of paper and board
•Basic types of paper are: •virgin fibre paper, which has never been used before to make paper or other products •recycled paper: printed or unprinted wastepaper collected from offices or households, which contains a minimum of 75% genuine waste. • Properties and uses of paper and board: •Cartridge paper: has textured surface and is great for sketching. •Layout Paper: thin and translucent, used for designing work. •Bleed-proof paper: ink doesn't spread out on the paper. •Tracing paper: used to copy images. •Solid white board: high quality surface, ideal for printing, used for primary packaging. •Mount board: used to mount drawings and photographs. •Corrugated board: used in a lot of secondary packaging, made with fluted inner core. •Duplex board: different colour and texture on each side. •Grey board: rigid and easy to cover with paper, so graphics can be printed onto it. It's found in game boards, hardback books and covered boxes. •Many paper based boards are laminated to other materials and the composite can be adjusted to create different properties for different purposes e.g. Paper is coated with polythene to make it waterproof.
Properties and uses of thermoplastics
Flexible, hard, shiny, transparent. Made mostly from wood, so it's more sustainable.
strong, tough and flexible. Used as crisp packets.
High Impact Polystyrene (HIPs):
rigid, comes in different colours. Used for making medicine boxes. Fairly cheap
Polyvinyl Chloride (PVC):
Cheap and durable, easy to print on but quite brittle. Used for blister packs.
Properties and uses of sheet and block modelling materials
Foam core board:
lightweight, polystyrene sandwiched between 2 pieces of paper/card. It will cut with
a clean edge.
Corrugated Plastic sheet:
Lightweight, rigid and weatherproof. Fairly stiff but can still be bent into
Expanded Polystyrene Foam (Styrofoam):
Lightweight, can be shaped using a hot wire cutter. Some
type are quite crumbly.
More compact, so you can work on it with machine tools without it crumbling.
Spiral wound tubes: Paper wound in a spiral, held together using glue.
They're light weight, but the tube shape keeps them strong. Often given a nice finish. Used for packaging
Making judgements about material properties:
Flexibility: A flexible material will be soft and movable.
Finish: If a blemish appears on the surface, the product can be finished by
Rigidity: the opposite of flexibility. Materials that have a level of rigidity are
useful for forming structural items.
Strength: A material with good strength will hold its shape under load.
Weight: Often the strength-to-weight ratio is considered.
Environmental and sustainable issues: A material can be chosen for its positive
effect on the environment. A positive quality of a material is the ease with
which can be recycled, or whether it is sourced from a sustainable outlet.