DT gcse core content

Composites definition + groups

made up of different materials which are combined to improve their properties, 3 groups : fibre, sheet, particle based

fibre-based composites

by mixing resin or concrete with fibres of glass or carbon, we can mould complex shapes, but reinforcing them with fibres makes them very strong

fibre - based composite example + use

glass-reinforced concrete used for boats/intrument cases

particle-based composites

made with smaller particles of material by mixing smaller particles of sand with larger particles of cement and aggregate, such as stones, we get a very strong and dense material

particle-based composites example + use

concrete used for buildings

sheet-based composites

often available in large sheets, made by mixing wood fibres or thin slices of wood veneers with resin, can use large sheets for furniture panels or interior construction

sheet-based composites example + use

MDF (medium intensity fibreboard) used for furniture + interior cladding

paper + board common examples + characteristics + uses

paper - variety of colours, sizes & finishes, used for newspapers…
card - thicker than paper, range of colours & finishes, easy to fold, cut and print, used for greeting card
cardboard - thickness over 300 microns, range of sizes & surface finishes, inexpensive, cut, fold and print easily, used for packaging e.g cereal boxes

what is a micron

1 millionth of a meter

ferrous metals characterisitcs + examples + why suitable for a product

contains iron + is magnetic, corrode quickly without a suitable finish, e.g stainless steel but is resistant to rust due to mixture of elements

non-ferrous metals characterisitcs + examples + why suitable for a product

do not contain iron, more corrosion resistant than ferrous metals, easier to bend, generally more expensive e.g bronze used for coins, instruments

main difference between ferrous and non ferrous metals

ferrous metals contain iron + corrode easily

similarity between ferrous and non ferrous metals

both non-renewable but recyclable

thermo polymers example + characteristics + why used in a product

soften when heated and harden when cooled, can be recycled and reheated many time, when reheated they return to original shape = plastic memory e.g nylon in cable insulation due to high temp resistance

thermosetting polymers example + characteristics + why used in a product

undergo chemical change when they set, once set cannot be reheated or remoulded e.g epoxy resin for kitchen countertops due to strong insulating properties

main difference between thermo and thermosetting polymers

thermoplastic polymers soften and can be reshaped upon heating, while thermosetting polymers harden permanently after being cured and cannot be remelted.

hardwood timbers example + characteristics + why used in each product

comes from deciduous trees that shed their leaves every year, grow slowly + take hundreds of years to grow fully, have a closer grain = usually denser, heavier, harder than softwood e.g oak used furniture due to durability

softwood timber example + characteristics + why used in each product

comes from confierous trees that have needles not leaves, grow much faster than deciduous, e.g cedar used for fencing because it's easy to work with

manufactured boards example + characteristics + why used in each product

hardwood or softwood made by gluing the fibres together, made in large sheets that are easy to work with generally cheaper than natural woods, e.g plywood used in cabinets due to strength

cotton :

Soft, breathable, absorbent, durable, wrinkles easily; used for T-shirts, jeans, and bedsheets.

Wool:

Warm, insulating, moisture-wicking, prone to shrinking; used for sweaters and coats.

Silk:

Smooth, shiny, strong, and lightweight; used for luxury clothing and accessories

polyester :

Strong, wrinkle-resistant, and quick-drying; used for sportswear, outdoor clothing, and upholstery.

Nylon:

Durable, stretchy, and moisture-resistant; used for swimwear, tights, and outdoor gear.

Acrylic:

Wool-like, warm, and lightweight; used for jumpers, blankets, and rugs.

Elastaine (spandex) :

Elastic, durable, and sweat-resistant; used for sportswear and leggings.

Viscose (rayon) :

Semi-synthetic, soft, breathable, and shiny; used for dresses, shirts, and linings.

Felt :

Non-woven, dense, and insulating; used for crafts, hats, and upholstery.

Gore-Tex:

Waterproof, breathable synthetic fabric; used for outdoor clothing and shoes.

Inputs

Devices that convert physical changes into electrical signals.

Switches

Detect user input.

Outputs

Devices that convert electrical signals into physical actions.

LEDs

Provide visual feedback.

Buzzers

Produce sound for alarms.

Motors

Create movement.

Microcontrollers

Small computer systems on a single integrated circuit.

Working Drawings

Precise, detailed drawings used to guide manufacturing or assembly.

Orthographic Projections

Show multiple views (top, front, side) of an object.

Isometric Drawings

Represent 3D objects on a 2D plane.

Exploded Diagrams

Show how parts fit together.

Life Cycle Assessment (LCA)

Evaluates a product's environmental impact from production to disposal.

Carbon Footprint

Measures the greenhouse gas emissions associated with a product or activity.

Flatpack/Self-Assembly

Minimizes transportation impact as products are shipped in compact forms.

New and Emerging Technologies

Innovations that enhance production, sustainability, or product functionality.

3D Printing

Allows rapid prototyping and customization.

AI and Machine Learning

Optimize manufacturing processes.

Renewable Energy Systems

Reduce reliance on fossil fuels.

Biodegradable Materials

Promote sustainability.

Modern Manufacturing

Relies on advanced technologies like automation, robotics, and CNC machines.

Traditional Manufacturing

Uses manual labor or simpler machinery for production.

what is an alloy

A mixture of two or more metals e.g brass or pewter- shiny,strong

electronic system elements + example

input, process, output e.g light sensor, switching, light

programming

microcontrollers detect an input from a sensor and based on its program will complete a specific output