What is Rapid Prototyping?: Page C

Cake
A term referring to the FDM process where a controlled extrusion head deposits very thin beads of material onto a build platform to form the first layer of a 3D object. Or, just plain ol' great music. Play it now...

CAD
Computer Aided Design

CAI
Computer Aided Inspection

Callipygian
Having a shapely buttocks.

(CAM)
A computer program that generates tool paths or other manufacturing data to fabricate tooling, usually by subtractive means. CAM programs may use a geometry definition from a CAD program as a starting point. Also known as Computer Aided Manufacturing

CAM2
Computer Aided Manufacturing Measurement

Color Map
A graphical technique to visualize differences between the measured configuration of an object and its CAD model; dimensional differences are mapped onto the CAD model using a color spectrum to indicate location and magnitude. A reference key maps the deviations to values.

Concept model / conceptual model
A part intended primarily for form or appearance study, but which typically cannot be used to either check fit to other parts, or provide functionality of the final part in an application.

Coordinate System
An origin or reference point in 3D (XYZ) space for locating or orienting an object or CAD model.

Carbon Black
A black pigment produced by the incomplete burning of natural gas or oil. It is widely used as a filler or pigment, particularly in the rubber industry. It produces useful ultraviolet protective properties.

Cast
(1) To form a "plastic" object by pouring a fluid monomer-polymer solution into an open mold where it finished polymerizing; (2) forming plastic film and sheet by pouring the liquid resin onto a moving belt or by precipitation in a chemical bath.

Casting (n)
The finished product of a casting operation; should not be used for molding.

Casting area
The moldable area of a thermoplastic in square inches for a given thickness and under a given set of injection molding conditions. Casting area is a measure of flow under actual molding conditions where flow is unrestricted by cavity boundaries.

Catalysis
Acceleration of a chemical reaction by catalysts.

Catalyst
A substance which speeds up the polymerization or cure of a compound when added in minor quantity as compared to the amounts of primary reactants, providing it does not become a component part of the chain; otherwise it is referred to as an initiator. See hardener, inhibitor, promotor.

Cavity
Depression in a mold made by casting, machining, hobbing, or a combination of these methods; depending on number of such depressions. Molds are designated as single-cavity or multicavity. Specially shaped open space in a mold, which is filled with the material.

Celluloid
A thermoplastic material made from plasticized cellulose nitrate and camphor. Alcohol is normally employed as a volatile solvent in order to assist plasticization, and is subsequently removed.

Cellulose
A naturally occurring polysaccharide made up solely of glucose units and found in most plants; the main constituent of dried woods, jute, flax, hemp, ramie, etc. Cotton is almost pure cellulose; however, in many other important natural cellulosic materials, the cellulose is associated with sizable quantities of impurities including lignin (a natural resin) and various hexosans, pentosans, and polyuronides collectively called hemicelluloses. Most commonly occurring carbohydrate; cotton, jute, flax, and hemp are almost pure cellulose.

Cellulose Acetate
An acetic acid ester of cellulose. It is obtained by the action, under rigidly controlled conditions, of acetic acid and acetic anhydride on purified cellulose usually obtained from cotton linters. All three available hydroxyl groups in each glucose unit of the cellulose can be acetylated, but in the preparation of cellulose acetate it is usual to acetylate fully and then to lower the acetyl value (expressed as acetic acid) to 52-56 percent by partial hydrolysis. When compounded with suitable plasticizers, it gives a tough thermoplastic material.

Cellulose Acetate Butyrate
An ester of cellulose made by the action of a mixture of acetic and butyric acids and their anhydrides on purified cellulose. It is used in the manufacture of plastics which are similar in general properties to cellulose acetate but are tougher and have better moisture resistance and dimensional stability.

Cellulose Triacetate
A cellulose material made by reacting purified cellulose with acetic anhydride in the presence of a catalyst. All three hydroxyl groups in each glucose unit of the cellulose are esterfied. It is used in the form of films and fibers. Films and sheets are cast from clear solutions onto "drums" with highly polished surfaces. The film, which is of excellent clarity, has high tensile strength, good heat resistance, and dimensional stability. centipoise A unit of viscosity, conveniently and approximately defined as the viscosity of water at room temperature.

CFRP Carbon-fiber-reinforced plastic
(CFRP)-a composite material of carbon fibers and a polymer matrix. chemical bond Cohesive forces between atoms in molecules, exerted by ions or pairs of electrons.

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Chemical Composition
The elements that make up a substance.

Chemical Property
Property of a substance related to a chemical change that the substance undergoes.

Chips and Salsa
Refers to computers. Chips = hardware; Salsa= software.

Cleavage
Tensile load (pounds per inch of width) required to cause separation of a 1": long metal-to-metal adhesive bond. This test is made by bonding together two rigid adherends and pulling them apart by means of an external load. [Also referred to as ASTM D 1062 D1062]

Climbing Drum
A method for determining peel resistance of the adheasive bond between a relatively flexible and rigid material. In a climbing drum peel test a thin sheet of metal is bonded to a rigid backplate. The tyhin sheet is clamped to a flanged drum, and the other end of the specimen is attached to the top clamp of the testing machine. The fixture is designed so that when a tensile load is applied by the testing machine, the drum rolls up the specimen, causing the adhesive bond to peel apart. The peel resistance over at least a 6" length of the bond is recorded. The results are determined as the eaverage peeling load requried, and this average peel torque is reported in inche-pounds per inch. [Also referred to as ASTM D 1781 or D1781]

CMM
Coordinate Measuring Machine

CNC Computerized Numerical Control
Computerized Numerical Control Refers to machine tools that have a computer and memory to control their operation. Most all non manual machine tools sold today will be CNC. [Also referred to as "cnc rapid prototyping"]

CNC M Code
In the process of CNC Machining, an M code is used to signal an action from a miscellaneous group of commands. M codes change cutting tools, turn on or turn off the coolant, spindle, or workpiece clamps, etc. [also referred to as M-Codes or m codes]

Coefficient of Thermal Expansion
A method to determine the linear thermal expansion of a material. The test is performed over a specified temperature rnge. Any given material will have a substantially different coefficient of thermal expansion at remperatures above its glass transitoin temterature (Tg). This can be misleading as to its performance, since service above the Tg is not recommended, therefore, the test is performed at a range of termperatures below Tg, and the linear coefficient of thermal expansion is reported for the range of termperatures used. [Also referred to as ASTM D696 or D 696]

Co-Evolution
A theory that a company can create new business, markets and industries by working with direct competitors, customers and suppliers.

Color Stability
Color stability - describes how the color changes over time. The lower the color change the better it is.

Computer Numerical Control (CNC)
Refers to a machine tool which is operated under automatic control, as opposed to manually by an operator.

Continuous Innovation Research Vision
The future weath and well-being of individuals, companies and society as a whole depends a great deal on innovation. Continuous innovation is the ongoing process aimed at creating product - market - technology - organization - combinations (PMTO) that are new to an individual, a group of people, an organization, a market sector or even society as a whole. This definition suggests four key elements:

• Innovation is a process and should be managed as such.
• The outcome of this procedss is at least one new element in existing PMTO-combinations.
• The extent to which the resulting innovation is new may range from incremental, small step innovation, through synthetic innovation, i.e. the creative recombination of existing techniques, ideas or methods, todiscontinuous, radical, quantum-leap innovation.
• The entity or 'the who' for which the innovation is new may range from the world, a particullar country/society or an industry, a company to an individual.

Successful continuous innovation is beneficial to a wide variety of stakeholders, including customers, employees and owners/ shareholders of companies. The achievement of such benefits requires company-wide involvement and commitment, cross-departmental and inter-organizational collaboration, ongoing learning (and unlearning), and deep insight into the process of continuous innovation. Continuous innovation is an essentially cross-disciplinary field of research. www.continuous-innovation.net

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Computer-Aided Design (CAD)
Also sometimes called computer-aided drafting, is a computer program which implements the functions of geometric design, drafting and documentation.

Computer-Aided Engineering (CAE)
A computer program which automates one or more engineering analysis functions to determine the mechanical, thermal, magnetic or other characteristics or state of a system. CAE programs may use a geometry definition from a CAD program as a starting point, and usually utilize some form of finite element analysis (FEA) as the means to perform the analysis. computer-aided manufacturing

Compression Mold
A mold which is open when the material is introduced and which shapes the material by heat and by the pressure of closing.

Compression Molding
A technique of thermoset molding in which the molding compound (generally preheated) is placed in the open mold cavity, mold is closed, and heat and pressure (in the form of a downward moving ram) are applied until the material has cured.

Compression Set
Teh residual decrease in thickness of a test speciment measured 30 minutes after it has been removed from a suitable fixture in which it had been subjected for a definite period of time to compressive deformation under specified conditions of load applicatinos and termperature. [Also referred to as ASTM D 395 or D395]

Compressive Modulus
The ratio of stress to corresonding strain below the proportional limit of a material. It is expressed in force per unit area (pounds per square inch) based on the average initial cross-sectional area. [Also referred to as "modulus of elasticity" or ASTM D695]

Compressive Strength
The compressive strength is calculated by dividing the maximum compressive load carried by the speciment during the test by the original minimum cross-sectional area of the specimen. It is reported in pounds per square inch. [See ASTM D695]

Concept Model
Fabricated from simple and readily available materials. Used to communicate the concept such as needed for concept selection. It may only focus on a subset of features of the design.

Condensation
A chemical reaction in which two or more molecules combine with the separation of water or some other simple substance. If difunctional or higher functionality molecules react, the condensation process is called polycondensation. See also polymerization. contact pressure resins Liquid resins which thicken or resinify on heating and, when used for bonding laminates, require little or no pressure.

Conformal Cooling
Cooling lines in an injection molding tool that closely follow the geometry of the part to be produced.

Copolymer
A polymetric system which contains two or more monomeric units.

Creep
The dimensional change with time of a material under load, flowing the initial instantaneous elastic deformation. Creep at room temperature is called cold flow. [Also referred to as ASTM D 2294 or D2294]

Cross-linking
Linking together of polymer molecules (macromolecules) by primary valences, resulting, in most cases, in a three-dimensional network; cross-linking of certain plastics can be carried out chemically by the addition of appropriate bridge-building monomers. When extensive, as in thermosetting resins, cross-linking makes one infusible, insoluble, super-molecule of all the chains.

CRP Carbon-Rreinforced Plastic
see CFRP.

Crystal
A solid body with periodically arranged "building units" (atoms or molecules) bounded by flat surfaces, and representing the most orderly possible condition.

Crystalline
Consisting of numerous tiny crystals that are not completely formed. Composed of crystals; having order.

Crystalline Melting Temperature (CMT)
Crystalline regions of a thermoplastic melt at this temperature. crystallinity A state of molecular structure in some resins which denotes stereo-regularity and compactness of the molecular chains forming the polymer. It normally can be attributed to the formation of solid crystals having a definite geometric form.

Cure
The changing of the physical properties of a material by chemical reactions such as polycondensation, addition polymerization. or vulcanization; usually accomplished by the action of heart and catalysts, alone or in combination with our without pressure.

Cured Durometer Hardness
Measure of the indentation hardness of a speciment. It is the extent to which a spring loaded steel indentor protrudes beyond a pressure foot into the material. [Also known as ASTM D2240]

Curing Temperature
Temperature at which a cast, molded, or extruded product, resin-impregnated reinforcement, adhesive, etc. is subjected to curing.

Curing Time (molding time)
In the molding of thermosetting plastics, the interval of time between the instant of cessation of relative movement between the moving parts of a mold and the instant that pressure is released.

Cycling Tests
This test is designed to accelerate the time in which weathering data can be collected. In this test, specimens are exposed to a number of cycles of climatic conditions such as hot-wet, cold-wet, ambient dry and hot dry.