New Rubber Thread Factory in Vietnam

Dak Lak, Viet Nam - The Viet Nam News reports the Dak Lak Rubber Thread Company (Dakruthread) has opened its new rubber thread factory in Hoa Phu Industrial Park, in the central highlands province of Dak Lak. Total investment in the factory has reached VND170 billion ($8.6 million) with a capacity to produce 4,000 metric tons per year. The factory will provide products for the international and domestic garment industry and will minimise imported items from Thailand and Malaysia. 

Latex Particle Size and Molecular Weight of Rubber

Manufacturer: We are a group of university students studying the molecular weight of Natural Rubber.
 Is there a correlationship between rubber molecular weight and latex particle size?


John Woon (Senior Latex Consultant):  While some studies by researchers indicated that the molecular weight of natural rubber is not directly related to the particle size of the rubber particles in latex which normally varies from about 0.02 μm to 3 μm, other studies showed that smaller rubber particles might contain rubber with higher average molecular weight.

This had been confirmed that by measuring the molecular weights of skim rubber and rubber from latex concentrate both obtained from the same batch of latex. Skim rubber which is made from smaller rubber particles showed lower molecular weight.

Also, there is no correlationship between different clones of the rubber trees and the average molecular weight.

Distorted Latex Dipped Products

Manufacturer:We observed our latex dipped products distorted on the formers and also on stripping. We have sent our latex compound for analysis and confirmed that the curatives are working OK. Where could we have gone wrong?

John Woon (Senior Latex Consultant): Assuming your curatives are adequate for the required degree of cross-linking and cure state, I suspect your "maturation" period might not be sufficiently long enough. "Maturation" is to allow for some degree of "pre-vulcanisation" besides allowing the surfactants and soaps to reach an equilibrium state.

If you start dipping without "maturation" or with insufficient maturation, you are bound to have problems of "bagging" or "blowing" or distortion due to weak latex gel strength. Also, the finished products would be under cured despite good cure temperature and time which would also result in distorted and over-sized products during stripping.