Tin plate processing

An electrolytic tin-plating process gives a coating 30 millionths of an inch thick. How many square meters can be coated with one kilogram of tin, density 7300 kg/m3 ... 

From a component manufacturing perspective, the removal of Pb from a Sn-Pb finish to create a pure Sn finish is virtually a drop-in replacement for Sn-Pb plating. Commercial tin-plating chemistries offer a wide operating window. The cost of pure-tin plating processes is equivalent to or less than commercial tin-lead plating processes. 

Plating Processes, Tin-Tead Solder Mlloy Fluoborate Plating Process for Printed Circuit Applications, HTPP3N 0272, Harshaw Chemical Co., Solon, Ohio. 

Hydrated Stannic Oxide. Hydrated stannic oxide of variable water content is obtained by the hydrolysis of stannates. Acidification of a sodium stannate solution precipitates the hydrate as a flocculent white mass. The colloidal solution, which is obtained by washing the mass free of water-soluble ions and peptization with potassium hydroxide, is stable below 50°C and forms the basis for the patented Tin Sol process for replenishing tin in staimate tin-plating baths. A similar type of solution (Staimasol A and B) is prepared by the direct electrolysis of concentrated potassium staimate solutions (26). 

Copper/silver-plated copper Solder-dipped copp>er/tin-plated aluminium Copper/tin-plated copper Copper/solder-dipped copper Copper/reflowed tinned copper Silver-plated copper/tin-plated copper Silver-plated copper/solder-dipped copper Gold-plated copper/tin-plated copper Aluminium/tin-plated aluminium (zincate process)... 

The arrangements for feeding the tin plate continuously through the instrument and for continuous recording are similar in principle in all these industrial installations, and the possibility of direct control of the process through a servo link is present in all of them. 

The chemical supplier can also identify any regulated pollutants in the facility s treatment chemicals and offer available substitutes. The federally regulated pollutants are cyanide, chrome, copper, nickel, zinc, lead, cadmium, and silver. Local and/or state authorities may regulate other substances, such as tin, ammonia, and phosphate. The current status of cyanide and noncyanide substitute plating processes is shown in Table 9.11... 

Tin Plating. In 320 B.C., Theophrastus of Eresus mentioned the plating of iron with tin (221). In 1820 Samuel Parkes described several processes for this art which, he said, flourished in Bohemia long before it was practiced elsewhere in Europe. About the beginning of the seventeenth century, said he, mines of tin were discovered in Saxony, and the Elector had the address to transplant the tin-plate manufactory to his own kingdom. In the year 1665, when Mr. Andrew Yarrington visited these manufactories, they were of such extent as to employ about 80,000 workmen and the tin-plates were sent to all parts of the civilized world.. . . The art of making tin-plate does not seem to have been... 

How do iron, cobalt, and nickel react with the oxygen of the air What is the rusting of iron What factors affect this process What will happen if we take two plates, one of galvanized iron and the other of tin-plated iron, scratch each of them with a file to remove the protective layer of metal, wet them with a 10% sodium chloride solution, and let them stay in the air ... 

Manottactuee op Tin Plates ok Sheet-tin.— As the superior quality of tin plates depends almost entirely upon the goodness of the iron which constitutes their basis, and the care taken in its preparation, it will be necessary, from the importance of the subject, to dwell at acme length upon this part of the process. 

Besides the foregoing method of refining, two others, long followed to some ex toot, are known—the first is a modification of Besbemer s process, and the second Is one patented by Mr. Parry of the Ebbe Yolo Iron Works. In (he first, the action of the blast is stopped when the melted iron has passed to the state of refined metal but as the iron prepared in this way has never been used in the manufacture of tin plates, it will he needless to prolong the description. The metal purified from common Welsh pig contains centcslmally—... 

It is necessary to revert here to the coke tin plates, which name, as already Bteted,-was originally applied to them in consequence of the kind of fuel used in the second refining operation. At present it means those produced from puddled iron rolled into bars similar to those described in tbe preceding, and called tinplate bars or tin bars. In all the subsequent processes tho. same modus op randi is followed, whether the tin bars be made from the puddled or from the hollow fire Iron—charcoal tin bars therefore the following description of the process to which the bars are subjected, previous to, and up to tliefr conversion into tin plates, applies equally to both kinds. 

Quality of Tin Plates.—The tests for tin plates are ductility, strength, and color and to possess these, the iron used must be of the best quality, and all the process be conducted with care and skill. The following conditions are inserted in some specifications, and will serve to indicate the strength and ductility of first-class tin plates —... 

Electrolytic metal deposition ( electroplating ) is an empirical art widely in use to cover corrosion-sensitive surfaces with a thin protecting metal layer, e.g. of tin, nickel, zinc, etc. The complete plating process comprises several partial processes such as mass transport, charge transfer, adsorption of adatoms, surface diffusion of adatoms, and finally nucleation and crystal growth. 

A large number of commercially important plating processes occur from complex ion baths in which the metal is a constituent of an anionic complex, e.g. copper, zinc, cadmium, silver and gold are all commonly plated from cyanide baths, and tin plates from a stannate bath in which [SnIV(OH)6]2 is present. Chromium is commonly plated from a chromate bath although in this case the background medium is acid rather than alkaline. Thus the mechanism of deposition of metals from anionic complexes is of particular interest. It will be instructive to comment on two situations, one occurring in alkaline baths, the other in acidic baths. 

Soda ash oan be used instead of sodium hydroxide. This process is carried out in wooden or iron vessels, lined with tiles and equipped with a wooden stirrer as well as lead or tin plated steel ooil through which an aqueous solution of glyoerine flows which has previously been chilled to about — 5 °C in an ammonia cooling equipment. 

Atmospheric attack of tin plate in humid atmospheres results in the corrosion and production of rust. This occurs in neutral or near-neutral conditions. The presence of contaminants, which change the pH, might result in the opposite process, namely detinning. 

Some of the factors that contribute to the internal corrosion of tin plate cans are (i) the ratio and concentrations of citric to malic acids which in turn depend upon the strain of fruit, the extent of ripeness (ii) nitrate present in the fertilizers may find its way into fruits and vegetables and the nitrate may be reduced to hydroxylamine and support the detinning process (iii) pesticides containing dithiocarbomates may find their way in and attack iron (iv) phosphates, citrates and the low pH of cola-type beverage may dissolve iron (iv) meats, fish and peas contain sulfur-bonded protein molecules, which can decompose to H2S and attack the tin and iron, forming the respective sulfides. Hydrogen sulfide can react with Sn and Fe, yielding FeS and SnS, which are not poisonous, but impart some color to the canned product. 

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