Celanese announces emulsions expansion in China

Dallas, TX -- Celanese Corp., a leading, global chemical company, Monday announced it is expanding its vinyl acetate/ethylene (VAE) manufacturing facility at its Nanjing, China, integrated chemical complex. The investment will support continued growth plans for the Celanese Emulsion Polymers business throughout Asia, including China, India and Southeast Asia and Australia. The expanded facility will double the company’s VAE capacity in the region and is expected to be operational the first half of 2011.

Rubber prices set to rise this week

According to an article in btimes.lcom.my on Ocober 24, "Malaysian rubber prices are set to rise further next week, with SMR 20 expected to hit 800 sen a kg, a dealer said. The market, he said, will see more foreign demand coming in, as the tight supply scenario in major producer countries has prompted traders to stock up.

"We saw continuous interest. We have received a few enquiries including from China, South Africa, Pakistan and South Korea," he said, adding that prolonged rains had led to lower production. During the week just ended, local rubber prices traded higher, extending the uptrend for five straight days on speculative buying.

On a Friday-to-Friday basis, the Malaysian Rubber Board official physical noon price for tire-grade SMR 20 rose 19 sen to 787 sen a kg from 768 sen last week and latex in bulk added 10.5 sen to 502.5 sen a kg from 493 sen previously. The unofficial closing price for tire-grade SMR 20 increased 20 sen to 787 sen a kg from 767 last Friday and latex in bulk appreciated 19.5 sen to 502.5 sen per kg from 493 sen last week."

ASTM Committee D11 Has Developed a New Standard for Measuring Chemical Allergens in Medical Gloves

It has been known for some years that residual accelerators used as part of the curative system in medical gloves could be a leading cause of allergic contact dermatitis in health care workers and other users.

A new ASTM International standard has been developed to allow rubber glove manufacturers to monitor the level of residual accelerators in their end products so that they could make manufacturing changes to reduce the allergen levels.

The new standard, D7558, Test Method for Colorimetric/Spectrophotometric Procedure to Quantify Extractable Chemical Dialkyldithiocarbamate, Thiuram and Mercaptobenzothiazole Accelerators in Natural Rubber Latex and Nitrile Gloves, was developed by Subcommittee D11.40 on Consumer Rubber Products, part of ASTM International Committee D11 on Rubber. Not only would D7558 be useful to medical glove manufacturers, but also to dermatologists and many end users of medical gloves.

Viscometers for Latex Compounds

Manufacturer: Under what circumstances do we use Brookfield Viscomter and Ford Cup for measuring the viscosities of our latex compounds?

John Woon (Senior Latex Consultant): Generally the rotational viscometers such as Brookfield Viscometer is used to determine the apparent viscosity of non-Newtonian fluid that has shear thinning and thixotropic properties (See ASTM D 2196).

On the other hand, if your latex compound is Newtonian or near-Newtonian especially when it is considerably diluted with water, you could use Ford Cup which is simpler (See ASTM D 1200).

For both methods, temperature of the sample during test must be recorded as this could affect the viscosity.

Natural Rubber Latex for Reconstituted Leather

Manufacturer: We are looking into the possibility of making the so-called reconstituted leather using waste leather scrap. Can you advise us what the process entails and the choice of the binding agent?

John Woon (Senior Latex Consultant): Briefly the process used involves precipitation (coagulatiuon) of diluted natural rubber latex in the "leather slurry" using aluminium sulphate as the coagulant. The slurry is then filtered, pressed and dried.

I found the evaporated latex concentrate to be superior to the normal centrifuged latex concentrate because the former has a wider range of rubber particle size i.e. there are more smaller rubber particles and hence bigger particle surface area in the evaporated latex. There is only one manufacturer for such latex in the world, namely, Revertex Malaysia.You can contact them by clicking the following link:
http://www.revertex.com.my/. I'm sure they would be more than pleased to tell you more about the process of making reconstituted leather.

Incidentally, reconstituted leather has been used for shoe insoles, heel lifts amd also as stiffeners for heels and toes.

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