Sponge Rubber Products

Both systems are designed to cut rubber efficiently from sheeting to form a variety of finished rubber and foam/sponge products. 

Maximum productivity is given by the shortest possible time of cure, provided the selected time and temperature do not produce an unacceptable level of defects or early failures in service. Sufficient cure must be given to prevent porosity, since badly undercured rubber will sponge at pressure release. It is better to risk a slight overcure rather than an undercure, since if the curatives are correctly chosen (in type and quantity) the compound should show a plateau effect, which means that a reasonable overcure will not have any marked effect on the physical properties of the product. 

Chicago, II., 13th-16th April 1999, Paper 69, pp.36 OPTIMIZATION OF THE PRODUCTION OF EPDM SPONGE RUBBER SEALS FOR THE AUTOMOTIVE INDUSTRY... 

The manufacture of sponge rubber products such as gaskets for heat exchangers is based on the inclusion in the compound of chemicals which cause gas formation during vulcanization and thereby produce the desired porosity. Sodium bicarbonate and ammonium bicarbonate are examples of popular blowing agents. 

Rubber products with a cellular structure have been used widely for many years. The earliest developments of these products predated World War I. The two forms of natural rubber—raw rubber, and latex, form the basis for different product types, one being blown dry rubber, and the other foamed and dried latex. Blown sponge and latex foam are distinctly different materials, although the end-products may appear simUar and have some overlapping applications. 

Covers only sponge rubber items, including chemically blown or expanded-rubber items having either open or closed cells. Also includes cellular products made from chemically or mechanically foamed latices or liquid elastomers. Provides word descriptions and photographs of defects. 

Spatulas, rubber Sponge rubber and sponge rubber products Stair treads, rubber Stationers sundries, rubber Stoppers, rubber... 

One of the advantages claimed for the technology in comparison with the sponge rubber ball system, is that it requires less maintenance. A major disadvantage perhaps in some situations more than others, is the momentary interruption in flow while the flow reversal is accomplished. The disruption of steady state conditions in the plant operation may be difficult to accommodate and could have implications for product quality. The cost of the complex piping arrangements and the control system could be expensive, particularly in a retrofit... 

Over 30,000 products are made of rubber. In the passenger car alone, approximately 600 items in 100 different parts amounting to 170 lb of rubber are used, and greater amounts of rubber will be used in cars of the future if current trends continue. In nontransportation uses, industrial mechanical goods, sponge- and foam-rubber cushionings, heels and soles, wire and cable insulation, and footwear are the most important uses. 

Cellular rubber may be described as an assembly of a multitude of cells distributed in a rubber matrix more or less uniformly. The cells may be interconnected (open cells) as in a sponge or separate (closed cells). Foam rubber made from a Uquid starting material such as latex, described earKer, is of open-cell type. Cellular products made from solid rubber are commonly called sponge (open cell structure) and expanded rubber (closed cell structure). 

The curing is carried out either freely using hot or steam or in a mold that is only partially filled with the molding compound. Synthetic rubbers, particularly SBR, are preferred as they allow precise control over level of viscosity required for obtaining consistent product quality. The sponge and expanded rubber products include carpet backing, sheets, profiles, and molding. 

It is of interest to note that Eastman used Bakelite for the Kodak camera in 1914 and that the Hyat Burroughs Billiard Ball Co., replaced celluloid with bakelite for its billiard balls in 1912 [4], The commercial development of the PF product is considered to be the beginning of the truly synthetic plastics era, and of the plastics industry, although cellulose nitrate had been known and in use for some time. The first synthetic rigid cellular plastic was produced accidentally, also by Baekeland in 1909, but the first commercial foam was sponge rubber [5]. 

Moulded products Prepared by compression or injection of rubber eompound into a closed mould. Typieal products are sponges, carpet underlay, sandals, shoes, rubber bands, connectors, curing tubes, curing flaps, lining mats, o-rings, rollers, bumpers, heavy-duty pads, seals, gaskets and wheels. 

The technology to manufacture sponge or expanded rubber is not so critical, but long retention of product quality is very difficult, unless a strict process control system is adopted. This paper highlights a process control system to be followed at all stages in production of expanded rubbers. 

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