Toxicity is usually related to irritation of the conjunctivae and the mucous membranes of the upper airway. Carbon fibers may be coated with a material to improve handling, known generically as sizing. Filament winding   A process for fabricating composites in which continuous reinforcing fibers, either preimpregnated with resin or drawn through a resin bath, are wound around a rotating, removable mandrel. Toughness   Tendency of a material to absorb work. Chem. Polyurethanes are another group of resins used in advanced composite processes. There are essentially no permeation data available for chemical mixtures. Several ketones are frequently found in PMC manufacture. Additives   Ingredients mixed into resin to improve properties. Some fundamental and easily implemented work practices that can be used to minimize exposures when working with advanced composites are: Employee exposures also can be controlled by scheduling operations with the highest exposures at a time when the fewest employees are present. However, like other hydrocarbons, benzene can cause chemical pneumonia if its liquid form is aspirated in to the lungs. Exposure to the high-melting solids like trimellitic anhydride and tetraphthalic anhydride can cause respiratory sensitization. Impregnate   To saturate the voids and interstices of a reinforcement with a resin. Skin   A layer of relatively dense material used in a sandwich construction on the surface of the core. Doubler   Localized area of extra layers of reinforcement, usually to provide stiffness or strength for fastening or other abrupt load transfers. Adhesive failure   A rupture of adhesive bond that appears to be a separation at the adhesive-adherend interface. Matrix   A material in which the fiber of a composite is imbedded; it can be plastic, metal, ceramic, or glass. Aramid fibers are used to achieve high-strength, high-modulus reinforcement in plastic composites. 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. www.zortrax.com | 2 / 13 SAFETY DATA SHEET Resin BASIC 2.2. Filaments   Individual fibers of indefinite length used in tows, yarns, or roving. SJ3325000. Synonyms & Trade Names Carbolic acid, Hydroxybenzene, Monohydroxybenzene, Phenyl alcohol, Phenyl hydroxide CAS No. Aramid fibers have several useful characteristics: Textile (continuous filament) glass fibers are the type used in composite reinforcement. Creep   The dimensional change in a material under physical load over time beyond instantaneous elastic deformation. Scarf joint   A bonded joint in which similar segments of adherends are cut away, with cut areas overlapped and bonded. Composite residues are often difficult to clean from operation equipment and molds. Weave   The pattern by which a fabric is formed from interlacing yarns. Phenolic resins are a group of the most versatile polymers yet invented. 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. health hazards found in the plastics industry and what can be done to control them. The aerospace industry, including military and commercial aircraft of all types, is the major customer for advanced composites. There are polymer matrix composites (PMC's), ceramic matrix composites (CMC's), and metal matrix composites (MMC's). The great majority of filling materials are embedded within compound granules that are large enough not to constitute an inhalation hazard. These compounds are formed by reacting the polyol component with an isocyanate compound, typically toluene diisocyanate (TDI); methylene diisocyanate (MDI) and hexamethylene diisocyanate (HDI) are also widely used. (1-3) Symptoms of acute toxicity in humans include irregular breathing, muscle weakness and tremors, loss of Structural bond   A bond joining load-bearing components of an assembly. Typically, a synthetic blasting agent, e.g., plastic media blast, is used. Inhalation of these amines can cause irritation of the nose and throat, and lung irritation with respiratory distress. Delamination   The separation of a laminated plastic material along the plane of its layers. Resins are used as the matrices to bind together the reinforcement material in composites. … These aromatic amines are considered to be only slightly irritating to the skin. Many manufacturers have replaced the ketones with the above hydrocarbon solvents to reduce the risk of flammability. Braiding   Weaving fibers into a tubular shape. 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. Applied Industrial Hygiene Special Issue: December 1989. 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. Typically, heat and pressure are used to shape and "cure" the mixture into a finished part. The number and variety of processes should give some indication of the wide spectrum of workplaces likely to be encountered by field personnel. The basic epoxy compounds most commonly used in industry are the reaction product of epichlorohydrin and bisphenol-A. Washington, DC 20210 Inhalation of very large amounts of benzene can also result in death. MDA is an animal carcinogen and a suspect human carcinogen by any exposure route: ingestion, inhalation, or dermal. Laser cutting. Several advanced composite processes involve some worker contact with the resin mixture. This type of data are often available for the solvents used, but very little data are available for the resins and curing agents. Honeycomb may also be metallic or polymer materials in a rigid, open-cell structure. Phenolic resins are a safer alternative when used as crosslinkers in rubber products. Amorphous   Polymers that have no order to their molecules, thus no crystalline component. Catalysts, inhibitors, flame retardants, and other additives may be included to obtain specific end-use properties and improve processing, storage, and handling characteristics. Because phenol is more soluble in the resin than in water, there is no likely significant health hazard through skin absorption. Bearing strength   The maximum bearing stress that will not cause a composite to fail when applied through a cylindrical fastener surface. B-basis allowable: material property exceeds the design allowable 90 times out 100. The second of the essential ingredients of an advanced composite system is the curing agent or hardener. Advanced composites exhibit desirable physical and chemical properties that include light weight coupled with high stiffness and strength along the direction of the reinforcing fiber, dimensional stability, temperature and chemical resistance, flex performance, and relatively easy processing. The part is then cured under heat and pressure (Figure III:1-6). Ceramic-matrix composites   Materials consisting of a ceramic or carbon fiber surrounded by a ceramic matrix, usually SiC (silicon carbide). This may involve drilling, sanding, grinding, or other manual touch-up work. Selection of the proper glove for protection is important. This combination of properties makes advanced composites very attractive for aircraft and aerospace structural parts. Heat and pressure are applied for curing. Often the glove selection process is one of trial and error. Axial winding   A type of filament winding in which the filaments are parallel to the axis. Eng. The measured value of Tg can vary depending upon the test method. Coefficient of thermal expansion   A material's fractional change in length for a given unit change of temperature. Fiber placement   A continuous process for fabricating composite shapes with complex contours and/or cutouts by means of a device that lays preimpregnated fibers (in tow form) onto a nonuniform mandrel or tool. They are typically supplied as nonreactive solids (no chemical reaction occurs during processing) and require only heat and pressure to form the finished part. 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. Fauske. Permeation data are available for many industrial chemicals, especially solvents. 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. Polymer-matrix composites manufacturing is a multibillion dollar industry in the U.S. and one of the few in which the U.S. is conceded to be slightly more advanced than competitors abroad. Like carbon fibers, glass fibers may also be coated with a sizing material to improve handling. In this process, the prepreg tape material is fed through an automated tape application machine (robot). This page requires that javascript be enabled for some elements to function correctly. Lung clearance mechanisms are effective for glass fibers. Polymer   A very large molecule formed by combining a large number of smaller molecules, called monomers, in a regular pattern. Vapors may also cause eye irritation. Dry winding   A type of filament winding in which preimpregnated roving is used. 34 (1995) 3096-3101. Pitch-based carbon fibers may be associated with an increased risk of skin cancer, although the evidence is weak. The technology of advanced composites manufacture is continually evolving, and field personnel will learn here what to expect in these processing facilities in the way of materials handled, manufacturing methods, machinery, potential worker exposures, and other relevant health and safety information. Heat-distortion temperature   Temperature at which a test bar deflects a certain amount under specified temperature and a stated load. Addition   A polymerization reaction in which no by-products are formed. Resin rich   Localized area filled with resin but lacking reinforcement fiber. Symptoms of systemic poisoning often involve an initial, transient CNS stimulation, followed rapidly by CNS depression. 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. Should the handling of these hardeners generate dust, measures should be taken to prevent inhalation. Interlaminar shear   The shearing force tending to produce displacement between two laminae along the plane of their interface; usually the weakest element of a composite. Isotropic Having uniform properties in all directions independent of the direction of load application. Fatigue   The failure of a material's mechanical properties as a result of repeated stress. Grinding, routing and sanding are frequently used methods in both processes. Finish   Material applied to fibers, after sizing is removed, to improve matrix-to-fiber coupling. Areal weight   The weight of fiber per unit area (width times length) of tape or fabric. Summary of Health Effects Phenol may cause irritation and burns by any route of exposure. Aramid   Aromatic polyamide fibers characterized by excellent high-temperature, flame-resistance, and electrical properties. Cure   To change the physical properties of a material irreversibly by chemical reaction via heat and catalysts, alone or in combination, with or without pressure. Aliphatic and cycloaliphatic amines are strong bases and are considered to be severe eye and skin irritants. These fibers are produced by manufacturing the basic polymer, then spinning it into either a paper-like configuration or into fiber. Seven manufacturing processes are covered, along with two preliminary processes and two finishing processes. The basic process types are described below. Tape laying   A fabrication process in which prepreg tape is laid side by side or overlapped to form a structure. 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. �������5�h��#���vyU^j"MS�q2�&�Q�����*r(͇ 'ᔸϴ�;�b:�`y.���@m����'����>{3Î ��O�jħK��$F�ɠ���ڠ��. LABEL ELEMENTS According to the Regulation (WE) 1272/2008: Pictograms: Signal Word: DANGER Hazard statements: H315 Causes skin irritation. Ingredients of the paint or coating being removed, such as lead or chromates, may also be of concern. Epoxy compounds are also referred to as glycidyl compounds. Other aromatic amines used in the advanced composites industry include m-phenylene diamine and the various isomers of toluenediamine. Once cured, the part cannot be changed or reformed, except for finishing. This chapter deals with a segment of the polymer composite industry known as advanced polymer matrix composites, or advanced composites. Exotherms may occur if the curing step is not done properly. In many advanced composites processes several chemicals or mixtures are involved. Composite products range from skateboards to components of the space shuttle. The advanced composite processes are discussed in more detail in Section V of this chapter. The selection of reinforcement material is based on the properties desired in the finished product. Much of the dust generated in these processes can be very fine and should be considered respirable. The most common dust-generating processes are machining and finishing of cured parts and in repair of damaged parts. Balanced laminate   All lamina except those at 0/90 are placed in plus-minus pairs (not necessarily adjacent) symmetrically about the layup centerline. These fibers differ from the wool type in that they are die-drawn rather than spun. Pitch   A residual petroleum product used in the manufacture of certain carbon fibers. 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. These resins range from low-viscosity liquids to high-molecular weight solids. With respect to the phenol-formaldehyde resins, the well-known hazards of both phenol and formaldehyde must be protected against. Of these, epoxy systems currently dominate the advanced composite industry. 800-321-6742 (OSHA) Two of the most widely used are the aromatic amines, MDA (4,4'-methylenedianiline) and DDS (4,4'-diaminodiphenyl-sulfone). Oriented materials   Composites whose constituents are aligned in a particular way. 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. Metal-matrix composites   Materials in which continuous carbon, silicon carbide, or ceramic fibers are embedded in a metallic matrix material. In June 1987, the International Agency for Research on Cancer (IARC) categorized continuous-filament glass fibers as not classifiable with respect to human carcinogenicity. The aromatic amines may permeate many of the commonly used protective gloves and thus may be particularly difficult to protect against. Interlaminar   Existing or occurring between two or more adjacent laminae. as a cleaning agent for removing residue from the process equipment. Pultrusion   A continuous process for manufacturing composites in rods, tubes, and structural shapes having a constant cross-section. Ramping   A gradual, programmed increase or decrease in temperature or pressure to control the cure or cooling of composite parts. Many of the materials, particularly the resins, curing agents, and fibers, present a potential dermal-exposure hazard. Selvage   The narrow edge of woven fabric that runs parallel to the warp. Draft angle   A mandrel's taper or angle for ease of part removal. One of the older plastics processes, injection molding is also the most closed process. Usually an inert atmosphere is provided inside the autoclave through the introduction of nitrogen or carbon dioxide. Product is difficult to ignite and tends not to support combustion once flame source is removed. The composites industry in the United States includes three manufacturing areas: Polymers, metals, and ceramics. Fracture toughness   A measure of the damage tolerance of a material containing initial flaws or cracks. Thermosetting resins predominate today, while thermoplastics have only a minor role in advanced composites manufacture. The FR 57(154): Another of the amines, DDS, has a significant amount of toxicological data as its pharmaceutical grade, Dapsone. Fabric, woven   A material constructed of interlaced yarns, fibers, or filaments. Carbon/carbon   A composite of carbon fiber in a carbon matrix. Legionnaire's Disease, see OSHA's Safety and Health Topics Page for updated information. The processes vary widely in type of equipment and potential worker exposure. Composites are classified according to their matrix phase. Isolation (e.g., isolated storage, separate process areas, enclosures, closed systems) and local exhaust ventilation are the primary engineering controls found in advanced composites processes. May cause allergic skin reaction in susceptible individuals. This means that, in many cases, glove and clothing selection must be a trial and error process. One or more may be introduced as part of the resin or curing agent, while another may be a part of the manufacturing process. In addition to traces of free formaldehyde, they may also contain free phenol, and contact with these resins in the uncured state is to be avoided. Leung, J.C. and H.K. These materials have also been adopted for use by the sporting goods suppliers who sell high-performance equipment to the golf, tennis, fishing, and archery markets. Potential worker exposure obviously will also vary widely, depending on the size and type of process being used. The industry can be generally divided into two basic segments, industrial composites and advanced composites. Specific hazards arising from Containers can burst violently when heated, due to excess pressure build-up. In fire situations beware … Some (such as methyl alcohol) are poisonous, and all are capable of extracting fat from skin. The supplier's Material Safety Data Sheet (MSDS) should be consulted for more specific hazard information. Physico-chemical hazards: none Health hazards: causes skin and eye irritation, may cause an allergic skin reaction Environmental hazards: none. 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. However, due to the same properties epoxy products are a notorious cause of allergic skin disease among workers. Glass-transition temperature (Tg)   The approximate temperature at which increased molecular mobility results in significant changes in properties of a cured resin. Kumpinsky, E. "A study on resol-type phenol-formaldehyde runaway reactions," Ind. Dusts may be generated in several ways in advanced composite processes. Hybrid composite   A composite with two or more reinforcing fibers. Small-Diameter reinforcement that is flexible and indefinite in length skin irritants high molecular weight is generally associated with glass-fiber.. Surrounded by a plastic material along the plane of its layers all voids between strands and filaments porous! 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