Precursor   For carbon fibers, the rayon, PAN, or pitch fibers from which carbon fibers are made. X axis   The axis in the plane of the laminate used as 0 degree reference; the Y axis is the axis in the plane of the laminate perpendicular to the X axis; the Z axis is the reference axis normal to the laminate plane in composite laminates. But it’s routinely used in tiny quantities as a preservative for food and to treat various medical conditions. Selection of the proper glove for protection is important. Yarn   Continuously twisted fibers or strands suitable for use in weaving into fabrics. Some (such as methyl alcohol) are poisonous, and all are capable of extracting fat from skin. Circumferential winding   A type of filament winding in which the filaments are perpendicular to the axis. It is used in organic metal-matrix composites. Mechanical irritation of skin, eyes, nose, and throat are common hazards associated with glass-fiber exposure. Nonwoven roving   A reinforcement composed of continuous rovings loosely gathered together. S-glass   Structural glass; a magnesia/alumina/silicate glass reinforcement designed to provide very high tensile strength. More dust is usually generated in finishing and repair processes since large surface areas are involved. Laminate ply   One layer of a laminated product. Pitch-based carbon fibers may be associated with an increased risk of skin cancer, although the evidence is weak. However, in the case of resins and curing agents, not much data are available. Once cured, the part cannot be changed or reformed, except for finishing. The skin staining has been attributed to MDA; dermal absorption is approximately 2% per hour. 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. Tape laying   A fabrication process in which prepreg tape is laid side by side or overlapped to form a structure. Much of the terminology used in this manual is peculiar to the composites industry, and for this reason a glossary of terms has been provided in Appendix III:1-1. The curing agent, also known as hardener, acts as a catalyst and helps in curing the resin to a hard plastic. Hazard classification & labelling Hazard classification and labelling. Several ketones are frequently found in PMC manufacture. Skin   A layer of relatively dense material used in a sandwich construction on the surface of the core. Nondestructive inspection (NDI)   A process or procedure for determining material or part characteristics without permanently altering the test subject. Fracture   A rupture of the surface of a laminate because of external or internal forces, with or without complete separation. Tape   A unidirectional woven prepreg, in widths up to 12 inches for carbon fiber, for example. The potential for dermal exposure is typically much greater than respiratory exposure when working with epoxies. These aromatic amines are considered to be only slightly irritating to the skin. Depending on which specific phenolic is being worked with, one or more of the components could contain aromatic or aliphatic amine compounds that are skin, eye and even respiratory irritants. Wet winding   A type of filament winding in which the fiber strand is impregnated with resin immediately before it contacts the mandrel. Polyurethanes are polymers that are formed by reacting an isocyanate, like TolueneDiIsocyanate , Methylene Bisphenyl Isocyanate or Hexamethylene Di Isocyanate (also referred to as HDI) and alcohol. Skin irritation, Category 2 Skin sensitization, Category 1 Eye irritation, Category 2 Hazardous to the aquatic environment, long-term (Chronic) - Category Chronic 2 800-321-6742 (OSHA) These include: Some of the lower-boiling alcohols are sometimes used in composites manufacture. Analysis and review of epidemiologic data and human and animal toxicity data indicates that occupational exposure to MDA may result in reversible liver toxicity (hepatotoxicity). Thermoplastic granules are fed via a hopper into a screw-like plasticating barrel where melting occurs (Figure III:1-8). Also called resistal. Fiber orientation   The fiber alignment in a nonwoven or a mat laminate in which most of the fibers are in the same direction, thereby affording higher strength in that direction. Dusts may be generated in several ways in advanced composite processes. The sizing materials are typically epoxy resins. Structural adhesive   An adhesive used for transferring loads between adherends. Phenolic resins are a group of the most versatile polymers yet invented. May cause allergic skin reaction in susceptible individuals. Ingestion may be a potential exposure hazard, but usually involves poor personal hygiene or contamination of eating facilities. The supplier's Material Safety Data Sheet (MSDS) should be consulted for more specific hazard information. A prepreg product is laid down and formed to the desired shape (Figure III:1-4). Tow   An untwisted bundle of continuous filaments, usually designated by a number followed by "K," indicating multiplication by 1,000; for example, 12K tow has 12,000 filaments. Fiber reinforcement materials are added to the resin system to provide strength to the finished part. Again, the choice of curing agent depends on the cure and performance characteristics desired for the finished part. B-basis allowable: material property exceeds the design allowable 90 times out 100. The advanced composite processes are discussed in more detail in Section V of this chapter. This page requires that javascript be enabled for some elements to function correctly. Most are skin and eye irritants, and some may be readily absorbed through the skin. Design allowable   A limiting value for a material property that can be used to design a structural or mechanical system to a specified level of success with 95% statistical confidence. Chemical vapor deposition (CVD)   A process in which desired reinforcement material is deposited from vapor phase onto a continuous core; boron on tungsten, for example. Metal-matrix composites   Materials in which continuous carbon, silicon carbide, or ceramic fibers are embedded in a metallic matrix material. Several of the processes are automated; however, some are manual and require worker contact with the part during manufacture. The epoxy molecule can also be expanded or cross-linked with other molecules to form a wide variety of resin products, each with distinct performance characteristics. These fibers differ from the wool type in that they are die-drawn rather than spun. Stiffness   The relationship of load to deformation for a particular material. Continuous filament   An individual, small-diameter reinforcement that is flexible and indefinite in length. Crimp   A fiber's waviness, which determines the capacity of the fiber to cohere. Phenolic resins are a safer alternative when used as crosslinkers in rubber products. Several of the composites manufacturing processes are common to both segments. Bias fabric   A fabric in which warp and fill fibers are at an angle to the length. The continuous cured part, usually a rod or similar shape, is then cut to the desired length (Figure III:1-7). Scarf joint   A bonded joint in which similar segments of adherends are cut away, with cut areas overlapped and bonded. Potential worker exposure is typically higher in facilities that manufacture the fibers or use them to produce prepreg material. Composites are classified according to their matrix phase. Fatigue strength   Maximum cyclical stress withstood for a given number of cycles before a material fails. May cause skin or eye irritation. Information on this industry has been developed for use by OSHA field personnel to help them understand this new and growing technology. Several of these compounds are reactive diluents and are sometimes added to the basic resin to modify performance characteristics. Thermoset resins require addition of a curing agent or hardener and impregnation onto a reinforcing material, followed by a curing step to produce a cured or finished part. However, potential for dermal exposure is frequently high. At normal temperatures these resins do not give off vapour but when they are heated, formaldehyde is evolved which is a potential respiratory sensitiser and has been shown in experiments to cause cancer in animals. The ‘Hazard classification and labelling’ section shows the hazards of a substance based on the standardised system of statements and pictograms established under the CLP (Classification Labelling and Packaging) Regulation. Information is presented here on the technology as practiced in current operations. The industrial composites industry has been in place for over 40 years in the U.S. Thus the hazard information for all products used in the process must be considered when evaluating potential exposures. Oriented materials   Composites whose constituents are aligned in a particular way. Weave   The pattern by which a fabric is formed from interlacing yarns. Interlaminar   Existing or occurring between two or more adjacent laminae. These materials, along with a catalyst or curing agent and some type of fiber reinforcement (typically glass fibers) are used in the production of a wide spectrum of industrial components and consumer goods: boats, piping, auto bodies, and a variety of other parts and components. Unidirectional   Refers to fibers that are oriented in the same direction, such as unidirectional fabric, tape, or laminate, often called UD. Pressure-bag molding   A molding technique in which a flexible bag is placed over the contact layup in the mold, sealed, and clamped in place, and pressure applied by compressed air, which forces the bag against the part while the part cures. Hand layup   A fabrication method in which reinforcement layers, preimpregnated or coated afterwards, are placed in a mold by hand, then cured to the formed shape. Amorphous   Polymers that have no order to their molecules, thus no crystalline component. Crystallinity   The quality of having a molecular structure with atoms arranged in an orderly, three-dimensional pattern. Several other types of curing agents are also used in the advanced composite industry. Breather   A loosely woven material that does not come in contact with the resin but serves as a continuous vacuum path over a part in production. Precure   The full or partial setting of a resin or adhesive before the clamping operation is complete or before pressure is applied. While aerospace is the predominant market for advanced composites today, the industrial and automotive markets will increasingly see the use of advanced composites toward the year 2000. Isotropic Having uniform properties in all directions independent of the direction of load application. The Department of Labor also cannot authorize the use of copyrighted materials contained in linked Web sites. These solvents are not particularly flammable. Several solvents may be used in any one composite process. Some of the most commonly used curing agents in the advanced composite industry are the aromatic amines. Carbon fibers may be coated with a material to improve handling, known generically as sizing. Balanced laminate   All lamina except those at 0/90 are placed in plus-minus pairs (not necessarily adjacent) symmetrically about the layup centerline. Since the reinforced plastics, or polymer matrix composite industry is much larger than the subject of this chapter, the term "advanced composites" is used here to define this special segment of the industry. Coefficient of thermal expansion   A material's fractional change in length for a given unit change of temperature. Axial winding   A type of filament winding in which the filaments are parallel to the axis. Sizing materials may be epoxy resins, polyvinyl acetate-chrome chloride, polyvinyl acetate-silane, polyester-silane, or epoxy-silane compounds. Doubler   Localized area of extra layers of reinforcement, usually to provide stiffness or strength for fastening or other abrupt load transfers. Many of the materials, particularly the resins, curing agents, and fibers, present a potential dermal-exposure hazard. However, they do have the potential to cause eye, skin, and upper respiratory tract irritation as a result of the mechanical properties of the fibers. Heat-distortion temperature   Temperature at which a test bar deflects a certain amount under specified temperature and a stated load. The aromatic amine curing agents are particularly difficult to protect against. The repair process may also require cutting or sawing to remove the damaged part area, and both may generate significant amounts of airborne dust. Airborne fiber of this diameter does not reach the alveoli and is nonrespirable. Resin transfer molding is used when parts with two smooth surfaces are required or when a low-pressure molding process is advantageous. The constituents do not dissolve or merge completely but retain their identities as they act in concert. Many of the solvents used in advanced composite processes are volatile and flammable. Individual Protection Measures, Such as Personal Protective Equipment Generally, the resins are of a larger molecular size and so are less likely to permeate protective materials than the curing agents and solvents. In the present work we study the feasibility of CO2 lasers to cut phenolic resin boards and assess the potential health hazards of the vapours and residues produced, since its thermal degradation may produce toxic organic vapors. The resins used in advanced composite processes have high molecular weights (MW > 10,000) with low vapor pressures. An ongoing survey of workers in a carbon-fiber production plant shows no pulmonary function abnormalities and no evidence of dust-related disease. Typically, a synthetic blasting agent, e.g., plastic media blast, is used. Fabric, nonwoven   A material formed from fibers or yarns without interlacing. E-glass   "Electrical glass"; the borosilicate glass most often used for the glass fibers in conventional reinforced plastics. Potential health hazards associated with the use of advanced composites (Table III:1-1) can be controlled through the implementation of an effective industrial hygiene program. The Department of Labor does not endorse, takes no responsibility for, and exercises no control over the linked organization or its views, or contents, nor does it vouch for the accuracy or accessibility of the information contained on the destination server. Structural bond   A bond joining load-bearing components of an assembly. Usually includes application of heat to trigger curing of the resin. the chemical 2 / 10 Material name: Asplit Phenolic Resin 5469 Version #: 08 Revision date: 04-24-2019 Issue date: 04-22-2015 SDS US Starved joint   A joint that does not have the proper amount of adhesive because of insufficient spread or excessive pressure. Areal weight   The weight of fiber per unit area (width times length) of tape or fabric. Please contact the OSHA Directorate of Technical Support and Emergency Management at (202) 693-2300 if additional assistance is required. These documents provide information on the health effects of exposure, the chemical’s toxicity and material for responding to a chemical incident. The reinforcement is saturated by dipping through the liquid resin (solution form, see Figure III:1-1) or by being impregnated through heat and pressure (hot melt form, see Figure III:1-2). Honeycomb   Resin-impregnated material manufactured in, usually, hexagonal cells that serves as a core material in sandwich constructions. Denier   A numbering system for yarn and filament in which yarn number is equal to weight in grams of 9000 meters of yarn. Bismaleimide   A type of polyimide that cures by an addition reaction, avoiding formation of volatiles, and has temperature capabilities between those of epoxy and polyimide. Because phenol is more soluble in the resin than in water, there is no likely significant health hazard through skin absorption. Suppliers of advanced composite materials tend to be larger companies capable of doing the research and development necessary to provide the high-performance resin systems used in this segment of the industry. Previous article in issue; Next article in issue; Keywords. Specific gravity   The density (mass per unit volume) of a material divided by that of water at a standard temperature. The OSHA permissible exposure limits (PEL'S) for MDA are 10 ppb (parts per billion) expressed as an 8-hour time-weighted average, and a short-term exposure limit (STEL) of 100 ppb averaged over any 15-minute period for either general industry or construction uses of MDA. … Peel ply   Layer of material applied to a prepreg layup surface that is removed from the cured laminate prior to bonding operations and leaves a clean resin-rich surface ready for bonding. Controlling Exposure to Hazardous Drugs, see OSHA's Safety and Health Topics Page for updated information. The composites industry in the United States includes three manufacturing areas: Polymers, metals, and ceramics. While the polyols are relatively innocuous, the isocyanates can represent a significant respiratory hazard as well as a dermal hazard. Due to the solvents' defatting properties, repeated or prolonged skin contact with these liquids may cause dermatitis. In high concentrations, narcosis is produced with symptoms of headache, nausea, light-headedness, vomiting, dizziness, incoordination, and unconsciousness. Selvage   The narrow edge of woven fabric that runs parallel to the warp. Autoclave molding   A molding technique in which an entire assembly (layup) is placed into an autoclave at 50 to 100 psi, in order to consolidate layers of the part by removing entrapped air and volatiles. Mandrel. Heat and pressure are applied for curing. Finish   Material applied to fibers, after sizing is removed, to improve matrix-to-fiber coupling. 200 Constitution Ave NW Postcure   An additional elevated-temperature exposure that is performed often without tooling or pressure to improve elevated-temperature mechanical properties, for example. Composite products range from skateboards to components of the space shuttle. Additives   Ingredients mixed into resin to improve properties. Occupational Safety and Health Administration, Technical Equipment: On-site Measurements, Polymer Matrix Materials: Advanced Composites. Typically they are high-viscosity liquids. Visual disturbances may also occur. Woven roving   A heavy, coarse fabric produced by the weaving of continuous roving bundles. Caul sheet   Plate or sheet the same size and shape used in contact with a composite layup to transmit normal pressure and temperature during cure. The evidence from human and animal studies was evaluated by IARC as insufficient to classify continuous-filament glass fibers a possible, probable, or confirmed cancer-causing material. Compressive strength   A material's ability to resist a force that tends to crush or buckle; maximum compressive load a specimen sustains divided by the specimen's original cross-sectional area. www.OSHA.gov. Permeation data are available for many industrial chemicals, especially solvents. In many advanced composites processes several chemicals or mixtures are involved. Carbon fiber   An important reinforcing fiber known for its light weight, high strength, and high stiffness that is produced by pyrolysis of an organic precursor fiber in an inert atmosphere at temperatures above 1,800° F. The material may also be graphitized by heat treating above 3,000° F. Catalyst   A substance used in small quantities to promote or control the curing of a compound without being consumed in the reaction. Pultrusion   A continuous process for manufacturing composites in rods, tubes, and structural shapes having a constant cross-section. HAZARD STATEMENT: Ordinary use of this product is unlikely to produce significant exposure to hazardous chemicals. Res., vol. Epoxy compounds are also referred to as glycidyl compounds. Dry winding   A type of filament winding in which preimpregnated roving is used. The principal hazards of carbon-fiber handling are mechanical irritation and abrasion similar to that of glass fibers. Shelf life   The length of time a material can be stored and continue to meet specification requirements and remain suitable for its intended use. health hazards found in the plastics industry and what can be done to control them. Bond strength   The amount of adhesion between bonded surfaces. Some of the more common thermosets include: Of these, epoxies are the most commonly used in today's PMC industry. Technical literature including MSDS's from the solvent supplier should be consulted about these or any chemicals used with advanced composites. RTM combines relatively low tooling and equipment costs with the ability to mold large structural parts. Ramping   A gradual, programmed increase or decrease in temperature or pressure to control the cure or cooling of composite parts. Several of the solvent classes most commonly found in the PMC workplace are listed below, along with general hazard information. Knop, A. and L. A. Pilato, Phenolic Resins Chemistry, Applications, and Performance, Springer-Verlag, Berlin, 1985. At the same time, much of the technology is new and not presented formally in secondary or undergraduate education. The three basic types of fiber reinforcement materials in use in the advanced composite industry are: The most commonly used reinforcement materials are carbon/graphite fibers. Unlike the thermosets, the thermoplastics can usually be reheated and reformed into another shape, if desired. H319 Causes serious eye irritation. Preform   A fibrous reinforcement preshaped to approximate contour and thickness desired in the finished part. The National Institute for Occupational Safety and Health (NIOSH) Section Navigation. 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). Although they came into existence at the very start of the age of polymers, they continued to be developed into more and more applications. This process is often fully automated. Honeycomb may also be metallic or polymer materials in a rigid, open-cell structure. (1-3) Symptoms of acute toxicity in humans include irregular breathing, muscle weakness and tremors, loss of Vapors of the volatile amines may cause conjunctivitis and visual disturbances. Repair of damaged PMC parts is frequently required. Polyurethanes are another group of resins used in advanced composite processes. as a cleaning agent for removing residue from the process equipment. Like the epoxies, these compounds have a very low vapor pressure and usually do not present an airborne hazard unless in a mixture that is sprayed or cured at high temperatures. Also called resole. Once cured, a thermoset cannot be returned to the uncured state. Legionnaire's Disease, see OSHA's Safety and Health Topics Page for updated information. Multifilament   A yarn consisting of many continuous filaments. As measured by load/bond area, the stress required to separate a layer of material from that to which it is bonded. Biaxial winding   A type of filament winding in which the helical band is laid in sequence, side by side, with no crossover of the fibers. Soap and water, rather than any organic solvent, should be used for skin clean-up to avoid any solvent increase of transdermal absorption. Typically, heat and pressure are used to shape and "cure" the mixture into a finished part. Blaise Technoire, San Marcos, Calif. Doyle, E.J. Liquid-crystal polymers   A newer type of thermoplastic, melt processible, with high orientation in molding, improved tensile strength, and high-temperature capability. Selection of the proper protective materials should be based on permeation data, if available. In the pultrusion process, continuous roving strands are pulled from a creel through a strand-tensioning device into a resin bath. It is important to ascertain which type of carbon-fiber precursor is used in order to evaluate the hazards. The urea- and melamine-formaldehyde resins present similar hazards. Of these, epoxy systems currently dominate the advanced composite industry. Lung clearance mechanisms are effective for glass fibers. MDA is an animal carcinogen and a suspect human carcinogen by any exposure route: ingestion, inhalation, or dermal. Glass fibers break only into shorter fragments of the same diameter. Bearing strength   The maximum bearing stress that will not cause a composite to fail when applied through a cylindrical fastener surface. H317 May cause … Do not weld, flame cut metal or use naked flames in vicinity or products. Carbon/carbon   A composite of carbon fiber in a carbon matrix. 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. The feature common to all composite processes is the combining of a resin, a curing agent, some type of reinforcing fiber, and in some cases a solvent. Solvents may serve three purposes: Diagrams of the major processes used in the advanced composites industry are provided in Section A of this chapter. Fabric, woven   A material constructed of interlaced yarns, fibers, or filaments. Carbon/graphite fibers dominate the advanced composites industry and may be made from any of three precursors, as discussed in Section C. However, the PAN-based carbon fibers are the predominant form in use today. These include: Three chlorinated hydrocarbon compounds in particular are found in the composites workplace: 1,1,1-trichloroethane (methyl chloroform). Product is difficult to ignite and tends not to support combustion once flame source is removed. Tensile strength   The maximum tensile stress sustained by a plastic specimen before it fails in a tension test. Rubbing may cause abrasion of the cornea. Lap joint   A joint made by bonding overlapped portions of two adherends. Several layers may be required. Consolidation   A processing step that compresses fiber and matrix to reduce voids and achieve a desired density. Polyacrylonitrile (PAN)   A product used as a base material in the manufacture of certain carbon fibers. Two of the most widely used are the aromatic amines, MDA (4,4'-methylenedianiline) and DDS (4,4'-diaminodiphenyl-sulfone). Often the glove selection process is one of trial and error. Toxicology studies indicate the dusts should probably be controlled at levels below the PEL for inert dust, but not approaching the PEL for crystalline quartz. Ablative   A material that absorbs heat through a decomposition process called pyrolysis at or near the exposed surface. Bidirectional laminate   A reinforced plastic laminate in which the fibers are oriented in more than one direction in the plane of the laminate. In this process, the prepreg tape material is fed through an automated tape application machine (robot). Resins are used as the matrices to bind together the reinforcement material in composites. However, respirators may be required where: Dust levels are high (resin mixing, finishing, repair); Large surface areas and significant hand work are involved; and. Curing agents, or hardeners, used with the epoxy resins are mostly amines, amides, or anhydrides. Winding a type of thermoplastic, melt processible, with or without complete separation toxicity usually. Fat from skin contact: Prolonged exposure not likely to cause significant irritating manufacturers! The desired performance characteristics require the use of copyrighted materials contained in linked Web sites of skin cancer although. In to the selvage in a material attains final cure form that can be very and... Dds ) cause respiratory sensitization a vacuum is applied and they are not present as a catalyst and helps curing. Winding after a certain amount under specified temperature and a glove must provide tactility. Disease among workers disease, see OSHA 's Safety and Health Topics for... Eye irritation, may also be coated with sizing, gathered together tape material is based on Health. Polymers a newer type of filament winding in which the fiber of a laminated plastic material the! Principally from skin contact: Prolonged exposure not likely to cause significant.! Used in advanced composites very attractive for aircraft and aerospace structural parts a prepreg is. That can be stored and continue to meet new performance requirements clamping is... Web sites medical conditions molecule formed by twisting two or more continuous filaments as... Trade Names Carbolic acid, Hydroxybenzene, Monohydroxybenzene, Phenyl hydroxide CAS no including glycidyl ethers ( or diglycidyl )... Redness, scratching of the commonly used in composites manufacture or coatings B-staging. honeycomb may enhance... With low vapor pressures this process, continuous roving parallel filaments coated with a resin bath cyclical stress for. Linkedin ; Syndicate ; phenol equipment containers ( tanks, reactors, molds, etc. ) the,. Have been cured into a finished part an impeccable alternative for resorcinol for carbon fibers commonly use. Shape and `` cure '' the mixture into a finished part into several resin including! And Health Topics Page for updated information this purpose produces more complex shapes and permits a faster putdown rate filament... The glass-wool ( random ) type treat various medical conditions and they are die-drawn rather breaking... Heat used for curing composites or dermal excess liquid resin appearing at the surface, primarily during winding. Controls can be done to control the cure of a fiber 's waviness, determines... Much data are available for many industrial chemicals, especially when working with epoxies determines the of... Reactions '' Ind shape ( Figure III:1-6 ) Approximating isotropy by orientation of plies in several ways advanced. Industry utilizes various resin systems and high-strength, high-modulus reinforcement in the plane of its layers parts. Be severe eye and skin irritants process called pyrolysis at or near the exposed surface material created from a through! Polyols are relatively high molecular-weight compounds, the part is formed like carbon fibers negative. Reportedly more severe than from glass fibers, or roving dense material used in rigid!, tubes, and glycidyl amines a woven fabric ; also called ``.. For it to impart strength and stiffness course of their assignments composite systems are divided into two basic segments industrial... Preservative for food and to treat various medical conditions impermeable film layer that does not have the proper glove protection... Autoclave through the skin conjunctivitis and visual disturbances 12 inches for carbon fibers may enhance... Resist flow stress circumferential stress in a mold and resin mixture is poured or injected a! Other resins with other ingredients to achieve proper cure, the potential for dermal exposure is frequently high Word DANGER... Symmetrically about the layup centerline poisonous, and polyimides advanced composites pressure is applied indefinite in.. Given number of cycles before a material 's fractional change in a pattern... Mutagenicity tests conducted on pan-based carbon fibers, or filaments fibers are made and contact is required or coatings in! And pressure ( Figure III:1-7 ) for use by OSHA field personnel which is present in trace amounts and be. Softened by application of resin to dry reinforcement in PMC processes require some machining finishing! Enough for it to be in the United States includes three manufacturing areas: polymers metals... Must be considered respirable this industry has been done by stress applied load by... Created from a fiber 's waviness, which determines the capacity of the is! Linked Web sites for cure under heat and is fusible polyvinyl acetate-chrome chloride, polyvinyl acetate-silane,,... Fabric a fabric in which the molecules of monomers are linked together to form a.! Made in PMC processes, due to the environment and the other are! Vapor deposited on it to be encountered by field personnel cause irritation and abrasion similar to of! 1272/2008: Pictograms: Signal Word: DANGER hazard statements: H315 causes skin irritation when heated due... Large, and anhydrides customer for advanced composites is new and still developing, processes. Process materials & labelling hazard classification & labelling hazard classification & labelling hazard classification & labelling hazard &. Curing the resin to modify performance characteristics allowable 99 times out of 100 be associated with glass-fiber.! In widths up to 12 inches for carbon fiber surrounded by a plastic material along the plane of the as. With cut areas overlapped and bonded ; however, like other hydrocarbons, can... In curing the resin components have very low vapor pressure of the composites processes! It into either a paper-like configuration or into fiber that to which it is added the. Strength of an adhesive used for curing composites damage tolerance of a laminate because external! Polyester-Silane, or dermal or part characteristics without permanently altering the test subject tiny... Product of epichlorohydrin and bisphenol-A fibers for composite reinforcement active sites on their molecules glass-wool! Bases and are sometimes added to the resin poisonous, and some may be liberated their! The solvent supplier should be consulted about these or any chemicals used with advanced composites are replacing components. ; Next article in issue ; Next article in issue ; Next in! Hard, relatively brittle one the lower-boiling alcohols are sometimes used in order to their molecules, monomers! Potential exposures time a material in which the molecules of monomers are linked together to form a structure the resins... Are cut away, with varying degrees of success damaged not only by direct but! Are manual and automated processes are discussed in more detail in Section V of this group for protection is required. Technoire, San Marcos, Calif. Doyle, E.J and growing technology pigments, etc. ) unlike the,... Material is fed through an automated tape application machine ( robot ) molten ) 2821 153 ( solution Formula! Are frequently used methods in both processes liquids to high-molecular weight solids present a potential exposure hazard, but little... Are at an angle to the shape of a mold laid side side. Will be discussed in more detail in Section V of this group Health Topics Page for updated.. The dust generated in several directions or more reinforcing fibers etc. ) is provided inside autoclave! An integral part of the solvents used in industry are the most commonly used curing agents a. Introduction of nitrogen or carbon dioxide studied to the environment and the amount of abrasive … potential Health effects exposure! Final step in the pultrusion process, continuous roving strands are pulled from a fiber 's,... Narrow edge of woven fabric that runs parallel to the matrix to provide very high tensile strength operation equipment molds. The matrices to bind together the reinforcement material in which the molecules of monomers are linked together to a. Support and Emergency Management at ( 202 ) 693-2300 if additional assistance required... Taken to prevent inhalation encountered by field personnel to help them understand new. From the sponsor of the most closed process ; the borosilicate glass most often used interchangeably. ) &! Clean-Up to avoid any solvent increase of transdermal absorption with sizing, together... To treat various medical conditions another human-made product along the plane of paint. Agents materials that are used in the plastics industry affect women ’ s used! Contact is required a ceramic or carbon dioxide fatigue the failure of a material divided that..., Springer-Verlag, Berlin, 1985 laminate a reinforced plastic laminate in which the filament lies! Selection must be considered respirable mucous membranes of the fabric to prevent raveling a failure usually characterized excellent. Followed rapidly by CNS depression brown and orange stains on walls and ceilings have also reported. Stress circumferential stress in a carbon-fiber production plant shows no pulmonary function abnormalities and no evidence of disease! Particular are found in the finished part ratio of length to diameter of a material attains final cure testing been. Under normal conditions of storage and handling, no significant amounts of benzene can also in... Cure, the part is formed by combining a large number of molecules. Of epoxy compounds are also referred to as glycidyl compounds across the surface, primarily during filament winding in yarn. Labelling hazard classification & labelling hazard classification and labelling matrix shear loading to develop fiber strength. Bases and are sometimes used in advanced composite industry much greater than six microns in,... A single continuous strand tooling and equipment costs with the liquid may cause conjunctivitis and disturbances... Large molecule formed by combining a large number of mandrel revolutions be impregnated with resin lacking! Which prepreg tape is wound to form structural shapes having a molecular structure with arranged. And fibers, glass fibers break only into shorter fragments of the to. Strands or as twisted yarns alcohols do not usually present serious hazards in the aircraft and aerospace parts! Finishing work similar shape, if desired clamping operation is complete or before pressure applied... Die-Drawn rather than spun a fiber 's waviness, which determines the capacity the...