Contact moulding

Contact moulding is a simple and well known method for fabrication of fibre-reinforced thermoset composites. Thermoset resins which cure at room temperature such as unsaturated polyester, vinyl ester, and epoxy are used to make glass, jute or carbon fibre-reinforced composites using contact moulding. A wide variety of structures can be fabricated using this technique without limitation with respect to the size and complexity of the shape of the structure. However, the process is very labour-intensive and time-consuming, so is used only for a short run or one-off production. 

Contact moulding Low tooling cost, simple process, no shape restriction Labor-intensive, high volatile emission, slow production rate Epoxy, polyester, vinyl ester 

Compression moulding Low cycle time, low volatile emission, structural integrity High tooling cost, average finish Epoxy, polyester, vinyl ester, polyimide, cyanate ester 

RTM Variety of reinforcement, closed mould, good tolerance Medium production time Epoxy 

RIM Fast cycle automation Resin selectivity Polyurethanes 

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London, Stationery Office, 2003, pp.4, 30 cm, 2/9/04. Plastics Processing Sheet No. 14 ASSESSING AND CONTROLLING STYRENE LEVELS DURING CONTACT MOULDING OF FIBRE-REINFORCED PLASTIC (FRP) PRODUCTS. HSE INFORMATION SHEET. 

This information sheet from the Health and Safety Executive summaries the health hazards that can arise from exposure to styrene. It provides practical advance to FRP manufacturers on how to assess and control styrene levels in the workplace and how these control measures should be monitored and maintained in accordance with the Control of Substances Hazardous to Health Regulations 2002. The document applies mainly to contact moulding processes, and aims to define what level of control is currently recognised as being reasonably practicable. EUROPEAN COMMUNITY EUROPEAN UNION UK WESTERN EUROPE... 

CONSTRAINED GEOMETRY CATALYST, 154 CONTACT ANGLE, 262 CONTACT MOULDING, 246 CONTINUOUS EXTRUSION, 314 CONTINUOUS MOULDING, 312 CONTINUOUS... 

Open-mould processes are thermoset moulding processes with open moulds in the male or female form. In this process the mould is made from a pattern and the reinforced thermoset is applied to the mould to reproduce the shape and finish of the mould. Typical examples would be boat hulls made from fibreglass-reinforced gel coats. Figure 6.10 shows the basic contact-moulding process. 

A widely used method of laminate construction is by the contact moulding process or hand lay-up . In this, a layer of catalysed unreinforced resin, known as the gelcoat , is brushed or sprayed onto the mould and allowed to cure and then layers of reinforcing-fibre impregnated with resin are built up behind (Fig. 6.3). Variations of this include resin injection and vacuum-assisted resin injection in closed moulds. After removal of the cured moulding from the mould, the gelcoat forms the outer skin and as such performs the two functions of decoration and protection ... 

Figure 9.18 Gratings made by a contact moulding method using a bisphenol A epoxy vinyl ester resin and its flame retardant, brominated equivalent. It was installed at the Enichem plant at Gela...

Filament winding The application of a pre-impregnated continuous length of fibre around the outside of a mandrel to produce pipes, pressure vessels and similar articles, is also a form of contact moulding. As with pultrusion, continuous reinforcement is passed through a bath of activated thermosetting resin that is cross-linked by heat, in this case on the mandrel. 

A preaccelerated, filled and thixotropic flame retardant orthophthalic for general contact moulding, capable of achieving BS476, Part 7, Class 2. Offers durable, excellent mechanical properties and good water resistance for automotive, industrial and marine applications. Lloyd s Registry approved. 

A preaccelerated. UV stabilised thixotropic, unfilled, flame retardant, isophthalic/HET resin for the contact moulding of continuous sheeting, roof structures, domes and canopies of high translucency, approved Class 2, BS 476 Part 7. 

A preaccelerated, filled, flame retardant rapid wet-out polyester designed as an inexpensive resin - supplied in a restricted range of colours - for contact moulding. Can achieve BS 476, Part 7, Class 1. 

A easily sanded, porosity-free, high build (2mm mx. wet-on-wet) primer, designed for the repair of osmosis and blister damage on composite surfaces. Excellent adhesion to composites manufactured of vinyl ester, polyester and most epoxies. Suitable for RTM, vacuum forming and contact moulds. 

Figure 4.5 Variation of (a) flexural strength, and (b) flexural modulus with glass content for contact moulding (Arvesen).

Manufacture was achieved by hand lay-up and contact moulding. Observations... 

Manufacture was achieved by contact moulding through hand lay-up additional time allowed for good wet-out. 

Manufacture was achieved through either contact moulding by hand lay-up, or filament winding of unidirectional rovings. 

Manufacture was achieved through contact moulding post curing 16 hours at 40°C (equivalent to 28 days at 20°C). 

Manufacture was achieved through contact moulding, hand lay-up. 

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