Which Thickener to Use for Latex?

Manufacturer:   Nice to meet you!!! We manufacture dipped latex dolls in Siluri, West Bengal.  We use to dip in the latex for 7 to 8 times to get required thickeness. Sometimes the thickeness is not even. We have decided to use latex thickeners. Can I know which thickenere is best. It is CMC or sodium polyacrylate. Many recommend CMC. But I don't know which grade to be used.  Is it better to use CMC with 350 centipodes ( 1 gram cmc in 100 grams water)?

Can I add CMC directly in latex or I should dilute in water. Can you also recommend the maximum dosage.

     

We use Cenex. And I want to reduce dipping from 8 to 5 times. By adding CMC will it cause drying problems???

John Woon (Senior Latex Consultant):  Both CMC and polyacrylate can be used. The sodium salt of CMC is generally recommended when choosing CMC.

You need to also seek the advice of your suppliers because CMC is available in a wide range of chain length and the degree of substitution. You should start with the "medium" viscosity at 2 to 5% solution.

Sodium or ammonium salts of polyacrylate have been widely used for latex. The solution viscosity is comparatively higher at low concentration. Some manufacturers prefer this to CMC because of this reason.

A 2 to 5% solution in water of the thicker should first be prepared before adding to the latex compound. Actual dosage can only be determined by lab experiments.

Any hydrophilic and water soluble materials such as latex thickeners might retard the drying and the finished products might have higher water sensitivity.

What Are the Best Alternatives to Ball Mills?

Manufacturer:  Hello Sir, Good Evening. First I'm very grateful to you because you give lot of information to many people very openly.           

Sir, I would like to know which equipment is best in place of ball mill because ball mill is very slow for grinding even fillers, you need big ball mills. So I want an equipment which is very fast in grinding for sulfur, accelerators, zinc oxides, pigments, fillers and other. Can I use colloid mills or any other options?

John Woon (Senior Latex Consultant): Good question! Yes, ball mill is one of the oldest mills used in the latex industry. To upgrade to one with higher throughput, very briefly, you have the following choices:

1) Attritor (Different people define this differently)

This is basically a batch process based on a stirred pot with minimal process variability. It is sometimes referred to as an internally agitated "high energy" ball mill.

2) Vertical or Horizontal Mill

This is a continuous process with controlled pump speed and is able to use smaller grinding media for finer particle size.There is an intensive agitation and mixing as a result of impact and shear.

3) Top Mill

This involves a rotating basket that constantly sucks the chemical into the basket whereby the particles are continuously "filtered" and ground by the media into fine particles. This is claimed to be simpler to operate and have a narrower particle size distribution compared to horizontal mill.

Amazon Fungus Eats Polyurethane

By Barry Copping

Students on a Yale University rainforest expedition have discovered a fungus with an appetite for polyurethane, offering the potential to solve the intractable problem of PU waste.
The Pestalotiopsis microspora fungus is the first to be found which can survive on a steady diet of polyurethane alone. A bonus is that it does this in an anaerobic (oxygen-free) environment similar to ambient conditions at the bottom of landfills.

The students were in the Ecuadorian jungle on Yale’s annual Rainforest Expedition and Laboratory with molecular biochemistry professor Scott Strobel. The mission was to allow "students to experience the scientific inquiry process in a comprehensive and creative way."

The group cultured the microorganisms found within the tissue of jungle plants they had collected, and assayed the bioactivity of the organisms.

The microbe’s remarkable behaviour was recorded by student Pria Anand, and Jonathan Russell isolated the enzymes by which the fungus degrades plastic as its food source. The Yale team conclude that the microbe is "a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation." They speculate that in the future, waste compactors might be replaced by giant fields of voracious fungi.
The work is published in the peer-reviewed journal Applied and Environmental Microbiology.