Further Study On Thickness Testing Standard For Natural Rubber Latex Condoms

Purpose:This paper verifies Article3.6in Annex F, ISO4074:2002Natural Latex RubberCondoms—Requirements and Test Methods through the experiment data. It is notprecise that the stipulation of the deviation constant mass is±10mg for the driedwashed testing slice, and needs to be modified. The study improves the quality testingpreciseness of the condom thickness to avoid the error on the condom thicknesstesting conclusion to maintain the fairness, justification and upgrade the condomquality management.Method:Prepare the condoms according to the methods specified in Annex C and AnnexF in ISO4074:2002, from12batches from9factories home and abroad selected assamples randomly. We do not clean the condoms with pre-washing or powdering asthe classical methods, instead, we wipe them as cleanly as possible with the absorbenttissue after unroll the condoms. We don’t number the condoms and the specimens foravoiding the additional mass of the pigment, but mark it with non-paint methodthrough the testing process. We get the cutting central point at the open end, closedend and the mid-part of the condoms with the ruler according to the Annex F in ISO4074:2002, then obtaining the test piece by cutting the condom with the cutting die.We get the original weight (gross weight) by balance scales, get the quality of the firstwash, the quality of the second wash, the quality of some batches of the third wash bymeans of washing and drying.Then, we get the differences in weight respectively between the gross and thefirst-round washed mass of the specimens, the gross and the second-round, the secondround and the third round. We calculate the thickness according to the formula in ISO 4074:2002, and get a series of changes on the specimen thickness, which issynchronous with the changing constant mass. Therefore, the faults could be causedon the testing conclusion because of using the large constant mass according to Article3.6, Annex F, in ISO4074:2002. It is necessary to stipulate the acceptable span of theconstant mass volume in washing the specimens in testing the condom thickness forthe accuracy purpose.Results:After washing two times, the average volume of the specimen weight of theeffective466specimens from the12lots is135±17.72mg, and95%of the frequencyranges from100.51mg to169.97mg. Lab One results that the average volume of theattached lubricant (and/or dressing powder) to the specimens is9.4±3.57mg, and95%of the frequency ranges from2.4mg to16.4mg; Lab Two results that the averagevolume of the attached lubricant (and/or dressing powder) to the specimens is6.5±1.95mg, and95%of the frequency ranges from2.7mg to10.3mg; Lab Threeresults that the average volume of the attached lubricant(and/or dressing powder) tothe specimens is5.6±1.14mg, and95%of the frequency ranges from3.4mg to7.8mg. The average volume of all the attached lubricant (and/or dressing powder) to thespecimens is6.8±2.68mg, and95%of the frequency ranges from1.55mg to12.05mg.The lubricant (and/or dressing powder) attached to412specimens from466afterwashing two times (i.e. the completed washing) is lower than10mg, accounting for88.4%of the total466specimens. The lubricant (and/or dressing powder) attached to409specimens from466even after the first-time washing is lower than10mg,accounting for87.7%of the total466specimens. The average thickness of thecondoms from the12batches is between0.0519mm and0.084mm. In Lab Two,93%of the volume of the attached lubricant (and/or dressing powder) is lower than10mg.In Lab Three,98.3%of volume of the attached lubricant (and/or dressing powder) islower than10mg. The result shows that it is not necessary to wash the specimenswhen we conduct the condom thickness testing because we can meet the requirementsthrough only wiping the condoms. The volume of condom thickness is near its midpart, and between the mid parts and closed ends. It is that1mg lubricant (and/ordressing powder) can add0.0005mm in condom thickness, and9.9mg lubricant (and/or dressing powder) can add0.0052mm in condom thickness, which counts7.4%of condom thickness averagely with the minimum,6.2percent and themaximum,10percent.Conclusion:It is necessary to modify the stipulation “Wash the specimens in propan-2-ol anddry to constant mass,±10mg” to “Wash the specimens in propan-2-ol and dry toconstant mass, less than1mg” in Article3.6, Annex F in ISO4074:2002Naturallatex rubber condoms—Requirements and test methods.Based on the analysis of the thickness in different parts of condoms, it is possiblethat one part of condom thickness testing can represent all the parts of condomthickness to improve work efficiency.The Chinese condom manufacturers need to upgrade the technology SOP and thequality management to improve the condom thickness manufacturing technology.