资源描述：
《新海绵术语大全帮助》由会员上传分享，免费在线阅读，更多相关内容在应用文档-天天文库。
1、DensityDensityisweightperunitvolume,weight/volume,andisexpressedaslbs/ft3(pcf).Densityisusuallymeasuredingrams/cm3andmultipliedby62.4toconverttolbs/ft3(pcf).Densitycanbeobtainedfromanysamplesize.Densityisnotrelatedtoporesize,i.e.,coarseporeandfineporefoam
2、scanhaveequaldensities.Densityisnotameasureoffirmness,stiffness,orloadbearingcapacity.ThatisdefinedbyIndentationForceDeflection(IFD)orCompressionForceDeflection(CFD). IndentationForceDeflection(IFD)IFD(previouslyILD)isonetestmethodtodetermineloadbearingca
3、pacity(firmnessorstiffness),andisexpressedinpoundsforceper50in.2atagivenpercentdeflectionofthefoam.Forexample:P215-50,FHAgradecarpetcushionfoamhasatargetIFDof50lbs/50in2atadeflectiondepthof25%oftheoriginalthicknessofthesampleafterarestperiodofoneminute,25
4、%R.Toobtainthe25%Rvalue,a50in.2circularindenterplatenisdrivenintoa15”x15”x4”foamsample,stoppingwhenitreachesadeflectionof1”,25%ofthe4-inchthickness.Thetestingdevicerecordstheforceinpoundsrequiredtoholdthisfoamindentedafteroneminute.Thehighertheforcereadin
5、g,thehighertheloadbearingcapacityofthefoam.Thisresultcanbereportedinmetricandthesamplesizecanbevaried.SagFactor(Modulus)istheratioofthe65%RIFDtothe25%RIFDvaluesandisexpressedinrealnumberswithonedecimal.Sagfactorgivesanindicationofcushioningquality.Ahighva
6、lueindicatesaresistanceto“bottomingout.”RecoveryRatioistheratioof25%RIFDreleasedto25%RIYDinitialwhenmeasuringIFDvaluesat25%deflection,65%deflection,andthenreleasedbackto25%deflection.Recoveryratioisexpressedasapercentage.GuideFactoristheratioof25%IFDtoden
7、sityandisexpressedinwholenumbers.Guidefactorisusefulindeterminingtherelativefirmnessoffoamswithdifferentdensities.Itisalsousedtocomparetheeconomyoffoams.Thehighertheguidefactor,themoreeconomicalthefoambecauseyougetafirmerfoamwithalowerdensity. Compression
8、LoadDeflection(CLD)CLDisalsoameasureoffirmnessandisexpressedinpoundspersquareinch(psi),atagivenpercentagedeflection.Thesamplesizeis2”x2”x1”thick.Theentiresampleiscompressedunderthe50in2indenterplateninthistest.Thepr
