Manufacturer and builder (9 / 1875)
Under the name of Argentine is known a style of calico-printing in which metallic luster is imparted to the woven tissue. Two or three modes of doing this have been practiced, none giving very satisfactory results. Finely-divided silver-leaf or precipitated tin is mixed with an alkaline solution of casein and printed on the fabric from a block or roller. The metallic luster is brough out by heavy calendering and hot-pressing.
Silver is particularly sensitive to the action of sulphurous fumes; and, as such fumes are always present more or less in the atmospheres of towns, fabrics thus prepared soon become blackened and unsightly. Tin is, therefore, preferable for this purpose, and should be prepared by precipitation from a diluted solution by means of zinc. A few pieces of sheet zinc are placed upright in a vessel capable of containing about a couple of gallons. Into this is poured about 6 quarts of a weak solution of zinc chlorid in which has been dissolved 100 grains of stannous chlorid or tin salt. Finely-divided metallic tin is precipitated, and when the action has ceased the fluid containing the precipitate is thrown upon a filter. The fine powder is then washed and dried, sifted through fine lawn, to separate the finest particles for use, and mixed with the casein as required. The resulting liquid may have a second portion of tin salt added to it, and be again subjected to the action of the sheets of zinc. Another mode of producing argentine and bronze styles is to print on the fabric with a mixture of the solution of silver, tin, lead, bismuth, or other easily reducible metal with some reducing agent, such as aldehyde, methyl, alcohol, sodium hyposulphite, etc., thickened with glucose. A design is thus produced in the reduced metal. These metals are affected more or less, however, by the fumes of sulphur. Gold and luminum are free from this objection; but the former is too costly and the latter too difficult of application to render their use general for this purpose.
Ei kommentteja :
Lähetä kommentti