45
2
Abrasion
Thismethodutilisesastandardeyeletmountedonarigidboardandthelacetobetested.Laces
shouldbestoredinastandardcontrolledatmosphereforatleast48hoursbeforetesting.The
equipmenthassixstationsfortestinglaces.Eyeletsaffixedtorigidboardsareplacedinthe
holdersprovided.Oneendofthelacetobetestedisclampedinacarrierandtheotherendis
passedthroughtheeyeletandthenfixedtoaweightcapableofapplyingatensioningforceof
4.46Ntothelace.Themachinemoveseachlaceadistanceof75mmthroughtheeyeletat100
cyclesperminute.Themovementofthecarriercausesthelacetorubintheeyelet.Eachstation
hasaseparatecounterand,whenalacebreaks,thecountisstoppedonthatstation.Whenall
sixlaceshavebroken,themachinewillstop.STM152isprovidedwithhandcontrolforease
ofsettingandisfullyguardedtocomplywithEuropeanHealthandSafetyrequirements.This
machinecanbeusedtotesteyeletsagainststandardshoelacesoralternativelyshoelaces
againststandardeyelets.
Shoelaceabrasion
Shoelacesthatbreakareafrustratingproblemandcanspoiltheperformanceofotherwisegoodfootwear.Predictingtheprobablelifeofa
shoelaceordeterminingitsabrasionresistancecanbecarriedoutusingtwoabrasiontechniquesdescribedbelow.Abrasionresistance
givesamuchbetterindicationthantensilestrengthoftheservicelifeofabootorshoelace.WithSATRAtestequipment,lacescanbe
assessedforabrasionresistanceusingashoelacetoshoelacetechniqueor,alternatively,ashoelacetoeyeletmethod.Twomachinesare
requiredtocarryoutthetwotestsandtheyareoutlinedhere.
STM152Lacetoeyeletmethod
Thismethodisaversatiletestwheretwosimilarlacesareabradedtogether.Lacesshouldbe
storedinastandardcontrolledatmosphereforatleast48hoursbeforetesting.Oneofthetwo
lacesusedateachofthesixstationshasbothendsofthelaceclampedinthecarrierprovided.
Thesecondlaceisthreadedthroughtheloopcreatedbythefirstlace.Oneendofthesecond
laceisfixedtoamovingcarrierwhiletheotherisattachedtoaweightthattensionsthelaceto
2.45N.Whenthemachineisstartedtheactionofthemovingcarriercausesthetwolacesto
abrade.Themachinemoveseachlaceadistanceof35mmatafrequencyof60cyclesper
minute.Eachstationhasaseparatecounterand,whenalacebreaks,thecountisstoppedon
thatstation.Whenallsixlaceshavebroken,themachinewillstop.STM439isprovidedwith
handcontrolforeaseofsettingandisfullyguardedtocomplywithEuropeanHealthandSafety
requirements.Thesamemachinecanbeusedtotesttheabrasioneffectsofrubbingthelace
throughalacecarrierorhook,forexampleeyelets,D-rings,skihooksandothers.
STM439Lacetolaceandlaceto
carriermethods
Thismachineisidealfordeterminingtheabrasionresistanceofalltypesoffabricsandleather
usedforfootwear,upholstery,clothing,glovesandmanyotherproducts.TheMartindaleisthe
internationally-acceptedteststandardforwearoffabricsanditisalsousedfordeterminingthe
susceptibilityoffabricstopilling.
TheSTM633canalsobeusedfortestingtheabrasionresistanceofrubbergloves,plasticand
rubbercoatedfabricsbysubstitutingthestandardabradantwithagritpaper.
Themachinecanbeusedforsoilingtestsforlightcolouredmaterials.Aspeciallyinkedfabric
replacesthestandardabradantforthistest.
Aninitialamountofthestandardabrasivefabricissuppliedwiththemachine.
STM633SATRA/Martindaleabrasionmachine