Composite Manufacturing ProcessesThermoset compositesShort fiber reinforcedContinuous fiber reinforcedPrepregresin transferThermoplastic compositesCommingleImpregnated

Composite Manufacturing ProcessesProcesses:Hand Lay-upPre-preg formingPressure moldingVacuum baggingFilament winding

Composite Manufacturing ProcessesProcesses:PultrusionSpray methodSheet moldingBulk moldingResin transfer molding

Hand lay-up

Hand lay-upAdvantages: low cost toolsversatile: wide range of productsDisadvantages: time consumingeasy to form air bubbles and disorientation of fibersinconsistency

Prepreg formingMachine

Prepreg forming

Prepreg formingAdvantages: orientation of fibers can be changedconsistent high productivityDisadvantages: continuous process needs more customerslimited shelf lifedelamination

Prepreg forming

Pressure molding

Pressure moldingAdvantages: wide range of shapes integrate partsconsistencystructural stabilityrelatively simpleDisadvantages: high cost of machinetime consuming to heat up, cool down and curingexpensive molds (strong materials required)no intricate partslarge volume of products

Vacuum baggingProcess

Vacuum baggingAdvantages: simple design any fiber/matrix combinationok with cheap mold materialbetter quality for the costDisadvantages: cannot be heated up too muchbreeder clothe has to be replaced frequentlylow pressure (760 mm Hg the most)slowest speedinconsistency

Filament winding

Filament winding

Filament winding

Filament winding productsCompressed air tanks High-pressure CO2 tanks and bottles Water softener systems Rescue air tanks Sail boat mastsCompressed Natural Gas tanks Defense/Aerospace systemsLightpoles

Filament windingAdvantages: using existing textile processes. quick, easy to handle package.parts can have huge size.Disadvantages: spinning speed is limited due to resin penetration and splashing, traveler speed and yarn breakage.curing by heat is not easy to apply.shape of the products limited (only cylindrical possible).

Pultrusion

Pultrusion

PultrusionAdvantages: Automated processes. High speed.Versatile cross-sectional shape.Continuous reinforcement.Disadvantages: Die can be easily messed up.Expensive die.Mainly thermoset matrix.

Spray method

Spray methodAdvantages: Continuous process Any materials can be used as mold.Error can be corrected by re-spraying.Disadvantages: Slow.inconsistency.No control of fiber orientation.Only one side finished.Environmental unfriendly.

Sheet molding

Sheet moldingAdvantagesHigh productivity thus inexpensiveconsistencyDisadvantageslow volume fraction.Only board can be made.

Bulk molding

Bulk moldingAdvantagesHighest volume fraction for short fiber reinforced composites (50%)Good mechanical propertiesFinish can be appliedInserts and attachments possibleDisadvantagesHigh temperature and high pressure Random fiber orientationCannot be used for intricate partsStaple fibers only.

Resin transfer moldinghttp://www.plastech.co.uk/Mtrtm.html

Resin transfer moldingAdvantagesComponents will have good surface finish on both sides Selective reinforcement and accurate fiber management is achievable Ability to build-in fiber volume fraction loadings up to 65% Uniformity of thickness and fiber loading, uniform shrinkage Inserts may be incorporated into moldings Tooling costs comparatively low Uses only low pressure injection Low volatile emission during processing Ability to produce near net shape moldingsProcess can be automated, resulting in higher production rates Ability to mold complex structural and hollow shapes Low resultant voids Ability to achieve from 0.5mm to 90mm laminate thickness Disadvantageswaste some material (spill) curing time longhard for intricate parts

Vacuum Assisted Resin Transfer Moldinghttp://www.futuremediacreations.com/technoire/vartm.htm

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