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Product Design & Manufacturing Glossary of Terms
To help you understand some of the terms used throughout the product development and manufacturing processes, we have provided a glossary of the most commonly used terms.
2D Production Drawing - Production drawings show how to manufacture the product. They detail important part dimensions and tolerances and describe in detail how assemblies are to be built. 2D production drawings are often electronically linked to the 3D solid model of the part or assembly.
3D Solid Model – A virtual 3D representation of components for mechanical design and analysis. All features of the final part or assembly being designed are represented in a three-dimensional representation that contains the entire CAD information needed to produce production parts.
Aesthetics – The look and feel of a design. While designing for fit and function, the aesthetic appeal of a part or assembly should be accounted for.
Blow Molding – Blow molding is a method of forming plastic whereby a hollow tube is made from molten plastic material and entrapped in a mold. Air is blown into the mold, expanding the tube and forcing it against the sides of the mold, thus forming into the shape of the part.
Boss – A cylindrical protrusion within a part, often designed to accept fasteners.
CAD – Short for “computer aided design”.
CNC Machining - Computer Numerical Control system in which the data handling, control sequences and response to input is determined by an on-board computer system at the machine tool.
Cycle Time - Period between the start of an operation and the start of the next occurrence of the same operation.
Direction of Pull – Refers to the motion of a part surface relative to a mold when the tooling is opened for part ejection.
Draft – The taper of features in the direction of pull. It allows deeper features to be produced in three-axis milling machines and it also helps parts release from the mold during ejection.
Ejection – The process of pushing a completed part out of a mold.
Ejector Pins – Steel pins incorporated into the B-side of a mold that push out the plastic part.
Ergonomics – A method of design engineering to create products that fit the natural tendencies and comfort of the user.
Extrusion – A manufacturing process that utilizes a softened billet of material which is forced through a shape (or die) to allow for a continuous form much like spaghetti.
FDM - Fused Deposition Modeling is a thermoplastic extrusion-based rapid prototyping technology provided by Stratasys.
FEA – Finite Element Analysis is a mathematical technique which breaks down a physical structure into substructures called "finite elements." 3D solid models of parts and assemblies are analyzed for stress, thermal and dynamic characteristics. The finite elements and their interrelationships are converted into equation form and solved mathematically.
Geometric Dimensioning and Tolerancing – (GD&T) is a symbolic language used on engineering drawings and computer generated three-dimensional solid models for explicitly describing nominal geometry and its allowable variation.
IGES File – Stands for “Initial Graphics Exchange Specification”. It is a common file format for exchanging CAD data and producing the tooling for injection molding.
Industrial Design - The visual features of shape, configuration, pattern or ornament applied to a manufactured product. Industrial Designers study both function and form, and the connection between product and the user.
Injection Molding - Manufacturing process where molten plastic is introduced into a tool or die with the use of pressure.
Living Hinge – Very thin section of plastic used to connect two parts and keep them together while allowing them to open and close. They require careful design and gate placement. A typical application would be the hinged flip-top cap on a shampoo bottle.
Manufacturability – The extent to which a new product can be easily and effectively manufactured at minimum cost and with maximum reliability.
Parting Line – The location where the pieces of a mold come together. Typically a thin line is created on the part here.
Product Design – The process of converting a product need into plans for a manufacture-ready product. For a product to be successful, the design of that product usually should include industrial design (which focuses on the user aspects of the product including form, aesthetics, consumer appeal, ergonomics, etc.) and design engineering (which focuses on the function and manufacturability aspects of the product).
Product Development – The process of converting product ideas into viable products. Successful product development requires a balance of soft requirements (how does it look and feel) with hard requirements (how does it function to fill the need).
Prototype - Physical model of a part or product during the product development process. Depending upon the purpose, prototypes may be non-working, functionally working, or both functionally and aesthetically complete.
Rapid Prototyping – Rapid prototyping takes virtual designs from computer aided design (CAD) or animation modeling software, transforms them into successive layers of liquid or powder material, and in this way builds up the model from a series of cross sections. These layers, which correspond to the virtual cross section from the CAD model, are joined together or fused automatically to create the final shape.
Reverse Engineering - The process of analyzing the construction and operation of a product in order to manufacture a similar one.
Rib – A reinforcing member of a molded part.
SLA - Stereo lithography is a rapid prototyping process that fabricates a part layer wise by hardening a photopolymer with a guided laser beam. Stereo lithography is frequently used as a general term for "rapid prototyping," but this is neither precise nor correct.
SLS - Selective Laser Sintering is a rapid prototyping technology in which powders are fused layer wise by a laser. The technology produces accurate parts and models in engineering polymers, metals and polymer-coated sand for casting applications. Speed is similar to stereo lithography, but material selection is wider.
STL File - A file format used in rapid prototyping to define the geometry of the part to be made. STL files are created by CAD programs by translating their native or neutral files into the STL format. The STL file defines the coordinates of numerous triangular facets that approximate the shape of an object or part.
Shrink – The change in size of the part during solidification, typically anticipated based on published material property data, and built into the mold design prior to machining.
Side Action Mold – A sliding cam arrangement within the mold that allows for the molding of parts with undercuts. The undercut-creating mold face is held in place during the injection process and then slides out of the way prior to ejection.
Sink – Undesired depressions in the surface of a part that are caused by the shrinking of resin as it solidifies. Sink is most common in thick sections of a part.
Straight Pull Mold – A mold without side actions. It is less expensive than a comparable mold with side actions.
Tooling - Generic term used to describe molds or dies used in the production of parts and assemblies. Examples include injection molds, blow molds, die cast dies, and stamping dies.
Undercut – A portion of the part geometry that would prevent the part from being ejected from a straight-pull mold without a portion of the mold passing through (and destroying) the part. The simplest example of an undercut feature on a part would be a through-hole aligned perpendicular to the direction of part ejection.
Value Engineering –A product design methodology concerned with optimizing the conceptual, technical and operational aspects of a project’s deliverables. Value engineering utilizes a series of proven techniques during the implementation phase of a project. |
