Materials Selection

Overview

In this lesson (Lesson 3 of 10) students explore how the properties of materials (wood types and recycled plastics) affect product performance in an Esky design, while also judging sustainability impacts across the product life cycle. Students will compare materials using design criteria and practise making justified choices.

Learning intentions

• Students will analyse how material properties (e.g. insulation, strength, moisture resistance, weight) influence suitability for an Esky.
• Students will investigate characteristics and sustainability considerations when selecting between wood and recycled plastics.
• Students will develop and apply design criteria to make a reasoned judgement about a material choice.
• Students will communicate a justified recommendation using clear evidence from testing and research.

Success criteria

• I can match at least 3 material properties to Esky requirements and explain why they matter.
• I can describe sustainability impacts of wood and recycled plastics (including sources and disposal/recycling pathways).
• I can use design criteria to judge which material is “best overall” for a specified Esky part (lid, base, lining, outer shell).
• I can justify my choice using evidence and appropriate technical language.

Curriculum links

• AC9TDE10K06: analysing and making judgements about how characteristics and properties can be combined to create designed solutions, including sustainability considerations.
• AC9TDE10P01: analysing needs/opportunities, and investigating and selecting materials to create designed solutions.
• AC9TDE10P04: developing design criteria (including sustainability) to evaluate design ideas and solutions.
• AC9TDE10P03: selecting, justifying, testing and using suitable technologies, skills and processes, and applying safety procedures to safely make designed solutions (through safe handling and simple tests).

Lesson structure (60 minutes)

1. 0–6 min · Hook (scenario + prompt). Teacher displays two sample material items (wood offcut + recycled plastic sheet/container) and asks: “Which would you trust to keep an Esky cold for longer, and why?” Students quick-write a claim and one reason.
2. 6–16 min · Mini-teach: properties that matter. Teacher models a “property-to-requirement” mapping for an Esky: insulation/thermal behaviour, moisture resistance, rigidity/strength, weight, durability, ease of fabrication, odour/taste transfer, and safety/handling. Students complete a partially filled table: requirement → possible property → “what I would need to check”.
3. 16–28 min · Material stations investigation (safe, simple tests). Teacher groups students (5–6 per group) and rotates through three stations:

• Station A: Moisture resistance (visual check, water exposure observation using provided samples).
• Station B: Surface behaviour (feel/scratch resistance with safe tools; compare finish impact).
• Station C: Thermal performance proxy (warm/cool water soak timing or temperature change observation using simple thermometers/timekeeping). Students record observations and note limitations of each test.

4. 28–36 min · Wood and recycled plastic: sustainability analysis. Teacher facilitates a guided comparison using prompts:

• Wood: sourcing, species/type, treatment, carbon storage (where applicable), longevity, recyclability/biodegradability, and risk of moisture damage.
• Recycled plastics: what “recycled” means (post-consumer vs post-industrial), contaminants, mechanical strength limits, thermal behaviour, and end-of-life (recyclable again or not). Students add at least 2 sustainability factors for each material to their table and circle the factor they think will most influence decision-making for the Esky.

5. 36–50 min · Judgement task: best material for an Esky part. Each group chooses one Esky component focus (outer shell OR lid OR base OR insulation lining concept). Teacher provides a short decision sheet with design criteria buckets:

• Function criteria (thermal retention, durability, moisture resistance, safety)
• Sustainability criteria (responsible sourcing, waste reduction/recycling potential, likely end-of-life) Students write a judgement statement answering: “Which material should we use and why—overall?” They must include evidence from station observations plus one sustainability justification.

6. 50–58 min · Share-out + peer critique. Groups do a 60-second presentation. Peers use a “2 Stars and a Question” sentence frame: two strengths, one question about evidence or criteria alignment.
7. 58–60 min · Exit ticket. Students complete: “My material choice for my Esky part is ___ because ___ (property evidence) and ___ (sustainability reason).”

Resources

• Sample wood types (e.g. untreated softwood and/or a hardwood offcut) and pre-prepared recycled plastic samples
• Simple thermometers or temperature probes, cups, warm/cool water source, timers
• Water exposure materials (trays, blotting paper, towels)
• Safety glasses, gloves where appropriate, and clear PPE reminders
• Scratch/finish comparison tools (safe, non-sharp) and rulers/labels
• Data recording sheets/table templates and decision sheets
• Marker pens, whiteboard/slide for property-to-requirement mapping
• Waste bins and separate disposal guidance for test materials

Assessment

• Formative: teacher circulates during stations, checking students’ recording accuracy and use of appropriate technical language.
• Formative: during share-out, peers identify whether groups clearly link “property → requirement → evidence → judgement”.
• Summative within lesson: exit ticket assessed for alignment to design criteria and inclusion of both property evidence and a sustainability justification.

Differentiation

• Support: provide sentence starters for property-to-judgement (“This property helps because…”, “A sustainability benefit is…”), and a simplified criteria checklist.
• Support: offer a “choice card” that narrows options (e.g. “If moisture resistance is priority, consider…”).
• Extension: ask students to critique one limitation of their test method and propose an improved way to evaluate the same property.
• EAL/SEN: allow students to demonstrate understanding with diagrams (e.g. labelled property-to-requirement arrows) and provide word banks for terms like “rigid”, “moisture-resistant”, “insulation”, “end-of-life”, and “recyclability”.