Cambridge Syllabus Notes

Design & Technology (0445) – Materials, Properties & Suitability for End‑Use

1. Why Materials Matter in Design

Materials determine whether a product meets its functional, aesthetic, economic and sustainability goals.
Choosing the right material is a continuous decision throughout the design process – from the initial brief to the final evaluation.
The examples below use textiles, but the same principles apply to the other specialist options (Resistant Materials, Systems & Control, Graphic Products).

2. Full Design‑Process Scaffold (Materials‑Centred)

Stage (AO)	What the Student Must Do	Materials‑Focused Activity (example)
1 – Identify the Need & Write a Design Brief (AO1)	Analyse the problem, list constraints and opportunities.	Brief: “Design a lightweight, waterproof jacket for teenage hikers that is affordable, recyclable and stylish.”
2 – Develop a Specification (AO1)	Write quantitative (e.g. tensile strength ≥ 500 MPa) and qualitative (e.g. soft hand) criteria.	Water‑repellency ≥ 5 mm, fire‑rating ≤ 0.5 s ignition, colour fastness ≥ 4 / 5.
3 – Research Materials & Existing Products (AO1)	Use textbooks, manufacturers’ data sheets, standards (ISO, ASTM), shop visits and user interviews.	Collect data for polyester‑cotton blends, GORE‑TEX membranes, recycled nylon.
4 – Idea Generation & Concept Development (AO2)	Sketch alternatives, use mind‑maps or SCAMPER, consider how each material influences form and function.	Concepts: woven jacket, laminated shell, 3‑D‑knitted panel.
5 – Material Selection & Evaluation (AO2/3)	Create a weighted decision matrix, score each material against every specification point, and justify the choice.	Matrix shows polyester‑cotton blend scores highest for strength, cost and recyclability.
6 – Implementation – Making the Product (AO2)	Plan preparation (pre‑shrinking), shaping (cutting, folding), joining (stitching, ultrasonic welding) and finishing (DWR coating, anti‑pilling).	Use a CNC fabric cutter, then seam‑seal with heat‑activated tape.
7 – Testing & Evaluation (AO3)	Carry out practical tests, record results, compare with the specification and suggest improvements.	Water‑penetration test (ASTM D2261), tensile test (ASTM D5034), abrasion (Martindale), fire‑spread (BS 5867‑2).
8 – Health & Safety (AO1)	Identify risks, use appropriate PPE and safe work‑practice.	Ventilate when cutting synthetic fibres; wear gloves and eye‑protection when applying adhesives.
9 – Communication & Use of Technology (AO2)	Produce technical drawings, CAD models, exploded views and a presentation board.	Pattern‑making in CLO 3D, exploded view in Fusion 360, PDF portfolio.
10 – Design in Society & Sustainability (AO3)	Analyse life‑cycle, carbon footprint, social impact and end‑of‑life options.	Calculate CO₂e for raw material extraction, use a “sustainability scorecard”, propose recycling or up‑cycling.

3. Common Content – Key Points (All Specialist Options)

Design brief & specification: clear, measurable criteria (AO1).
Research: reliable sources, data sheets, standards, user feedback.
Idea generation & selection: divergent thinking, evaluation matrix, justification (AO2).
Implementation: preparation, shaping, joining, finishing – linked to chosen material.
Testing & evaluation: match each specification point to a test; record, analyse and suggest improvements (AO3).
Health & safety: risk assessment, PPE, safe handling of chemicals and equipment.
Communication & technology: hand sketches, orthographic & isometric drawings, CAD/CAM, 3‑D visualisation, digital portfolios.
Design in society & sustainability: life‑cycle analysis, carbon footprint, recycling symbols, social & economic impact.

4. Specialist Options Overview

4.1 Resistant Materials

Core topics: material properties, preparation, shaping, joining, finishing, smart/modern materials, environmental symbols.
Typical properties to test: strength, hardness, elasticity, thermal conductivity, corrosion resistance, fire‑rating.

4.1.1 Typical Materials & Their Characteristics

Material	Typical Strength (MPa)	Density (kg·m⁻³)	Key Advantages	Key Disadvantages	Common Uses in D&T
Aluminium (6061‑T6)	≈ 310	2700	Lightweight, corrosion‑resistant, easy to machine	Lower strength than steel, soft surface	Bike frames, aircraft skins, heat‑sinks
Hardwood (e.g., oak)	≈ 90	710	Good wear resistance, attractive grain	Moisture swelling, heavier than softwoods	Furniture, tool handles, decorative panels
Polypropylene (PP)	≈ 35	900	Low cost, chemical resistance, recyclable	Poor UV stability, low impact resistance	Packaging, automotive interiors, laboratory equipment
Glass‑Fiber Reinforced Polymer (GFRP)	≈ 150‑200	2200	High strength‑to‑weight, corrosion‑free	Brittle, careful moulding required	Boat hulls, sports equipment, structural panels

4.1.2 Smart / Modern Materials (Syllabus Requirement)

Thermo‑chromic inks: change colour with temperature – used in novelty packaging.
Shape‑memory alloys (e.g., NiTi): return to a pre‑set shape when heated – used in self‑locking fasteners.
Phase‑change materials (PCMs): store/release latent heat – incorporated in insulated jackets.

4.1.3 Product‑Testing Checklist (Links to AO3)

Property	Test Method (IGCSE level)	What to Record	Pass/Fail against Specification
Tensile Strength	Grab‑tensile test (ASTM D5034)	Maximum load (N) / cross‑sectional area (mm²) → MPa	≥ specified value?
Hardness	Brinell or Rockwell hardness test	Hardness number (HB or HR)	Meets required range?
Thermal Conductivity	Steady‑state heat‑flow method	W · m⁻¹ · K⁻¹	Within design limits?
Corrosion Resistance	Salt‑spray test (ASTM B117) – time to first rust	Hours of exposure	Meets durability target?
Fire Behaviour	Vertical flame test (BS 5867‑2)	Ignition time, after‑flame time, melt‑drip	Within safety limits?

4.1.4 Environmental & Recycling Symbols (Syllabus Sub‑topic)

♻️ Recyclable – material can be re‑processed into a new product.
⚠️ Hazardous – requires special disposal (e.g., certain composites).
🌱 Biodegradable – breaks down naturally within a reasonable time‑frame.
Include the appropriate symbol on the product label and on the design portfolio.

4.2 Systems & Control (Sidebar)

Core concepts required by the syllabus: structures (static & dynamic), mechanisms (levers, gears, cams), basic electronics (circuits, sensors, actuators), simple control systems (on/off, feedback).

Link to Materials: the choice of material influences strength, weight and flexibility of structural components and the durability of moving parts.

Example – Tensioned Fabric Pavilion

Structure – steel cables (high tensile strength) hold a polyester‑coated membrane (lightweight, weather‑proof).
Mechanism – winches with gear reduction raise/lower the membrane.
Control – limit switches stop the winch when the desired tension is reached; a simple feedback loop maintains shape under wind load.
Testing – measure membrane sag under a simulated wind load and compare with calculated deflection.

4.3 Graphic Products

Key drawing skills: orthographic projection, isometric drawing, perspective, exploded views, technical sketches, pattern making.
Technology used: CAD (AutoCAD, Fusion 360), vector graphics (Illustrator), 3‑D modelling for visualisation, specialised pattern‑making software (CLO 3D, Optitex).
Relevance to textiles: creating garment patterns, technical specification sheets, visual presentations and marketing material.

Workflow for a garment

Hand sketch the concept.
Develop a flat pattern in a CAD pattern‑making tool.
Produce orthographic drawings of seams, fasteners and any technical components (e.g., waterproof zippers).
Generate an exploded view showing layers – fabric, lining, membrane coating.
Export drawings and a bill of materials to PDF for the design portfolio.

5. Textiles – Detailed Properties, Characteristics & Suitability

5.1 Types of Fibres

Natural fibres: cotton, wool, silk, linen, jute.
Synthetic fibres: polyester, nylon, acrylic, polypropylene.
Blended fibres: combinations such as cotton‑polyester, wool‑acrylic, or high‑performance mixes (e.g., aramid‑polyester).

5.2 Key Properties & Simple Test Methods (IGCSE level)

Property	What It Describes	Typical Test (IGCSE)
Tensile Strength	Resistance to breaking under tension	Grab‑tensile test (ASTM D5034) – σ = F/A
Elasticity (Elongation)	Ability to stretch and recover	% elongation at break in the same tensile test
Absorbency	Moisture uptake – important for comfort	Weigh dry sample, soak, blot dry, re‑weigh; calculate % gain
Thermal Insulation	Retention of heat	Hot‑plate method or “hand‑warmth” comparative test
Durability (Abrasion)	Resistance to wear	Martindale tester – cycles to failure
Fire Resistance	Ignition time, flame spread, melt behaviour	Vertical flame test (BS 5867‑2) – record ignition & after‑flame time
Weight (GSM)	Mass per unit area – influences drape & handling	Weigh a 10 cm × 10 cm square (g) × 100 = g · m⁻²
Drape	How the fabric hangs under its own weight	Standard drape test – compare angle of drape circle with reference values
Texture & Hand	Surface feel, smoothness, perceived comfort	Subjective assessment using a hand‑feel chart (soft, smooth, coarse, etc.)

5.3 Comparative Table of Common Fibres

Fibre	Source	Typical Tensile Strength (MPa)	Absorbency	Thermal Insulation	Fire Behaviour	Typical End‑Uses
Cotton	Plant – seed‑cotton	≈ 300	High	Moderate	Flammable; burns quickly	Casual clothing, towels, denim
Wool	Animal – sheep	≈ 250	Moderate (wicking)	High (crimp & trapped air)	Self‑extinguishing; chars	Winter coats, blankets, suitings
Silk	Animal – silkworm cocoon	≈ 500	Low	Low	Flammable; melts	Formal wear, linings, decorative textiles
Polyester	Synthetic – PET polymer	≈ 600	Low (hydrophobic)	Low‑to‑moderate	Melts, may drip; can be flame‑retarded	Sportswear, upholstery, outdoor garments
Nylon	Synthetic – polyamide	≈ 800	Low	Low	Melts; can be treated for fire‑resistance	Parachutes, swimwear, technical textiles
Polypropylene	Synthetic – polypropylene polymer	≈ 400	Very low (hydrophobic)	Low (does not absorb water)	Self‑extinguishing; does not melt easily	Geotextiles, disposable garments, packaging

5.4 Matching Fibre Properties to End‑Use Requirements

End‑Use	Key Functional Requirements	Best‑Fit Fibre(s) & Reasoning
Summer T‑shirt	High absorbency, soft hand, low weight	Cotton – excellent moisture uptake & comfortable feel.
Mountain Hiking Jacket	Water‑repellency, high tensile strength, wind resistance, moderate insulation	Polyester‑cotton blend with DWR coating – combines strength & breathability; optional insulated lining of wool or a PCM‑filled layer.
Fire‑fighter Protective Overalls	Fire resistance, durability, low melt, abrasion resistance	Aramid‑based blends (e.g., Kevlar®) or flame‑retarded cotton/polyester with a silicone‑based outer coating.
Medical Surgical Gown (disposable)	Liquid barrier, low absorbency, lightweight, cost‑effective	Polypropylene non‑woven – hydrophobic, inexpensive, recyclable.
Parachute Canopy	Very high tensile strength, low stretch, lightweight	Nylon (high‑tenacity) – excellent strength‑to‑weight and low elongation.
Luxury Evening Dress	High sheen, smooth hand, drape, low stretch	Silk – natural luster, soft hand, excellent drape.

5.5 Smart Textiles (Optional Extension)

e‑textiles: conductive yarns (silver‑coated nylon) for embedded sensors or heating elements.
Phase‑change fibre blends: store body heat and release it when temperature falls – used in high‑performance outdoor apparel.
Colour‑changing fibres: thermochromic or photochromic dyes that respond to temperature or UV light – used in fashion and safety garments.

6. Sustainability, End‑of‑Life & Recycling

Life‑cycle stages: raw‑material extraction → manufacturing → distribution → use → end‑of‑life (reuse, recycle, energy recovery, landfill).
Carbon‑footprint calculation (simple method): multiply material mass (kg) by an emission factor (kg CO₂e · kg⁻¹) taken from a published database.
Recycling symbols to include on the product label:
- ♻️ Recyclable
- ⚠️ Hazardous (e.g., composites with epoxy resin)
- 🌱 Biodegradable
Design for disassembly: use mechanical fasteners rather than permanent adhesives where possible, and select fabrics that can be separated from liners for separate recycling streams.
Case study – Recycled Polyester Jacket:
1. Material: 100 % recycled PET bottles.
2. Manufacturing impact: 75 % lower CO₂e than virgin polyester.
3. End‑of‑life: can be re‑melted into new polyester fibres.

All tables, test methods and symbols are aligned with the Cambridge IGCSE Design & Technology (0445) syllabus and the associated assessment objectives (AO1‑AO3). Use this note as a scaffold for lesson planning, student revision and exam preparation.

Properties and characteristics, suitability for end-use