During college or technical school training, you may be able to obtain a summer job in a rubber goods plant. The experience can help you decide whether you like the work, and it may also be an advantage if you want full-time employment in the field when you graduate. Another useful experience would be to visit a local rubber goods plant. Some companies allow group tours of their facilities to educate the public about their operations.
Rubber goods are formed from natural or synthetic materials. Different products go through different processes, but generally all rubber is heated, shaped, and finished. Most of this work is done by machine.
The first step in rubber goods production is breaking up and mixing the crude rubber. Rubber cutters operate machines to cut bales of crude rubber into pieces. Rubber-mill tenders tend milling machines that mix, blend, knead, or refine scrap, crude, or synthetic rubber. The machines have corrugated rolls that break the rubber apart and soften it. Rubber is then mixed with chemicals to give it various desirable properties. Formula weighers operate tram cars on monorails beneath storage bins to collect and weigh ingredients. Rubber is mixed with ingredients such as zinc oxide, sulfur, stearic acid, or fillers in mixing machines such as banbury mixers. Chemists and others decide which chemicals to use, and they test samples of the mix before further processing. Foam rubber mixers, frothing-machine operators, and cement mixers tend special machines that mix air and chemicals into rubber to produce foam rubber and rubber cement.
Mixed and heated rubber is then shaped in one of several ways. It may be squeezed into sheets, molded in shapes, or extruded into tubing or other forms. Calender operators run machines that form rubber sheets of specified thickness. Sponge-press operators run machines that form and cure sponge rubber into sheeting for gaskets, insulation, and carpet padding. Dusting-and-brushing-machine operators may dust the sheets with talc to keep them from sticking together before further processing. Other workers shape rubber into products using various processes, including building up thin layers (plies) of rubber sheeting. Among these workers and products are self-sealing-fuel-tank builders, who make airplane fuel tanks; belt builders, sectional-belt-mold assemblers, v-belt builders, and belt-builder helpers, who make rubber belts; and expansion-joint builders, who make expansion joints for ends of rubber hoses.
Some rubber is formed by molding. Pourers fill curing molds with latex using a hose or a machine lever on a conveyor-belt machine. Some rubber products are formed by injection. Injection-molding-machine tenders inject hot rubber into molds to form molded products. Products such as balloons and rubber gloves are formed by dippers, who dip forms into liquid compounded latex rubber to coat them. Most other molded rubber products, including tires, are pressed and heated in molds. Foam-rubber molders make foam cushions and mattresses this way. Press tenders make hard objects such as golf and bowling balls. Arch-cushion press operators heat-press sponge rubber into arch cushions for rubber shoes and boots. Other molding is done by spraying. Foam dispensers spray liquid foam rubber into shaped plastic sheets to make padded dashboards and door panels for vehicles. Skin formers shape the plastic sheeting for these products. Mold strippers remove molded items from molds and prepare molds for further use . Mold cleaners clean, store, and distribute these molds.
The final method of forming rubber is extrusion. In this method, rubber is forced through dies to form continuous shaped rubber products such as tubes and strips. Extruder operators and extruder helpers set up and run extrusion machines. They select the proper die and install it on the machine, feed rubber stock into the machine, and set the speed at which the rubber is to be forced through the die. Extruder tenders regulate and run machines that extrude rubber into strands for elastic yarn. In shoe and boot making, wink-cutter operators extrude and cut rubber strips for rubber soles.
Rugs and other fabric goods are often given a rubber backing using calenders, which are machines that press materials between rollers to give a particular finish. Among the workers who operate these machines are four-roll calender operators, who use calenders to coat fabric with rubber to a specified thickness. Calender-let-off operators use machines to cure and dry fabrics after they are coated. Calender-wind-up tenders accumulate the coated fabric into rolls of specified size. Fabric normalizers shrink rubberized fabric to increase its strength.
Rubber is cured after it assumes its final shape. In curing, rubber is subjected to heat and pressure to increase its hardness, durability, stability, and elasticity. One such curing process is vulcanization. Foam-rubber sheeting is cured by foam-rubber curers, who roll a latex mixture into curing ovens. Belt-press operators and v-belt curers cure rubber transmission and conveyor belting. Weather-strip machine operators mold and vulcanize sponge-rubber beading to make weather-stripping for automobiles.
Rubber sheets, strips, and tubing must be cut into lengths and shapes to form products of specified types and sizes. Rubber-goods cutter-finishers use machines to cut, drill, and grind rubber goods, and they verify the sizes of goods using rulers, calipers, gauges, and templates. Extruder cutters cut extruded rubber into lengths. Automatic-die-cutting-machine operators stamp out rubber shapes using machines with sharp dies. Roll cutters use a lathe to cut rolls of rubber or rubberized fabric. Rubber-cutting-machine tenders use a guillotine-type machine to cut rubber slabs. Molded-rubber-goods cutters use cutting dies to trim molded articles.
Other workers cut rubber for specific products or purposes. These workers include strap-cutting-machine operators, who cut leg straps for hip boots; band machine operators, who cut rubber bands from special tubing; and hose cutters, who cut rubber hose into specified lengths. Mat punchers punch automobile floor mats from sheeting. Splitting-machine operators cut scrap tires or rubber sheets into pieces for reclamation.
Rubber items made of a single piece of rubber often need to go through a finishing process. Buffers may buff items to smooth and polish them; dippers may coat them with vinyl. Workers called openers pull weather-stripping through a machine to force apart sides stuck together during curing. Machine skivers bevel edges of shoe parts to prepare them for cementing or stitching. Padded-products finishers repair defects in padded automobile parts by injecting wrinkles and gaps with liquid rubber foam. Other workers do many other specialized finishing tasks, such as splicing tubing, rolling rings on the mouths of balloons, pressing seams on shoes together to make them watertight, and crimping the edges of articles to reinforce them.
The final processing of rubber items may involve assembling several pieces, decorating surfaces, and quality inspections. Workers who assemble items position and cement or stitch pieces together to make such goods as footwear, shock absorbers for airplane gas tanks, pneumatic airplane deicers, inflatable animals and figures for parades, and many other types of rubber goods. Among the specialized workers who decorate rubber goods are those who print designs or lettering on balloons, brand names on rubber hoses, and designs on rubber sheeting that will be made into footwear. Once goods are finished, rubber goods inspectors make sure company standards are met and repair defects they find.