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A
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| Abrasion |
The wearing away of a surface by rubbing or scraping. |
| Absorption |
The penetration into one material by another. |
| Acetone |
A flammable solvent with a low health hazard, used to
thin and clean up uncured epoxy resins. It's usefulness for
cleanup is limited by its rapid evaporation rate. |
| Adherent |
A material which is held to another material by an
adhesive. |
| Ambient |
Existing environmental conditions, including
temperature, pressure and humidity. |
| Amine Blush |
A sticky or greasy film which forms on the top of some
amine- or polyamide-cured epoxy resins. It is removable by
scrubbing with soap and water. |
| Amine Carbamate |
The chemical nomenclature for amine blush (see above). |
| Aqueous |
Solutions or mixtures containing water. |
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B
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| B Staged |
Epoxy resin which is cured enough to be hard and
brittle, with little or no strength, is said to be "B
Staged." |
| Bag molding |
A technique in which fluid pressure is applied to a
plastic in a mold through a flexible membrane. |
| Bubble |
A spherical void trapped within a plastic material,
created by trapped air. |
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C
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| Carvel Planking |
A traditional style of wooden boat construction in which
the wood strips, or planks, for the hull are placed with a
gap between them on purpose, so that a swellable caulking
material can be applied later which will make the boat
watertight. |
| Cast |
To form a plastic material into a desired shape by
pouring it into a mold. |
| Chalking |
Some polymer films gradually degrade from ultraviolet
light exposure (sunlight). One sign of that degradation is
formation of powder on the surface of the film. This process
is called "chalking." |
| Cohesion |
The force holding a substance together. |
| Composite |
A material matrix consisting of a thermosetting polymer
resin and a reinforcing fabric. The fabric provides the
strength and the resin distributes the load and provides
dimensional stiffness. |
| Compressive Strength |
The ability of a material to resist a crushing force. |
| Cross Laminate |
A laminate in which some of the layers, with regard to
the strongest direction, are laid up at right angles to
others. |
| Cure |
The process of hardening of a catalyzed resin. |
| Curing Agent |
A chemical that causes a resin to cure; a hardening
agent. |
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D
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| Debonding |
An adhesive failure between two surfaces glued together,
typically occurring between layers of laminating resin or
between a coating and a substrate. |
| Delamination |
A split in a laminated plastic along the plane of its
layers. |
| Diluent |
A liquid added to a plastic resin to lower the viscosity
of the resin. |
| Dimensional Stability |
The ability of a resin system to retain precise size and
shape after cure. |
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E
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| Elongation |
The increase in length of a material under tension. |
| Epoxy Resin |
A thermosetting resin used in tooling applications. |
| Exotherm |
Chemical reaction producing heat. |
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F
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|
| Fiber Pattern |
The thread size and weave of fiberglass cloth. |
| Flash Point |
The temperature at which a flammable material ignites. |
| Flexible Molds |
Molds which can be stretched to remove cured plastics. |
| Flexural Strength |
The strength of a material in bending. |
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G
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|
| Gel |
A semi-solid state in a liquid resin. |
| Gel Time |
The amount of time required for the mixed hardener and
resin to gel. |
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H
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|
| Hardener |
A reactive chemical which causes a resin to cure; a
curing agent. |
| Heat Distortion Point |
The temperature at which a test bar deflects under a
given flexural load and a prescribed amount of heat. |
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I
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|
| Impregnate |
To saturate reinforcement with plastic. |
| Inert |
Chemically inactive. |
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L
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|
| Laminate |
To join sheets or layers of a material with a bonding
agent, such as using epoxy resins to bond layers of
fiberglass cloth. |
| Lay-up |
The positioning of reinforcing material and a plastic in
a mold or over a model. |
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M
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|
| Mil |
0.001 inch. |
| Mold |
The cavity or matrix containing a plastic. |
| Mold Release |
An agent used to prevent a plastic from sticking to the
mold. |
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P
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|
| Parallel Laminate |
A laminate in which all layers of the reinforcement are
aligned parallel to the strongest direction in tension. |
| Plasticity |
That property of plastics which permits them to be
permanently shaped without breaking when sufficient shaping
force is applied. |
| Polyesters |
Thermosetting plastics of the type used in fiberglass
boat hull and automobile body construction. |
| Polyurethane |
Thermosetting plastic used for foam insulation, flexible
molds, protective coatings, and abrasion resistant castings. |
| Porous Mold |
A mold made of bonded or fused particles of various
sizes, which, when completed, will permit the passage of air
or liquids through the mass. |
| Post Cure |
A process employed after the initial cure, in which a
plastic is given a final oven cure to achieve optimum
physical properties. |
| Pot Life |
The amount of time in which resin and hardener can be
used after mixing. |
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R
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|
| Reinforcement |
Material used to strengthen a plastic, such as
fiberglass. |
| Resin |
Liquid, semi-solid organic material occurring naturally
or produced synthetically. With respect to plastics a resin
is the primary material which is polymerized (cured) to a
useful plastic product. |
| Room Temperature |
77ºF |
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S
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|
| Safety Hardener |
A curing agent having minimum toxic effects on the human
body. |
| Solvent |
A type of liquid used to dissolve another material. |
| Spline |
To prepare a surface to desired contours by working a
paste material. |
| Spray-up |
A technique employing a spray gun to prepare a
reinforced plastic article. |
| Substrate |
Any surface on which an adhesive or coating is spread. |
| Sweat-out |
The formation of a liquid on the surface of a cured
plastic; exudation. |
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T
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| Tack |
Stickiness. |
| Tensile Strength |
The strength of a material in tension. |
| Thermal Conductivity |
The ability of a material to conduct heat. |
| Thermoforming |
Shaping a plastic by heating it to its softening point
and cooling it on a mold. |
| Thermoplastic |
A plastic which is capable of being re-formed a number
of times by heating. |
| Thermosetting Resin |
A plastic which cures through chemical reaction to an
essentially infusible material. Thermosetting resins cannot
be re-formed after final cure. (Refer to "Epoxy Resins") |
| Thixotropic |
A property of materials which are quite thick while
standing and become thinner when agitated. |
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U
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|
| Undercure |
The condition of a molded article which results when not
enough time or temperature has been applied to bring about
final cure and achieve maximum physical properties. |
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V
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|
| Viscosity |
Thickness. |
| Voids |
Air pockets trapped within a material, such as a
plastic-fiberglass laminate. |
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W
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|
| Working Life |
The period of time after mixing a resin and hardener in
which the material remains a liquid. Varies with type of
plastic, amount of mixed material, and ambient temperature. |
