FOAMING(材料成型-泡沫塑料的成型)

1、FoamingFoaming Overview Processes to create foams Mechanical, Chemical, Physical, Syntactic (hollow spheres) Processes to shape and solidify foams Molding, RIM, Foam-in-place, Extrusion, Casting, Expanded foam molding Rebond materials Foam product characteristicsFoaming Mechanical foaming Mix air in

2、to the resin while in a liquid state Plastisols, vinyl esters, urea formaldehydes, phenolics, polyestersFoaming Mechanical foaming Mix air into the resin while in a liquid state Plastisols, vinyl esters, urea formaldehydes, phenolics, polyestersPolyester foamPhenolic foamPhenolic foamFoaming Chemica

3、l foaming Foaming agents or blowing agents Chemical reaction that forms a gas/vaporBread (yeast foam)Urethane foamFoaming Physical foaming Gas is forced into a liquid or molten resin Pressure is released quickly Foam is createdShaving creamFoaming Syntactic foams Physically mix in hollow beads Beads

4、 are usually glass or plastic Wide density capabilityFoams Self-healing plastics Beads filled with reactive resin Initiator (catalyst) mixed into the surrounding plastic Beads crack under pressure of crack growthSelf-healing foamsProcesses to Shape and Solidify Foams Molding RIM Foam-in-place Extrus

5、ion Casting Expanded foam molding (EPS) RebondFoam MoldingFoam InletExpandable MoldLiquid Resin with Foaming AgentFill PositionFoam MoldingFoam InletExpandable MoldLiquid Resin with Foaming AgentExpanded PositionMolded foamsReaction Injection MoldingFoaming AgentFoamed PartMoldIn-line MixerResinPart

6、 AResinPart BRIMFoam-in-placeRefrigerator WallsFoamFoaming Injector NozzleExtrusion FoamingPaperPaperExtruder (Resin and Foaming Agent)SawBelt DriveExpanded FoamExtrusion foam lineCasting FoamsResin and Foaming AgentExpandedFoamOpen PanCasting Foams Skiving the Foamed BunFoam Spraying Foaming agents

7、 mixed as they exit the spray nozzleExpanded Foam Molding PS is the standard material used Can be done with PP or PE as wellExpanded Foam MoldingTiny BeadsExpansionChamberStoragePartMoldSteam or Hot AirSteam or Hot AirUnexpandedExpandedEPS beadsEPSRebond Scrap from other foaming processes Ground/cho

8、pped up Molded into sheetsMaterial Considerations for Foamed Parts Most thermoplastic and thermoset materials can foamed by one or more of the methods The most commonly foamed resins are PVC, Polyurethane, PS, PE, PP, Epoxy Phenolic, ABS, Ureaformaldehyde, Silicone, Ionomers and Cellulose AcetatesFoam Applications Strength to weight ratios Thermal insulation (Celestia product) Energy absorption Load bearingEnergy TransmittedEnergy (gs)Frequency (Hz)Natural vibration frequencyTruck = 4-6, 12-14/ Tra