FRP Technology

Synthetic resins have become increasingly important over the years, finding wide application in a variety of fields. Not least have been the tremendous strides made in the use of fibre reinforced resin systems. Although by far the bulk of all fibre reinforced products are made from unsaturated polyester r~sins reinforced with glass fibres, other resins and other fibres are playing an increasingly important role. It is with this in mind that the present book has been written. An attempt has been made to combine within one book information on the various resin systems and reinforcing fibres in use today, together with some properties and processing details. Since most of the resins available are formulated products rather than pure chemical compounds, some information has been included on commercially available materials. For convenience, where commercial data have been included, these have been located at the end of the appropriate chapter or, where only limited data are presented, at the end of the appropriate section. Such data have been included for the benefit of designers and fabricators, to indicate the wide choice of materials available and to enable them to select materials without having to approach a vast number of suppliers and then to sift through an even greater number of data sheets.

1 General Introduction.- 1.1 Introduction.- 1.2 Why Use FRP?.- 1.3 Which Resin?.- 1.4 Reinforcements.- 1.5 Process Development.- References.- 2 Designing in FRP.- 2.1 Introduction.- 2.2 Design.- 2.2.1 Material selection.- 2.2.2 Process selection.- 2.2.3 Section thickness.- 2.2.4 Flanges and corners.- 2.2.5 Inserts.- 2.3 Flat Sheets.- 2.4 Building and Cladding Panels.- 2.5 Hollow Structures.- References.- 3 Moulds.- 3.1 Introduction.- 3.2 Plaster Moulds.- 3.3 Wooden Moulds.- 3.4 GRP Moulds.- 3.4.1 Single one-part moulds.- 3.4.2 Split moulds.- 3.4.3 Matching moulds.- 3.5 Epoxide Resin Moulds.- 3.5.1 Single-stage casting.- 3.5.2 Two-stage casting.- 3.6 Steel Moulds.- 3.6.1 Hot press moulding.- 3.6.2 Centrifugal moulding.- 3.6.3 Transfer and injection moulding.- 3.6.4 Pultrusion.- 3.7 Aluminium Alloy Moulds.- 3.8 Nickel Shell Moulds.- 3.9 Other Moulds.- References.- Suppliers.- 4 Moulding Processes.- 4.1 Introduction.- 4.2 Contact Moulding—Wet Lay-up.- 4.2.1 Hand lay-up.- 4.2.2 Spray lay-up.- 4.3 Vacuum Bag Moulding.- 4.3.1 Wet lay-up.- 4.3.2 Prepreg systems.- 4.4 Pressure Bag Moulding.- 4.5 Resin Injection or Resin Transfer Moulding.- 4.6 Pressure Injection.- 4.7 Vacuum Impregnation and Injection.- 4.7.1 Vacuum impregnation.- 4.7.2 Vacuum injection moulding—Hoechst process.- 4.7.3 Vacuum injection—British Rail process.- 4.7.4 Monoforming.- 4.7.5 CSI process—Crystic Systems Ltd.- 4.8 Foam Reservoir Moulding.- 4.9 Cold Press Moulding.- 4.10 Hot Press/Matched Metal Moulding.- 4.10.1 Liquid resin/chopped strand mat.- 4.10.2 Liquid resin/preform.- 4.10.3 Sheet moulding compounds (SMC) and prepregs.- 4.10.4 Dough or bulk moulding compounds (DMC or BMC).- 4.11 Transfer Moulding.- 4.12 Injection Moulding.- 4.13 Filament Winding.- 4.13.1 Wet lay-up.- 4.13.2 Prepregs.- 4.13.3 Other applications.- 4.14 Centrifugal Moulding.- 4.15 Continuous Sheet Manufacture.- 4.16 Pultrusion.- 4.17 Sandwich Construction.- 4.18 Moulding with Preformed Materials.- 4.18.1 C-Flex planking system.- 4.18.2 ‘Duradense’ building system.- 4.19 Trimming and Finishing.- References.- 5 Common Faults Found in GRP Mouldings.- 5.1 Introduction.- 5.2 General Faults with Polyester Mouldings.- 5.3 Spray Moulding Faults.- 5.4 Faults with Translucent Sheeting.- 5.5 Press Moulding Faults.- 5.6 Resin Injection Faults.- 5.7 Vacuum Moulding Faults.- 5.8 Filament Winding Faults.- 5.9 Centrifugal Casting Faults.- 5.10 Faults with Epoxide Resin Systems.- Reference.- 6 Bonding and Jointing Reinforced Plastics.- 6.1 Introduction.- 6.2 Adhesive Bonded Joints.- 6.2.1 Surface preparation.- 6.3 Mechanical Joints.- References.- 7 Maintenance and Repair of FRP Structures.- 7.1 Introduction.- 7.2 Maintenance.- 7.3 Repairs to GRP Structures.- 7.3.1 Surface damage.- 7.3.2 Small impact fractures.- 7.3.3 Holes.- 7.3.4 Repair of holes where internal access is impossible.- 7.3.5 Repairs to pipes.- Reference.- 8 Site Application of Laminates.- 8.1 Introduction.- 8.2 Steel Structures.- 8.2.1 Initial preparation.- 8.2.2 Laminate application.- 8.2.3 Alternative laminating procedure.- 8.2.4 Alternative resin systems.- 8.3 Concrete Structures.- 8.3.1 Crack treatment.- 8.3.2 Preparation of concrete substrate.- 8.3.3 Application of the laminate.- 8.4 Wooden Structures.- 8.5 Repairs to Pipelines—Concrete, Steel or Thermoplastic.- 8.6 On-site Tank Production.- References.- 9 Polyester Resins.- 9.1 Introduction.- 9.2 Polyester Resins.- 9.2.1 Glycols.- 9.2.2 Unsaturated acids.- 9.2.3 Saturated acids.- 9.2.4 Monomers.- 9.2.5 Inhibitors.- 9.3 Commercial Resins.- 9.3.1 Gelcoat/topcoat resins.- 9.3.2 General purpose resins.- 9.3.3 Chemical resistant resins.- 9.3.4 Reduced flammability resins.- 9.3.5 Low styrene emission resins.- 9.3.6 Low shrink/low profile polyester resins.- 9.3.7 Special purpose resins.- 9.3.8 Casting resins.- 9.3.9 Foamed polyester resins.- 9.3.10 Commercially available polyester resins.- References.- 10 Catalysts, Accelerators and Inhibitors for Unsaturated Polyester Resins.- 10.1 Introduction.- 10.2 The Curing Reaction.- 10.3 Catalysts or Initiators.- 10.3.1 Diacyl peroxides.- 10.3.2 Ketone peroxides.- 10.3.3 Hydroperoxides.- 10.3.4 Dialkyl and diaralkyl peroxides.- 10.3.5 Peroxyesters.- 10.3.6 Perketals (peroxyketals).- 10.4 Accelerators or Promoters.- 10.4.1 Metal compounds.- 10.4.2 Tertiary amine accelerators.- 10.4.3 Mixed metal salt/t-amine accelerators.- 10.5 Inhibitors.- 10.6 Commercially Available Materials.- References.- 11 Epoxide Resins.- 11.1 Introduction.- 11.2 The Resins.- 11.2.1 Bisphenol A based resins.- 11.2.2 Glycidyl ester resins.- 11.2.3 Glycidyl amine resins.- 11.2.4 Glycidyl ethers of novolac resins.- 11.2.5 Brominated resins.- 11.2.6 Other resins.- 11.3 Diluents.- 11.3.1 Reactive diluents.- 11.3.2 Non-reactive diluents.- 11.4 How to Choose an Epoxide Resin.- 11.5 Commercially Available Resins.- References.- 12 Curing Agents for Epoxide Resins.- 12.1 Introduction.- 12.2 Selection of Curing Agent.- 12.3 Amine Curing Agents.- 12.4 Anhydride Curing Agents.- 12.4.1 Accelerators for anhydride cured systems.- 12.5 Polyamide Curing Agents.- 12.6 Other Curing Agents.- 12.7 Some Typical Laminating Systems.- 12.7.1 Site applications.- 12.7.2 Alternative to polyester resin.- 12.7.3 Electrical laminates.- 12.7.4 Carbon fibre composites.- References.- Curing Agent Suppliers.- Some Suppliers of Formulated Curing Agents.- 13 Other Resin Systems.- 13.1 Introduction.- 13.2 Furane Resins.- 13.3 Vinyl Ester Resins.- 13.4 Friedel-Crafts Resins.- 13.5 Silicone Resins.- 13.6 Polyimide Resins.- 13.7 Phenolic Resins.- 13.8 Melamine and Urea-Formaldehyde Resins.- References.- 14 Reinforcements.- 14.1 Introduction.- 14.2 Surfacing Tissue.- 14.3 Glass Fibre Reinforcements.- 14.3.1 Continuous filament rovings.- 14.3.2 Chopped strands.- 14.3.3 Chopped strand mat.- 14.3.4 Continuous strand mat.- 14.3.5 Woven glass fabrics.- 14.4 Carbon Fibre.- 14.5 Aromatic Polyamide (Aramid) Fibres.- 14.6 Other Reinforcing Fibres.- 14.6.1 Polyester fibres.- 14.6.2 Polyacrylonitrile fibres.- 14.6.3 Nylon.- 14.6.4 PVC and PVDC.- 14.6.5 Cotton.- 14.6.6 Sisal.- 14.6.7 Asbestos.- 14.6.8 Paper.- 14.6.9 Jute.- 14.6.10 Boron fibres.- 14.7 Commercially Available Reinforcements.- References.- 15 Dough and Sheet Moulding Compounds and Prepregs.- 15.1 Introduction.- 15.2 Dough and Bulk Moulding Compounds (DMC, BMC).- 15.3 Sheet Moulding Compounds (SMC).- 15.3.1 Manufacture of SMC.- 15.4 Prepregs.- 15.4.1 Manufacture of prepregs.- 15.5 Commercial Products.- References.- 16 Fillers and Pigments.- 16.1 Introduction.- 16.2 Mineral Fillers.- 16.2.1 Carbonates.- 16.2.2 Silica and silicates.- 16.2.3 Aluminium silicates and clays.- 16.3 Glass Fillers.- 16.4 Metal Oxide Fillers.- 16.5 Metallic Powder Fillers.- 16.6 Other Fillers.- 16.7 Thixotropic Additives.- 16.8 Flame Retardant Fillers.- 16.9 Pigments and Dyes.- References.- 17 Miscellaneous Materials.- 17.1 Internal Lubricants.- 17.2 Skin Formers.- 17.3 Light Stabilisers.- 17.4 Release Agents and Sealing Compounds.- 17.4.1 Wax release agents.- 17.4.2 Polyvinyl alcohol (PVA).- 17.4.3 Spray release agents.- 17.4.4 Silicone release agents.- 17.4.5 Sheet release agents.- 17.4.6 Cellulose acetate.- 17.4.7 Nitrocellulose.- 17.4.8 Shellac.- 17.5 Core Materials.- 17.5.1 Balsa wood.- 17.5.2 Firet Coremat.- 17.5.3 Intercel.- 17.5.4 Honeycombs.- 17.6 Coupling Agents.- References.- Some Suppliers.- 18 Laminating Equipment.- 18.1 Introduction.- 18.2 General Equipment.- 18.2.1 Rollers.- 18.2.2 Brushes.- 18.2.3 Catalyst dispensers.- 18.2.4 Mixing and metering equipment.- 18.2.5 Casting equipment.- 18.2.6 Mixers.- 18.2.7 Light sources for curing polyester resins.- 18.3 Spray Equipment for Polyester Resin Systems.- 18.3.1 Catalyst injection.- 18.3.2 Catalyst spray.- 18.3.3 Twin pot system.- 18.3.4 Filler spray equipment.- 18.3.5 Flock gun.- 18.3.6 Roving cutters.- 18.4 Equipment for Saturating Glass Mat.- 18.5 Gelcoat Application Equipment.- 18.6 Resin Injection Equipment.- 18.7 Epoxide Resin Spray Equipment.- 18.8 Epoxide Resin Metering Equipment.- 18.9 Furane Spray Equipment.- Suppliers.- 19 Handling and Safety Precautions.- 19.1 Introduction.- 19.2 General Precautions.- 19.2.1 Remedial measures.- 19.3 Epoxide Resins.- 19.4 Curing Agents.- 19.4.1 Aliphatic amines.- 19.4.2 Aromatic amines.- 19.4.3 Cycloaliphatic amines.- 19.4.4 Polyamide curing agents.- 19.4.5 Anhydride curing agents.- 19.4.6 Other curing agents.- 19.5 Furane Resins.- 19.6 Polyester Resins.- 19.7 Peroxide Catalysts.- 19.8 Fillers and Pigments.- 19.9 Barrier and Cleansing Creams.- 20 Test Specifications.- 20.1 Introduction.- 20.2 Chemical Properties.- 20.2.1 Acid value of unsaturated polyester resins.- 20.2.2 Chemical resistance.- 20.2.3 Acetone extractables.- 20.2.4 Chlorine content.- 20.2.5 Epoxide content.- 20.2.6 Hydroxyl content of unsaturated polyester resins.- 20.2.7 Organic peroxides.- 20.2.8 Water resistance.- 20.3 Fire and Smoke Tests.- 20.3.1 Flammability tests.- 20.3.2 Smoke evolution tests.- 20.4 Mechanical Properties.- 20.4.1 Compressive strength and modulus.- 20.4.2 Flexural strength and modulus.- 20.4.3 Tensile strength and modulus.- 20.4.4 Interlaminar shear strength (ILSS).- 20.4.5 Impact strength.- 20.5 Physical Properties.- 20.5.1 Density and specific gravity.- 20.5.2 Gel time.- 20.5.3 Hardness—indentation.- 20.5.4 Shrinkage.- 20.5.5 Viscosity.- 20.6 Thermal Properties.- 20.6.1 Heat deflection temperature.- 20.6.2 Martens heat deflection temperature.- 20.6.3 Coefficient of expansion.- 20.6.4 Flash point.- 20.7 Electrical Properties.- 20.7.1 Arc resistance.- 20.7.2 Dielectric constant (permittivity) and power factor.- 20.7.3 Dielectric breakdown voltage and dielectric strength.- 20.7.4 Dust fog tracking and erosion.- 20.7.5 Volume and surface resistivity.- 20.8 Miscellaneous Test Specifications.- 20.8.1 Colour.- 20.8.2 Loss on ignition for GRP.- 20.8.3 Visual defects in mouldings.- 20.8.4 Reinforcements.- 20.8.5 General specifications.- References.- Appendices.- 1 Trade Names.- 2 General Material Suppliers.- 3 Company Names and Addresses.- 4 Units, Prefixes and Conversion Factors.