Flax-based composite ship hulls offer a 14% reduction in global warming potential compared to traditional fiberglass.

Why It Matters

This research provides critical data for designers and manufacturers in the marine industry to make more informed material choices. By understanding the trade-offs in environmental impact, designers can proactively select materials that align with sustainability goals and mitigate end-of-life disposal issues.

Key Finding

While flax-based composite ship hulls offer significant environmental benefits like reduced greenhouse gas emissions and material resource use, designers must be aware of potential increases in terrestrial ecotoxicity and the impact of energy sources on the overall footprint.

Key Findings

• Flax fibre-reinforced biocomposite ship hulls showed a 14% decrease in Global Warming Potential (GWP) compared to glass fibre-reinforced polyester hulls.
• Terrestrial Ecotoxicity Potential (TETP) increased by 357% for the biocomposite hull due to flax cultivation fertilizers.
• Human Toxicity Potential (HTP) decreased by 13% and Abiotic Depletion Potential (ADP) for material resources was reduced by 75% for the biocomposite hull.
• Electricity consumption is a primary environmental impact driver for flax fibre-reinforced biocomposite hulls.

Research Evidence

Aim: To comparatively assess the environmental sustainability of flax fibre-reinforced composite ship hulls versus traditional glass fibre-reinforced composite ship hulls across their life cycle.

Method: Life Cycle Assessment (LCA)

Procedure: A comparative LCA was conducted using ISO 14040 and ISO 14044 methodologies and OpenLCA software with the Ecoinvent database to evaluate environmental impacts from raw material extraction to end-of-life.

Context: Marine vessel construction, specifically recreational ship hulls.

Design Principle

Life Cycle Thinking: Evaluate the full environmental impact of material choices from cradle to grave, considering all stages of a product's existence.

How to Apply

When specifying materials for marine structures, conduct a comparative LCA to understand the full environmental implications of alternatives like flax composites versus traditional materials.

Limitations

Environmental impacts are influenced by specific system and boundary conditions considered in the study; local production of flax fibre and use of recyclable bio-resin could further improve eco-design.

Student Guide (IB Design Technology)

Simple Explanation: Using plant-based fibres like flax instead of glass fibres for boat hulls can make them much better for the planet, especially by reducing pollution that warms the Earth. However, growing flax can sometimes harm the soil and water, so we need to be careful about how it's grown and powered during manufacturing.

Why This Matters: Understanding the environmental footprint of materials is crucial for responsible design. This research shows how material choices directly impact sustainability metrics, guiding you to make more eco-conscious decisions in your design projects.

Critical Thinking: Given the trade-off between reduced global warming potential and increased terrestrial ecotoxicity with flax composites, what strategies could a designer employ to mitigate the negative impacts while still leveraging the benefits?

IA-Ready Paragraph: A comparative Life Cycle Assessment (LCA) of flax fibre-reinforced composite ship hulls versus traditional glass fibre-reinforced composite hulls reveals significant environmental benefits for the flax-based option, including a 14% reduction in global warming potential and a 75% reduction in material resource depletion. However, it also highlights an increase in terrestrial ecotoxicity due to agricultural inputs for flax cultivation, underscoring the need for careful consideration of material sourcing and processing methods in sustainable design.

Project Tips

• When choosing materials for your design, think about their entire life cycle, not just how they look or perform initially.
• Research the environmental impact of different material options using tools like Life Cycle Assessment (LCA).

How to Use in IA

• Cite this study when discussing the environmental benefits or drawbacks of composite materials in your design project's material selection section.

Examiner Tips

• Demonstrate an understanding of comparative environmental impacts of materials, not just their functional properties.

Independent Variable: ["Material type (flax fibre-reinforced biocomposite vs. glass fibre-reinforced polyester)"]

Dependent Variable: ["Global Warming Potential (GWP)","Terrestrial Ecotoxicity Potential (TETP)","Human Toxicity Potential (HTP)","Abiotic Depletion Potential (ADP)"]

Controlled Variables: ["Ship hull design and size","Manufacturing processes (assumed similar for comparison)","End-of-life scenarios"]

Strengths

• Follows established ISO standards for LCA.
• Utilizes a comprehensive database (Ecoinvent).
• Includes sensitivity analysis to identify key impact drivers.

Critical Questions

• How would the results change if the flax was sourced locally versus internationally?
• What are the specific end-of-life management strategies considered, and how do they influence the overall assessment?

Extended Essay Application

• Investigate the feasibility of using locally sourced, sustainably grown flax for a composite product, performing a simplified LCA to compare its environmental impact against a conventionally sourced material.

Source

Life cycle assessment of glass fibre versus flax fibre reinforced composite ship hulls · Scientific Reports · 2025 · 10.1038/s41598-025-00811-y