Composites / Plastics: Most Popular Articles

Composite Materials Properties Database
Database of composite material properties.

A Brief History of Kevlar
Introduction to Kevlar fibers and their properties.

Dictionary of Composite Materials Technology
Introduction to the Composite Materials Glossary.

Wind Turbine Blades - Composite Materials
Sandia Developing New Wind Turbine Blade Manufacturing Processes, from your About.com Guide

Vacuum Bagging: Basics - Composite Materials
Basic techniques for vacuum bagging laminates, from your About.com Guide

Diffusion Coefficient
A factor of proportionality representing the amount of substance diffusing across a unit area through a unit concentration gradient in unit time.

Index of Carbon/Graphite Composite Material Properties
Index of material properties for carbon and graphite composite materials.

Lincoln Composites Builds Largest CNG Fuel Tank
Lincoln Composites has designed, manufactured, and qualified the largest natural gas vehicle (NGV) fuel tank in the world. These tanks allow the cost of the CNG package of the vehicle to be lowered by hundreds of dollars while also reducing the vehicle weight by hundreds of pounds.

Resin Transfer Molding
A closed-mold pressure injection system which allows for faster gel and cure times as compared to contact molded parts.

Prepreg
Short for preimpregnated.

Compression Molding
A method of molding in which the molding material, generally preheated, is first placed in an open, heated mold cavity.

Modulus of Elasticity
The ratio of stress (nominal) to corresponding strain below the proportional limit of a material.

What's a Composite?
A brief description and definition of composite materials.

Axial Load
A pure tension or compression load acting along the long axis of a straight structural member.

Coefficient of Linear Expansion
The change in length per unit length resulting from a one degree rise in temperature, expressed in degrees.

Magnesium Stearate
A white, soft powder used as a lubricant and stabilizer.

Sieving
Separation of a mixture of various-sized particles, either dry or suspended in a liquid, into two or more portions, by passing through screens of specified mesh sizes.

Index of Fiberglass Composite Materials Properties
Index of material properties for fiberglass composite materials.

Polyethylene Terephthalate
A saturated, thermoplastic, polyester resin made by condensing ethylene glycol and terephthalic acid, which has assumed a role of primacy in fibers and molding materials.

Cellulose Fibers, Natural
Natural fibers of cellulose have been used as a reinforcement material, e.

Materials Database - Composite Materials
Search the MatWeb Database for material properties, from your About.com Guide

Recycled Cellulose/Glass Composite Replaces Marine Plywood
All-A-Board composite, made from recycled plastic cellulose and glass fiber, is gaining acceptance in the marine industry as a plywood replacement.

Gel Permeation Chromatography
A column chromatography technique employing as the stationary phase a swollen gel made by polymerizing and cross-linking styrene in the presence of a diluent which is a nonsolvent for the styrene polymer.

Essential Resources for Composite Materials
A collection of the most useful online resources for the composites industry.

Composites FAQ
Frequently asked questions about composite materials.

Sheet Molding Compound
A fiber glass reinforced thermosetting compound in sheet form, usually rolled into coils interleaved with plastic film to prevent autoadhesion.

Plastic Flow
(1) A fluid movement that is proportional to the pressure in excess of a certain minimum pressure (yield value) to begin the flow.

Aldila Introduces New Graphite Golf Shafts
Aldila is introducing two new HM-40 graphite golf shafts.

Elastic Strain
That which is instantly and fully recovered when the load causing it is removed.

Mineral Spirits
A refined petroleum distillate (150-200 C) having a low aromatic hydrocarbon content, with volatility, flash point, and other properties making it suitable as a thinner and solvent.

Thermogravimetric Analysis
A testing procedure in which changes in weight of a specimen are recorded as the specimen is heated in air or in a controlled atmosphere such as nitrogen.

Linear Expansion
The increase of a planar dimension, measured by the linear elongation of a sample in the form of a beam which is exposed to two given temperatures.

Composite Materials Glossary - F
Index for the Dictionary of Composite Materials Technology - F

Extruder
A machine for producing more or less continuous lengths of plastic sections.

Pot Life
The length of time that a catalyzed resin system retains a viscosity low enough to be used in processing.

Hoop Stress
The circumferential stress in a material of cylindrical form subjected to internal or external pressure.

Fiber Volume Fraction of a Composite Materials
The volume of fiber in a cured composite.

Stress-Strain Diagram
The curve which results from plotting the applied stress on a test specimen in tension versus the corresponding strain.

Secant Modulus
The slope of the line connecting the origin and a given point on the stress-strain curve, or the ratio of nominal stress to corresponding strain at any specified point on the stress-strain curve expressed in force per unit area.

Golf Club Market Report
A recent market report predicts a growth rate of over 25% annually in the Chinese and Indian golf club market. As the demand for high performance products has increased, carbon fiber composites have overtaken steel as the material of choice for golf shafts.

Viscometer
An instrument used for measuring the viscosity and flow properties of fluids.

Ambient Temperature
The temperature of the medium surrounding an object.

SACMA Recommended Methods Test Manual for Composites
Review of the Suppliers of Advanced Composite Materials Association (SACMA) Recommended Methods test manual.

Composite Materials Glossary - C
Index for the Dictionary of Composite Materials Technology - C

Dissipation Factor-Electrical
The ratio of the power loss in a dielectric material to the total power transmitted through the dielectric, the imperfection of the dielectric.

Stress Concentration Factor
The ratio of the maximum stress in the region of a stress concentrator (notch) to the stress in a similarly strained area without a stress concentrator.

Flexural Modulus
The ratio, within the elastic limit, of the applied stress on a test specimen in flexure, to the corresponding strain in the outermost fibers of the specimen.

Impact Resistance
The relative susceptibility of plastics to fracture under stresses applied at high speeds.

Composite Materials Glossary - S
Index for the Dictionary of Composite Materials Technology - S

Carbon Fiber Prices - Composite Materials Date: 08/19/99
Accusations of carbon fiber price fixing, from your About.com Guide

St. Venant's Principle
The difference between the stresses caused by statically equivalent load systems is insignificant at distances greater than the largest dimension of the area over which the loads are acting.

Composite Materials Glossary - A
Index for the Dictionary of Composite Materials Technology - A

Viscosity, Intrinsic
A measure of the capability of a polymer in solution to enhance the viscosity of the solution.

Brookfield Viscometer
The Brookfield Synchro-Lectric Viscometer is an instrument used for measuring the viscosity of plastisols and other liquids of a thixotropic nature.

Poiseuille's Equation
An equation for calculating the pressure drop of a fluid, in laminar flow, through a cylindrical tube.

Woven Fabric
A planar structure produced by interlacing two or more sets of yarns, fibers, rovings, or filaments where the elements pass each other essentially at right angles and one set of elements is parallel to the fabric axis.

Thermal Stability
The resistance to permanent change in properties caused solely by heat.

Amorphous Silica
A naturally occurring or synthetically produced oxide of silicon characterized by the absence of pronounced crystalline structure, and which has no sharp peaks in its X-ray diffraction pattern.

Fiberglass Insulation - Composite Materials Date: 06/29/98
How fiberglass insulation works, from your About.com Guide

Sieve Analysis
A determination of the proportions of particles lying within certain size ranges in a granular material by separation on sieves of different size openings.

Material Properties T300/5208 Carbon Epoxy
Material properties of T300/5208 carbon epoxy unidirectional prepreg.

Flexural Strength
The strength of a material in bending, expressed as the stress on the outermost fibers of a bent test specimen, at the instant of failure.

Material Properties Generic E-Glass Epoxy
Material properties of generic E-glass epoxy unidirectional prepreg.

Yield Strength
(1) The stress at the yield point.

Endurance Limit
The stress level below which a specimen will withstand cyclic stress indefinitely without exhibiting fatigue failure.

Top 20 Engineering Achievements of the 20th Century
Neil Armstrong announced the 20 top engineering achievements of the 20th Century at a National Academvy of Engineering NAE meeting

Dielectric Loss
A loss of energy which eventually produces a rise in temperature of a dielectric placed in an alternating electrical field.

Hydroxyl Value
A measure of hydroxyl (univalent OH) groups in an organic material.

Linear Polymer
A polymer in which the molecules form long chains without branches or cross-linked structures.

Stand-Alone System
A system that is completely operational without requiring external support.

Abrasion Resistance
The ability of a material to withstand mechanical action such as rubbing, scraping, or erosion, that tends progressively to remove material from its surface.

Composite Materials Glossary - Abbreviations and Acronyms
Abbreviations and acronyms from the composite materials glossary

Glass Transition Temperature
The approximate midpoint of the temperature range at which there occurs a break or discontinuity in the curve when molar volume V is plotted against temperature.

Effective Modulus of Elasticity of Concrete
The deformation of concrete under load is partly due to instantaneous elastic deformation and time-dependent creep.

Composite Materials Glossary - Suggest a Word
Suggest a new word for the Composite Materials Glossary, or report an error in an existing definition.

Polyacrylate
A family of thermoplastic engineering resins made by the polymerization of an acrylic compound such as methyl methacrylate.

Draw Ratio
(1) A measure of the degree of stretching during the orientation of a fiber or filament, expressed as the ratio of the cross-sectional area of the undrawn material to that of the drawn material.

Banbury Mixer
An apparatus used for mixing or compounding plastics and interspersing reinforcing fillers in a resin system.

Composite Materials Glossary - Symbols
Symbols from the composite materials glossary

Welding
The joining of two or more pieces of plastic by fusion at adjoining or nearby areas either with or without the addition of plastic from another source.

Fracture Strength
The normal stress at the beginning of fracture.

Coextrusion
The process of extruding two or more materials through a single die with two or more orifices arranged so that the extrudates merge and weld together into a laminar structure before chilling.

Sacrificial Protection
A means of reducing metallic corrosion in an electrolyte by coupling it to another metal that is electrochemically more active.

Fumed Silica
An exceptionally pure form of silicon dioxide made by reacting silicon tetrachloride in an oxy-hydrogen flame.

Proof Load
A predetermined load, generally a multiple of the service load, to which a specimen or structure is subjected before acceptance.

Bearing Stress
The applied load divided by the bearing area.

Modulus of Rupture
The force necessary to break a specimen of specified width and thickness expressed in pounds-force per square inch.

High Frequency Welding
A method of welding thermoplastics in which the surfaces to be joined are heated by contact with electrodes of a high frequency electrical generator.

Aprotic Solvent
An organic solvent that does not exchange protons with a substance dissolved in it.

Homopolymer
A polymer resulting from the polymerization of a single monomer; a polymer consisting substantially of a single type of repeating unit.

Linear Relation
The straight line relationship between variables.

Vinyl Ester Resin
This SMC material designed for automotive uses exhibits heat resistance and toughness.

Composite Materials Glossary - D
Index for the Dictionary of Composite Materials Technology - D

Ball Mill
A cylindrical or conical shell rotating about a horizontal axis, partially filled with a grinding medium such as natural flint pebbles, ceramic pellets or metallic balls.

Quaternary Carbon Atom
A carbon atom bonded to four other carbon atoms with single bonds.

K-Factor
A term for thermal insulation value or coefficient of thermal conductivity, which is the amount of heat that passes through a unit cube of material in a given time when the difference in temperature difference across the cube is one degree.

Glass Fiber Reinforcements
A family of reinforcing materials for reinforced plastics based on single filaments of glass ranging in diameter from 3 to 19 micrometers.

Lower Explosive Limit
Lower limit of flammability or explosibility of a gas or vapor at ordinary ambient temperatures expressed in percent of the gas vapor in air by volume.

Kirksite
An alloy of aluminum and zinc, easily castable at relatively low temperatures, often used for molds.

Drop Test
Technique for measuring the durability of a part or material by subjecting it to a free fall, from a predetermined height into a surface, under prescribed conditions.

Isotactic Polymer
Pertaining to a type of polymeric molecular structure containing a sequence of regularly spaced, asymmetric atoms arranged in like configuration in a polymer chain.

Faying Surface
The surface of a material in contact with another to which it is or will be joined.

Coupling Agent
A chemical substance capable of reacting with both the reinforcement and the resin matrix of a composite material.

Deburr
The removal of undesirable sharp edges, burrs and fins remaining on a manufacture part after completion of finish machining processes.

Notes for the Composite Materials Properties Database
Notes for the composite materials properties database.

QUANTUM Demonstrates High Pressure Composite Hydrogen Tank
QUANTUM Technologies has demonstrated an all-composite hydrogen storage tank that stores hydrogen at 10,000 psi (700 Bar). At 10,000 psi, 80% more hydrogen fuel can be stored in a given space than at 5,000 psi -- dramatically increasing the range of fuel cell mobile applications.

Bismaleimide Resins
These addition-type polyimides or maleimide-based polyimides are used in high performance structural composites requiring higher temperature use and increased toughness.

Water Absorption
(1) The amount of water absorbed by a composite material when immersed in water for a stipulated period of time.

Dielectric Test
The application of a higher than rated voltage for a specified time, in order to determine the capability of insulating materials to withstand breakdown.

Gas-Liquid Chromatography
A variation of the gas chromatography process in which the chromatographic column is packed with a finely divided solid impregnated with a nonvolatile organic liquid.

Composite Materials - The Pultrusion Process: 10/13/97 from About.com
An overview of the pultrusion manufacturing process, from your Mining Company Guide

Brale
A diamond penetrator of specified spheroconical shape used with the Rockwell hardness tester for hard metals.

Factors of Safety - Composite Materials Date: 12/22/97
Information about the role of composites in the F-117A crash, from your About.com Guide

Bonded Fabric
A web of fibers held together by an adhesive medium which does not form a continuous film.

Molecular Distillation
A process for the separation of polymers into fractions of different molecular weight at the lowest possible temperature to avoid damage.

Shear Rate
The overall velocity over the cross section of a channel with which molten or fluid layers are gliding along each other, or along the wall, in laminar flow.

Thermal Degradation
Molecular deterioration of materials such as resins and organic fibers because of overheating.

Addition Polymerization
A chemical reaction in which simple molecules (monomers) are added to each other to form long-chain molecules (polymers) without by-products.

Dictionary of Composite Materials Technology - Preface
Preface to the Dictionary of Composite Materials Technology.

Polydispersity
The state of nonuniformity in molecular weight of a material.

Stiffener
A stringer or other light structural member used to maintain shape or give rigidity to structures of stressed skin construction.

Molal Solution
A solution which contains one mole of the solute per 1000 grams of the solvent.

Shipset
The full complement of a part assembly required to equip and complete one specified aerospace vehicle for full operation.

Composite Materials Glossary - T
Index for the Dictionary of Composite Materials Technology - T

Emerging Applications of Ceramic and Metal Matrix Composites
Many of the 500 papers presented during the 27th Annual Cocoa Beach Conference & Exposition on Advanced Ceramics & Composites focused on composites, both ceramic and metal matrix, and discussed mechanical behavior, design, fibers/interfaces, processing, and applications. Potential applications under development include components for armor, nuclear energy, and automobiles.

Carbitol
Monoethyl ether of diethylene glycol; a water-miscible solvent.

Composite Materials Glossary - B
Index for the Dictionary of Composite Materials Technology - B

Radius of Gyration
The radial distance from a given axis at which the mass of a body could be concentrated without altering the rotational inertia of the body about that axis.

Material Properties AS/3501 Carbon Epoxy
Material properties of AS/3501 carbon epoxy unidirectional prepreg.

Basic Design Principals of Structural Sandwich Composites
Section 1.2 of MIL-HDBK-23A, basic design principles of structural sandwich composites..

Griffith Equation
A relationship that can be used for analyzing the balance of energy applied and released in bond breakage as a crack propagates.

Diallyl Phthalate
In the monomeric form, a colorless liquid ester widely used as a cross-linking monomer for unsaturated polyester resins, and as a polymerizable plasticizer for many resins.

An Introduction to Laminated Composite Theory
Presentation materials from a short course on laminated composite theory by Dr. Steve Griffin.

Composite Turbine Fan Blades Superior to Titanium Blades
UCSD engineers working with NASA and the USAF are developing composite turbine fan blades for jet engines. Initial tests show the composite blades are superior to the titanium blades they would replace.

Essential Composite Materials Reference Books
The three books every composites engineer needs.

Composite Materials Glossary - L
Index for the Dictionary of Composite Materials Technology - L

Blowing Agent
Any substance which alone or in combination with other substances is capable of producing a cellular structure in a plastic.

Textile Materials
General term for fibers, yarn intermediates, yarns, fabrics, and products made from fabrics.

Acetylation
The substitution of an acetyl radical for an active hydrogen.

Adsorption Chromatography
The analytical separation of a chemical mixture (gas or liquid) by passing it over an adsorbent bed that adsorbs different compounds at different rates.

Fabric Terminology for Composite Materials
Definition of terms used to describe engineering fabrics.

Centistokes
One one-hundredth of a stokes, which is the unit of kinematic viscosity and is equal to the viscosity in poises divided by the density of the fluid in grams per cc.

Acrylic Fiber
Generic name for a manufactured fiber in which the fiber-forming material is any long chain synthetic polymer composed of at least 85% by weight of acrylonitrile units -CH2CH(CN).

Fick's Equation
Diffusion equation for moisture migration.

Trade Name Index (D - E) - Composite Materials
Composite materials listed by trade name, from your About.com Guide

Shear Modulus
The ratio of shearing stress to shearing strain within the proportional limit of a material.

Fick's Second Law of Diffusion
The time rate of concentration change is related to the second derivative of the concentration gradient through the diffusion coefficient.

Condensation Polymerization
A process in which water or some other simple substance separates from two or more of the polymer molecules upon their combination.