Serum obtained during latex centrifuging, containing 10 to 15 percent of rubber content. The rubber content is recovered by spontaneous coagulation or acid coagulation.Skim Rubber:
Rubber obtained by coagulation of skim latex, this rubber has a very high protein content.Skin:
Partially dry film formed on the surface of latex left exposed to the air and unstirred. Sludge:
Substances that get settled at the bottom of the latex tank comprising the magnesium ammonium phosphate, sand, dirt and other heavier matter in the latex. A sludge trap is provided at the outlet of the latex tank to rid the latex outflow of the sludge.Sol:
A term, often used in academic publications, to denote a colloidal dispersion, usually of very fine particle size.Solvent Roughening, Solvent Wrinkling:
Terms used to describe the process of producing a rough, irregular pattern of wrinkles on the outside of a latex dipped product by immersing the wet gel in a solvent.Solvent Stripping:
A (rarely used) method of stripping in which the dipped product is swollen in a solvent to facilitate removal from the former.Spontaneous Coagulation:
Coagulation of field latex stored without the addition of preservatives. This coagulation is presumed to be due to the development of acidity from the activity of bacteria.Stabilizer:
A substance which, when added to latex, increases or modifies its colloidal stability. Such substances are usually, but not necessarily, surfactants.
An antioxidant, i.e. a substance which stabilizes the polymer.Stability:
- Resistance of colloidal dispersion to destabilization.
- Resistance of polymer to degradation.
- Term used to describe the increase in viscosity shown by natural (dry) rubber during storage.
- Sometimes used to mean the similar increase in viscosity of rubber in natural latex (not the viscosity of the latex) that occurs in the first 2-3 months after concentration.
Dipping process which uses no coagulant or gelling agent.Strainability:
Ease with which latex concentrate can be sieved or filtered. Usually measured as the number of liters of latex that passes through a filter before it becomes clogged. This measure is used more in extruded thread technology than in other branches of latex processing.Stripping:
Removal of dipped latex products from the formers after drying/vulcanizing.Stripping Aid:
Substance, usually added to the coagulant in a coagulant dipping process, to facilitate subsequent removal of the latex product from the former. Various powders are usually used as stripping aids.Styrene Butadiene Rubber (SBR):
Most widely used synthetic rubber produced by the co-polymerization of styrene and butadiene. It rubber possesses good abrasion resistance and ageing characteristics. Sub-stage Latex:
Concentrated NRL produced (in effect) by one half concentrations, e.g. by partial creaming (or centrifugation) followed by full centrifugation. The resulting concentrate has approximately two thirds the amount of NRS found in normal concentrate. This latex can be an intermediate between normal latex concentrate and double centrifuged latex.Sulphur:
Main vulcanizing agent of rubber products including dipped latex goods.Sulphur Donor:
Chemical which acts as source of sulphur in the vulcanization reaction. Tetra methyl thiuraudisulphide is such a chemical.Surfactant:
Surface active agent substance preferentially adsorbed at an interface between two phases. In latex technology the interface is usually the rubber particle-serum interface but in foam technology, it may equally be the air-serum interface.Synergies:
Spontaneous contraction of latex gel, resulting in expression of serum to the surface.Synergism, Synergy:
Term used to describe the positive interaction of two additives in a formulation. For example, the increased rates of vulcanization given by combinations of dithiocarbamates and thiazole accelerators.Synergist:
Additive to enhance the action of another.Synthetic Latex:
Aqueous colloidal dispersion of any synthetic polymer (plastic or rubber) whether made directly by emulsion or polymerization or by emulsification of solution of a preformed polymer, or by any other means.