Development Of Concentrated Natural Latex Specially Used In The Production Of Condoms

At present,the consistency quality of concentrated natural latex homemade is relatively poor,although the indicators have reached the national standard,but there appeared a series of problems in the production of applications,limiting its application in high-end products,leading to the long-term dependence on imports about the concentrated latex used in domestic high-end latex products especially the condoms.In this paper,we first studied the differences of concentrated latex from Hainan and Thai in the physical and chemical indexes,the size and distribution of molecular weight and the content of metal ions.On these basis,we improved the traditional latex production process,and used the new latex preservative system to instead the traditional TT/ZnO preservation system,which solved the adverse effects on the latex processing technology from the TT/ZnO storage system.And the content of non-rubber component of concentrated latex was reduced by dilution centrifugation process to prepare the concentrated latex samples for condom.The samples were tested for 3 months and sent to the products factory for products trial experiments.The results showed that the conventional physical and chemical indexes of concentrated latex samples from Hainan and Thai are all reached the national standard of GB/T 8298-2008,and the difference was small;Among them,the content of non-rubber and nitrogen in the concentrated latex of Hainan is higher than that of Thai concentrated latex;the thermal stability of concentrated latex in Thailand is 59.2% higher than that of Hainan;The molecular weight of the concentrated latex from Thai is higher than that of Hainan,but the physical and mechanical properties of the two kinds of samples are very similar;The content of metal ions in the concentrated latex is quite different.The content of magnesium in concentrated latex of Hainan is 13.5% higher than that of Thailand,the content of magnesiumis 57.1% higher,the content of copper ion is 37.9% higher,and the content of manganese ion is 37.8% higher than that of Thailand.Nine concentrated latex samples were prepared by a new preservation system and dilute the latex before centrifugal process.The content of non-rubber in the samples is relatively low,and always lower than 1.1% in the storage period;the content of metal ion in the latex is relatively low,especially the content of copper and free calcium and magnesium ion;the content of volatile fatty acid value and hydroxide potassium in the concentrated latex samples is relatively low,the conventional physical and chemical indicators have reached the national standard,the preservation quality is better;the viscosity value of pre-vulcanized latex is very good,and the increase is very small during the 20-day storage;the samples provided to the product factory for trial production test after stored for 3 months.The results show that the latex process test of the indicators are conventional,the trial production of products with good film-forming performance and initially meet the trial requirements.