Composites / Plastics Sitemap - Page 13 2013-05-23
Methyl Ethyl Ketone
A colorless, flammable liquid with an acetone-like odor.
Methyl Ethyl Ketone Peroxide
A curing agent for polyester resins.: methyl ethyl ketone peroxide methyl ethyl ketone polyester resins geneva
The radical CH-3, existing only in organic compounds.
A low viscosity, commercially available epoxy curing agent.
A photoinstigator used for the visible light curing of unsaturated polyester and as an accelerator for anhydride cured systems.
An effective curing agent for epoxies.: geneva
Derived from the combination of urea and formaldehyde, the first stage in the production of urea-formaldehyde resins.
A low viscosity liquid used as a curing agent.: anhydride viscosity geneva
See METER.: nbsp
Abbreviation for melamine-formaldehyde.: nbsp definition melamine formaldehyde mf abbreviation
Chemical symbol for magnesium.: chemical symbol
A high beryllia content glass designed specifically for high modulus of elasticity.
Abbreviation for MEGAHERTZ.: nbsp definition abbreviation
Abbreviation for methyl isobutyl ketone.: nbsp definition abbreviation
Abbreviation for METHYLIMINOBISPROPYLAMINE.: nbsp definition abbreviation
One of a series of crystalline silicate minerals characterized physically by a perfect basal cleavage.
A proprietary early phenolic reinforced cotton material.
The integration of micromechanics and macromechanics in composite design.
See GAMMIL.: nbsp definition
The SI-approved prefix for a multiplication factor to replace 10^-6.
See BIODEGRADATION.: nbsp definition microbial degradation
Composites employing submicron fibers with high aspect ratios, or fine hollow spheres or fibers for reinforcement.
Also known as MICROCRAZING.: nbsp definition
Minute cracks in the resin matrix.: resin matrix cracks
Composed of crystals of microscopic size, which are sometimes defined as those having maximum dimensions of one micron.
A derivative of chrysotile asbestos, consisting of tiny rod-shaped particles of hydrated magnesium silicate.
A nondestructive technique for detection and identification of organic contaminants on the surfaces of polymeric materials.
Small panicles of cross-linked polymer of very high molecular weight and containing closed loops.
A test for microindentation hardness using a calibrated diamond force indenter, under a test load of 1 to 1000 grams.
One millionth of an inch or one thousandth of a mil.
The concepts, math-models, equations and detailed studies used to predict unidirectional composite (ply) properties from constituent material properties, stresses and strains, geometric configuration and fabrication process variables.
(1) Instrument for measuring small lengths under the microscope.
The use of this term, formerly designated by mu, has been replaced by micrometer, designated by mu-m.
An animal or plant of microscopic size (bacterium or fungus) which can grow on some organic polymer materials.
The technique of passing x-rays through a thin metal section in contact with a fine-grained photograph to obtain a radiograph which can be viewed at 50-l00X to observe constituents and voids.
Visible at magnifications greater than ten diameters.
Residual stresses that vary from tension to compression in a distance that is small compared to the gage length in ordinary strain measurements.
The segregation within a grain, crystal or particle.
A casting imperfection microscopically un-detectable and consisting of interdendritic voids.
Tiny, hollow spheres used as fillers to impart low density to plastics.
See MICROSCOPIC STRESSES.: stresses nbsp
An outline of the individual grains of a suitably prepared specimen.
Unit of pressure equal to 10^-6 ton.: nbsp definition
Small voids or holes in a material of such size that when filled with air (or some other additive) they scatter light because of the difference in refractive index between the material and the additive.
A heating process similar to DIELECTRIC HEATING.: metal matrix composites microwave radiation ceramic matrix vacuum bag uniform grain
The stress corresponding to a permanent deformation of 1 ppm strain of 10^-6 after short term loadings of continuously increasing value.
The middle surface of a laminate which is usually the z = 0 plane.
A laminate whose orientation is a mirror image about its midplane.
Abbreviation for metal-inert gas fusion welding.: metal inert gas abbreviation fusion
The transfer of a constituent of a plastic compound to another contacting substance, e.
A unit of length equal to 0.001 inch.: nbsp definition diameters fibers
Superficial growth produced by fungi on various surfaces.
Chemical agent which destroys, retards or prevents the growth of mildew.
The ability of a material to resist fungus growth that can cause discoloration and ultimate decomposition of a coating's binding medium.
Continuous glass strands hammer-milled into small modules of filamentized glass.
See MILLED FIBERS.: fibers
A system for the identification of planes and directions in any crystal system by means of integer sets.
The SI-approved prefix for a multiplication factor to replace 10^-3.
One thousandth of a liter.: milliliter thousandth liter
A unit of length previously used to describe the wavelength of electromagnetic radiation, equal to 10^-9 meters.
(1) The mechanical treatment of metal powder or mixtures as in a ball mill to alter shape or size of particles or coat them.
One thousandth part of a poise (measure of viscosity) or 1/10 of a centipoise.
Mindlin Plate Theory
A nonclassical plate theory formulated by the author.
Any naturally occurring, homogeneous inorganic substance having a definite chemical composition and characteristic crystalline structure, color and hardness.
Strong inorganic acids, such as nitric, sulfuric and hydrochloric.
Generic term for all nonmetallic inorganic natural and synthetic fibers.
An aggregate .: blast furnace slag glass wool mineral wool rock wool molten glass
The voltage which a unit thickness of insulator will withstand for one minute without breakdown.
Abbreviation for MULTIPLE INTERNAL REFLECTION.: internal reflection abbreviation nbsp
In woven fabrics, a pick not properly interlaced which causes a break in the weave pattern.
See HOLIDAYS.: misses holidays nbsp
Many reported versions exist.: polyester resins rigid pvc laminates polypropylene laminate
Devices used to intimately intermingle two or more materials to a defined state of uniformity.
Means of thorough intermingling of two or more materials.
The length of time to mix a batch of materials.: length of time
A combination of two or more substances intermingled with no constant percentage composition, in which each component retains its essential original properties.
System A previous system of units derived from the meter, kilogram and second.
Abbreviation for METAL MATRIX COMPOSITES.: metal matrix composites abbreviation mmcs nbsp
Abbreviation for MULTI-AXIAL MULTI-LAYER warp knit.
Chemical symbol for the element manganese.: element manganese nbsp definition chemical symbol
Chemical symbol for molybdenum.: nbsp definition chemical symbol mo mo
The property of a material which allows it to flow when a shearing force larger than the yield value has been applied.
Braided structures formed using 2-D or 3-D braids without axial yarns that readily bend to conform to varied shapes.
A rule defining the number of members required for a statistically determinate structure.
A trade name for methylene-bis-ortho-chloraniline, which was widely used as a curing agent prior to alleged findings that it is a carcinogen.
A weave similar to nonwoven, unidirectional reinforcement having a major reinforcement in the warp direction with a ratio of ways to fill yarns of usually 20:1.
A full scale replica or dummy usually constructed of easily worked materials.
A replica or scale miniature having proportions similar to the original.
Modes I and II
Two types of failure in lap joints have been designated types I and II.
Synthetic resins modified by the incorporation of other materials, which alter the processing characteristics or physical properties of the basic resins.
Any chemically inert ingredient added to resin formulation that changes its properties.
A number which expresses a measure of some property of a material: modulus of elasticity, shear modulus, etc.
See DYNAMIC MODULUS.: nbsp
(1) The slope of the initial straight portion of a stress-strain curve.
The ratio of change in stress to change in strain between two points on a stress-strain curve.
The ratio of change in stress to change in strain derived from the tangent to any point on a stress-strain curve.
The ratio of change in strain in the initial straight line portion of a stress-strain curve following the removal of any crimp.
See YOUNG'S MODULUS.: modulus young nbsp
Modulus at 300%
The tensile stress necessary to elongate a specimen to 300% of its original length.
Modulus in Compression
The ratio of the compression stress to the strain in the material, over the range for which this value is constant.
Modulus in Flexure
The ratio of the flexure stress to the strain in the material, over the range for which this value is constant.
Modulus in Shear
The ratio of the shear stress to the strain in the material, over the range for which this value is constant.
Modulus in Tension
The ratio of the tension stress to the strain in the material over the range for which this value is constant.
Modulus of Elasticity in Torsion
The ratio of the torsion stress to the strain in the material, over the range for which this value is constant.
Modulus of Resilience
The energy that can be absorbed per unit volume without creating a permanent distortion.
Modulus of Rigidity
The ratio of shear stress to the displacement per unit sample length.
Modulus of Rupture
The force necessary to break a specimen of specified width and thickness expressed in pounds-force per square inch.
The graphical representation of the variation of the stress and strain components resulting from rotating coordinate axes.
Used for determining slope and deflection of a beam in which the slope and deflection bear the same relation to the bending moment as the shear force and bending moment respectively do to the load.
A measure of the scratch resistance of a material.
(1) A constituent present in a material to some indefinite extent.
A nondestructive technique, obtained by a plot of stress wave factor vs. the number of interference fringes, which provides data on axial displacement of a laminate at nominal stress.
The pick-up of moisture from the air by a material on its surface only.
A material or a coating that retards or bars water vapor or moisture from passing through.
The amount of moisture in a material determined under prescribed conditions and expressed as a percentage of the weight of the moist specimen, that is, the original weight comprising the dry substance plus any moisture present.
The amount of transient moisture present in a composite profile which changes slowly with time, excepting the first few surface plies, which can change significantly.
The condition reached by a sample when the net difference between the amount of moisture absorbed and the amount desorbed, as shown by a change in weight, becomes insignificant.
The moisture present in a material, expressed as a percentage of the moisture-free weight, as determined under definite prescribed conditions.
Moisture Vapor Permeability
See SPECIFIC PERMEABILITY.: moisture vapor vapor permeability mvp geneva nbsp
Moisture Vapor Transmission
A rate at which water vapor will pass through a material at a specified temperature and relative humidity (g-mil/24 hr-100 in).
A solution which contains one mole of the solute per 1000 grams of the solvent.
A solution which contains one mole or gram molecular Weight of the solute per liter of solution.
(1) The cavity or matrix into or on which the plastic composition is placed and from which it takes form.
An assembly of ground flat plates, usually containing dowel pins, bushings and other components of injection or compression molds excepting the cavities and cores.
An edge which is used in final form as it comes from the mold, and particularly one which does not have fiber ends along its length.
(1) The forming of a polymer or composite into a solid mass of prescribed shape and size by the application of pressure and heat.
Molding, Contact Pressure
A method in which the pressure is only slightly greater than necessary to hold the materials together during the operation, i.
Molding or laminating in which the pressure used is greater than 14 kg/cm^2 or 1380 kPa (200 psi).
See INJECTION MOLDING.: injection molding nbsp
Molding, Low Pressure
See LOW PRESSURE MOLDING.: pressure molding nbsp
Granules or pellets of polymers or resins; usually mixed with additives such as plasticizers, stabilizers, fillers and colorants; ready for processing by extrusion, molding, or other forming processes into finished products.
(1) The period of time occupied by the complete sequence of operations on a molding press requisite for the production of one set of moldings.
A test for determining the molding index of thermosetting molding powder which comprises molding the specimen compound in a standard flash-type cup mold under prescribed conditions, and expressing the molding index as the total minimum force in pounds required to close the mold.
See MOLDING COMPOUNDS.: molding compounds nbsp
The pressure applied to the ram or press used to force the softened plastic to completely fill the mold cavities.
Molding Pressure, Compression
The unit pressure applied to the molding material in the mold.
Molding Pressure, Transfer
The pressure applied to the cross-sectional area of the material pot or cylinder, expressed in psi.
Molding Pressure Bag
See PRESSURE BAG MOLDING.: molding nbsp
The decrease in dimensions expressed in inches per inch, between a molding and the mold cavity in which it was molded; both the mold and the molding being at normal room temperature when measured.
See TRANSFER MOLDING.: transfer molding nbsp
See MOLD RELEASE AGENT.: mold release agent lubricant nbsp
Deformities caused during the molding operation.: mold marks deformities molding
A term for prepreg containing a chemical thickening agent.
Mold Release Agent
A lubricant applied to mold surfaces to facilitate release of the molded article.
Seam Line on a molded or laminated piece differing in color or appearance from the general surface, caused by the parting line of the mold.
(1) The immediate shrinkage which a molded part undergoes when it is removed from a mold and cooled to room temperature.
See MOLD RELEASE AGENT.: mold release agent nbsp
(1) A mass numerically equal to the molecular weight of a substance.
A unique phenomena of intermolecular forces which causes different materials to adhere in contrast to cohesion for similar materials.
A process for the separation of polymers into fractions of different molecular weight at the lowest possible temperature to avoid damage.
See ORIENTATION.: molecular orientation nbsp
The apparatus used for molecular distillation or separation of polymer fractions.
The volume occupied by one mole, numerically equal to the molecular weight divided by the density.
The smallest unit quantity of matter which can exist by itself and retain all of the properties of the original substance.
An effective flame retardant for halogen containing polyesters.
The stress couple that causes a plate to bend or twist.
The perpendicular distance from an axis to the line of action of a force.
An axis around which a force couple acts.: parallel forces axis
A progressive plot of internal bending moments developed within a loaded beam.
Moment of Inertia
The relation between the resultant torque about an axis and the angular momentum.
The reaction generated by a shear load which generates a moment load.
The continual sampling, measuring or recording of a process.
Trade term for a batch of resin which has set and become unusable during processing.
A prefix denoting a single radical.: nbsp definition prefix
A compound with a single acid function.: nbsp definition
A compound with a single amino group.: nbsp definition amino group
Pertaining to acids or salts which have one displaceable hydrogen atom per molecule.
A family of organic acids whose molecules contain a single carboxylic (-COOH) group.
A type of lightweight construction in which all stresses are carried by the thin covering or skin as in an aircraft fuselage.
The state of uniformity in molecular weight of all molecules of a substance or of a polymer system which is homogeneous in molecular weight.
A compound with a single ester group.: nbsp definition ester group
See MONOFILAMENT.: nbsp definition
(1) A single fiber or filament of indefinite length generally produced by extrusion.
See MONOMOLECULAR FILM.
(1) A relatively simple compound, usually containing carbon and of low molecular weight, which can react to form a polymer by combination with itself or with other similar molecules or compounds.
Pertaining to a monomer.: nbsp definition monomer
Unit of polymer molecule containing the same kinds and numbers of atoms as one of the monomers.
A layer that is one molecule thick, a monolayer.: monolayer molecule
An isothermal reversible reaction in a binary system, in which a liquid, on cooling, decomposes into a second liquid of a different composition and a solid.
See also p-CHLOROPHENYLDIMETHYLUREA.: nbsp definition
A radical or atom with a valency of one.: nbsp definition valency atom
A hard wax derived from lignite, used as a mold lubricant.
A mathematical relationship used for modeling of composites which accounts for filler agglomeration effects.
The study of the physical form and structure of a material.
See MOLDING.: materials and processes moulding molding abbreviation nbsp
Abbreviation for METAPHENYLENE DIAMINE.: diamine abbreviation mpda
Abbreviation for metallic particle molding.: nbsp definition molding abbreviation particle
Abbreviation for Military Standards.: nbsp definition military standards abbreviation
Abbreviation for METHYLTETRAHYDROPHTHALIC ANHYDRIDE.
A method for producing a fabric wherein yarns are inserted in different directions from 0 degrees to 90 degrees and various bias angles with the Raschel knitting machine and using a multiaxial magazine insertion mechanism.
A mold with two or more mold impressions; a mold which produces more than one molding per molding cycle.
In filament winding, a winding that requires more than one circuit before the band repeats by laying adjacent to the first band.
Plain rovings are essentially unidirectional looped rovings which combine longitudinal strength with a traverse component by way of loops which are spun or crimped.
A multitude of fine, continuous filaments (often 5 to 100 individual filaments) usually with some twist in the yarn to facilitate handling.
Multilayer Ceramic Composites
A method for dramatically increasing the strength of ceramic composites utilizing a multilayer approach.
Fabrics formed by braiding back and forth or overlapping in the same direction.
Usually spoolable filaments produced by chemical vapor deposition (CVD).
Multiple Internal Reflection
An infrared analytical technique for surface analysis of composite systems which utilizes increased attenuation from the successive reflection of the beam from the sample surface.
Stress that is applied to a body in many directions.
Aluminum potassium silicate.: potassium silicate nbsp definition aluminum
Abbreviation for MOISTURE VAPOR PERMEABILITY.: moisture vapor permeability mvp abbreviation nbsp
Abbreviation for MOISTURE VAPOR TRANSMISSION.: moisture vapor vapor transmission abbreviation mvt nbsp
Abbreviation for man year or man years.: nbsp definition abbreviation
Abbreviation for MICROYIELD STRENGTH.: abbreviation mys
n-beta-(Aminoethyl)-gamma-Aminopropyl Trimethoxy Silane
A silane coupling agent used in reinforced epoxy, phenolic, melamine and polypropylene resins.
A solvent with a good thermal and chemical stability, and a high flash point.
Abbreviation for (1) normal, designating those hydrocarbons or hydrocarbon radicals when molecules contain a single unbranched chain of carbon atoms.
Number of molecules having molecular weight Mi.: molecular weight molecules
(1) Number of segments or bonds in a polymer chain.
Abbreviation for National Association of Corrosion Engineers.
Nadic Methyl Anhydride
An accelerator for epoxy resin.: epoxy resin accelerator geneva
The SI prefix for a multiplication factor which replaces 10^-9.
The unit of length used for describing the wavelength of light and equivalent to 10^-9 meters or 10 Angstroms, same as the older term millimicron.
An aromatic hydrocarbon with two ortho-condensed benzene rings.
Textiles not exceeding 12 inches (30 nun) in width.
Abbreviations for (1) National Aerospace Standard, (2) Naval Aircraft Standard, (3) National Academy of Science.
Abbreviation for National Aeronautics and Space Administration (formerly NACA).
Abbreviation for Naval Air Systems Command.: nbsp definition abbreviation naval air systems
A general purpose, finite element, computer code used to conduct stress analysis of a laminate.
An uncombined metal found in the earth's crust.: earth native metal
Catalysts used in stereospecific polymerization reactions, particularly catalysts made from titanium chloride alkyls or similar materials.
Bonding substance obtained from natural occurring materials such as blood, casein, collagen, dextrin or starch.
Room temperature aging.: room temperature
Wood is a natural composite material containing an orientated hard phase, for strength and stiffness, and a softer one for toughness.
Natural fibers include those of vegetable origin constituted of cellulose, a polymer of glucose bound to lignin with varying amounts of other natural materials.
Abbreviation for butadiene-acrylonitrile copolymers.
Abbreviation for National Bureau of Standards.: nbsp definition national bureau of standards nbs abbreviation
See TRIAZINE RESINS.: triazine resins
Abbreviation for Nondestructive Evaluation.: nbsp definition abbreviation
Abbreviation for Nondestructive Inspection.: nbsp definition abbreviation
A process which manipulates material without significant loss or wastage such as avoiding machining.
The concentration of plastic deformation in a localized region of a sample under tension.
A mat made by continuously chopping rovings onto a carrier of woven roving.
An agent which reduces the speed of a reaction.: nbsp definition catalyst
(1) Prefix meaning new and denoting a compound related to an older one.
An important intermediate used in the production of alkyd and polyester resins.
A mineral of sodium or potassium-aluminum silicate, occurring worldwide in igneous rocks.
A naturally occurring mineral composed of feldspar and nephelite with the unique property of contributing almost no opacity, used as a filler in epoxy and polyester resins.
See NEPHELINE.: nbsp definition
Little lumps of tangled fibers found in yarn or fabrics.
See NESTING.: nbsp definition
In reinforced plastics, the placing of plies of fabric so that the yarns of one ply lie in the valleys between the yarns of the adjacent ply.
A perfect fit condition without interference or clearance.
The effective load carrying area at a cross section.
The analysis of filament-wound structures which assumes (1) that the stresses induced in the structure are carried entirely by the filaments, and the strength of the resin is neglected; and (2) that the filaments possess no bending or shearing stiffness, and carry only the axial tensile loads.
Polymers obtained by the polymerization of monomers having two or more functional groups which become interconnected with sufficient interchain bonds to form a large three-dimensional network.
An atomic or molecular arrangement in which primary bonds form a three-dimensional network.
The line of demarcation across the section of a beam in bending which experiences neither tension nor compression stresses due to internal moment forces.
A chemical reaction in which the hydrogen ion of an acid and the hydroxyl ion of a base unite to form water, the other product being a salt.
A nondestructive technique used for the detection of bonding defects in laminates.
The SI unit of force which, when applied to a body having a mass of one kilogram gives it an acceleration of one meter per second per second.
A flow characterized by a viscosity that is independent of shear rate; the rate of shear is directly proportional to the shearing force.
A liquid material that has Newtonian flow characteristics.
A 3M Corporation refractory fiber containing 62% alumina, 14% boron oxide and 24% silica.
Nexus Polyamide Fibers
Those polyamide fibers used commercially as reinforcements for the vinyl ester laminates.
Chemical symbol for nickel.: nbsp definition chemical symbol nickel
Small thickened places in a yarn of fiber.: nibs yarn
A SiC fiber manufactured by Nippon Carbon Company.
A notch, cut, indentation, or surface or edge discontinuity which can originate as a point of fatigue failure.
A high temperature resistant material.: nickel aluminide resistant material brittleness whiskers dispersion
Abbreviation for National Institute for Occupational Safety and Health, a division of the Center of Disease Control, Public Health Service, Department of Health, Education and Welfare.
A compound of nitrogen and a metal.: nbsp definition nitrogen
An organic cyanide.: nbsp definition
A solvent and reactant.: nbsp definition
An apparatus used to measure nitrogen and other gases evolved by a chemical reaction.
Abbreviation for NADIC METHYL ANHYDRIDE.: nbsp definition nma abbreviation
Abbreviation for n-METHYL-2-PYRROLIDONE.: pyrrolidone abbreviation nbsp
Abbreviation for nuclear magnetic resonance.: nuclear magnetic resonance nbsp definition nmr abbreviation
Abbreviation for NEAR-NET SHAPING.: abbreviation nns nbsp
A precious metal with a highly positive potential relative to the hydrogen electrode and having a marked resistance to chemical attack.
Abbreviation for tri(n-octyl n-decyl) trimellitate.
Irregular particles of a metal powder with knotted, rounded or other similar shapes.
A parallel filament wound test specimen used for measuring strength properties of the material by testing the entire ring, or segments of it (abbreviation for Naval Ordnance Laboratory).
The names of chemical substances and the systems used for assigning them.
The optimum choice or target dimension called out on the drawing before any tolerances are applied.
A tension, compression or shear stress calculated on the basis of PA or MCI where A and I are based on nominal dimensions without regard to local geometric discontinuities such as holes and grooves.
A graph containing several (usually three) parallel scales graduated for different variables so that when a straight line connects values of any two, the related value may be read directly from the third at a point intersected by the line.
Synonym for AZELAIC ACID.: synonym
(1) That which does not bum, preferred to incombustible by fire authorities.
An inspection method which does not destroy the part or impact its serviceability.
A test to determine the characteristics or properties of a material or substance that does not involve its deterioration or destruction (e.
That which does not burn with a flame.: nbsp definition flame
Lacking the property of absorbing and retaining an appreciable quantity of moisture from the air.
That which originates from curing and hygrothermal stress.
One in which the rate of shear is not proportional to the shearing stress.
Nonclay ceramic materials which, when mixed with water, do not exhibit the rheological property of plasticity.
Having no concentration of electrical charge on a molecular scale, thus incapable of significant dielectric loss.
Aromatic and petroleum hydrocarbon groups, characterized by low dielectric constants.
For purposes of general classification, a plastic that has a modulus of elasticity either in flexure or in tension of not over 700 kg per sq cm (10,000 psi) at 23 C and 50 percent relative humidity when tested.
Reflectance other than the mirror reflectance that occurs at the angle equal and opposite to the incident angle, diffuse reflectance.
Ingredients of a composition which, after drying, are left behind on the material to which it has been applied.
(1) A planar structure produced by loosely bonding together yarns, rovings.
A mat of glass fibers in random arrangement, used in reinforced plastics.
A prefix which stands for normal, it is used to indicate the parent compound from which a substance may be derived, usually by removal of one or more carbon atoms with attached hydrogen.
A material which can be added in small amounts to the matrix resin of carbon fiber reinforced epoxy composites.
A type of selvage produced by a shuttle loom.: nbsp definition selvage loom shuttle
A concentration of alloying components or constituents that have lower melting points in those regions which are the last to solidify.
Normal Storage Modulus
The component of applied normal stress which is in phase with the normal strain, divided by the strain.
The stress component perpendicular to a plane on which the forces act in the plane of the bondline.
Trademark for a modified type of polypropylene oxide (PPO).
A nick, indentation or flaw which can act as a surface stress riser.
A condition related to the severity of stress concentration produced by a given notch.
The susceptibility of a material to brittle fracture at points of stress concentration.
The distance from the surface of the test specimen to the bottom of the notch.
The percentage reduction in area after complete separation of the metal in a tensile test of a notched specimen.
Notched Off-Axis Test
A tensile test used to determine the combined Mode I (crack opening) and Mode n (forward shearing fracture) behavior of composites.
The section perpendicular to the longitudinal axis of symmetry of the specimen where the cross-sectional area is intentionally at a minimum value in order to serve as a stress riser.
Ratio of me resilience determined on a plain specimen, to the resilience determined on a notched specimen.
A mechanical press used for notching internal and external circumferences as well as along a straight line.
Notch Rupture Strength
The ratio of the applied load to original area of the minimum cross section in a stress rupture test of a notched specimen.
The extent to which the sensitivity of a material to fracture is increased by the presence of a surface inhomogeneity such as a notch, a sudden change in section, a crack, or a scratch.
See NOTCH ACUITY.: nbsp definition sharpness
Notch Tensile Strength
The maximum nominal (net-section) stress that a notched tensile specimen is capable of sustaining.
Trade name for fine particle microcrystalline silica.
A very fine-grained type of quartz, typically about 99.5% quartz.
See EPOXY-NOVOLAC RESINS and PHENOLIC NOVOLACS.: alternate spellings resins nbsp
Cross-linked, three-dimensional, phenolic-aldehyde fibers typically prepared by the acid-catalyzed, cross-linking of a melt-spun novolac resin with formaldehyde.
Abbreviation for NEOPENTYL GLYCOL.: glycol abbreviation npg
Abbreviation for Naval Research Laboratory.: nbsp definition naval research laboratory nrl abbreviation
A resin for use as a matrix resin, chopped fiber molding compound or for a high-temperature adhesive.
Nuclear Magnetic Resonance Spectroscopy
An instrumental analytical technique for the determination of the number of hydrogen atoms in a complex organic molecule and the characteristic grouping in which they occur.
Chemical substances which when incorporated in plastics form nuclei for the growth of crystals in the polymer melt.
The assumption of no difference between expected values of test measurements at different levels of the factors from a round-robin series of tests.
Number-Average Molecular Weight
The average molecular weight of a high polymer expressed as the first moment of a plot of the number of molecules in each molecular weight range against the molecular weight.
An alternative to woodflour as a filler to produce an improved processability and gloss in the final composite at the possible expense of stiffness, which is believed to arise from the lower aspect ratio.
Abbreviation for NONVOLATILE MATTER.: abbreviation
Generic name for all long-chain polyamides which have recurring amide groups (-CO-NH-) as an integral part of the main polymer chain.
A nylon polymerized in the presence of a nucleating agent, consisting of finely dispersed silica, which promotes the rate of growth of spherulites and controls the number, type and size.
Generic name for a manufactured fiber which was the first one of major commercial importance to be made of wholly synthetic materials.
Relatively coarse strands of nylon used for fishing lines, brush bristles, jacket strings, surgical sutures, etc.
A type of nylon with lower elongation at break than nylon 6 or 6/6, but capable of attaining these properties by reinforcement with glass fibers- The resin has low melt viscosity, good flexural strength and modulus, and resists alkalis and hydrolytic degradation.
See NYLON.: nylon resins nbsp
Nylon Zytel ST
A nylon identified by the initials for Super Tough rather than the conventional numbering system.
A manufactured fiber containing at least 85 % of a long chain polymer of vinylidene dinitrile.
Abbreviation for NONDESTRUCTIVE TESTor testing.: abbreviation
Chemical symbol for oxygen.: chemical symbol oxygen
Abbreviation for ORTHO.: nbsp definition abbreviation
Abbreviation for oxyacetylene applied to welding.: nbsp definition oxyacetylene abbreviation
Abbreviation for oxyacetylene welding.: nbsp definition abbreviation
An additive to improve fire retardancy.: nbsp definition fire retardancy
The general term for all 8-carbon organic radicals.
Abbreviation for outside diameter.: nbsp definition abbreviation diameter
Abbreviation for 4,4'-oxydianiline.: nbsp definition abbreviation
Abbreviation for OXYFUEL GAS CUTTING.: abbreviation
The trimmed material from formed panels or blanks.
See OFF-AXIS.: axis nbsp
Not coincident with the symmetry axis.: symmetry axis nbsp
An in-plane shear test method.: shear test test method axis
The distance along the strain coordinate between the initial portion of a stress-strain curve and a parallel line that intersects the stress-strain curve at a value of stress that is used as a measure of the yield strength.
Offset Yield Strength
The stress at which the strain exceeds (by a specified amount, the offset) an extension of the initial proportional part of the stress-strain curve.
In woven fabrics, the difference between the percentage of warp crimp and the percentage of filling crimp.
Applied to either vendor or in-house items which are immediately available or open stock.
Abbreviation for OXYFUEL GAS WELDING.: gas welding abbreviation
(1) An S-shaped fairing or molding.: cross section molding
Abbreviation for oxyhydrogen applied to welding.: abbreviation
The unit of electric resistance.: nbsp definition electric resistance electromotive force ampere conductor
Abbreviation for OXYHYDROGEN WELDING.: abbreviation
Any of numerous mineral, vegetable and synthetic substances, and animal or vegetable fats that are generally unctuous, slippery, combustible, viscous, liquid or liquefiable at room temperatures, soluble in various organic solvents, but not in water.
Oil of Bitter Almonds
Synonym for BENZALDEHYDE.: bitter almonds nbsp definition synonym
Oil of Mirbane
A synonym for NITROBENZENE.: nbsp definition synonym
The ability of a material to withstand contact with an oil without deterioration of physical properties, or geometric change.
An ivory colored powder used as a lubricant in extruding polyethylene.
Generic name for a manufactured fiber in which the fiber-forming substance is any long chain synthetic polymer composed of at least 85% by weight of ethylene, propylene or other olefin units.
See POLYOLEFINS.: nbsp definition plastics
The group of unsaturated hydrocarbons of the general formula CnH2n such as ethylene and propylene.
A polymer consisting of only a few monomer units such as a dimer, trimer, tetramer, etc.
See ON-AXIS.: axis nbsp
Coincident with the symmetry axis.: symmetry axis nbsp
Heat sensitive organic salts containing arsenic or antimony fluoride anions combined with certain reducing compounds which function as curing agents for epoxy resins.
Abbreviation for OUT-OF-ROUNDNESS.: roundness abbreviation nbsp
A general term to describe the degree to which a material obscures a substrate as opposed to transparency which is the degree to which a material does not obscure a substrate.
Describes complete opacity.: nbsp definition
Open Cell Foamed Plastic
See CELLULAR PLASTICS.: cellular plastics nbsp
In coated abrasives, when the individual abrasive grains are spaced at predetermined distance from one another, the open coat covers about 50 to 70 percent of the coated surface with abrasive.
Open Mold Processes
A family of techniques for composite fabrication which makes use of single cavity molds and requires little or no external pressure.
The time that a prepreg material can be left at ambient temperature without adversely affecting the molding characteristics of the resin.
The stress to which a structural unit is subjected in service.
The fabrication of composites exhibiting optical clarity is a difficult requirement.
A method of weaving in which light-emitting optical fibers run in the warp direction and conventional fibers in the fill direction.
One having the highest stiffness (or strength) per unit mass (or per unit cost).
Oral Lethal Dose
The amount of a substance taken by mouth that would kill within 14 days half (50%) of those test animals exposed.
An uneven surface texture of a plastic article or its finish somewhat resembling the surface of an orange.
Orbital Pad Sander
A portable sanding machine consisting of a backup pad that moves in small circles at high speed.
Forming a superlattice.: superlattice
Designation of any chemical compound containing carbon with the exception of some of the simple compounds of carbon, such as carbon dioxide, which are frequently classified as inorganic compounds.
The study of the composition, reactions and properties of carbon chain and/or carbon-ring compounds.
See PEROXIDE.: peroxide organic peroxides nbsp
Substances containing carbon-to-metal linkages which can be used as stabilizers and polymerization catalysts.
See SILICONES.: nbsp definition
The process of stretching a hot plastic article to realign the molecular configuration, thus improving mechanical properties.
The relative angle of the warp direction in a fabric to the chosen zero direction shown on the face of the drawing and would probably be the yarn or tow direction in a unidirectional tape.
Orientation Release Stress
The internal stress remaining in a plastic sheet after orientation, which can be relieved by reheating the sheet to a temperature above that at which it was oriented.
Materials, particularly amorphous polymers and composites, whose molecules and/or macroconstituents are aligned in a specific way.
(1) The specific position of substituting radical or group on the benzene ring.
A type of weave used for 3-D composites in which the fibers are orientated in the X-Y-Z directions.
A device, possibly a composite, that is surgically introduced into the human body.
Having three mutually perpendicular planes of elastic symmetry.
Abbreviation for Occupational Safety and Health Administration, the federal agency established by the Department of Labor, Bureau of Labor Standards, to enforce occupational safety and health standards.
An instrument for measuring osmotic pressure, consisting of a membrane which is permeable to solvents but impermeable to polymer molecules of a specific size range and reservoirs on each side of the membrane containing respectively the polymer solution and a solvent.
The passage of substances through a semipermeable membrane.
The hydrostatic pressure at which the flow of solvent through the membrane of an osmometer just stops.
A theoretical formula used in the determination of shear stress.
Viscometer in the form of a U in which the liquid flows from a bulb at a higher level on one side of the U, through a capillary, to a receiving bulb on the other side.
The evolution of embedded gas from a material by heat.
The radial deviation of the actual profile from ideal roundness.
The difference between me largest and smallest radius of a measured profile.
The deviation from 90 degrees with reference to a surface.
A surface, of revolution symmetrical about the polar axis which forms the end closure for a filament-wound cylinder.
Exposure of a material to a temperature higher or for a period of time longer, or both, than that recommended by the manufacturer.
Bending a material through a greater arc than required in the finished part to compensate for springback.
The onset of thermal decomposition in a thermo-setting resin due to overheating or excessive molding time.
Small groove placed in molds to allow excess material to flow freely to prevent weld lines.
A simple adhesive joint, in which the surface of one adherend extends past the leading edge of another.
A nonwoven fibrous mat of glass or synthetic fiber used as the surfacing sheet in laminated plastics.
Particles of a powder which are coarser than the maximum permitted by a given specification for particle size.
The cycling at a stress level that is higher than used at the end of the test.
Abbreviation for overexpanded as applied to hexagon honeycomb.
Any process which increases the proportion of oxygen or acid-forming element or radical in a compound.
See ANTIOXIDANT.: nbsp definition oxidation
(1) Epoxide.: nbsp definition ethylene oxide oxygen atom synonym oxirane
Value The percent of oxygen absorbed by an unsaturated raw material during epoxidation; a measure of the amount of epoxidized double bond.
A prefix denoting the -0- radical or (primarily in Europe) the -OH radical.
Oxyfuel Gas Cutting
A cutting process in which metals are heated by an oxyfuel gas flame followed by a chemical reaction of the heated metal with a compressed oxygen jet to effect separation.
Oxyfuel Gas Welding
A welding process for metal joining involving melting with a flame of a fuel gas such as acetylene or hydrogen.
See OXYFUEL GAS WELDING.: gas welding ohw geneva
The ratio of the storage modulus to the angular frequency, determined during forced harmonic oscillation.
An accelerating cocurative for epoxies.: nbsp definition
Abbreviation for PARA and (2) PICO- (10^-12).: abbreviation nbsp
Symbol for (1) extent of reaction, (2) hydrostatic pressure, (3) load, and (4) permeability constant.
Symbol for breaking load.: nbsp definition breaking load
Abbreviation for PASCAL.: nbsp definition pascal abbreviation
Abbreviation for (1) PLASMA ARC WELDING.: nbsp definition plasma arc arc welding abbreviation
Abbreviation for POLYAMINOBISMALEIMIDE RESINS.: resins abbreviation
The ability of a material to retain its original quality after prolonged storage.
The filling of the mold cavity without undue stress on the molds or causing flash to appear on the molding.
Braids having a solid square cross section and fabricated on machines with square arrays with up to sixteen horn gears.
A material in which P/M compacts are embedded during the presintering or sintered operations.
Abbreviation for POLYAMIDE-IMIDE RESINS.: polyamide imide resins abbreviation nbsp
Composite surfaces can be painted to enhance their appearance and/or to provide a desired surface property such as improved electrical properties and resistance to water, solvents, chemicals and abrasion.
Abbreviation for polyester alkyd resins.: nbsp definition resins abbreviation polyester
Usually refers to a number of cartons of roving placed on a wooden skid and strapped together as a shipping unit.
Abbreviation for PLASMA ARC MACHINING.: plasma arc pam pam abbreviation nbsp
Abbreviation for POLYACRYLONITRILE.: nbsp definition pan pan abbreviation
Distortion of a plastic container which occurs during aging or storage, caused by the development of a reduced pressure inside the container.
Fibers derived from a polyacrylonitrile precursor.
Abbreviation for POLYAZELAIC POLYANHYDRIDE.: papa papa abbreviation
A term applied to all kinds of matted or felted fiber sheets formed on a fine wire screen from a water suspension.
These products range from two ply paper thin films to thick boards.
A chromatographic analytical separation technique for complex mixtures involving the progressive absorption of the dissolved components onto a special grade of paper.
(1) The specific position of substituting radical or group on the benzene ring.
A very low molecular weight polymer of formaldehyde, or a mixture of polyoxymethylene glycols, in the form of a white solid which easily depolymerizes by heating to yield formaldehyde gas and water vapor.
A formula for elastic moduli relative to a displaced reference coordinate frame, analogous to that for moments of inertia.
See LAMINATE, PARALLEL.: nbsp
Used loosely to denote a specified range of variables, characteristics or properties relating to the subject being discussed; or an arbitrary constant as distinguished from a fixed or absolute constant.
A chemical compound which is the basis for its derivatives, e.
A filler material, calcium carbonate.: nbsp definition calcium carbonate filler material paris
A hollow plastic melt, tube extruded from the die head of a blow molding machine expanded within the mold.
An abbreviated trade name for a partially aromatic nylon reinforced composite material (LNP Engineering Plastics).
A unit or subassembly that combines with others to make up a component.
A relative term applied to treatment given to cold worked material to reduce the strength to a controlled level or effect stress relief.
An electrical discharge that only partially bridges the insulation between conducting materials.
That which is done to a lower level than full prestressing which eliminates all possibility of cracking under service or working loads.
Fiber board formed with a 4-12% phenol binder using limited pressure.
The diameter of a particle, usually expressed in mils or micrometers.
Particle Size Distribution
The relative percentage by weight or number of each of the different size fractions of particulate matter.
A lubricant, often wax, silicone or fluorocarbon fluid, used to coat a mold cavity to prevent the molded piece from sticking to it, and thus to facilitate removal of the piece from the mold.
The mark on a molded or cast article caused by flow of material into the crevices between mold parts.
Parts per Billion
A measure of proportion by weight equivalent to one unit weight of a substance per billion (10') unit weights of its matrix.
Parts per Million
A measure of proportion by weight, equivalent to one unit weight of a substance per million (10^6) unit weights of its matrix.
Abbreviation for POLYARYLSULFONE RESIN and PHOTO-ACOUSTIC SPECTROSCOPY.
The International System of Units term for the pressure or stress of one newton per square meter.
The changing of the chemically active metal surface to a less active state.
Adhesive composition having a characteristic plastic-type consistency, that is, a high order of yield value.
Abbreviation for POLYAMINOTRIAZOLES.: nbsp definition pat pat abbreviation
A material form around which refractory material is placed to make a mold for casting metals.
Chemical symbol for lead.: chemical symbol for lead nbsp definition
Abbreviation for POLYBENZIMIDAZOLES.: nbsp definition abbreviation pbi
PBT or PBZT
Abbreviation for POLYPHENYLENE BENZOBISTHIAZOLE.: pbt abbreviation
Abbreviation for POLYBUTYLENE TEREPHTHALATE.: terephthalate abbreviation
Abbreviation for POLYCARBONATE RESINS.: polycarbonate resins abbreviation
Abbreviation for POLYCAPROLACTONE.: nbsp definition abbreviation
Abbreviation for POLYCHLOROTRIFLUOROETHYLENE.: nbsp definition pctfe abbreviation
Abbreviation for preliminary design.: nbsp definition preliminary design abbreviation
Abbreviation for PHENYLENEDIAMINE.: nbsp definition abbreviation
Abbreviation for POLYETHYLENE.: polyethylene abbreviation nbsp
(1) That portion of a DTA or DSC curve attributed to single process occurrences which are normally characterized by a deviation from the established base line.
Peak Exothermic Time
The time interval between the initial mixing of reactants of a thermosetting polymer until the highest exothermic temperature is reached.
That temperature indicated at the time of maximum peak value of DTA or DSC curve.
Peanut Hull Flour
Ground peanut hulls, treated by drying to remove water and sometimes by extraction of volatiles with caustic or toluene, used as low-cost fillers in polyethylene.
See SUSPENSION POLYMERIZATION.: suspension polymerization nbsp
Abbreviation for POLYETHERETHERKETONE.: ketone peek abbreviation
The detachment of one layer from another because of poor adherence.
A removable outside fabric ply molded onto the surface of a laminate to provide a chemically clean surface for bonding when it is removed.
Strength The force required to peel apart two sheets of material that have been joined with an adhesive.
See SCOTCH TAPE TEST.: scotch tape peel test nbsp
Abbreviation for POLYETHYLENE GLYCOL.: polyethylene glycol peg abbreviation nbsp
Abbreviation for POLYETHERIMIDE.: pei pei nbsp definition abbreviation
Abbreviation for POLYETHERKETONE.: nbsp definition abbreviation
A high performance matrix resin with properties intermediate between K-3 polyimide and J-2 polyamide amorphous resin having exceptional solvent and flame resistance as well as hot/wet performance.
Tablets or granules of uniform size, consisting of resins or mixtures of resins with compounding additives which have been prepared for molding operation by shaping in a pelletizing machine or by extrusion and chopping into short segments.