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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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Tuesday, September 18, 2007

Dunlop and Talalay Latex Foam

Student: In the manufacturing of latex foam products such as the mattresses, what are the main differences between the so called Dunlop process and the Talalay process? What gelling mechanism is involved in each case?

JohnWoon: Very briefly, in the Dunlop process, the gelling system is done in a one-stage operation. For gelling, zinc oxide and sodium silicofluoride (SSF) are used. The compounded latex (with curatives, soap etc) is first frothed mechanically before the addition of the gelling agents (i.e zinc oxide and SSF) followed by moulding.

SSF would undergo hydrolysis resulting in a drop in the latex pH due to the formation of hydrofluoric acid. This, coupled with the formation of zinc ammines, would lead to the gelling of the latex in the foam.

In the case of the Talalay process, a measured quantity of slightly foamed latex is poured into the mould to only partially fill it. After the mould has been closed, the latex is expanded by vacuum to completely fill the mould. The foamed latex is prevented from collapsing by rapidly dropping the temperature to -30°C and freezing it solid.

At this point, carbon dioxide gas is passed through the latex leading to a drop in pH and hence gelling. The temperature is then increased to 115°C to set and vulcanise the latex.


You are at the site for answers and solutions to all your problems in natural rubber latex processing and manufacturing of industrial, household and medical gloves, condoms, catheters, baby teats and baby pacifiers, toy balloons, latex foam products, latex threads etc.

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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]

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