US1333579A - Plaster-board - Google Patents

Description

. 1. SQHUMACHEH.

PLASTER BOARD. APPLICATION FILED JULY 5. l-9l9.

1,333,579. Patented Mar. 9,1920.

Edges Uieyamfied add al'denai ,bga $12111 or cement glue.

Inventor cfohn flckwnuwhezby 7M X kisji'laz-neyrs UNITED STATES- PATENT. orrioii.

JOHN SQHUMACHER, 0]? LOS ANGELES, CALIFORNIA.

PLASIER-BOARD.

Specification of Letters Patent.

Patented Mar. 9,1920.

. Application filed July 5, 1919. Serial No. 308,765.

for plasterboard is brittle, after it has hare dened, and will break and chip at the edges with rough handling. The finished lengths of plaster board are set up on end during handling and transportation. During such handling the edges are sometimes broken and chipped, the surface sheets broken away from the plaster body, and the board otherwise marred at the edges. When the edges of the board become wet due to lack of protection during damp weather, or during puttying, the moisture is absorbed by the plaster causing it to swell slightly and the paper sheets to loosen at the edges.

The principal object of this invention is to provide a plaster board having the exposed edges of the plastic body case-hardened and waterproofed. Thus, swelling by the absorption of moisture, loosening of the paper sheets due to absorption of moisture,

is prevented. V

These objects will be more fully understood. as will also other objects and corresponding accomplishments of my invention, from the following detailed description of a preferred embodiment thereof. For the purpose of this description reference is had to the accompanying drawing, in which:

Figure 1 represents in perspective a frag ment of the end of a finished length of plaster board; Fig. 2 is a section through the and chipping of the edges during'handling plaster board at one end, the view being on an enlarged scale; Fig. 3, is a perspective view of fragments of two'lengths of plaster board at a seam or joint, illustrating the seam produced with my improved plaster board; and Fig. 4 is a View similar to Fig. 3

' showing a seam'between lengths of plaster board which are not case-hardened and have swelled due to the absorption of moisture.

The plaster board shown herein is preferably made of plaster placed between sheets of paper which have been treated so as to ferring more particularly the covering sheets of paper are indicated by of plastic composition ing the edges.

retard permeation by moisture. During the process of manufacture the units of plaster board are piled in stacks prior to the settingand aretrimmed to the finished length. dimenslons. The board is permitted to set while in the stack, and later further dried by placing in dry kilns. In the process just described I prefer to angle the stacks of units so that they stand upon their side edges, suitably spaced'apart, in which position they are placed in the kiln; During this 1n1t1al' handling, especially when angling the units, the edges may become marred.

The plaster board shown herein has the "general appearance of ordinary plaster board and the initial steps in the process of manufacturmg are carried outas usual. Reto the drawing,

5 and 6, and theintermediate body or layer Immediately after the units have 'been trimmed, and while in the stack, a sizing or cement glue, for illustration one having the ngredients gelatin glue, alum, and potash. is applied to the exposed edges of the plas tic body. This may be done in any manner found convenient as by spraying or paint However, my invention is not limited to the application of theglue while the board is soft. The application may be made at any time. Sufiicient glue should be pregnate the plastic body, forming when dry case-hardened'edges. Such an edge is indicated by 8 in-Figs. 2 and 3. When thoroughly dry the plastic body, atthe edges hardened and water-proof. The edges are thus reinforced and molsture reslstant.

Referring to Fig. 4, lengths of plaster board-A and B having untreated edgesare :joined by a plaster putty C. This putty is moist when applied, and the moisture therefrom w1ll permeate the edges of the plaster board lengths at the seam. This results in applied'so that the latterwill imwhere it has been impregnated, will be case treated according to my invention. The plaster putty F- dries'and hardens without the moisture permeating the edges of the plaster board lengths at the seams, the glue preventing the same. Thus, a smooth wall is secured.- Q

In the foregoing description, I have de- I scribed my product as formed by using paper which retards permeation of moisture. However, the invention is not limited to plaster board formed by this process.

What I claim is: i 1. A plasterboard comprising a. plastic body having its edges impregnated with a reinforcing and Waterproofing substance.

2. A plaster board comprising a body of plastic material disposed between fibrous I covering sheets adhering thereto, the exposed edges of said body being impregnated With a case-hardening and Waterproofing substance.

3. Aplaster-board comprising a body of plastic material, and top and bottom paper covering sheets adhering thereto, the ex- 5. A plaster board comprising a body of plastic material and top and bottom paper covering sheets "adhering thereto, the exposed edges of said body being impregnated with a reinforcing substance.

r 6. A plasterboard comprising a body of plastic material disposed ,between fibrous covering sheets adhering thereto, the exposed edges, of said body having a reinforc-' ing and-waterproofing substance )applied thereto.f

In witness that -I claim the foregoing I have hereunto subscribed my name this 26th day of June, 191-9.

JOHN SOHUMACHER'.

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