Technology-Driven Composite Engineering Consulting Company.
be advised that this Glossary of Composites and
Outsource Terms is a compilation of technical terms
often used in the engineering and manufacturing
or daily business. If you find any information or
link to be incorrect, please e-mail: J
& J Mechanic.
of Composites Terms |
In composites, a sound generated by defects
within the laminate, such as plastic deformation,
crack initiation or crack growth.
A non-destructive test (NDT) method by which
the location and severity of active flaws
are determined by monitoring the acoustic
emissions from the defects. A particularly
useful NDT technique to determine structural
adequacy of FRP tanks and vessels.
The state in which two surfaces are held together
at an interface by forces or interlocking action
The effect, on materials, of
exposure to an environment for an interval of
time; the process of exposing materials to an
environment for an interval of time.
VOID Air entrapment
within and between the plies of reinforcement;
non interconnected, spherical in shape.
VENT Small outlet, to prevent
entrapment of gases.
based on resins composed principally of polymeric
esters, in which the recurring ester groups
are an integral part of the main polymer chain,
and in which ester groups occur in most cross
links that may be present between chains.
The surrounding environmental conditions such
as pressure or temperature.
RESINS A synthetic
resin derived from the reaction of urea, thiourea,
melamine or allied compounds with aldehydes,
The difference of the properties along the directions
parallel to the length or width into the lamination
planes; or parallel to the thickness into the
planes perpendicular to the lamination.
which, when added to the molding material or
applied on the surface of the molded object,
make it less conducting (thus hindering the
fixation of dust).
CONTENT The solid residue remaining
after a reinforcing substance has been incinerated
(or strongly heated).
RATIO The ratio
of length to diameter of a fiber.
A hardness value obtained by measuring the
resistance to penetration of a sharp steel
point under a spring load. The instrument,
called a Barcol Impressor, gives a direct
reading on a 0-100 scale. The hardness value
is often used as a measure of the degree
of cure of the plastic.
(yarns, rovings, fabrics) from which the sizing
or finish has been removed; also, such glass
before the application of sizing or finish.
WINDING In filament
winding, a type of winding in which the helical
band is laid in sequence, side by side, with
the crossover of the fibers eliminated.
A reinforced plastic laminate with the fibers
oriented in various directions in the plane
of the laminate: a cross laminate. See also
The agent applied to glass mat or performs
to bond the fibers prior to laminating or
A condensation product formed by reaction
of two (bis) molecules of phenol with acetone
(A) used as a component in one type of traditional
corrosion resistant FRP resin.
An undesirable rounded elevation of the
surface of a plastic, whose boundaries may
be more or less sharply defined. The blister
may contain process fluid.
The amount of adhesion between bonded surfaces;
a measure of the stress required to separate
a layer of material from the base to which
it is bonded. See also peel strength.
A resin catalyst system that provides improved
corrosion resistance in some chemical environments
that are reactive to the Cobalt in the more
commonly used MEKP/CoNap catalyst system.
A fire retardant (halogen) which is used
to reduce or eliminate a resin's tendency
to burn. Often used in conjunction with
chemicals such as antimony trioxide and
pentoxide to achieve a maximum Class 1 fire
retardancy rating and often used in ducting
An intermediate stage in the reaction of certain
thermosetting resins in which the material swells
when in contact with certain liquids and softens
when heated, but may not entirely dissolve or
fuse; sometimes referred to as resistol. The
resin is an uncured prepreg or premix is usually
in this stage.
Hydraulic pressure required to burst a vessel
of given thickness. Commonly used in testing
filament-wound composite structures. (2) Pressure
required to break a fabric by expanding a flexible
diaphram or pushing a smooth spherical surface
against a securely held circular area of fabric.
The Mullen expanding diaphram and Scott ball
burst machine are examples of equipment used
for this purpose.
A secondary laminate wrapped around two
or more components in an edge-to-edge configuration
used to join them together.
of a mechanical and unpredictable nature.
A measure of the difference in length of the
strands in a specified length of roving as a
result of unequal tension; the tendency of some
strands in a taut horizontal roving to sag lower
than the others.
Depression in mold; the space inside a mold
wherein a resin is poured; the molded article;
which forms the outer surface of the molded
article (often referred to as the die); also,
the space between matched molds. (Depending
on number of such depressions, molds are designated
as Single-Cavity or Multiple-Cavity).
An homogenous material created by the synthetic
assembly of two or more materials (selected
reinforcing elements and compatible matrix
resin) to obtain specific characteristics
MOLD A mold which is open when
the material is introduced and which shapes
the material by heat and by the pressure of
closing. Also 'compression molding'.
ability of a material to resist a force that
tends to crush; the crushing load at the failure
of a specimen divided by the original sectional
area of the specimen.
A process for molding reinforced plastics
in which reinforcement materials, such as
mat and woven roving saturated with resin,
are applied to a mold. The cure is either
at room temperature using a catalyst-promoter
system or by heat in an oven with no additional
AGENT Any chemical
substance designed to react with both the reinforcement
and matrix phases of a composite material to
form or promote a stronger bond at the interface;
a bonding link.
The change in dimension of a plastic under
load over a period of time, not including
the initial elastic deformation.
The formation of a three-dimensional polymer
by means of inter-chain reactions resulting
in changes in physical properties.
To change the properties of a resin by chemical
reaction, which may be condensation or addition
-- usually accomplished by the action of
either heat or catalyst or both, and with
or without pressure.
AGENT A catalytic
or reactive agent which when added to a resin
causes polymerization; synonymous with hardener.
TEMPERATURE Temperature at which
a cast, molded, or extruded product, a resin-impregnated
reinforcement, an adhesive, etc., is subjected
TIME The period
of time during which a part is subjected to
heat or pressure, or both, to cure the resin;
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.
(Further cure may take place after removal of
the assembly from the conditions of heat or
- The complete, repeating sequence of operations
in a process or part of a process. In molding,
the cycle time is the period (or elapsed
time) between a certain point in one cycle
and the same point in the next.
Permanent, unchanging loads on the FRP structure
caused by walkways, platforms or similar
split a laminated plastic material along
the plane of its layers. Physical separation
or loss of bond between laminate plies.
That temperature at which the weight of
steam associated with a certain weight of
dry air is adequate to saturate that weight
of air. When air at less than 100% relative
humidity is cooled to the temperature at
which it becomes saturated, the air has
reached the minimum temperature to which
it can be cooled without precipitation of
the moisture (dew).
Additional stress produced where abrupt
changes in geometry, materials and/or loading
occur in an FRP laminate.
SCANNING CALORIMETRY (DSC)
DSC is used to determine the glass transition
temperature and the degree of cure of an
FRP laminate by measuring the heat flow
into and out of a sample as the material
which is heated at a constant heating rate
under a nitrogen purged atmosphere. The
degree of cure may be determined by repeated
heating of a sample beyond the glass transition
temperature. If the laminate was undercured,
the glass transition temperature will continue
A borosilicate glass; the type most used
for glass fibers for reinforced plastics;
suitable for electrical laminates because
of its high resistivity.
A corrosion-grade glass exhibiting corrosion
resistant properties superior to "E"
glass. Superior resistance to acids and
alkalis is obtained through the application
of special treatments and sizings to "E"
That part of the total strain in a stressed
body which disappears upon removal of the
stress; opposed to plastic deformation.
Caused by stretching; the fractional increase
in length of a material stressed in tension.
When expressed as a percentage of the original
gage length, it is called percentage elongation.
Plastics based on resins made by the reaction
of epoxides or oxiranes with other materials
such as amines, alcohols, phenols, carboxylic
acids, acid anhydrides and unsaturated compounds.
The liberation or evolution of heat during
the curing of a plastic product.
A process for fabrication of a composite
structure in which continuous reinforcements,
either previously impregnated with a matrix
material or impregnated during the winding,
are placed over a rotating and removable
form or mandrel in a previously prescribed
way to meet certain stress conditions.
A relatively inert material added to a plastic
mixture to reduce cost, to modify mechanical
properties, to provide thixotropy, to serve
as a base for color effects or to improve
the surface texture.
The strain or stress level present at the
onset of significant laminate damage. The
laminate damage is the result of resin microcracking,
debonding of fibers in the resin matrix
and, occasionally, of local failure of fibers.
ELEMENT ANALYSIS (FEA)
A method of analysis used in situations
that are difficult to model by standard
engineering techniques. The finite element
method operates on the assumption that any
continuous function over a global domain
can be approximated by a series of functions
operating over a finite number of small
dub-domains. The series of functions are
piecewise, continuous and will approach
the exact solution as the number of sub-domains
That interval of time in connection with
the use of synthetic thermosetting resins,
extending from the introduction of a catalyst
into a liquid adhesive system until the
interval of gel formation.
An inorganic product of fusion in the form
of a filament which has cooled to a rigid
condition without crystallizing. Glass filaments
are combined, cut, woven or matted into
many types of reinforcements.
A resin combined with chlorine or bromine
to increase fire retardancy. See also Bromine.
The process of placing and working successive
plies of reinforcing material or resin-impregnated
reinforcement in position on a mold by hand.
DISTORTION TEMPERATURE (HDT)
The temperature at which a standard test
bar deflects under a stated load.
The angle at which continuous filaments
are placed relative to the longitudinal
mandrel axis in the filament winding process.
The circumferential stress in a material
of cylindrical form subjected to internal
or external pressure.
Loading produced by a fluid head.
A test in which static fluid head is used
to produce test loads.
The difference in weight before and after
burning; as with glass, the burning off
of the binder or size. Used to determine
the amount and types of glass reinforcement
A substance which retards a chemical reaction;
used in certain types of monomers and resins
to prolong storage life.
One in which the strength properties are
equal in all directions, such as contact-molded
laminates or metals.
An analytical procedure in which composite
physical properties are predicted from an
examination of the properties and interaction
of the individual plies that comprise the
The continuous, usually flexible reinforced
resin barrier on the inside surface of the
FRP laminate used to protect the laminate
from chemical attack or to prevent leakage
Pressure, vacuum, thermal or other variable
loads that may be applied to a structure.
A fibrous material consisting of randomly-oriented
chopped or swirled filaments loosely held
together with a binder.
The resin in which the glass reinforcements
The ratio of the stress or load applied
to the strain or deformation produced in
a material that is elastically deformed.
A simple molecule which is capable of reacting
with like or unlike molecules to form a
polymer; the smallest repeating structure
of a polymer.
Bond strength, in pounds per inch of width,
obtained by peeling the layer. See bond
The passage or diffusion of a gas, vapor,
liquid or solid through a barrier without
physically or chemically affecting it.
Process fluids that have penetrated the
FRP liner or structural wall.
A measure of the acidity or alkalinity of
a process fluid.
Change in dimensions of an object under
load that is not recovered when the load
is removed; opposed to elastic deformation.
An individual layer of reinforcement within
a total laminate comprised of several such
A plug is basically an exact finished part
or the exact shape and size you want your
final fiberglass product to be. The plug
is the male part that we pull a female mold
from. When we lay-up fiberglass in a mold,
the part has to be able to be pulled from
the mold - so every angle must be obtuse
(at least a degree or two) or else the part
wouldn't lift out of the mold. If your existing
parts or plugs don't have an angle to them,
we'll either need to rebuild them with angles
or add a bit to your current part to achieve
the desired angle. Overall, this usually
won't change the look of your part but it's
a critical step to making fiberglass pieces.
An ongoing inspection program with thorough
documentation and evaluation that provides
a knowledgeable basis for determination
for appropriate maintenance or timely replacement
of individual pieces of equipment.
When a material is stretched, its cross-sectional
area changes as well as its length. Poisson's
Ratio is the constant relating these changes
in dimensions, and is defined as the ratio
of the change in width per unit width to
the change in length per unit length.
Thermosetting resins, produced by dissolving
unsaturated, generally linear, alkyd resins
in a vinyl-type active monomer such as styrene,
methyl styrene and diallyl phthalate. The
resins are usually furnished in solution
form, but powdered solids are also available.
A high molecular weight organic compound,
natural or synthetic, whose structure can
be represented by a repeated small unit.
Some polymers are elastomers while others
are plastics. When two or more monomers
are involved, the product is called a co-polymer.
Additional elevated temperature cure, usually
without pressure, to improve final properties
and/or complete the cure. In certain resins,
complete cure and ultimate mechanical properties
are attained only by exposure of the cured
resin to higher temperatures than those
The directions in which the principle tensile,
compressive and shear stresses are located
in combined stress analysis. There are three
principle directions which are mutually
A chemical, itself a weak catalyst. See
The term "ROVING" is used to designate
a collection of bundles of continuous filaments
either as untwisted strands or as twisted
yarns. Glass rovings are predominantly used
in filament winding.
The ratio of ultimate stress to allowable
stress, or some similar ratio of units expressing
An action or stress resulting from applied
forces which causes or tends to cause two
contiguous parts of a body to slide relative
to each other in a direction parallel to
their plane of contact. In interlaminar
shear, the plane of contact is composed
of resin only.
A treatment consisting of starch, gelatin,
oil, wax or other suitable ingredient which
is applied to fibers at the time of formation
to protect the surface and aid the process
of handling and fabrication, or to control
the fiber characteristics. The treatment
contains ingredients which provide surface
lubricity and binding action but, unlike
a finish, contains no coupling agent.
Stable operating or other load conditions
that do not change with time.
The relationship of load and deformation;
a term often used when the relationship
of stress to strain does not conform to
the definition of Young's modulus. See also
modulus of elasticity.
The elongation per unit length of a material.
Preferential attack of areas under stress
in a corrosive environment, where this factor
alone would not have caused corrosion.
Stress relaxation occurs when the stresses
in the structure decrease while the deformation
is held constant. Under this condition,
the FRP laminate will assume a permanently
deformed shape after mechanical and thermal
loads are removed.
That portion of a total laminate that is
designed to take the imposed equipment loads.
Normally does not include the sacrificial
portion of the corrosion barrier or liner.
A term used to describe a safety factor
between 1.0 and 2.0. Equipment may be designed
for "survival" when subjected
to infrequent or unlikely upset conditions
of short duration.
Fiber made of materials other than glass,
such as polyester.
The change in temperature through the FRP
laminate from the interior to the exterior
of the equipment. The change in temperature
per unit of wall thickness.
Capable of being repeatedly softened by
increase of temperature and hardened by
decrease in temperature.
A plastic which, when cured by application
of heat or chemical means, changes into
a substantially infusible and insoluble
Concerning materials that are "gel-like"
at rest but that are fluid when agitated.
Materials having high static shear strength
and low dynamic shear strength at the same
Temporary loads of limited duration.
A crack occurring in the resin matrix at
right angles to the direction of the reinforcements.
A reinforced plastic laminate in which substantially
all of the fibers are oriented in the same
The transverse threads or fibers in a woven
fabric; those fibers running perpendicular
to the warp. \
A slow passage of process fluid through
an FRP laminate that can occur when a leak
path is established by extensive cracking.
A heavy glass fiber fabric made by the weaving
of roving and used as the primary structural
material in the laminate.
The first stress in a material, less than
the maximum attainable stress, at which
an increase in strain occurs without an
increase in stress.
of Outsource Term |
A specific product or group of products is the
focus, often when they are of high volumes and
where per-piece pricing is paramount. The U.S.
or Canada company still controls the process (equipment),
materials, technical know how, and quality management.
The contractor has more control over the process
and the manufacturing operation.
VENTURE: A separate
company is formed between different country or
area based companies for a specific purpose, such
as a manufacturing purpose. Joint ventures are
generally of a long term nature.
Performing or sourcing any part of an organization’s
activities at or from a location outside the company’s
The customer maintains control of the process
(equipment), materials, technical know how, and
quality systems and standards. The shelter provider
maintains control of the plant, labor, administration,
and the day-to-day manufacturing responsibilities.
Costs are expressed on some fixed basis—hourly,
weekly, etc. Technically, the shelter is an extension
of the present shelter receiver's manufacturing
operation; another department.
Sourcing is generally the broadest term used in
the field. It reflects the simple but essential
point that everything the organization does has
to be ‘sourced’ in some way –
internally, externally, or a mix of the two.
Sourcing-as-strategy is a powerful way to improve
an organization’s ability to serve customers,
compete in its markets, and grow. It’s a
strategic approach to outsourcing that involves
mapping the markets the organization plans to
serve, the competitive advantages it seeks in
each market, and then identifying the sources
of those competitive advantages – whether
they come from inside or outside the organization.
long-term agreements accomplish a purpose in a
China, such as a manufacturing venture. The agreement
defines the purpose and benefits for the Canada
or U.S. and China-based companies and the contribution
each will make such as capital, process, materials,
systems, management, etc.
This type of outsourcing focuses on utilizing
manufacturers having existing capabilities in
process, materials, quality systems, and technical
more terms or definitions to us