Summary
Highlights
Physical properties describe a material's intrinsic traits before use (e.g., density, color, texture). Working properties describe how a material behaves when manipulated (e.g., workability, machinability, hardness, toughness, tensile strength, elasticity).
Hardwoods (e.g., oak, mahogany, beech, balsa) come from deciduous trees, are generally denser, and have a closer grain. Softwoods (e.g., redwood, larch, pine, cedar) come from coniferous trees, grow faster, and are typically cheaper. Examples and common uses for each type are provided, highlighting properties like strength, durability, and resistance to elements.
This section covers timber-based composites like MDF (medium-density fiberboard), plywood, blockboard, hardboard, and chipboard, detailing their properties, advantages, and typical applications. It also discusses polymer-based composites such as carbon fiber reinforced plastic (CFRP) and glass reinforced plastic (GRP), emphasizing their lightweight, strong, and corrosion-resistant nature for uses in automotive and marine industries.
Ferrous metals (e.g., mild steel, medium carbon steel, cast iron) contain iron, are magnetic, and can rust. Non-ferrous metals (e.g., aluminum, copper, tin, zinc) do not contain iron, are not magnetic, and resist rust. Alloys (e.g., brass, stainless steel, duralumin) are mixtures of metals or metals and other elements, designed to enhance specific properties like corrosion resistance, strength, and ductility.
Various types of paper, from thin translucent layout paper to heavy cartridge paper, are discussed with their GSM (grams per square meter) and uses. Different boards, including mounting board, corrugated board, folding box board, foil-lined board, solid white board, and foam board, are explained, highlighting their structural properties and applications in packaging, modeling, and presentation.
Natural fibers like cotton, linen, and wool are detailed, focusing on properties such as absorbency, breathability, durability, and flame resistance, as well as their common applications. Man-made fibers, including polypropylene, nylon, and polyester, are also covered, noting their quick-drying, elastic, and crease-resistant qualities. Textile treatments for fire retardancy, stain resistance, and water resistance are also mentioned.
Smart materials respond to external stimuli like temperature or light. Examples include thermos ceramics (hard and stable at high temperatures), shape memory alloys (return to original shape when heated), thermochromic and photochromic pigments (change color with temperature or light), LCDs (liquid crystals changing light to dark with electrical voltage), quantum tunneling composites (change electrical conductivity with pressure), and reactive glass (changes tint).
Thermoplastics (e.g., acrylic, ABS, LDP, PET, polypropylene, PVC, HDP) can be repeatedly reheated and reshaped, making them recyclable. Thermosets (e.g., urea formaldehyde, polyester resin, epoxy resin, melamine formaldehyde) cannot be reheated or reshaped once cured, due to cross-links in their molecular structure, making them brittle and heat-resistant. Elastomers like natural rubber and neoprene are also covered, known for their elasticity and resistance properties.