topic 4 design SL

bro 110 terms the ib on fire fr

Absorbed moisture

The moisture within timber that is contained in the cells walls.

Additive techniques

Manufacturing techniques that add material in order to create it.

Aesthetic appeal

Favourable in terms of appearance.

Aesthetic characteristics

Aspects of a product that relate to taste, texture, smell and appearance.

Air-drying

The stacking of sawn timber in the open or in large sheds, hence there is little control over the drying process.

Alloy

A mixture that contains at least one metal. This can be a mixture of metals or a mixture of metals and non-metals.

Assembly line production

A volume production process where products and components are moved continuously along a conveyor. As the product goes from one work station to another, components are added until the final product is assembled.

Automated production

A volume production process involving machines controlled by computers

Batch production

Limited volume production (a set number of items to be produced).

Bio-compatibility

The product ensures the continued health of a biological environment.

Bowing

A warp along the length of the face of the wood.

Brittle

Breaks into numerous sharp shards.

Chemically inert

Lack of reactivity with other materials.

Composite

A material comprised of two or more constituent materials that have different properties.

Compressive strength

The ability of a material to withstand being pushed or squashed.

Computer numerical control (CNC)

Refers specifically to the computer control of machines for the purpose of manufacturing complex parts in metals and other materials. Machines are controlled by a program commonly called a "G code". Each code is assigned to a particular operation or process. The codes control X, Y, Z movements and feed speeds.

Continuous flow

A production method used to manufacture, produce or process materials without interruption.

Craft production

A small-scale production process centred on manual skills.

Creep

The slow, permanent deformation of a solid material under the influence of a mechanical stress.

Creosote

A material that penetrates the timber fibres protecting the integrity of the wood from attack from borer, wood lice and fungal attack.

Cupping

A warp across the width of the face of wood, in which the edges are higher or lower than the centre.

Density

The mass per unit volume of a material.

Design for assembly

Designing taking account the assembly of the product at various levels, such as component to component, components into sub-assemblies and subassemblies into complete products.

Design for disassembly

Designing a product so that when it becomes obsolete it can easily and economically be taken apart, the components reused or repaired, and the materials recycled.

Design for manufacture

Designing specifically for optimum use of existing manufacturing capability.

Design for materials

Designing with the aim of reducing the quantity of material required.

Design for process

Designing to enable the product to be manufactured using a specific manufacturing process, for example, injection moulding.

Dry rot

When timber is subject to decay and attack by fungus.

Ductility

The ability of a material to be drawn or extruded into a wire or other extended shape.

Elasticity

The extent to which a material will return to its original shape after being deformed.

Electrical insulator

Reduces transmission of electric charge.

Electrical resistivity

The measure of a material's ability to conduct electricity. A material with low resistivity will conduct electricity well.

Electro-rheostatic

This smart property relates to a fluid that can undergo a dramatic change in its viscosity when exposed to an electric field.

Equilibrium Moisture Content (EMC)

The value at which the moisture content of wood achieves an equilibrium with the environment (which can be affected by humidity and temperature).

Felting

A method for converting yarn into fabric by matting the fibres together.

First generation robots

A simple mechanical arm that has the ability to make precise motions at high speed. They need constant supervision by a human operator.

Free moisture

The moisture within timber that is contained within the cell cavities and intercellular spaces.

Glass

A hard, brittle and typically transparent amorphous solid made by rapidly cooling a fusion of sand, soda and lime.

Grain size (metals)

Metals are crystalline structures comprised of individual grains. The grain size can vary and be determined by heat treatment, particularly how quickly a metal is cooled. Quick cooling results in small grains, slow cooling results in large grains. Grain size in metals can affect the density, tensile strength and flexibility.

Hardness

The resistance a material offers to penetration or scratching.

Hardwood

The wood from a deciduous (broadleaved) tree.

Joining techniques

Methods that are used to join two similar or dissimilar materials together.

Kiln drying

Placing stacks of sawn timber in a kiln to reduce the moisture content in wood. Heat, air circulation, and humidity are closely controlled.

Kiln seasoning

Thermally insulated chamber, a type of oven, which produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes.

Knitting

A method for converting a yarn into fabric by creating consecutive rows of interlocking loops of yarn.

Knots

Imperfections in timber, caused by the growth of branches in the tree that reduces its strength.

Lacemaking

A method for creating a decorative fabric that is woven into symmetrical patterns and figures.

Laminated boards

Sheets of material made from layers of veneers (e.g. plywood).

Lamination

Covering the surface of a material with a thin sheet of another material typically for protection, preservation or aesthetic reasons.

Load capacity (Robots)

The weight a robot can manipulate.

Machine to machine (M2M)

Wired and wireless communication between similar devices.

Magneto-rheostatic

This smart property relates to a fluid that can undergo a dramatic change in its viscosity when exposed to a magnetic field.

Man-made timber

Also known as engineered wood or composite wood, these are wood products that are made by binding or fixing strands, particles of fibres, veneers of boards of wood together with adhesives or other fixing methods to create composite materials. Typical examples include MDF, plywood and chipboard.

Mass

Relates to the amount of matter that is contained with a specific material. It is often confused with weight as we use Kg to measure both. Mass is a constant whereas weight may vary depending upon gravitational pull (where it is being measured).

Mass customization

A sophisticated CIM system that manufactures products to individual customer orders. The benefits of economy of scale are gained whether the order is for a single item or for thousands.

Mass production

The production of large amounts of standardized products on production lines, permitting very high rates of production per worker.

Material selection charts

A chart used to identify appropriate materials based on the desired properties.

Mechanical properties

Properties of a material that involve the relationship between stress and strain or a reaction to an applied force.

Mechanized production

A volume production process involving machines controlled by humans.

Multi task robots

A type of robot that can perform more than one task in a manufacturing environment.

Natural fibres

Materials produced by plants or animals that can be spun into a thread, rope or filament.

Non-toxic

Absence of toxic breakdown products/lack of reactivity.

One-off production

An individual (often craft-produced) article or a prototype for larger-scale production.

Oxidization resistance

A property of a metal that means that it does not readily react with oxygen and degrade.

Paper-based rapid prototyping

Often the first step in a rapid prototyping process, paper prototyping is widely used in UCD for designing and testing interfaces.

Particle boards

A material made from different sizes of wood chips and joined with glue.

Photochromicity

A property of a smart material. The material changes colour in response to an increase in light. When the light source is removed, it returns to its original colour.

Physical properties

Any property that is measurable that describes a state of materials, for example, mass, weight, volume and density. These properties tend to be the characteristic of materials that can be identified through non-destructive testing (although some deformation is required to test hardness).

Piezoelectricity

A property of a smart material. The material gives off a small electrical discharge when deformed.

Plasticity

The ability of a material to be changed in shape permanently.

Pultrusion

A continuous manufacturing process used to create composite materials that have a constant cross-section. Reinforcing fibres are saturated with a liquid polymer resin and then pulled through a heated die to form a part.

Reforestation

The process of restoring tree cover to areas where woodlands or forest once existed. If this area never returns to its original state of vegetative cover the destructive process is called deforestation.

Seasoning

The commercial drying of timber which reduces the moisture content of wood.

Second generation robots

Robots that are equipped with sensors that can provide information about their surroundings. They can synchronize with each other and do not require constant supervision by a human; however, they are controlled by an external control unit.

Shape memory alloys

Metals that, after deformation, can spring back into their original shape when heated.

Shaping techniques

Manufacturing methods for modifying the shape of a material, such as cutting and abrading.

Single task robots

Robots that can perform one task only.

Smart material

Materials that have been designed to have one or more properties that can be modified when subject to an external stimuli in a way that the output can be controlled.

Softwood

The wood from a coniferous (evergreen) tree.

Stiffness

The resistance of an elastic body to deflection by an applied force.

Strain

The response of a material due to stress, defined as the change in length divided by the original length.

Stress

A force on a material divided by the cross-sectional area of that material.

Super alloys

An alloy that exhibits excellent mechanical strength, resistance to thermal creep deformation, good surface stability and resistance to corrosion.

Synthetic fibres

Fibres made from a man-made material that are spun into a thread; the joining of monomers into polymers by the process of polymerisation. Examples include polyester, acrylic, nylon, rayon, acetate, spandex, and Kevlar.

Tempering

A heat treating process designed to increase the toughness of an iron-based metal by heating it and allowing it to cool in air. Tempering decreases the hardness of the material, which usually increases the ductility and decreases the brittleness.

Tensile strength

The ability of a material to withstand pulling forces.

Thermal conductivity

The measure of how fast heat is conducted through a slab of material with a given temperature difference across the slab.

Thermal expansion

A measure of the degree of increase in dimensions when an object is heated. This can be measured by an increase in length, area or volume. The expansivity can be measured as the fractional increase in dimension per kelvin increase in temperature

Thermo-electricity

This refers to a smart material that when heated can produce an electric current. A thermoelectric material is comprised of two dissimilar conductors.

Thermoplastic

A type of plastic that can be heated and formed into a new shape repeatedly.

Thermosetting plastic

A type of plastic that once formed into a shape, cannot be reformed into a different shape

Third generation robots

Autonomous robots that can operate largely without supervision from a human. They have their own central control unit. Swarms of smaller autonomous robots also fit in this category.

Toughness

The ability of a material to resist the propagation of cracks.

Transparency

Ability to allow light to be transmitted with minimal scattering allowing a clear view through material.

Twisting

A distortion in which the two ends of a material do not lie on the same plane.

Volume

The quantity of three-dimensional space enclosed by a boundary, for example, the space that a substance solid, liquid, gas, or shape occupies or contains.

Warping

A distortion in wood caused by uneven drying, which results in the material bending or twisting.

Wasting/subtractive techniques

Manufacturing techniques that cut away material in order to create a component.

Weaving

The act of forming a sheet like material by interlacing long threads passing in one direction with others at a right angle to them.

Weight

Relies on mass and gravitational forces to provide measurable value. It is technically measured as a force, which is the Newton, i.e. a mass of 1 Kg is equivalent to 9.8 Newton [at sea level on earth].