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JW Latex Consultants (and Rubber Consultants,乳胶顾问) offer solutions to your problems in Natural Rubber latex and Synthetic Rubber latex processing and the manufacturing of latex products (condoms, catheters, medical gloves, baby teats and soothers, toy balloons etc) Quick answers through e-mails are possible at reasonable cost.

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Send Your Enquiry and Orders To: woonsungliang@yahoo.com.sg

Problem Solving Through E-Mails with John Woon Latex Consultants Is Possible
可以通过电子邮件与JW乳胶顾问来解决问题

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Saturday, August 25, 2012

New Book Launched - "Practical Latex Technology"




JW Latex Consultants are pleased to announce the launching of our second 128-paged book, "Practical Latex Technology". It contains answers to more than 100 questions plus other very useful tips and ideas! 


For easy of reference, it is divided into 5 Parts:

Part 1: Vulcanisation (Vulcanization), Vulcanisation of Latex and Prevulcanised Latex
Part 2: Properties of Rubber and Latex
Part 3: Problems of Latex Processing and Finished Products
Part 4: Compounding Ingredients and Processing Aids
Part 5: Miscellaneous Subjects

Get your copy for a one-time investment of only $85.00 dollars while it's still available!

Wednesday, August 22, 2012

Nanotechnology Makes Better Glues

Israeli researchers from the Weizmann Institute of Science and Schenkar Engineering have enhanced the structure of epoxy glue with nanotechnology to generate a product with double the binding strength of conventional adhesives for aerospace industry applications.

The scientists added minuscule particles of tungsten sulfide (WS2) to conventional glue at concentrations of 0.5 percent. Thus far, nanostructured WS2 has been used for the chemical storage of hydrogen and the metal lithium, material for solid-state secondary lithium battery cathodes, as well as a dry lubricant and as catalyst in hydrodesulfurization of crude oil.

The research team projects that the nano-glue will be helpful to aviation and space engineers in the development of new vehicles in the atmosphere and beyond. They say the material also can be useful to engineers in numerous other industries.

Tuesday, August 14, 2012

How Does Prevulcanisation Inhibitor Works?

Manufacturer: We are manufacturing rubber mouldings using SMR rubber. We often encounter scorch problems of our rubber compounds due to uncontrolled curing rate even when we use sulphenamide. Our associate had recommended that we should try to use "Prevulcanisation Inhibitor'. How can this help us?

John Woon (Senior Latex Consultant):  The best way to control the vulcanization behaviour of the rubber is through careful choice of curatives and accelerator. Very often, for a more "plateau" and less scorchy cure, one normally uses sulphenamides while for intermediate scorch delay, MBT, MBTS or a blend of both are used.

In order to improve productivity, secondary accelerators such as thiurams and DPG are added to reduce the cure time. However this is achieved at the expense of optimal cure state and the final physical properties.

To prevent this problem, one could use "Prevulcanization Inhibitor" i.e. you can achieve the scorch safety you want without affecting the physical properties.

Here is how it works:

1) Sulphenamide reacts with sulphur forming a complex polysulphide
2) Polysulphide in turn reacts further with rubber, liberating MBT and forming rubber-polysulphides
3) MBT released act as a catalyst for the formation of intermediate polysulphides
3) Rubber-polysulphides then inter-react resulting in vulcanized rubber

Prevulcaniszation Inhibitor (PI) mops up MBT by reacting stoichiometrically with it. Hence vulcanization is delayed until all the PI has been consumed.

I suggest you experiment with different levels (e.g. 0.1 to 0.4 phr) of PI. One good example of PI is Cyclohexylthio-phthalimide.
Molecular Structure of 17796-82-6 (1H-Isoindole-1,3(2H)-dione,2-(cyclohexylthio)-)





Monday, August 13, 2012

Evaporated Natural Rubber Latex Concentrate

Manufacturer: Why is the viscosity of evaporated latex concentrate higher than that of centrifuged latex concentrate at the same total solid content.

John Woon (Senior Latex Consultant): When field latex is concentrated using only the evaporation process, no separation occurs as in the case of centrifuging. Hence, it retains all the fine rubber particles which are normally removed in the serum of the centrifuging process.

As a result, the average particle size of evaporated latex concentrate is very much lower than that of the centrifuged latex. This accounts for it's higher viscosity.


Why Are Butyl and synthetic Polyisoprene Latices Called "Artificial Latices"?

Manufacturer:  We were told that Butyl and synthetic Polyisoprene latices are actually termed "Artificial latics". Why and how are these made?


John Woon (Senior Latex Consultant): Good question!

Both Butyl rubber and synthetic Polyisprene rubber cannot be produced using the conventional emulsion polymerization as in the case of Nitrile and Polychloroprene latices.

To obtain the latex of Butyl and synthetic Polyisoprene rubbers, the rubber is first dissolved or swollen in a solvent followed by emulsification in water and subsequent removal of the solvent by distillation. Hence the term "Artificial Latices".

The emulsion is subjected to high shear to get a particle size of less than 1000 nm. Needless to say, the choice of emulsifiers (surfactants) is of utmost importance. For more details please refer to my separate report to you.






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What has the bouncing ball to do with tyres?

Latex Gloves Educational Articles from the Malaysian Rubber Export Promotion Council

How do you select your medical gloves?

Rubber Chemicals: Carcinogenicity, Mutagenicity, Clastogenicity.

Why is Compression Set measurement important?

Assessment of Latex Stability

Joule Effect

Poor Flocking Quality Of Household Gloves

Creaming of Latex

What is Vulcanization?

History of Latex Dipped Products

Applications of Prevulcanized Latex

Defoamer Creating Havoc in Glove Factory

Problems With Milling Rubber Chemicals

Medical Gloves From Guayule Latex

Introduction to SMG Gloves

 

 

Click on The Following Links to Read More Articles:

[Advantages of Vulcanization] [Applications of PV Latex] [Bacteria and Latex] [Chemical Toxicity] [Cross-Linking Density] [Biodegradability] [Black Articles] [Blooming] [Bouncing Ball] [Compression Set] [Condoms] [Creaming] [Defoamer] [FDA] [Fatty Acid Soaps] [Flame Retardant] [Flocking] [Food Packaging] [Glove Demand] [Glove Selection] [Guayule Latex] [History of Gloves] [Joul Effect] [Latex Stability] [Latex Thread] [Milling Problem] [MREPC Articles] [Nano Polymer Particles] [Nano ZnO] [Polychloroprene] [REACH] [SMG] [Storage Hardening] [Vulcanization] [Vytex] [Yulex]

Disclaimer:
The information and data contained in this site are believed to be accurate and reliable. However it is the responsibility of the visitors and readers to satisfy themselves that the information is workable under their own processing conditions. Hence the owners of this site make no warranties concerning the suitability of the information given in this site.

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