US1203011A - Process of making slips for casting earthenware articles. - Google Patents

Description

CHARLES J. KIRK, OF NEW CASTLE, PENNSYLVANIA.

PROCESS 01E MAKING SLIPS FOR CASTING EABIHENWARE ARTICLES.

L23Al1lt No Drawing.

To all whom it may concern:

Be it known that I, CHARLEs J. Kink, a citizen oi the United States, residing at New Castle, in the county of Lawrence and State of Pennsylvania, have invented new and useful Improvements in Processes of Making Slips for Casting Earthenware Articles, of which the following is a specification.

This invention relates to improvements in ceramics and more particularly to an improved process of making a slip for casting earthenware articles.

The art of forming earthenware articles by casting from liquid slip has been recognized in the ceramic industry for some time but has not come into commercial prominence until recent years. Heretofore most commercial earthenware articles were formed by pressing and the clay was treated in the following manner for this process: The ball clays, china clays, flint and spar weighed in a scale in the exact proportions and placed in a blunger with the proper amount of water and blunged until thoroughly mixed and liquefied, the. slip so formed was run. through a lawn or screen and pumped into a filter press under about sixty pounds pressure taking out the water and leaving the clav about the consistency of putty which was then ready for pressing. When casting from slip came into vogue it was discovered that a slip made from the putty-like pressing clay would not cast properly but would do so upon adding to the slip-so formed certain proportions of soda salts. As far as known, all casting slips have heretofore been made by mixing and treating the ingredients as above described in the formation of pressing clays and filling a second blunger about onequarter full of the slip from the first blunger, before it had been passed through the filter press. Salts in the form of silicate of soda and carbonate of soda, together with cakes of pressing clays were then added and blunged until the slip formed in the second blunger weighed about twenty-eight ouncesto the American pint. This slip after having been run through a second lawnyor screen and over magnets, to take out the iron, was then ready for casting. The proportions and ingredients forming this casting. slip Specification of Letters Patent.

Patented Unit. 31, 19316.

Application filed December 29, 1913. Serial No. 809,406;

have been determined, by experience and therefore, as far as known, all potteries engaged in the casting art have, since the time that art originated, continuously employed the above described process for making casting slips, believing it necessary to first form the pressing clay and then add the salts to the pressing clay in asecond blung'er in order to form a casting slip of the desired character.

This invention contemplates the making of the casting slip in a single blunger and thereby doing away with the filter press and handling of the pressing clay which reduces the time and cost of making materially.

In accordance with this invention it has been discovered that instead of first placing the ball clays, china clays, the flint, spar and water in the blung r, if the ball clays, water and salts are first thoroughly blunged and then the other ingredients added a casting slip of a proper character is formed. This improved process employs a single blunger in which are placed ball clays, water and salts and thoroughly blunged to which is then added the china clays, flint, spar and scraps from the casting shop and blunged until the proper weight is secured. This slip after having been run through a lawn or screen and over magnets is then ready to be conveyed to the molds. The proportions of the ingredients in this slip are not a part of this invention, as the proper proportions for forming a casting slip are well known in the art and every manufacturer uses a different formula.

This improved process is adapted for use in producing a slip for casting any kind of earthenware articles.

What I claim is:

The process of making slip for easting earthenware articles comprising the thorough blunging of ball clays. water and soda salts in the proper proportions in a blunger and then adding china clays, flint and spar in the proper proportions until the desired weight is obtained.

CHARLES J. KIRK.

Witnesses NORMAN A. MARTIN, N. CUNNINGHAM.

topics of this patent may be obtained for five cents each. by addressing the Commissioner of .Patents, Washington, D G.