Paper and Board Flashcards
what questions should be asked when selecting materials
How do they look?
What are they commonly used for?
How can they be manufactured?
How do they perform in use?
What makes them unique - are they the most durable, the lightest etc?
what are paper and boards used for
- packaging
- drawing a sketching
- model making
selection criteria for paper and board
- how easy it is to recycle
- how expensive it is
- what it will be used for
- if it has any special properties, eg better for printing, rigidity, transparency etc.
what methods can be used to develop paper and board
- textured
- embossed
- laminated with other materials to make them waterproof
- printed on
why is it important that we are able to recycle paper
As the paper-making process involves cutting down trees to create wood pulp, as well as using harmful chemicals such as bleach, it is important that we can recycle paper and cardboard so that new wood pulp, needed to create paper, is kept to a minimum
what is paper made from
cellulose fibres in wood and grass
what is tension
a pulling force
what is compression
a pushing force
what is bending
forces at an angle to a material
what is torsion
a twisting force
what is shear
forces acting across a material
how to increase the tensile strength of paper or card
a polymer can be added to it
- it can also be laminated with a polymer
how to increase the compressive strength of paper or board
the inside can be “crimped”, this creates a wave like structure of triangles commonly referred to as corrugated cardboard
- this gives it great compressive strength as as it spreads any force applied across the waves of triangles
what does it mean when paper is scored
- it has a scratch in it which intends for the paper to be easily folded
what causes card to crease
When paper or card is folded, the forces are applied at an angle. This is a bending force on the card. The inner particles of the material are under compression, and the outer particles are under tension. This force causes the card to crease
how to increase the shear force resistance of paper or board
- laminate with a polymer
what is virgin paper
paper that does not contain recyclable material
how many times can paper and board be recycled before it had to be mixed with new fibres
7 times
how do companies respond to deforestation
by replanting trees they have removed, although they will take a while to grow back
why is the use of hardwood trees a problem when it comes to deforestation
because they take a long time to mature, around 60 yrs