Formation of Skin and Lumps in Latex Dipping Tank

Manufacturer: I kindly request you to spare sometime to look into the matter and

suggest your opinion.

In some occasions we experience some problems like formation of skin and lumps in the dipping tank (lump comes along with the former) even using latex with acceptable latex parameters like low V.F.A, good M.S.T, KOH Number and maintaining process parameters like coagulant

concentration, oven temperature, former temperature in good condition. Parameter wise the latex is seems to be good, but performance wise it behaves not good.

Is there any other test method to verify the quality and stability behaviour of centrifuged latex before using for processing ? Kindly advise how to tackle the matter.

John Woon (Senior Latex Consultant): Please take note that sometimes the usual latex concentrate properties such as VFA Number, MST, KOH, etc. do not fully tell you how the latex would perform in a given latex product manufacturing process. Different batches of the latex concentrate with similar properties might behave quite differently even in a well established dipping process.

If you are encountering the coagulum and skinning problem with only certain batches of latex (especially over a one-year period) it might be due to the latex itself, probably as a result of seasonal changes in the inherent latex properties which could not be detected by the usual standard tests.

However, if you are facing the problems consistently with every batch of latex over a long period, you should investigate to see if the causative factors actually come from the dipping process itself.

I believe there is a strong possibility that your formers could be insufficiently dried before they enter the latex dip tank. This could result in the formation of skins and coagulum when the fluid coagulant comes into contact with the latex surface.