A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Accelerator
- A chemical used to increase the rate of cure of resin at room temperature.
- Acetone
- A cleaning fluid used in RP/C context to remove uncured resin. A Flammable Liquid.
- Additive
- substances added to resin to impart specific performance qualities, such as ultraviolet inhibitors, fire retardant and air inhibitors.
- Adhesive Failure
- A loss of bond that appears to be a separation at the adhesive/adherent interface.
- Air Dry
- cure at room temperature without the application of heat or pressure.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Bag Molding
- A technique for forming plastic laminates or composites by means of air pressure, vacuum and/or heat in a flexible or semi-flexible bag or autoclave, usually in connection with a rigid die or mold
- Benzoyl Peroxide (BPO)
- The catalyst used in conjunction with aniline accelerators or where heat is used as an accelerator.
- Bi-Directional
- An arrangement of the reinforcing fibers strands in which the strands are laid at right angles to each other, a directional pattern which gives maximum product strength in two planes.
- Bias Fabric
- A fabric in which warp and fill fibers are at an angle to the length.
- Binder
- Bonding resin applied to glass fibers to hold fibers in position.
- Blank
- The foam core of a surfboard or sailboard that the shaper begins with.
- Bond Strength
- As measured by load/bond area, the stress required to separate a layer of material from that to which it is bonded. The amount of adhesion between bonded surfaces.
- Buckling (composite)
- A failure mode usually characterized by fiber deflection rather than breaking because of compressive action.
- Butt Joint
- A joint in which parts are joined with no overlap.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Carbon Fiber
- An important reinforcing fiber known for light weight, high strength and high stiffness that is produced by pyrolysis of an organic precursor fiber in an inert atmosphere above 1800°F. The material may also be graphitized by heat treated above 3000°F.
- Catalyst
- In the common terminology of the reinforced composite industry, a catalyst is actually the initiator that causes the chemical reaction that turns a liquid polyester resin into a solid. The type of initiator employed depends upon the temperature at which the reaction will take place.
- Cavity
- The space between matched molds (pressure molds) in which the laminate is formed. Also a term for a female mold.
- Chopped Strand
- Continuous strand yarn or roving cut up into uniform lengths, usually from 1/32" to 1/2" long.
- Chopper Gun
- A special spray gun used for spray-up laminating which chops predetermined lengths of fiberglass roving or strands, and deposits them together with catalyzed resin at the same time onto the mold surface.
- Cloth
- A fine weave of woven fiberglass fabric.
- Color Pigment
- Dispersions ground coloring materials in a thick liquid, which are compatible with the resin system in which it will be used. When added to the resin, the pigment dispersions give it color
- Composite
- Dissimilar materials laminated together to form a single structure, for example, resin, gel coat, glass. A material created from a fiber (or resinreinforcement) and an appropriate matrix material in order to maximize specific performance properties. The constituents do not dissolve or merge completely but retain their identities as they act in concert.
- Compression Molding
- A technique for molding thermoset plastics in which a part is shaped by placing the fiber and resin into an open mold cavity, closing the mold, and applying heat and pressure until the material has cured or achieved its final form.
- Contact Molding
- A molding technique in which reinforcement and resin are placed in a mold, with cure taking place at room temperature with a catalyst/promoter system or in a heated oven. No additional pressure is used.
- Core
- The central component of a sandwich construction to which the sandwich faces or skins are attached; also, part of a complex mold that forms undercut parts.
- Cure
- To change the physical properties of a material irreversibly by chemical reaction via heat and catalyst, alone or in combination, with or without pressure.
- Cure Temperature
- The temperature at which a material attains final cure.
- Cure Time
- The time required for the liquid resin to reach polymerized state after the catalyst has been added.
- Curing Agent
- A catalytic or reactive agent that brings about polymerization when it is added to a resin.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Delamination
- Failure of internal bonding between layers of resin and reinforcement. It appears as a separation of the layers.
- Denier
- A numbering system for yarn and filament in which yarn number is equal to weight in grams of 9000 meters of yarn.
- Diethylaniline (DEA)
- Accelerator used in conjunction with BPO catalyst or as a co-promoter for cobalt/MEKP systems.
- Diluent
- Diluting (reducing or thinning) agent.
- Dimethyl Aniline (DMA)
- Accelerator used in conjunction with BPO catalyst or as a co-promotor for cobalt/MEKP systems. More effective than DEA.
- Draft
- The degree of taper allowed on the sides of a mold so the part can be removed.
- Duplication Mold
- A mold made by casting over or duplicating another article. Also referred to as splashing.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Encapsulating
- Enclosing an article in a closed envelope of plastic by immersion. Milled fibers or short chopped strands are often poured with the catalyzed resins into open molds for casting electrical components.
- Epoxy Resin
- Thermosetting resin usually of a two-part type, that when combined, cure and form into an extremely hard and tough product. They will adhere better and shrink less than polyester resins, have generally greater strength, although they are more costly.
- Exothermic Heat
- The heat given off by the resin developed internally during the curing process, or "polymerization." It is caused by the reaction of the accelerator and the catalyst when mixed in polyester resins, and by the hardener in epoxy resins.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Fading
- Loss of color in the gel coat.
- Female Mold
- The type of mold where the part is made inside a cavity with the inter surface of the mold (cavity) being the outer surface of the part, Commonly used in the production of fiberglass boats where the outer surface of the molded part is formed by the inter surface of the mold.
- Fiber
- An individual rod of glass of sufficiently small diameter to be flexible, having a known or approximate limit of length.
- Fiberglass
- Fibers similar to wool or cotton fibers, but made from glass; sometimes called fibrous glass. Glass fiber forms include cloth, yarn, mat, milled fibers, chopped strands, roving, woven roving and knitted fabrics.
- Fill or Sanding Resin
- A general purpose polyester resin used to fill voids in reinforcing material in the initial lay-up of a surfacing application. It usually contains wax.
- Finishing Resin
- A polyester Resin containing wax (surfacing agent) which floats to the surface to exclude the air from the resin surface, thereby allowing it to cure or "set up."
- Fire-Retardant Resin
- A Resin type which has been formulated with chemicals to reduce or nearly eliminate its tendency to burn when once cured or "polymerized." It should be noted that fire retardant resins are not "fire proof."
- Fish Eye
- A circular separation in a gel coat film generally caused by contamination such as silicone, oil, dust, water.
- Foam
- In RP/C context this term usually refers to rigid foam plastics of three types: polystyrene ("Styrofoam"), polyurethane (including the pour-in-place type), and polyvinyl chloride (PVC).
- Fracture
- A rupture of the surface of a laminate because of external or internal forces, with or without complete separation.
- FRP
- Fiberglass Reinforced Plastics.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Gel Coat
- A surface coat layer of either colored or clear, non-reinforced polymer resin. It provides a protective coating for the fiber glass composite part and a cosmetic enhancement of the molded part.
- Glassing
- Applying (laminating) fiberglass cloth with resin to a shaped blank.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Hand Lay-up
- A fabrication method in which reinforcement layers, preimpregnated or coated afterwards, are placed in a mold by hand, then cured to the formed shape.
- Hardener
- A substance used to promote or control curing action by taking part in the reaction.
- Honeycomb
- Resin-impregnated material manufactured in usually, hexagonal cells that serve as a core material in sandwich constructions. Honeycomb may also be metallic or polymer materials in a rigid, open cell structure.
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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Laminate
- A material composed of successive layers of composite materials (resin and reinforcements) bonded together. The product.
- Lamination
- The layering of composite materials and the eventual bonding together of these layers. The process.
- Lay-up
- Placing reinforcing material onto the mold and applying resin to it; can be done by hand or using mechanical applicators. Lay-up is sometimes used as term for the work piece itself.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Male Mold
- The type of mold where a part is made up over the mold instead of inside the mold, with the outside surface of the mold creating being inner surface of the molded part. A swimming pool is an example.
- Mat
- A fibrous reinforcing material composed of chopped filaments (for choppedstrand mat) or swirled filaments(for continuous-strand mat) with a binder to maintain form; available in blankets of various widths, weights and lengths.
- Master (Plug)
- The tool used to build molds for the manufacture of fiberglass parts.
- MEK Peroxide (MEKP)
- Abbreviation for methyl ethyl ketone peroxide; a strong oxidizing agent (free radical source) commonly used as catalyst for polyester resins.
- MEK Solvent
- Abbreviation for methyl ethyl ketone; a colorless, flammable liquid commonly used in clean-up procedures.
- Mold
- (1) The tool from which a plastics part is made and from which it takes its form. (2) The process by which a plastic part is made. (3) To shape plastics parts by heat and pressure. (4) The assembly of all components that function collectively in the molding process.
- Molding
- The forming of plastic and composite materials by various means, such as contact, pressure, matched die, and continuous laminating into a given shape of a mold, and holding that shape by the mold until the resin cures or hardens.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Orange peel
- Backside of the gel coated surface that takes on the rough wavy texture of an orange peel.
- Orthophthalic Resin ("Ortho")
- Orthophthalic acid based polyester resin. Considered a "general purpose" resin.
- Oxidizer, I
- n RP/C context a chemical agent that initiates or promotes combustion in other materials, thereby causing fire either of itself or through the release of oxygen or other gases.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Parting Agent
- Any material used to coat the mold to prevent the molded part from sticking to the mold when being removed, or a material used to keep resin from sticking to any part of the work. Common release agents are wax, polyvinyl alcohol (PVA), cellophane, glass, and "Formica". Wax and PVA are commonly used in female mold factory production boat-building. See mold release.
- Pigment
- An opaque ingredient used as a coloring agent for resin and in gel coats to impart color.
- Ply
- The number of single yarns twisted together to form a plied yarn; one of the layers that make up a stack or laminate.
- Plug
- See Master - Both terms used to imply the same meaning. Form identical in shape to the finished object over which a mold is fabricated.
- Polyvinyl Alcohol (PVA)
- A liquid water soluble release agent for polyester.
- Pot Life
- The length of time that a catalyzed resin remains workable.
- Pre-cure
- The full or partial setting of a resin or adhesive before the clamping operation is complete or before pressure is applied.
- Premix
- Reinforcing material mixed with resin, and usually with pigment, filler and catalyst, before placing in the mold. Premix can be extruded into ropes or used in bulk form.
- Prepreg
- Abbreviation for pre-impregnated glass fibers. Resin-impregnated cloth, mat, or filaments in flat form that can be stored for later use. The resin is often partially cured to a tack-free state called "B Staging". Such additives as catalyst, inhibitors, flame retardant and others, may be added to obtain specific end-use properties and improve processing, storage and handling characteristics.
- Pre-Release
- Premature release of the gel coat or laminant from the mold.
- Primary Laminate
- Laminate applied after the skin coat has cured. Generally thicker than the skin coat.
- Promoted Resin
- Polyester resin to which an accelerator has been added. Resin which does not have accelerator is said to be "unpromoted ". Resin which has the promoter added before the user adds the catalyst is said to be "pre-promoted".
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Reinforced Molding Compound
- A compound supplied by raw material producer in the form of ready-to-use materials, as distinguished from premix.
- Reinforcement
- A material added to the matrix to provide the required properties; ranges from short fibers through complex textiles forms.
- Release Agents
- Materials that are used to prevent cured matrix material from bonding to tooling. A lubricant, often wax, that prevents the adhesion of the part to the mold. An internal lubricant such as zinc stearate is used in high temperature molding to obtain release where wax would melt or be absorbed.
- Resin
- A material, generally a polymer, that has an indefinite and often high molecular weight and a softening or melting range and exhibits a tendency to flow when it is subjected to stress. Resins are used as the matrices to bind together the reinforcement in material in composites.
- Resin Rich
- Localized area filled with resin but lacking reinforcement fiber. Rich- An area, especially in a laminate, where too much resin has been applied in relation to the fiberglass reinforcing material. The opposite of a Dry Spot or "resin starved" area. Also referred to as a "resin pocket" and "resin streak." Resin Starved, Localized area lacking sufficient resin for wetout of the fibers.
- Resin Transfer Molding (RTM)
- A molding process in which catalyzed resin is transferred into an enclosed mold into which the fiber reinforcement has been placed; cure normally is accomplished without external heat. RTM combines relatively low tooling and equipment cost with the ability to mold large structural parts.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Sand Coat
- The resin layer which is sanded to blend and refine contours of the board (also referred to as the hot coat).
- Sandwich Construction
- A type of fiberglass construction which resembles a sandwich consisting of relatively dense but high-strength facings bonded to a less dense but thicker intermediate material or "core". Core materials include plastic foams, end grain balsa, honeycomb, lumber and plywood.
- Sandwich Lay-up
- A lamination composed of two outside layers of reinforced material such as glass mat and inside layer or layers of honeycomb, glass cloth, or other lightweight material.
- Set
- To convert a resin into a fixed or hardened state by chemical or physical action, such as condensation, polymerization, vulcanization, or gelation.
- Shape
- The foam blank as completed by the shaper
- Skin
- A layer of relatively dense material used in a sandwich construction on the surface of the core.
- Skin Coat
- The first layer of laminate next to the gel coat.
- Spray-Up
- A process in which glass fibers and resin are simultaneously deposited in a mold
- Stabilizer
- An additive for polyesters to maintain liquid characteristics such as; gel time, viscosity and liquidity.
- Structural Bond
- A bond joining load-bearing components of an assembly.
- Styrene Monomer
- A water-thin, liquid used to thin polyester resins prior to cure and which serves as the chemical which links the polyester chains together to form a dense solid during the curing process. An unsaturated hydrocarbon, used in plastics. In polyester, it is a co-reactant diluent.
- Substrate
- Any material which provides a supporting surface for other materials.
- Surfacing Agent
- Solution added to polyester resin or used in association with it to prevent air from reaching the surface of polyester resin so the resin can cure.
- Surfacing Mat
- A tissue of staple fibers well bonded with a medium which "wetsout" rapidly in polyester and other contact resins. It is principally used to provide resin rich surfaces on RP moldings.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Tensile Strength
- The maximum tensile stress sustained by a plastic specimen before it fails in a tension test.
- Thermoset
- A plastic material that once cured cannot be returned to the uncured state. Thermoset will undergo or has undergone a chemical reaction caused by heat, catalyst, ultraviolet light, etc., before it becomes a solid.
- Thickener
- Material added to resin to thicken or increase the viscosity of the resin so it will not flow as readily. A common thickener used with polyester and epoxy resins is fumed silica, which helps make the resin thixotropic.
- Thinner
- Material added to resin in order to thin or lower the viscosity of the resin. There is a limit to the amount of thinner that can be added without affecting the desirable qualities of the resin. It is generally better to choose an alternative resin.
- Thixotropic
- A term describing material more jelly-like at rest than when stirred or agitated, as agitation (shear) reduces the gel and increases the flow. Thixotropic resins are used where it is necessary to minimize runs and sags on vertical surfaces.
- Tint
- A transparent coloring agent for resin.
- Tooling Resins
- Resins, chiefly epoxy and silicone, that are used as tooling aids.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Undercut
- Negative or reverse draft on the mold. Split molds are necessary to laminate (fabricate) parts with undercuts.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Vinyl Ester Resin
- A type of polyester resin with improved physical properties, especially at elevated temperatures, over either Ortho or Iso polyesters.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Warp
- The yarns running lengthwise and parallel to the selvage in a woven fabric.
- Wax
- A mold release agent.
- Weave
- The construction of a fabric through a pattern of interlacing of yarns. In plain weave, the warp and fill fibers alternate to make both fabric faces identical; in satin weave, the pattern produces a satin appearance, with the warp tow over several fill tows and under the next one (for example, eight harness satin would have warp tow over seven fill tows and under the eighth).
- Weft
- The yarns running perpendicular to the warp in a woven fabric; also called fill or "woof"'.
- Wetout
- The saturation of all voids between strands and filaments of porous materials with resin.
- Wetout Rate
- The speed with which a reinforcing material can be completely saturated with resin. This rate is usually determined visually and measured in elapsed time.
- Wetting Agent
- A surface-active agent that promotes wetting by decreasing the cohesion within a liquid.
- Woven Cloth
- A woven continuous filament cloth used where very high strength is important.
- Woven Roving
- A heavy, coarse fabric produced by the weaving of continuous filament roving bundles. They drape well, are quickly impregnated, and intermediate in price between mats and knitted fabric reinforcements.
- Woven Tape
- Tapes of various thickness woven from continuous filament yarns.
