Rubber cellular

Sodium bicarbonate (VII) Inorganic C02 100-130 125-130 Low cost. Suitable for cellular rubber but insufficiently powerful for most plastics. Erratic in decomposition. 

The low hardness has led to uses in printers rollers and stereos. It is, however, to be noted that when the material has been used to replace cellular rubbers or flexible polyurethane foams in sealing applications, problems have arisen where it has not been appreciated that although the rubber is very soft it is for practical purposes incompressible. 

Withdrawn) 1974 AMD 1 Laboratory methods of test for determination of smoke generation charactenstics of cellular plastics and cellular rubber materials. Part 1 Method for testing a 25 mm cube test specimen of low density material (up to 130 kg/metres cubed) to continuous flaming conditions (AMD 7688) dated 15 July 1993. Withdrawn, superseded by BS ISO 5659-2 1994... 

Withdrawn) 1974 AMD 1 Laboratory methods of test for determination of smoke generation charactenstics of cellular plastics and cellular rubber materials. Superseded by BS ISO 5659-2 1994... 

A form of cellular rubber in which the cells are non-intercommunicating, self-contained units. It has low thermal conductivity. Expanded rubber is buoyant and does not absorb water and was therefore initially used in both the soft rubber and ebonite forms in the construction of lifebuoys and other marine buoyancy equipment. The most commonly used polymer is now polyurethane for both flexible and rigid systems. 

The presence of small cells or voids in rubber articles. Porosity may be unwanted due to lack of pressure during vulcanisation, or intentional as in cellular rubber. 

BS 4735. Assessment of Horizontal Burning Characteristics of Small Specimens of Cellular Plastics and Cellular Rubber Material When Subjected to a Small Flame, BSI, London. 

Dining the preparation of cellular rubber by thermal decomposition of calcium, strontium or barium azides, various additives were necessary to prevent explosive decomposition of the azide in the blended mixture. 

Ba azide has not been used as an expl, bur it has been used in the manuf of fluorescent lamps and radio tubes (Ref 12a 19)- It has also found use as a blowing agent during the vulcanization of cellular rubber (Ref 22). The expl reaction of Ba azide is prevented by adding gelatin, machine oil or Neugen (polyethylene glycol laurate)... 

Physical Stabilization Process. Cellular polystyrene, cellulose acetate, polyolefins, and poly(vinyl chloride) can be manufactured by this process, Chemical Stabilization Processes. Cellular rubber and ebonite are produced by chemical stabilization processes. 

To overcome the brittleness of GPPS, the material was modified by incorporation of polybutadiene. Impact-modified polystyrene (IPS) was invented by Ostromislensky [1] and has been commercialized since the 1950s. IPS consists of a polystyrene matrix with embedded cellular rubber particles. By rubber... 

In the case of cellular rubber, the ASTM uses several classifications based on the method of manufacture [11,12]. Cellular rubber is a general term covering all cellular materials that have an elastomer as the polymer phase. Sponge rubber and expanded rubber are cellular rubbers produced by expanding bulk rubber stocks, and are open-cell and closed- cell, respectively. Latex foam rubber, which is also a cellular rubber, is produced by frothing a rubber latex or liquid rubber, gelling the frothed latex, and then vulcanizing it in the expanded state. 

Cellular polymers, especially polystyrene and polyurethane, are also widely used for pipe and vessel insulation. The use of cellular rubber and cellular poly(vinyl chloride) in insulation for small pipes is attributed to their ease of application, combustion properties, and low thermal conductivity. 

Cellular rubber is a generic term and includes latex foam produced chiefly by aeration of compounded latex, which is of necessity open-cell because water must be removed rapidly during processing (1). ASTM D 1055 defines flexible cellular rubber as "a cellular organic polymeric material that will not rupture within 60 seconds when a specimen 200 by 25 by 25 mm is bent around a 25-mm diameter mandrel at a uniform rate to produce 1 lap in 5 seconds in the form of a helix at a temperature between 18 and 29 C." The structure of latex foam rubbers consists of a network of open or interconnecting cells. Latex foam rubbers are made from rubber lattices or liquid rubbers. They are manufactured in sheet, strip, molded, or specific shapes (3). 

The scope of this method states that it is not applicable to the testing of cellular rubbers, but it has been used for that purpose. 

MII M-18351F(SH) Mattresses and Mattress Ticks, Berth, Synthetic Cellular Rubber, Naval Shipboard, 22 April 1981, 19 pp (FSC 7210) (SH)... 

MIL-STD-293 Visual Inspection Guide for Cellular Rubber Items, 18 October 1956, 63 pp (93GP) (SH) Validated by Notice 1, 16 June 1988. 

This is a comprehensive volume containing much useful information on many aspects of rubber and rubber-like products. There is a short section on cellular rubber, including properties of eight (8) foam rubbers. Notice 1, 24 July 1987, incorporated two (2) page changes. 

Has a number of test methods on cellular rubber for which ASTM methods are substituted. 

BS 5111 Laboratory Methods of Test for Determination of Smoke Generation Characteristics of Cellular Plastics and Cellular Rubber Materials... 

ISO 4651-88 Cellular Rubbers and Plastics — Determination of Dynamic Cushioning Performance, 2nd Edition, 13 pp... 

This standard specifies a procedure for determining the dynamic cushioning performance of cellular rubber materials and rigid and flexible plastics by measuring the peak deceleration of a mass when it is dropped on a test piece. The test is intended primarily for quality assurance. However, since this type of test is also used to obtain design data notes are given in Annex A to assist in this objective. The method is applicable solely to packaging materials. 

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