Reinforcing and Stiffening

• There are five terms used to describe what type of force can act on a material.
• Compression is a pushing force that squashes a material.
• A bending force applies compression and tension simultaneously.
• Torsion refers to a twisting force applied to a material.
• A shear force acts across a material, such as when using scissors.
• Adding a polymer increases the tensile strength of paper or card.
• Laminating paper or card with a polymer increases its tensile strength.
• To increase compressive strength, the inner layer of card can be crimped.
• Corrugated cardboard is created by adding parallel folds to the material.
• Corrugated cardboard spreads force across its wave-like structure, increasing its compressive strength.
• Corrugated cardboard is commonly used for packaging products for transportation.
• Encapsulating involves enclosing a material in a thin film of a different material.
• Laminating and encapsulating can prevent cross-contamination in food packaging.
• Laminating can enhance the aesthetics of a product, such as adding a metallic finish.
• When paper is folded, a bending force is applied to the material.
• The inner particles of folded card are under compression, while the outer particles are under tension.
• Cutting paper with scissors applies a shear force.
• Thicker or laminated paper has greater shear force resistance.