Sources, Origins & Life Cycle Assessment
Where Do Materials Come From?
Every material in a product starts as a raw resource extracted from the earth, grown in a field, or harvested from an animal. You need to know the primary source of each material category and the main processes involved in converting it into a workable form.
Sources & Origins by Category
Paper is made from cellulose fibres derived from wood (mainly softwood trees like spruce and pine) and sometimes grasses such as bamboo. Logs are chipped, pulped in water with chemicals, and the resulting slurry is pressed, dried and rolled into sheets. Recycled paper skips the tree-felling stage by re-pulping waste paper, though each cycle shortens the fibres and reduces quality.
Trees are felled and converted into usable planks through conversion (sawing methods include through-and-through and quarter sawn). The green timber must then be seasoned — either air-dried (stacked outdoors for months) or kiln-dried (heated in a controlled chamber for days). Manufactured boards like MDF, plywood and chipboard are made from timber waste — fibres, veneers or chips bonded with resin.
Metals are extracted from ore mined from the earth. The ore is refined — iron ore is smelted in a blast furnace to produce pig iron, which is then converted into steel. Aluminium is extracted from bauxite ore using electrolysis, an extremely energy-intensive process. Copper ore is smelted and electrolytically refined to high purity. Alloys (e.g. brass = copper + zinc, stainless steel = iron + chromium + nickel) are created by mixing metals to improve properties.
Most polymers come from crude oil. Crude oil is separated into fractions by fractional distillation. The naphtha fraction is then broken down further by cracking to produce monomers like ethene and propene. These monomers are then polymerised — joined into long chains — to create materials such as polyethylene, polypropylene and PVC.
Textile fibres come from three main sources. Animal sources: wool from sheep, silk from silkworms. Vegetable sources: cotton from the cotton plant, linen from flax. Chemical/synthetic sources: polyester and nylon from crude oil (same petrochemical route as polymers). Raw fibres are cleaned, carded (aligned), spun into yarn, and then woven or knitted into fabric.
You must know the primary source and the main conversion process for each material category: paper (cellulose from wood → pulping), timber (trees → conversion & seasoning), metals (ore → smelting/electrolysis), polymers (crude oil → fractional distillation & cracking), textiles (animal/vegetable/chemical → spinning).
Life Cycle Assessment (LCA)
A life cycle assessment (LCA) examines the environmental impact of a product at every stage: raw material extraction, processing, manufacture, distribution, use, and end-of-life disposal. It considers energy consumption, water use, carbon emissions, pollution and waste at each stage.
The five stages of an LCA are: 1. Raw material extraction → 2. Processing & manufacture → 3. Distribution & transport → 4. Use & maintenance → 5. End-of-life disposal (recycle, landfill or incinerate).
Why LCA Matters for Designers
An LCA helps designers make informed choices. If the biggest environmental impact of a kettle is the energy used to boil water (the "use" stage), then improving insulation to keep water hot longer would have a bigger effect than switching to a lighter plastic for the casing. LCA data can also reveal hidden problems — for example, a "biodegradable" polymer that only breaks down under industrial composting conditions, not in a home compost bin.