papers and boards Flashcards
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what is paper made from
Paper is made from wood pulp from trees
at what weight is a paper clasified as a board
Paper with a weight of 170gsm or more is classified as board
how many times can paper be recycled
Paper can only be recycled 5 or 6 times
what percentage of recylced paper is made from virgin pulp
Recycled paper contains between 10% to 80% virgin pulp
why are papers given spray
Paper can be given spray on coatings to improve its texture and performance.
what’s grams per square metre
the weight of paper and card, abbreviated as g/m2 or gsm, this is the weight of a single sheet of paper measuring 1mX1m. Anything weighing greater than 170gsm is classified as a board.
what is a micron
one-thousandth of a millimetre - used to measure the thickness of paper. Depending on the type of board, different sheets may weigh the same but different thicknesses.
what is virgin fibre paper
paper made from entirely from ‘new’ wood pulp. Wood fibres are called cellulose. Chemical are used to break down or ‘pulp’ the fibres by removing the lignin.
what is recycled paper
paper made from wood pulp using some re-pulped paper. Because of the environmental impact of making virgin fibre paper it is becoming more expensive. Recycled paper is commonly used instead.
what is the mechanical pulping process
method of mechanically separating wood fibres to make paper. Raw wood chippings are soaked in 100 times their weight in water and pulverised with large steel rotor blades.
what is the chemical pulping prosses
chemical pulping process uses caustic soda and sodium sulphate to break down the wood pieces and chemically remove the lignin, this separates the fibres without breaking them producing a much stronger pulp.
what is lamination
Surface coatings applied during the paper making process are sometimes called laminates.
what are the two types of laminates
spray on coatings which reduce absorbency to give clearer printing and increase strength. - normally applied during the printing process.
The other form of laminating (what we use in school, picture on right) involves applying a film of clear plastic between 1.2 and 1.8mm thick to either one or both sides of paper or thin card. It is usually applied to finish documents such as menus, posters, signs, identity badges and other printed documents
what is the perpouse of lamination
- Improve strength and resistance to bending, creasing or ripping
- Waterproof the document, allowing it to be wiped clean and prevent smudging or going soggy
- Improve appearance, making the document shiny,
- Increase the lifespan of the printed document.
