US1995904A - Manufacture of roofing or siding material - Google Patents

Description

March 26, 1935. J. c. SHERMAN MANUFACTURE OF ROOFING 0R 'swme MATERIAL Filed May 19, 1934 Patented Mar. 26, 1935 PATENT, OFFICE I MANUFACTURE or MA ROOFING OR SIDING TERIAL John Q. Sherman, Gotham, Maine, assignor to Brown Company, Berlin, N. H., a corporation of Maine Application May 19, 1934, Serial No. 726,503

5 Claims.

This invention relates to the manufacture of construction or building material such as is useful for covering the roof, side walls or other parts of a building. It relates more particularly to building material that comes in. the form of rolls, strips, or shingles of tapering thickness and that is laid as succeeding courses with its thickest edge presented to view.

In accordance with the present invention, I progressively deposit pulp fibers from aqueous suspension on an endlessly moving wire cloth,

generally known as Fourdrinier wire, to a depth progressively varying across the wire, thereby forming a web of transversely tapering thickness, whereupon ,1 dry the resulting continuous waterlaid web while maintaining its tapering thickness and impregnate the dried web .with molten asphalt or other suitable waterproofing material to produce a continuous web of building material'tapering in thickness from edge to edge. Such a web may, if desired, be cut into so-called individual or strip shingles having maximum thickness at their butt or exposed edges so as to impart the desired ornamental appearance and solidity to the roof or side walls of a building on which they are laid. Such a web may, if desired, also be coated with blown asphalt and surfaced -with crushed slate or similar granular material in the usual way, particularly when it is to be cut into individual or strip shingles. I The foregoing practice may be extended to the progressive deposition of pulp fibers from aqueous suspension on the endlessly moving Fourdrinier wire as a Web of stepped surface configuration across the wire, each step consisting essentially of a longitudinal zone or lane of transversely tapering thickness, that is, presenting an inclined upper surface relative to the under surface of the web. Such a web of transversely stepped surface configuration may, as such, be put through all the steps of my method, including the steps of drying and impregnation, to produce a web which may be applied to the roof, side walls, or other parts of a building so as to give the appearance and the solidity of a plurality of individual courses of strip material of tapering thicknes s. If desired, however, such a web may be cut longitudinally at the junctures of the steps to form individual strips of transversely tapering thickness, which strips may in turn be cut into individual or strip shingles, if desired.

In effecting a deposition of fibers from aqueous suspension toprogressively varying depth across the Fourdrinier wire, I progressively supply an aqueous suspension of fibers, that is, an aqueous pulp suspension, to the wire while causing the water of such suspension to flow through the-wire for a period of time progressively varying across the wire. In order to realize a web of transversely stepped surface configuration, such as 5 hereinbefore described, the water of the aqueous pulp suspension being progressively supplied to the Fourdrinier wire is caused to fiow through the wire for a period of time progressively varying repeatedly across the wire, in consequence of which the fibers are deposited from aqueous suspension to progressively varying depth repeatedly across the wire. It is thus seenthat I am enabled by the practice of my invention to form a web consisting either of a single strip of transversely tapering thickness or consisting of a multiplicity of longitudinal zones or lanes, each of which is of transversely tapering thickness, a web consisting of a multiplicity of such zones being characterized by junctures whereat the upper faces of the various zones are elevated from the body of the web and slope relative to the under face of the web.

With the foregoing and other features and objects in view, I shall now describe my invention in greater detail with reference to the accompanying drawing Wherein,

Figure l'illustrates diagrammatically and conventionally a machine for the practice of my method, beginning with an aqueous suspension of fibers or aqueous pulp suspension and ending with an impregnated web.

' Figure 2 depicts in perspective a-shield such as may be used in effecting a progressive or gradual variation in the time of fiber deposition across the wire.

Figures 3 and 4 illustrate diagrammatically the severance of the impregnated web into individual shingles and strip shingles, respectively.

Figure 5 depicts in perspective a shield such as may be used in effecting a deposition of fibers over a period of time progressively varying repeatedly across the wire.

Figure 6 is a plan view of the wet end of a machine such as shown in Figure 1 but modified for the formation of a web of stepped surface configuration transversely of the wire.

Figure 7 shows in perspective a fragment of such latter web in the form of finished building material. I

Figure 8 is a plan view of the wet end of a machine, such as shown in Figure 1, but equipped with a head-box adapted to feed aqueous pulp suspensions at different consistencies or fiber densities to the wire.

' vantage in the machine of the present inven-- wire.

tion, only that stretch of wire passing the fiberdepositing station being shown.

Referring now to Figure 1, at 10 is shown a reservoir for the aqueous suspension of fibers, from which reservoir suspension may be delivered progressively as needed through a valved pipe 11 entering into the head-box 12 of the webforming machine near its bottom. The aqueous suspension of fibers may be at any suitable consistency or fiber density for web formation, say, at 4% to 2%, the particular consistency depending upon the speed -at which the web-forming machine is being run and the average thickness of web desired. Any suitable fiber or fiber mixtures may be used in preparing the aqueous pulp suspension, for instance, beaten rags; wood pulp, wool, asbestos, etc. Such fiber or fiber mixtures may undergo preliminary conditioning, as ordinarily, in a heater and/or hollander before being diluted with water .to the desired webforming consistency and passed to the reservoir 10. A suitable head or pool of aqueous pulp suspension is constantly maintained in the headbox 12, a Fourdrinier wire "13 being caused to move endlessly about a cylinder mold 14, part of whose periphery constantly moves past such pool of aqueous pulp suspension. The side walls 15 of the head-box 12 may engage over imperiorate rings at the ends of the cylinder mold so as to confine the flow of pulp suspension through the.Fourdrinier wire 13 and thence through the perforated peripheral portion ofthe cylinder mold on which the Wire rides. The bottom 16 of the head-box is shown provided witha rubber seal 17 at its front edge engaging the wire as it enters the pool of pulp suspension while wrapped about the cylinder mold. The peripheral portion 18 of the cylinder mold through which the water of the aqueous pulp suspension constituting the pool has an opportunity to fiow is included between stationa'ry radialpartitions 19 defining a suction chamber inside of the cylinder mold, the lower partition preferably terminating, as shown, substantially at the seal 17 and the upper partition preferably terminating at or slightly above the surface of the pool. The water of the aqueous pulp suspension entering into such suction chamber is removed therefrom by a pipe 20- terminating near the lower comer 21 of the chamber and leading into a hollow pipe 22 on the finished web along transverse lines :c:c, as

which the cylinder mold may be journalled for retation as ordinarily by means of its end headers (not shown), which may serve as the end closures for the suction chamber. The pipe 22 may lead, as usual, to a suitable suction pump (not shown) that is operated to create the desired degree of vacuum in the suction chamber.

As already indicated, pulp is deposited from aqueous suspension on the Fourdrinier wire to progressively varying depth across the wire. To bring this about, I provide means for effecting a deposition of fibers on the wire for a period of time progressively varying across the wire. Such means may, as shown in Figure 2, take the form of an arcuate shield or partition 23 arranged immediately'under the cylinder mold in between the partitions 19, through which shield the water of the aqueous suspension of fibers must flow in order to lead to a. deposition of fibers on the The shield is made up of two cylindrically triangular portions, namely, an imperforate portion 23a and a perforate or foraminous portion 23b, the line of juncture between the two portions extending from one comer 230 of the shield to the diagonally opposite corner 23d. It will thus be seen that as the Fourdrinier wire moves a past the shield 23 of the suction chamber, suction is applied for a minimum period of time at that point on the wire moving past the point 23d of the shield, whereas suction is applied for a maximum period of time at that point of the wire moving past the point 230 of the shield. Between these two points on the wire, suction will be applied for a progressively varying period of time, determined by the cylindrically diagonal line of juncture between the points 23d and 23c, that is, for the varying time intervals .required for the various points across the wire to move out of the zone of suctional action of the shield portion 23b into the zone of suctional inaction afforded by the shield portion 2311. By virtue of the triangular shape of the shield portions 23a and 23b, the fibers deposit from aqueous suspension on the wire as a web of transversely tapering thickness, which web is shown as being carried by the wire over a suction box 24 and into the nip of a pair of press rolls 25, the web thereby being dewatered and compacted sufficiently to be self-sustaining. In order to main-- tain the transversely tapering thickness of the web as Water is being pressed therefrom by the rolls 25, it is desirable that these rolls define a tapered nip corresponding to the taper presented by the web entering into such nip. The partially dewatered web emerging from the press rolls 25 may be removed from the wire and put through a suitable drier. As shown, a doctor blade 26 is arranged near the lower press roll 25 and ensures a removal of the web from the wire so that it may be led through a drying chamber indicated conventionally at 27, wherein the web may undergo the drying action of hot air or any other suitable drying medium while it is being looped, as shown, over rolls. The dried web progressively issuing from the drying chamber may be led through a bath 28 of molten asphalt or other suitable waterproofing material. The impregnated web may then be coated with blown asphalt and surfaced with slate or other similar granular material as customary in the roofing industry. The web of material thus finished may be applied in strip form to the roof, side walls, or other parts of a building in succeeding courses.

In some instances, it may be desirable to cut shown in Figure 3, to produce a series of individual shingles 29 of tapered form, the thick edge 29a of the web constituting the butt edges of the shingles. Such individual shingles may, as already indicated, carry a coating of blown asphalt and be surfaced with slate or similar granular ,material embedded in the coating. They may be a roof in the customary manner of laying strip shingles of this type.

When it is desired to form a web of transversely stepped surface configuration, such as hereinbefore described, the shield for the suction chamber of the cylinder mold may take the form shown in Figure 5, consisting essentially of two shields, such as shown in Figure 2, placed endedge to end-edge, with the end-edge 23c of the perforated portion 23b coincident with the 'endedge 23 of the imperforate portion 23a. Accordingly, a web consisting of longitudinal zones or lanes of transversely tapering thickness will be deposited on the wire, such a web 33 being shown on the wire 13 in Figure 6. Such a web may be partially dewatered as it is being carried by the wire 13 over a suction box and a pair of press rolls, the upper roll 34 of which is shown in Figure 6 as being made up of frusto-conical portions designed to exert pressure on the web while maintaining its transversely stepped surface configuration. The web may then be dried, impregnated, and otherwise. treated, as described in connection with the web consisting of only a single transversely tapering strip. A fragment of a finished web possessing a regularly stepped surface configuration is shown in Figure '7, the web therein shown consisting of two steps, each step of which is of tapering thickness and presents an upper face inclined relative to the under face of the web. The web is further shown therein as being coated with blown asphalt 35 and surfaced with granular material 36 embeded in the coating. Such a web may be applied in succeeding courses to the roof, side walls, or other parts of a building, in which case the web may, as it is being applied, be unwound as a continuous strip from a roll. If desired, however, such a web may be cut longitudinally at the juncture z-z between the steps to produce individual strips, which may in turn be out into the individual or strip shingles shown in Figures 3 and 4. it is to be understood, of course, that one may, according to my invention, form a web of transversely stepped surface configuration consisting of more than two steps, and further that such a web may also be used as such or cut into individual strips, individual shingles, or strip shingles. Ordinarily, however, it is preferable to use the web of transversely stepped surface configuration as such for the purpose of covering the roof, side walls, or other parts of a building, as this makes for quick and easy coverage of a large area and minimizes the number of joints in a given area of coverage through which water may leak. Again, such a web may be shipped and handled in convoluted or roll form and, when applied to the roof or side walls of a building, is characterized by less'tendency to curl or be lifted by wind pressure on account of its comparative massiveness and continuity of structure.

There are ways of promoting the deposition of fibers from aqueous suspension as a web of transversely tapering thickness or as a web of transversely stepped surface configuration. Thus, as shown in Figure 8, the head-box 12-of the machine may be divided transversely of the wire by partitions 3'7 into three compartments A, B and C. Each partition may include gates 37a adjustable in height so as to permit an overflow of aqueous pulp suspension from the compartments A and C into the compartment B. Thegates are also preferably adjustable toward and from the wire so as to permit them to clear closely the web deposited on the wire. thereby avoiding eddies near the surface of the web such as would ,tend to impair the desired formation or interfelting of the fibers. The end compartment A may be supplied with aqueous pulp suspension from a tank 38; and the end compartment C may be supplied with aqueous pulp suspension from another tank 39. The aqueous pulp suspension supplied to the compartment A may, however, be of much greater consistency or fiber density than that supplied to the compartment C. ,The gates 37a may be adjusted in height so that aqueous pulp suspension constantly overflows into the compartment C in practically equal volume from each of the two compartments A and C, with the result that there is constantly maintained in the compartment B aqueous pulp suspension of a consistency or fiber density intermediate those maintained in the compartments'A and C. By thus supplying the head-box 12 with pulp sus pensions at different consistencies or fiber densities, it is possible to accentuate the effect of the shield 23 in causing a deposition of pulp fibers to progressively varying depth across the wire, for the pulp fibers tend to build up to greatest depth at the zone of the wire coming into contact with the aqueous pulp suspension having the greatest consistency or fiber density. While Figure 8 illustrates the feeding of pulp suspensions of different densities to a machine. designed to form a web 1 consisting of a single strip of transversely tapering thickness, it is, of course, possible to apply the principle therein illustrated in producing a web of transversely stepped surface configuration. Another way of promoting the deposition of the fibers from aqueous suspension to progressively varying depth across the wire is to use a wire which, as shown in Figure 9, is of progressively varying mesh or weave transversely thereof, the edge portion 13a on which the thin portion of the web is to be formed being of finest mesh or weave and the edge portion 13b on whichthe thick portion of the web is to be formed being of coarsest mesh or weave. During the initial deposition of fibers from aqueous suspension on the wire, the total suctional force is greatest at the coarsest portion 13b of the wire, thereby conducing to maximum deposition of pulp fibers thereat from aqueous suspension. Once a substantial layer of fibers have deposited on the wire. however, the effect of the varying size of openings transversely of the wire becomes less important, as the suctional force at any point on the wire is influenced in large measure by the thickness of the layer of fibers at such point. It is, of course, possible to provide a wire consisting essentially of a number of widths of such wire as is shown in Figure 9 when a web of transversely stepped surface configuration is to be produced.

vantage in producing webs whose average thickness is much greater than the webs or felts of substantially uniform thickness heretofore used in making roofing, siding, or similar building material, as this means that the thickest edge presented to view has improved ornamental appearance and solidity. By virtue of the greater average thickness of the webs that I may advantageously produce by my invention, it becomes necessary, however, to subject such, webs to a longer period of impregnation, unless their compactness or fiber density per unit of volume is reduced so as to permit of quicker or easier penetration of the molten asphalt or other water proofing impregnant thereinto and therethrough. Accordingly, in making the webs of the present invention, it is distinctly desirable that their compactness, after drying, be as low as permissible,

as this means that their impregnation with molten machine but before it has reached substantial dryness. As pointed out in that application, water-soluble soaps, such as ammonium oleate,

are highly desirable and inexpensive surfacetension-reducing agents, although volatile organic solvents such as acetone and alcohol may also be used. The surface-tension-reducing agent serves to restrain shrinkage of the web during drying to such an extent that despite the fact that the web has undergone suctional and compressive dewatering forces, it can, be dried to a final compactness value much less than it would possess if its drying were to take place in the absence of a surface-tension-reducing agent. By virtue of the lower compactness of webs dried in the presence of a surface-tension-reducing agent, it is possible to produce a finished product having a higher content of asphalt or other waterproofing material than ordinarily and thus possessing better weathering qualities. I do not, however, herein claim the feature of using a surface-tension-reducing agent in the fabrication of the webs of the present invention, as this feature, although a highly desirable one, constitutes no part of the present invention.

I claim:

1. A method of producing building material which comprises progressively depositing fibers from aqueous suspension on an endlessly moving Fourdrinier wire to progressively varying depth across the wire, thereby forming a web of transversely tapering thickness, progressively drying the web while maintaining its tapering thickness, and impregnating the dried web with waterproofing material.

2. A method of producing building material which comprises progressively depositingflbers from aqueous suspension on an endlessly moving Fourdrinier wire to a depth progressively varying repeatedly across the wire, thereby forming a web of transversely stepped surface configuration, progressively drying the web while maintaining its configuration, and impregnating the dried web with waterproofing material.

3. A method of producing building material which comprises progressively supplying an aqueous suspension of fibers to an endlessly moving Fourdrinier wire while causing the water of such suspension to fiow through such wire for a period of time progressively varying across the wire, thereby forming a web of transversely tapering thickness, progressively drying the web while maintaining its tapering thickness, and impregnating the dried web with waterproofing material.

4. A method of producing building material which comprises progressively supplying an aqueous suspension of fibers to an endlessly moving Fourdrinier wire while causing the water of such suspension tov flow through such wire for a' period of time progressively varying repeatedly across said wire, thereby forming a web of transversely stepped surface configuration, progressively drying the web while maintaining its configuration, and impregnating the dried web with waterproofing material.

5. The combination with a cylinder mold, an endlessly moving Fourdrinier wire, a portion of which passes about such cylinder mold, and

means for progressively supplying an aqueous suspension of fibers to said portion of wire passing about said mold, of partitions defining a suction chamber within said mold arranged to exert suction on said portion'of wire, said partitions including an arcuate shield past which said mold and said portion of wire move, said arcuate shield comprising two portions of cylindrical curvature and of generally triangular shape, one such portion being imperforate and the other such portion being perforate.

JOHN C. SHERMAN.

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