Spray lay-up

A level of automation using a twin gun system can be achieved by applying the reinforcement as a roving, which is chopped in one gun and the cut staple combined with resin that has been admixed in the correct proportions in the other gun. The admixing in the gun can be carried out, with latest equipment, within the gun to curtail emissions, and the chopped reinforcement/mixed resin spluttered onto the mold. Emissions are reduced by using 

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Spray drying Spray lay-up Spray painting Spray pyrolysis Spray recrystallization Sprays... 

Injection moulding - Elastomers Compression moulding - Composites Hand/spray lay-up - Composites... 

HAND/SPRAY LAY-UP PROCESS CAPABILITY MAP FOR COMPOSITE MATERIALS... 

Virtually unlimited Unlimited Often 2- 10 Ship 1 Spray lay-up... 

Virtually unlimited Unlimited, often 2-10 <1000 Spray lay-up Mine hunters... 

With RTSs, however, where the resin is liquid and requires curing, in-house mixing is the norm, especially in the hand and spray lay-up sector, and in many press-molding and resin transfer molding operations. Resin suppliers now offer resins formulated and possibly pigmented to meet a set specification, but it still requires the processor to add the reinforcement and initiate the curing reaction. 

Compared with hand and spray lay-up, the RTM process also offers an... 

Resin type Hond/sproy lay-up Hand/spray lay-up FR/low smoke compressiof)... 

General polyesters are usually orthophthalic acid based resins, which are used in applications based on open moulds and hand and spray lay-up moulding. Resins with a low level of styrene emission are ideal for these applications. 

Other polyester products include flag poles, doors, waste bins, ski rack enclosures, ski poles, fish hatchery basins, water slides and storage vessels. Many reinforced plastic products are protected by an outer gel coat layer which can be built in during composite construction most easily in hand and spray lay-up processing. 

Hand lay-up and spray lay-up Same as above Used in molding large complicated shaped objects including boat huUs, laige tanks, and hot tubs Laying resin impregnated reinforcing fabric by hand on a mold and end up with a gel coat of resin... 

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