Graphics - Materials and Components
What are the main factors in choosing paper and board?
Cost and quality (brightness/thickness) Finish Strength and weight Flexibility and rigidity Environment and sustainability
Cost and quality of paper
Expensive paper makes your item feel high quality. It also adds to the final price of the product. Expensive paper is only worth using for luxury products.
Give three types of finishes.
Fillers Paints Varnishes
Finishes
Finishes are applied to a model or product to protect it from damage and dirt and to improve its appearance.
What is PET used for?
Fizzy drinks bottles
Describe foam board
Foam board comprises of a polystyrene sheet laminated between two pieces of card. It has a good strength to weight ratio Usually white in appearance
Foam
Foam core board is made by lamination polystyrene foam between card. It's stiff but lightweight - good for mounting posters and making models.
What are bioplastics used for?
Food packaging
Greaseproof paper
For baking cups, as an example
Aluminium foil
For insulation Bacterial barrier
What is grey board used for?
Game board Hardback books Ring binders Covered boxes
Describe PVC
Good chemical and weathering resistance Cheap Durable but brittle Easy to print on Available in a variety of colours Moulded using injection moulding and extrusion
How is paper usually measured in?
Grams per square metre (gsm). It's a measure of density. It is sold up to 220 gsm, at which point it is called board.
What are the disadvantages of using recycled paper?
Harmful chemicals such as bleach may be used to make the paper white, and recycled paper isn't as strong as virgin paper.
Describe cartridge paper
Has a textured surface Good quality drawing paper
Describe HIPS
High impact polystyrene Rigid Comes in a variety of colours and thicknesses Can be vacuum formed Fairly cheap
Describe solid white board
High quality bleached surface, ideal for printing
Why is virgin paper used?
It is stronger and whiter, and usually is used for food because it reduces risk of contamination.
Give 6 types of paper.
Layout Cartidge Bleed-proof Tracing Coloured Grid
Describe duplex board
Less expensive alternative to solid white board One side is bleached and coated for printing Other is uncoated and unbleached Available in a wide variety of widths and sizes
Describe expanded polystyrene foam
Lightweight Easily shaped with a knife (more accurately with a hot wire cutter) Some are crumbly (used for protective packaging) Some dense Can be hard to get a good quality finish Can be joined using PVA or specific styrofoam adhesives. To paint it you have to 'fill' the surface
Describe corrugated plastic sheet
Lightweight Rigid Weatherproof Stiff but can be bent into shapes
Describe layout paper
Lightweight and thin paper Semi-translucent Inexpensive
Virgin paper
Made from new wood pulp, not recycled material.
Varnishing
Made of a synthetic resin (acrylic, cellulose) dissolved in an organic solvent; used to make something shiny.
Paints
Made up of a pigment (colour) and a vehicle (solvent that carries pigment). There are many types of vehicles (water, cellulose, acrylic, oil, etc.)
What is board usually measured in?
Microns (μ). It describes the thickness of the board. There are 1000μ in 1 mm.
What is mount board used for?
Model making High quality picture or drawing mounting
What is card used for?
Model-making
What is corrugated plastic sheet used for?
Modelling objects with large flat surfaces and square edges Sign boards Students' folders
Finish
Money can be saved by using cheaper recycled board laminated with high quality paper for packaging that'll be thrown away.
Are plastics sustainable?
Most plastics are made from crude oil, which will eventually be used up (so they're not sustainable). However, some plastics can be recycled. Most plastic waste still ends up in landfill sites; they don't rot away naturally so can't be composted.
What is coloured paper used for?
Mounting work Adding colour to construction models
What is duplex board used for?
Normally used for packaging (food, in particular)
Priming
Not all varnishes/paints stick well; some have to be primed first.
How does painting work?
Once the paint has been applied, the vehicle evaporates and leaves the pigment. Water based and acrylic paints take less time than oil.
What are spiral wound tubes used for?
Paper would in a spiral, held together with glue. Light but strong. Often given a nice finish. 3D printing surface. Snack containers (smarties tube)
What is acetate used for?
Photocopiable clear film See-through packaging Camera film
How can paper be laminated?
Plastic coating Aluminium foil Greaseproof paper Wax coating Foam
Thermoplastics
Plastics that can be moulded by heating and can be re-moulded if heated again
What is acrylic used for?
Point of sale stands Available as rods, tubes as well as sheets
Plaster filler
Powder mixed with water into a thick paste. This fills small cracks and improves the surface finish of foam models.
What is cartridge paper used for?
Primarily used for sketching Suitable for pencils, crayons, pastels, gouache, inks and watercolours
What is solid white board used for?
Primary packaging (for individual items)
Blow moulding
Process for making hollow plastic forms by blowing compressed air into a heated thermoplastic.
Injection moulding
Process in which hot liquid plastic is injected by force into a mould.
Line bending
Process used to bend straight lines in a heated thermoplastic
What is expanded polystyrene used for?
Protective packaging Modelling
What are the benefits of using recycled paper?
Recycled paper saves energy as less raw material is processed, and is good for the environment.
Describe grey board
Rigid Easy to cover with paper
Sizing
Sealing the absorbency of the paper's surface to accept more ink. The coating affects the brightness of the paper.
What is corrugated board used for?
Secondary packaging to protect products during transit
Give 5 types of board.
Solid white board Mount board Corrugated board Duplex board Grey board
Strength and weight
Some materials can withstand high impact force (cardboard, grey board) so can be used for heavy-duty packaging. Stronger materials are usually heavier or bulkier though - adding to transport costs.
What is foam board used for?
Some packaging Mainly mounting work and models
Laminating
Sticking together layers of thinner card to achieve a board. A whole range of boards can be made from this.
Describe acrylic
Stiff but brittle Can shape and polish edges to high gloss Wide variety of colours
Describe corrugated board
Strong and lightweight Rigid Great impact resistance Fluted inner core layered between two pieces of board Usually brown
How does varnishing work?
The solvent evaporates and leaves a thin protective layer of transparent varnish. Using UV varnish on paper gives it a professional-looking finish and makes it more durable.
Fillers
These are used to fill the cracks or holes in a surface (particularly in modelling).
Describe mount board
Thick coloured rigid board Usually constructed of multiple layers
Describe bleed-proof paper
Thin paper Limits the amount of bleed from ink to provide a sharp edge for marker work (ink bleeds on some paper because paper fibres suck ink away)
Describe tracing paper
Thin, translucent Proportionally high cost
Why do we laminate?
To get a composite of different qualities for different purposes
Flexibility and rigidity
To make 3D products, paper and board must easily fold over without breaking but rigid enough to keep its shape.
Describe polypropylene
Tough Flexible Good impact resistance Available in a variety of colours Can be moulded using injection/blow
Describe PET
Tough and very good at keeping the fizz in
What is HIPS used for?
Toys Jewel CD cases Yoghurt pots
Wood filler
Used for balsa wood, plywood or MDF
What is layout paper used for?
Used for general design work (sketching)
What is grid paper used for?
Used in easy sketches for dimensions quickly (isometric, etc.)
What is tracing paper used for?
Used to copy images
What is bleed-proof paper used for?
Used when drawing with felt-tips or marker pens
Environment and sustainability
Using recycled materials preserves woodland and saves energy that would have been used to pulp new wood. However, they may contain toxic chemicals unsuitable for packaging food. Laminated paper is also hard to recycle, because it is difficult to separate paper from other materials.
How are plastics shaped and formed?
Vacuum forming Blow moulding Injection moulding Line bending
Vacuum forming
Vacuum forming is a process in which simple hollow shapes are created by sucking air from underneath a heated thermoplastic sheet (HIPS) draped over a mould (remember *draft angles* and *rounded edges* for the mould!)
Describe expanded polystyrene
Very light Impact absorbing Styrofoam
Give 4 types of thermoplastics
*Acetate* *Polypropylene* *HIPS* *PVC* Expanded polystyrene Acrylic Bioplastic PET
What are the steps to line bending?
1. A line is marked on the thermoplastic using nonpermanent pen. 2. The plastic is heated evenly on both sides until it is soft. The heating elements used on the strip heater should not be touched. 3. Finally, the plastic is bent along the line using a jig (mould).
What are the benefits of using jigs and formers? (2 points)
1. Accurately locate, bend, or aid in the construction of a product 2. Saves time by making it possible to create identical items
What are the steps to injection moulding?
1. An expensive mould is made normally from steel. 2. Granules of plastic are placed in the hopper. 3. Heaters melt the plastic into a hot liquid which is pushed towards the mould by an Archimedean screw. 4. A hydraulic ram forces the plastic under huge pressure into the mould. 5. The mould is cooled and the object is released.
How does priming work?
1. Clean surface 2. Prime the surface; this is a first coat that seals the surface of the material and gives the finish something to stick to. 3. Apply the finish (brushes, spray cans, rollers) in several thin coats; each will dry quickly and be less likely to have drips/streaks. 4. Smooth the finish using fine sandpaper after each coat has dried. Wipe dust off with clean cloth before applying the next coat.
What are the three ways of achieving different properties of card or paper?
1. Coating 2. Sizing 3. Laminating
What 4 main materials are used for block modelling?
1. Foam core board 2. Corrugated plastic sheet 3. Expanded polystyrene foam 4. Machining foam
How is the size of paper measured?
1. Paper going from A0 (area of 1m2) to A1, A2 and so on. 2. As the paper gets smaller the number increases. 3. A1 is half the size of A0, A2 is half the size of A1 and so on. 4. The width of A3 paper is the length of A4. The length of A3 paper is double the width of A4.
How is filler applied?
1. Test on a sample to check suitability. 2. Lightly rub down the surface using sandpaper to give a rough surface for the filler to stick to (keying) 3. Make sure the surface is clean. 4. Apply filler to needed areas and leave to dry until hard. 5. Sand filler back to a smooth flat surface using rough then smooth sandpaper. 6. Repeat if necessary
Describe card
A rigid surface that's easy to print onto.
What are the steps to blow moulding?
1. Using a machine similar to an injection moulding machine, thermoplastic is heated to produce a hot tube of plastic to use for the moulding process. 2. The mould is wrapped around this tube which is heated from the outside. 3. Compressed air is pushed into the mould which makes the plastic expand into the mould. 4. The mould is cooled and the finished product is released from the machine.
What is expanded polystyrene foam used for?
3D models
Wax coating
Also for waterproofing (e.g. coffee cups)
What is machining foam used for?
Architectural models
Describe coloured paper
Available in different colours and thickness (versatile)
Describe bioplastics
Biodegradable, plant-based
What is PVC used for?
Blister packs Vinyl records Insulation for electrical wires
Plastic coating
Can be coated with polythene to make it waterproof
Describe grid paper
Can be printed with a square or isometric grid
What is polypropylene used for?
Chairs Storage boxes Heavy duty bottles Sometimes used in crisp packets
Coating
China clay or chalk is sprayed onto the surface to make it smoother.
Describe acetate
Clear but not tough Flexible Shiny and transparent/translucent Usually in thin sheets Partially biodegradable due to plant-base
Describe machining foam
Compact (much more so than expanded polystyrene) Can be worked on without crumbling Detailed pieces