Wood:

• Durability: Moderate. Susceptible to rot, warping, and insect infestation if not treated.
• Weather Resistance: Poor without treatment. Requires regular sealing or painting to protect from rain, sun, and frost.
• Maintenance: High. Requires regular cleaning, sanding, and re-treatment with sealant or paint.
• Cost: Generally low to medium, depending on the type of wood.
• Suitability: Can be suitable if properly treated and maintained. Attractive aesthetic. However, the maintenance requirements are a significant drawback for an outdoor bench.

Metal (e.g., Aluminium or Steel):

• Durability: High. Resistant to rot, warping, and insect infestation. Steel can be prone to rust if not treated.
• Weather Resistance: Good, especially aluminium which is naturally corrosion-resistant. Steel requires protective coatings (e.g., paint, galvanization).
• Maintenance: Low to medium. Requires occasional cleaning. Steel may need repainting to prevent rust.
• Cost: Medium to high, depending on the type of metal and the complexity of the design.
• Suitability: A very good option for an outdoor bench due to its durability and weather resistance. Aluminium is particularly advantageous.

Plastic (e.g., Polypropylene or HDPE):

• Durability: Moderate. Can become brittle with age and exposure to sunlight.
• Weather Resistance: Good. Resistant to rain, sun, and frost.
• Maintenance: Low. Easy to clean.
• Cost: Low to medium.
• Suitability: A viable option, particularly for benches where low maintenance is desired. However, the long-term durability and aesthetic may not be as desirable as wood or metal. Consider UV stabilisers to improve resistance to sunlight degradation.

Conclusion: The best material depends on the priorities. Metal (especially aluminium) offers the best combination of durability, weather resistance, and low maintenance, making it the most suitable choice for a long-lasting outdoor garden bench. Wood can be suitable with proper treatment, but requires more upkeep. Plastic is a good low-maintenance option, but may not be as durable or aesthetically pleasing.

Several production techniques are suitable for manufacturing plastic food containers. Here are three examples:

1. Injection Moulding: This process involves injecting molten plastic into a mould.

   • Advantages: High volume production, good surface finish, complex shapes can be created, relatively low per-unit cost for large batches.
   • Disadvantages: High initial tooling cost (mould creation), not suitable for low volume production, requires precise temperature control.

2. Blow Moulding: This technique is used to create hollow plastic containers. A parison (a hollow tube of plastic) is inflated inside a mould using compressed air.

   • Advantages: Suitable for producing lightweight, hollow containers, relatively fast production, good for large volumes.
   • Disadvantages: Limited to hollow shapes, tooling costs can be high, potential for uneven wall thickness.

3. Thermoforming: A plastic sheet is heated and then shaped over a mould using vacuum or pressure.

   • Advantages: Low tooling cost, suitable for producing large, thin-walled containers, good for prototypes and low-volume production.
   • Disadvantages: Not suitable for complex shapes, can result in a less durable product compared to injection moulding, may require additional reinforcing.

The choice of production technique depends on the volume of production, the complexity of the container design, the required material properties (e.g., strength, flexibility), and the budget available.

Cardboard:

• Impact Resistance: Low. Offers limited protection against impacts.
• Cushioning: Moderate. Can provide some cushioning when layered, but not as effective as foam.
• Cost: Low. A very cost-effective option.
• Environmental Impact: Relatively low, especially if made from recycled cardboard. Biodegradable.
• Suitability: Suitable for light-duty protection, especially when used in multiple layers. Good for internal dividers and padding. Not ideal for heavy or high-impact items.

Plastic (e.g., Polypropylene or Expanded Polystyrene - EPS):

• Impact Resistance: Moderate to high, depending on the type of plastic. EPS is particularly good at absorbing impacts.
• Cushioning: High. EPS foam provides excellent cushioning. Rigid plastics can also offer good protection.
• Cost: Medium. EPS is relatively inexpensive. Rigid plastics can be more expensive.
• Environmental Impact: Can be high, especially if made from virgin plastic. Recycling is possible, but not always widely available.
• Suitability: Excellent for protecting fragile items. EPS foam is particularly well-suited for custom-moulded packaging. Rigid plastics are suitable for protective cases.

Foam (e.g., Polyurethane Foam):

• Impact Resistance: High. Excellent at absorbing impacts and vibrations.
• Cushioning: Very high. Provides superior cushioning compared to cardboard or plastic alone.
• Cost: Medium to high.
• Environmental Impact: Can be difficult to recycle. Some types of foam are made from petroleum-based products.
• Suitability: Ideal for protecting very fragile items. Often used in combination with cardboard or plastic for added protection. Can be custom-moulded to fit specific items.

Comparison Table:

Conclusion: A combination of materials is often the best approach. Cardboard can provide structural support, while plastic or foam can offer cushioning and impact protection. The choice of material depends on the fragility of the item, the distance it needs to be transported, and the budget. For highly fragile items, a combination of EPS foam and a sturdy cardboard box is often the most effective solution. Consider the environmental impact of the chosen materials and explore options for recycling or using recycled materials.