Lined Sheet Rubber

In some equipment, such as filter drums, extruded profiles such as division strips are affixed on to the lined sheet rubber and then cured. These profiles can be strips of different cross sections for enabling other components to be fixed in the rubber lined equipment such as drum filters (see Figure 7.3). 

The production of a rubber lining includes the preparation of the rubber compound followed by processing to form the lining sheet, substrate preparation, lining application, vulcanisation and inspection. All these stages require thorough quality control, especially compound manufacture and sheet preparation, as chemical resistance depends on satisfactory dispersion of the individual ingredients and undetected flaws in the sheet will cause problems in service. 

The lining sheet is prepared by calendering in thin plies up to 1 mm in thickness, followed by combining the individual layers on the calender to form a finished sheet, usually between 3 mm and 6 mm thick. Alternatively, lining sheet can be manufactured by the roller die process in which the sheet is extruded and then passed through rollers to give the finished thickness. Extrusion is also used for the preparation of unvulcanised rubber tubes suitable for lining pipes up to 200 mm in diameter. 

Trapped air - Air that is enclosed between two materials between steel and lining or two lining sheets. Note trapped air can occur between vulcanized and un-vulcanized rubber. 

As an internal insulation in a process vessel, reducing the surface temperatures on the membrane to an acceptable level. Examples (1) Steel pickling tank in a steel mill, lined with rubber sheet. Top service temperature of the rubber 160°F, but bath temperature 210°F. The brick lining provides sufficient insulation to get the surface temperature of the rubber sheet down to 140°F. (2) The same system to protect the membrane in process vessels or (3) to prevent live steam from cutting out the asphalt membrane on a floor. 

On any structure composed of two or more dissimilar components, there will be a difference in the coefficients of thermal expansion of those components. Take, as an example, a steel tank lined with a sheet rubber lining and inner-lined with 8 inches of "acid brick."... 

Sometimes, when the design calls for a sheet rubber lining, the steel vessel... 

Description Rubber Linings Thin Plastic Linings Glass-reinforced Plastic Linings Sheet Linings (Adhesively Bonded) Proprietary... 

Because of its structure and composition the cellular glass is an excellent insulating material for the inside hot surfaces of process equipment. It has a weight of only 12 Ib/ft (0.19 g/cm ). For example, a process vessel handling 65% sulfuric acid at 350°F/177°C would have an outer shell of mild steel, an inner membrane of sheet rubber or vinyl, and an inner insulation of four 4 in. courses (layers) of acid brick laid up with a silicate mortar. As a result of the extra thickness of the lining, the outer steel walls and vessel supports would have to be heavy. 

Application of a Coating System to Interior Surfaces of New and Used Rail Tank Cars Sheet Rubber Linings for Abrasion and Corrosion Service... 

Hydrocyclones can be manufactured from dough-molded compound fiberglass, cast iron, or sheet metal lined with polyurethane. Metal and fiberglass cyclones are lined with rubber or with hard metal (Ni-hard or 28% chrome white iron). Burgess and Abulnaga (1991) presented a finite element analysis of fiberglass cyclones. 

The technology of these etectrowinning processes is very simple, The cells are open OD iele tanks lined with rubber or plastic and the lines of anode and cathode plates are placed alternatively with a separation of 5 15 cm the cells are connected monopolar and one arrangement is shown in Fig. 4.S, The anodes are lead alloy sheets which in the sulphate medium form a lead oxide coating the metal additions to the lead (c.g. silver) arc to catalyse oxygen evolution and therefore reduce the anode overpotentiaL The starter sheets for the cathodes are aluminium or titanium and the metal is deposited until there is a layer 3-5 cm thick, at which point the cathodes are removed from the cell. The metal is then Stripped from the starter sheets and these are reused. The electrodes are typically Q,3-0.5 m in area but the anodes are always larger than the cathodes to prevent... 

Membranes are applied directly to the metal or concrete surface to protect from corrosion by any liquor that penetrates the brick lining through pores and cracks. Membranes consist of sheet material bonded to the metal or concrete, e.g., flexible PVC sheet, or it may be formed in situ (e.g., polyester resin reinforced with glass fiber, or synthetic rubber sheet, lead, polyisobutylene, polyethylene and asphalt). 

In the past chemical cure linings have been employed on a wide scale. These linings, usually based on natural rubber or acrylonitrile-butadiene rubber consist of a standard lining compound with a chemical activator such as dibenzylamine incorporated in the formulation. Prior to the application of the lining to the substrate, the individual sheets of rubber are dipped or brush coated with carbon disulphide or a solution of a xanthogen disulphide in a solvent. The carbon disulphide or xanthogen disulphide permeates the rubber and combines with the dibenzylamine to form an ultra-fast dithiocar-bamate accelerator in situ, and thus the rubber rapidly vulcanises at ambient temperature. 

The calender was developed over a century ago to produce natural rubber products. With the developments of TPs, these multimillion dollar extremely heavy calender lines started using TPs and more recently process principally much more TP materials. The calender consists essentially of a system of large diameter heated precision rolls whose function is to convert high viscosity plastic melt into film, sheet, or coating substrates. The equipment can be arranged in a number of ways with different combinations available to provide different specific advantages to meet different product requirements. Automatic web-thickness profile process control is used via computer, microprocessor control. 

The application of two roll mills in the downstream of such mixing lines is preferred, especially if the two roll mills are equipped with stock blenders (Figure 35.14). After discharging, the rubber batch will be sheeted on the two roll mill. By putting the sheet through the stock blender, the free surface from which the ethanol and moismre can be evaporated is rather big allowing the chemical reaction to proceed even at somewhat lower temperatures. A smdy by Zuuring et al. has shown... 

Figure 35.43 shows a general layout of a dual-purpose calender line for coating steel cord and textile cord. The heart of the production line is the four-roll calender in an S-configuration. Two mbber sheets are formed in the upper and lower nip. The thin sheets are guided to the middle nip and the cords are coated in the middle nip between the two rubber sheets. Generally outer roll bending is applied on rolls 2 and 3 to compensate the roll deflection caused by the nip force in nip 2. Rolls 1 and 4 can be set crossed respectively to rolls 2 and 3. 

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