Papers and boards - Specialist Technical Principles

All the theory we did in Y10. Graphics DT AQA GCSE

How is paper made

• Trees are cut down, debarked and chipped

• Chips are made into pulp by using chemicals

• The pulp is mixed with chalk and chemicals to change opacity and absorbency of the paper - this is called sizing

• The excess water and chemicals are drained by calendaring, pressing the paper to a uniform thickness

• The finished paper will be dried and wound into large rolls to be sent to factories

What are the available forms of paper

• Sheet - single piece of paper

• Roll - used on an industrial scale to be fed into machinery for the printing of books and magazines

• Ply - two or more layers of paper combined

How many mm in a micron

1 mm = 1000 microns

How to measure paper

• Length and width (mm)

• Weight (gsm)

• Thickness (microns)

Corrugated card

• Corrugated with many layers so that is durable

• Used for parcels

Tracing paper

See-through so you can use it for mathematical drawings and tracings

Duplex board

• Lined with wax

• Used for food and drinks packaging

Cartridge paper

• Bleed proof

• Thicker than normal layout paper

• Used for art

Types of fastener and what they do

 

• Treasury tag - connects varying numbers of sheets through punched holes

• Binder clip - holds sheets together, can be removed

• Staple - holds sheets together in a permanent way, using a stapling tool

 

Types of seals and how they work

• Wax seal - wax seal melted over the area, then left to harden

• Gummed envelope - a water soluble gum along the envelope flap. Moisten (lick) to seal

• Self-adhesive envelope - a covering over the glue is peeled off to be able to seal an envelope

 

Types of binding and how they work

• Saddle stitch - wire on a role is fed through pages and cut to make staples

• Perfect bound - pages are glued at the spine

• Comb bound - combs fit through punched holes. Low cost

 

Hand tools for cutting paper and what they do

• Guillotine - used to trim paper accurately

• Perforating tool - cuts perforations, allows tearing

• Craft knife - used for cutting and scoring

Safety tools when cutting and how they work

• Metal ruler - keeps fingers away from sharp blades

• Cutting mat - non slip. Protects table underneath

How does die cutting work

• Die is pressed against the card and the steel cuts into the card

• Sharp blades are arranged to produce a cut, while rounded blades are arranges to produce a crease

• The arrangement of sharp and rounded blades makes a net, as the card is stamped by the die cutter

• The dies are pressed or rolled onto the paper, cutting multiple layers at once

How does laser cutting work

• A design is created on 2D design and set to the laser cutter

• Using high power lasers, the laser cutter burns the material to cut or engrave it, depending on the design

Advantages of using a laser cutter

• It can engrave and cut

• It can cut complex shapes precisely

• It is safe

What is the purpose of laminating

• To improve paper’s properties

• Makes it waterproof, more durable, less likely to fade

How does laminating work

• A polymer pouch covers the paper

• Then it is bonded by heat in a machine

How does perforating work

• Uses a toothed cutter to create a series of cuts, allowing the material to be torn easily

 

How does scoring / creasing work

• A blunt tool like a creaser is used so that paper can be folded

Advantages of offset lithography printing

• Inexpensive

• Prints on a variety of papers

• High speed

DIsadvantages of offset lithography printing

• High set up costs

• May stretch paper or affect colour

What is embossing

• Creating 3d images on papers and boards

How does embossing work

• A male and female die is made with the relief pattern cut into the surface

• The plates are then pressed into the paper using heat and pressure

• Can be used for braille or to improve aesthetics

What is UV spot varnishing

• Used to enhance an image or text

• Protective finish

How does UV spot varnishing work

• Varnish is sprayed onto the surface after printing

• Protects the print and gives it a high-gloss finish

• The varnish is dried out before other processes like folding

• The sheets are passed under UV lights to dry the varnish immediately

 

 

What are the steps of offset lithography printing (6 marks)

• Offset lithography printing is used in mass production

• Litho-printing cylinder has a relief image. This is a mirror image

• Litho-printing aluminium is dampened with water to repel ink

• Ink is applied to metal plate

• Ink is transferred to the offset blanket cylinder as it rotates

• Ink is transferred to the paper or card as it goes through rollers

• Only one colour of the CMYK spectrum can be done at a time

Why is the CMYK spectrum used to print on white paper

• It uses a combination of individual colours to block out the white paper background at varying levels, to create an image that the human eye will see as a full colour image

 

What are some things to consider when selecting materials for a product and why

• Aesthetics

  • how it will appear to the customer

  • use of colours, textures, or forms

• Function

  • Does it perform well

• Cultural factors

  • What is trending

  • Faith and ethnicity of the user

  • E.g. The implications the colour red has in different countries

• Physical properties

  • Absorbency

  • Density

  • Fusibility

• Costs

  • How much it costs to convert raw material