Shoe-Making

Another study revealed effects, ranging from mild to severe, of benzene exposure in factory workers in China (Yin et al. 1987c). The primary activities in these factories were the manufacture of paints, shoes, rubber, leather, and/or adhesives (Yin et al. 1987c). Of the 528,729 workers, 95% were exposed to mixtures of benzene, toluene, and xylene, while 5% (26,319 workers) were exposed to benzene alone at 0.02-264 ppm in air in 95% of the work stations. Over half of the work stations had levels of benzene in the air of less than 13 ppm about 1% had levels of 13-264 ppm. Benzene toxicity, as indicated by leukopenia (leukocyte <4,000/mm3), aplastic anemia, and leukemia, was seen in 0.94% of the workers exposed to benzene and 0.44% of the workers exposed to the mixtures. Similar toxicity was found in employees of 28 of the 141 shoe factories studied (124 cases in 2,740 employees) (Yin et al. 1987c). A positive correlation was observed for prevalence of adverse benzene effects and benzene concentration in data from these 28 shoe factories. The authors determined that the affected people were exposed to benzene concentrations >29 ppm. In one workshop, there were 4 cases of aplastic anemia in 211 workers. These workers were exposed to benzene at a mean concentration of 324 ppm during an 8-month period of employment. The prevalence of aplastic anemia in the shoe-making industry was about 5.8 times that in the general population. The main limitation of this study is the lack of information on the duration of exposure. 

We follow a scruffy pair of shoes making tracks down the sidewalk. A black bag bounces against his knees. Shouting and police sirens can be heard. 

Obtain a womans high-heeled dress shoe and a woman s athletic walking shoe. For each shoe, make imprints of the floor contact surfaces. Determine the total... 

While sitting, remove your footwear if you are going to don chemical boots or if the PPE has integral boots. If you are going to wear shoes make certain they will not puncture the chemical suit. 

If you haven t conducted this t3q)e of training before, make a list of the questions you had when you first learned about the subject. Put yourself in your students shoes. Make note of the difficult or chsilleng-ing areas of the subject. These are areas that your students may question. The more preparation you put into potential questions, the fewer times your students will be able to stump the professor. ... 

Year 1894. The T. A. Bata Shoe Company in Zlfn, The Czech Republic by the siblings Tomas, Anna and Antonin Bat a - the eighth generation of shoe-making Batas. (http // www.batova-vila.cz/EN/ Thomas-Bata-Foundation-History, html)... 

Polyurethanes Usually very good adhesion to many substrates and high adhesion strengths. Applications in the shoe-making industry and for film lamination... 

Polychloroprene High elasticity and adhesion strength. Primarily used in the shoe-making industry... 

In shoe making, the previously moistened leather is wiped (pulled) over the last by heated irons. The folds appearing at the round edges of the shoe are smoothed away by heat treatment with a hot air blower or a smoothing iron (the leather shrinks at these high temperatures). So the finish has to be heat resistant. In addition, the finish must not scratch under the rubbing by the irons. The shoe sole is injection molded on in a further operation. The finish coat therefore has to be solvent-fast and the dyes may not migrate into the shoe sole. 

Some 500 years ago during Columbuss second voyage to what are now the Americas he and his crew saw children playing with balls made from the latex of trees that grew there Later Joseph Priest ley called this material rubber to describe its ability to erase pencil marks by rubbing and in 1823 Charles Macintosh demonstrated how rubber could be used to make waterproof coats and shoes Shortly there after Michael Faraday determined an empirical for mula of CsHs for rubber It was eventually determined that rubber is a polymer of 2 methyl 1 3 butadiene... 

Splitting. In most modem large tanneries that make upholstery leather, and in some that make shoe uppers leather, the hides are spHt in the lime condition. In splitting the hides are cut to the desired thickness with a horizontal belt knife. The hides are fed into the machine grain up. The clearance between the grain and the blade is maintained by a series of narrow rollers supported by a mbber roUer underneath the spacing roUers. The grain layer is then cut to the thickness desired to an accuracy of about 0.1 mm. 

Buffiag may be only to remove surface blemishes such as iasect bites or minor healed scratches, or the buffing may be to make a suede surface. Newbuck is a light suedeiag of the grain of catde hide leather. Sheepskin suede is usually buffed on the flesh side of the skin. SpHts may be buffed to make buck shoe leather or heavy garment leather, often called ranch hide. The variations depend on the desires of the customer. 

Tetrahydronaphthalene [119-64-2] (Tetralin) is a water-white Hquid that is insoluble in water, slightly soluble in methyl alcohol, and completely soluble in other monohydric alcohols, ethyl ether, and most other organic solvents. It is a powerhil solvent for oils, resins, waxes, mbber, asphalt, and aromatic hydrocarbons, eg, naphthalene and anthracene. Its high flash point and low vapor pressure make it usehil in the manufacture of paints, lacquers, and varnishes for cleaning printing ink from rollers and type in the manufacture of shoe creams and floor waxes as a solvent in the textile industry and for the removal of naphthalene deposits in gas-distribution systems (25). The commercial product typically has a tetrahydronaphthalene content of >97 wt%, with some decahydronaphthalene and naphthalene as the principal impurities. 

The RIM process was originally developed for the car industry for the production of bumpers, front ends, rear ends, fascia panels and instrument housings. At least one mass-produced American car has RIM body panels. For many of these products, however, a number of injection moulding products are competitive, including such diverse materials as polycarbonate/PBT blends and polypropylene/EPDM blends. In the shoe industry the RIM process has been used to make soling materials from semi-flexible polyurethane foams. 

If the PPE is personal in nature and can be used by the employee off the job, the payment issue may be left up to labor and management. Examples cited in the memorandum include safety shoes, nonspecialty safety glasses, and cold-weather gear. OSHA makes it clear that, If shoes and cold-weather gear is subject to contamination of hazardous substances and cannot be safely worn off-site it should be paid for by the employer. ... 

Since it possesses good properties of both PVC plastics and polyurethane elastomers, it has been used in those areas where PVC and polyurethane have traditionally played dominant roles. For example, it is a very promising replacement for flexible PVC used for medical purposes and in the food industry [I6,l7], because it essentially eliminates the concern regarding plasticizer contamination. It has been used in combination with the copolymer of butadiene and acrylonitrile (NBR) to make the abrasion-resistant aprons and rolls used on textile machines [18]. A PVC/TPU/ABS blend serves as a substitute for leather [19]. This could have a tremendous impact on the shoe industry. It has also been found to have an application as a building coating [20,21]. This trend will certainly grow and more applications will be found. This in turn should bring new developments in the material itself. 

Dust is continually being introduced to the conditioned space by clothing fibers, skin particles, shoe dirt, room processes and the outside air make-up. Dust particle sizes range from 1 pm to 75 pm, smaller particles being described as smoke. In an apparently clean office there may be as many as 30 million particles per cubic meter. 

Problem 31.7 1 Irradiation of poly(-l,3-butadiene), followed by addition of styrene, yields a graft copolymer that is used to make rubber soles for shoes. Draw the structure of a representative segment of this styrene-butadiene graft copolymer. 

On a sparse Monday, at several tables, young professionals met for dinner, still dressed in the athletic shoes that got them to and from their offices, to discuss the more routine matters that make people friends. It was an off-night for the gay boulevarding on Eighth Avenue, which crowds it like a parade on weekends and in good weather. 

The full-prepolymer, quasi-prepolymer, and one-shot techniques may appear to be quite similar, but they each have important bearing on equipment requirements and physical properties. The full-prepolymer method, for example, is die process of choice for making high-performance cast elastomers with superb dynamic properties, such as industrial bumpers and bushings. Quasi-prepolymers are used in less demanding applications like shoe soles, adhesives, and spray elastomers. One-shots make up the rest, including most foams and elastomers. 

Methylenedianiline is used to make an intermediate in the manufacture of polyurethane rubber used for making automobile parts, shoe soles, rubber wheels, and insulation foam. 

---