US1709475A - Wall board - Google Patents

Description

A ril 16, 1929. G, Q TT 1,709,475

WALLBOAR D Filed NOV. 9, 1928 INVENTOK 5 at 5 Gilberfflfloyy fff 7 9 m A H15 TORNEY Patented Apr. 16, 1929.

UNITED STATES GILBERT A. HOGGATT, OF KENMORE, NEW

PATENT OFFICE.

YORK, ASSIGNOB TO CERTAIN-TEED PROD UCTS CORPORATIC NZ OF NEXV YORK, N. Y., A CORPORATION OF MARYLAND.

WALL

Application filed November This invention relatcsto the elimination of the wavy and irregular edges often present in the paper goig into the manufacture of plaster wallhoard. The object of this invention is to eliminate these wavy edges and to secure a feeding lof'fla't' wallboard paper into the wallboard machine.

Vallboard paper is dried to about 4%; moisture content at the paper mill and it is wound into rolls 40" to in diameter and shipped to the wallboard plants. \Vhen exposed to the air this paperwill gradually take up moisture along the edges or butts of the rolls in varying amounts depending upon the temperature and relative humidity of the air. Normally itwill contain from about 5 to 8'}: moisture after exposure for any appreciable time. 'l.l1e.nio1sture from the air gradually penetrates the exposed edges or butts of the roll for a distance of 2" t0 6" in from the edge of the sheet. The edges of this pa per-having absorbed moisture, expand, ar d in running rolls of paper which have been exposed to atn'iospheric conditions into the wallboard machine it is found that the edges so saturated and expanded, curl up, with the result that the edges are wavy. If these waves are not eliminated before the paper passes through the forming rolls they will quite often remain in the sheet until the gypsum core has'setor hardened and the finished board will then have a wavy or irregular edge which is very undesirable.

To climi nate these wavy edges I have found it practical to install heating apparatus dircctly beneath the edges of the sheets as they o into the plasterboard machine. The heating ammratus may be of any convenient or practicable kind and I do not wish to be limited to the specific form of heater which is herein described as illustrative of my improved method and apparatus.

In the accompanying drawings Figure 1 represents a side elevation of a part .of the ordinary plasterboard machine.

Figure 2 is a perspective view 0f.an illustrative example ot-a heating unit.

Figure 3 is a bottom view of a plasterboard sheet passing over a pair of heaters constructed in accordance with my invention.

Figure 4 is an end view of the plasterboard sheet shown in Figure 3.

In Figure 1. and 2 designate rolls of wallboard paper as they are set up in the plaster- BOARD.

9, 1928. Serial NO. 318,132.

board machine. 3 represents a guiding roll.

ft and 5 are the ordinary foi'ining rolls used In plasterboard manufacture. ll) indicates plaster composition which is fed in between the two sheets. 6 represent. the plasterboard sheet as it is fed into the machine. 8 represents a plate of metal, preferably brass. to -'which a metal angle bar, 9, is attached. The bar 9. may be attached to a convenient support in order to -fix the plate, 8, into proper position beneath the edge of the plasterboard sheet. I'employ two bar and plate constructions for each sheet, one under each edge. 7

represents the ordinary type of ele tric spa e heater which has been found satisfactory in the practice of this invention. A suitable number of these heaters are attached to each plate.

As the plasterboard sheets are led toward the forming rolls the edges thereof are dried 'by virtue of the heat supplied directly be- .neath them through plates 8. It has been found convenient to heat these plates by the common electric space heater, although [do not wish to lilnit llIYSClfl'U the use of this particular heater as a means of practicing my invention. The electric heaters are convenient because the heat may he controllcdby means of switches which allow one, two or three heaters to be energized. The electric heaters occupy a vcry-small'sparc and have been found quite satisfactory in the practice of this invention.

It can be seen that as the wallboard paper passes over these heaters the moisture content along the edges is decreased by virtue of the fact that thc'moisture present in the edges is vaporized anddriven oft. Proper regulation of the heatapplied in the plates will dry the edges to the same degree of dryness pres- 4 cut in the sheet as it comes from the paper mill. T

edge of wallboard comprising drying the 's the sheet is fed into the plaster board n. thine with a uniform morsture'conedges of the paper sheets as they are fed into the wallboard machine until the moisture content of the sheets is uniform.

3. The method of reducing the moisture content in the edges of a wallhoard-sheet com rising heating said edges as the sheet is fed into the machine until the moisture content of the sheets is uniform. v

4. In combination with a wallboard machine, heating units positioned under the edges of the \vnllhonrd. sheet as it is fed into the machine. 7

5. In combination with a. wellboard inachine, heaters applieddirectly underneath the edges of the wallhoard heetes it is fed into the machine.

6. In combination with a. wallboard machine heaters applied directly beneath the edges of the wallboard sheet as it fed touniform to eliminate wavy edges in the fin- 1 ward the tormingrolls, whereby the wavy edges due to excessive moisture in saidsheet are eliminated.

7. In combination with \vallboard'apparatus, heaters positioned beneath the edges of thc-wallhoard sheet as it is fed from the feed rolls to the forming rolls whereby the moisture content in the wailooard sheet is made ished product. I I

i 8. Ina Wellboerd niach1ne,in combination, feed rolls for feeding the. cover sheets into I the machine, forming rolls for forming the wallhosrd elements into a sheet of wallboard. and heaters positioned between said feed and forming rolls whereby the moisturecontent in the cover sheets is made uniform.

9. In a wallhos-rd machine, in combination, feed rolls for feeding the cover sheets into the machine, forming rolls for forniin the wait board elements into a sheet of wall o heaters positioned between said feed a e-l forming rolls whereby the wav edges in the finished product are eliminated 10. In a wallboard machine, in comuiz a tion, feed rolls for feeding thecover shots into the machine, forming rolls for form? the wallboard elements into a sheetof .we'll board, and heaters positioned between said feed and forming rolls whereby wavy edges in the cover sheets, due to an uneven moisture content thereof, are eliminated;

, 11. In a wallboard machine, in combine--- tion, feed rolls for feeding the cover sheets in 0 the machine, forming rolls for forming the wallboard elements into a sheet of wali board, and heaters positioned between-said. feed and forming rolls whereby excess moisture content in the edges of the cover sheets is eliminated andtheyare straightened be fore running through the forming rolls. 12. In a wallboard machine, in combination, feed rolls, forming rolls and heaters positioned between the two to drv the cover sheets uniformly.

13. In a wallboard machine, in combination, feed rolls, forming rolls and heaters positioned between said feed and forming; rolls to remove, by drying, the waves in tlic edges of the wallhoard sheets.

' 14. In a wallboard machine, in oombination, feed rolls, forming, rolls and heaters poe sitioned between said feed and formingrolls whereby all portions of the wallboard sheet are reduced to a uniform moisture content.

In testimony whereof Iafiix my signature.

GILBERT A. HOGGAT'I ard, and

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