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Publication numberUS1765312 A
Publication typeGrant
Publication dateJun 17, 1930
Filing dateApr 8, 1925
Priority dateApr 8, 1925
Publication numberUS 1765312 A, US 1765312A, US-A-1765312, US1765312 A, US1765312A
InventorsSteffens Walter L
Original AssigneeCarey Philip Mfg Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Insulating materials and process of manufacture of same
US 1765312 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Patented June 17, 1930 UNITED", STATES PATENT OFFICE WALTER L. STEFFENS, OF WYOMING, OHIO, ASSIGNOR'TO THE PHILIP CAREY MANU- FACTURING COMPANY, CORPORATION OF OHIO D INSULATING MATERIALS AN D PROCESS OF MANUFACTURE OF SAME No Drawing.

factory for'insulating material as has heretofore occurred when what is commonly known as 85% magnesia covering has been used. My improved insulating material has a low rate of heat transmission, has high insulating value, is mechanically strong, is

light in weight, and when manufactured has a non-powderin refractory surface and can be manufactured at a comparatively low cost. In the preferred process of manufacture of my insulating material I first mould a block composed of a major proportion of carbonate of magnesia, preferably about and a minor proportion of asbestos. This block is dried. After drying it is heat treated to shrink same and is then milled to form and size. For some purposes when the material is to be used on surfaces where it willbe subjected to. a comparatively high temperature i.'e., 750 to 800 degrees F., I have found it desirable to subject it to heat treatment at a temperature approximately the temperature to which it is to be subjected in use. When this block has been formed to desired'size and. form I preferably treat it to a solution of sodium silicate by dipping it ina bath so as to impregnate it with the sodium silicate. The preferred impregnating solution to obtain the result desired is a solution consisting of six (6) parts of water to one (1) part 40 B. sodium silicate. Such a solution enables me to by treating the carbonate magnesia asbestos block for a period of about one and one half minutes to impregnate a block of about 1 to 2 inches thick with the requisite amount of sodium silicate so as to Application filed April 8, 1925. Serial No. 21.725.

form an insulating material of desired strength and other qualities set forth above. I

A solution containing appreciably more sodium silicate and less water or more water and less sodium silicate would not give the proper impregnation. By this I do not mean that the solution could not be varied slightly as to the relative quantities but no latitude can be allowed'beyond the limits of the formula stated. Insulating material differs in thickness due to the purpose for which it is to be used and I have found that to get a satisfactory impregnation it is preferable to treat the material if 1 inch thick to the impregnation treatment for about 1 minute, if 1 inches or 2 inches thick I treat it for a minute and a half and greater thicknesses in like proportions. After the sodium silicate treatment the blocks are air dried at normal room tem erature and then they are subjected to furt er drying in a heated room. I have found that this method of drying after impregnation enables me to make the material without danger of warp ing as generally occurs Where it is immediately submitted to the action of heat before the excess moisture has dried out. In the process of manufacture of my insulation material the order of treatment after moulding and drying the block may be varied by either heat treating, milling and then impregnating, or b heat treating, impregnating and then milhng, or by any variation in'the order of the three steps of heat treating, milling and impregnating, without departing from my invention. Wherever in the speci cation or claims I have used the expression block ll would have it understood as meaning a piece of insulating material, whether in the form of a cylindrical pipe covering, a fitting for a valve, what is known as lagging or whatever other form of moulded insulating material.

Claims- 1. In the manufacture of insulating mate-' eat um silicate, the fluidity and strength of the solution and the duration of the treatment being such that the block is completely 1m: regnated with said solution and thereafter hardened substantially throughout.

2. In the manufacture of insulating mate rial, the process which comprises forming a block composed of a major pro rtion of magnesia and a minor proportion 0 a suitable fibrous binder, and sub]ecting the block'to the action of an aqueous solution of sodium silicate containing six (6) and one 1) part of sodium silicate, the duration of the treatment being such that said block is completely impregnated with said solution and thereafter hardened substantially throughout.

3. In the manufacture of insulating material, the process which comprises forming a blockcomposed of a major proportion of magnesia and a minor proportion of a suitable fibrous binder, soaln'ng the block with an aqueous solution of sodium silicate for at least one minute in the case of a block one inch thick and prolonging the soaking in the case of blocks of greater thickness for at least one-half minute for each inch of thickness or fraction thereof in excess of one inch, the fluidity and stren h of said solution being such that said b ock is completely impregnated with said solution and thereafter hardened substantially throughout.

4. In the manufacture of insulating material, the process which comprises forming a.

,block composed of a major proportion of magnesia and a minor proportion of a suitable fibrous binder, drying said block, milling said block, soaking said block with an aqueous solution of sodium silicate, air drying said block, and then heat treating the same, the fluidity and strength of said solution and the duration of the soaking being such that said block is completely impregnated, and the temperature of said heat treatment being at least as great as that to which said block will be s'ub ected in actual use.

5. In the manufacture of insulating material, the process which comprises forming a block com osed of approximately eighty-five per cent 85%) of magnesia and approximately fifteen per cent (15%) of asbestos, drying said block, milling said block, soakmg said block with an aqueous solution of sodium silicate containing six (6) parts of water and one (1) part of sodium silicate, such soaking being continued for at least one minute in the case of a block one inch thick and bemg prolonged, in the case of blocks of greater thickness, for at least one-half minute for each inch of thickness or fraction thereof in excess of one inch, then air drying sa d block and heat treating the same at 'a temperature between 500 and 800 F., the fluidity and strength of said'solution and the duration of the treatment with said solution parts of water

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2596285 *Sep 15, 1949May 13, 1952Petcar Res CorpMethod of forming beaded structure
US2804398 *Nov 22, 1954Aug 27, 1957Southwestern Petroleum Co IncMethod of preserving and fireproofing a structural member and resultant article
US3932161 *Apr 9, 1973Jan 13, 1976Mcnish Thomas GordonFibrous insulating materials
Classifications
U.S. Classification264/133, 427/443.2
International ClassificationC04B28/00, C04B28/10
Cooperative ClassificationC04B28/105
European ClassificationC04B28/10M