US 1866312 A
Description (OCR text may contain errors)
July 5, 1932. E. c. LoETscHER PROCESS OF MAKING DOOR PANELS OF FIBROUS MATERIALS 2 Sheets-Sheet l Filed Dec. l2, 1929 July 5, 1932 1 I E. c. LoETscHER 1,866,312
nm/Ma Mmmm 25 prescribed areas of the panel.
Patented July 5, 1932 PATENT OFFICE EMIL C. LOETSCHEB, F ID'UBUQUE, IOWA PROCESS OFMAKING DOOR PANELS 0F FIBROUS MATERIALS 'Application led December 12, 1929. Serial No. 413,454.
6 iibre, and more particularly to a method for reproducing on the surface of such articles not only the graining of the natural wood, 4but the ornamental effect of the grain running in different directions throughout varous portions of the surface.
In a copending application, filed by me on even date herewith, I describe a process for manufacturing door panels and the like, in
which the ornamentation was carried out in v the surface contour as well as in the treatment of the graining effect of natural woo-d. For convenience, the same or a similar door panel will be used for the present disclosure, which will be directed more particularly to the treatment of the thin bakelized sheets grained and colored in imitation of a natura-1 wood and forming the surface layer of the composite panel, whereby the several grained areas are made to register exactly with the The objects and purpose ofthe invention will more clearly appear from the description which follows, together with the figures of the accompanying drawings, in which Figure 1 is a View in front elevation of a door having a panel made in accordance with the process herein disclosed;
Figure 2 is a view in cross section through the door;
Figure 3 is a perspective view of a continuous sheet of the grained paper used for the surface of the panel;
Figure 4 is a perspective view showing the manner in which the transverse strips are cut from the grained paper;
Figure 5 is a view in elevation showing the effect of superimposing the strips upon the main sheets of grained paper to reproduce the effect of a mitered frame;
Figure 6 is a perspective view of relative positions of the several layers Ofpaper; and Figure 7 is a view in vertlcal section through the lower die plate with the strips of paper attached thereto and the main sheet in position to be applied over the plate.
The door of which the panel 1 of composite material forms the central portion, composes an outer frame made up of stiles 2-2 and rails 3-3 surrounding the panel. These stiles and rails are preferably of wood and are rabbeted about their inner edges to intert with a tongue la formed about the outer edge of the panel. The panel 1 has a rectangular central portion 1b of uniform thickness throughout but relatively thin as compared with the rails and stiles, and an outer marginal portion increasing in thickness from its inner to its outer edge by several steps in the form of a series of flat or beveled surfaces separated by abrupt narrow shoulders.
Moreover, these irregular surfaces meet at each corner of the panel at angles after the manner of a miter joint and for this reason this marginal portion has the appearance of a mitered frame or moulding between the outer frame of the door and the thin central panel. In fact, in an all-wood door the mitered frame or moulding members and the central panel are al1 separate pieces assembled and glued together, and which are replaced by the one-piece panel 1 having a compressed fibrous base.
It may be stated in this connection that the mitered frame or moulding between the outer frame of the door and the thin center panel could be eliminated so far as the structural features are concerned, but such a door would be quite plain and unattractive, and therefore it has become the practice to .enhance the appearance of doors by the addition of the intermediate frame. This. frame may be more or less elaborate as to surface contour, ranging from the. stepped, flat and beveled contour of the present disclosure to plain beveled surfaces, although these are invariably mitered at the corners not only to give the effect vof symmetry but also to take advantage of the contrast in the grainlng. Thus n a door of hardwood with a natural or varnished finish, the grain of the wood in the stiles 2, 2, the vertical members of the mitered frame and the center panel would run lengthwise or vertically of the door while the grain in the rails 3, 3 and cross members of the mitered frame would run transversely.
Hence, in making a composite panel the surfaces are preferably finished to reproduce the same effect as would be found in a wood door, even to the lines of the miter joints which are usually visible.
Having explained that the outer surface finish of the composite panel is obtained by the use of what is termed a bakelized paper, the method of reproducing the desired ornamental effects will now be discussed.
Without going into detail as to the processing of the material of which the panel is made,.it is sufficient to state that the base of the panel is a suitable cellulose fibre, such as would be obtainable from cornstalks, which having been reduced to a pulp, is formed into a mat, dried and eventually compressed in a hydraulic press to its final shape, as well as to a density comparable to that of solid wood. Prior to the final pressing operation, however, the surface of the fibrous mat is coated with varnish and dried, a solution of bakelite varnish being preferably used. Then a layer of kraft paper is laid over the surface of the mat, this kraft paper having been coated with the same varnish. And finally, a layer of thin bakelized paperpainted and colored in imitation of 'the natural wood being reproduced, is laid over the sheets of kraft paper and the assembled materials then compressed between the dies in the press, the opposing faces of the dies having the surface contour of the panel cut or impressed therein. If the surface contour is somewhat elaborate necessitating the bending of the sheets of paper `around numerous sharp angles, a dry molding mixture composed of equal parts of bakelite and wood flour, is spread in a thin coating between the surfaces of the mat and the layers of paper. The assembled materials are heated before the pressure is applied, whereby 'the varnish and the molding mixture are rendered plastic, which allows the sheets to take the contour of the dies without tearing or distortion. So much for the process of manufacture which, of course, may be varied to `,suit the particular working conditions.
Referring now to the treatment of the outer layers of bakelized paper, it may be stated that a thin grade of alpha-cellulose paper is used and in the course of its preparation is printed with an over-all design in imitation of the characteristic graining of a particular kind of wood, such as mahogany, walnut, etc., then colored or dyed to correspond to the color of the wood, and finally subjected to impregnation by a solution of bakelite varnish, which is preferred because of its exceptionally hard and wear-resisting qualities. The paper may also be grained by the use of graining rollers, the simplest method being to grain the paper uniformly so that it runs in the same direction lengthwise of the sheet as in Figure 3. With a quantity of this grained paper on hand, the rst step in preparing an outer layer for one face of the panel is to cut a sheet 5 to the length and width necessary to cover the entire surface, with the grain running lengthwise. Now from the same material, two narrow strips 6 are cut from its side edge portion along lines converging at angles of 45 (Figure 4) the length of these Strips being equal to the width of the main panel sheet 5 and their width being equal to the width of the end areas corresponding to the transverse members of the mitered frame. These strips 6, one at each end, eventually are laid over and register with the main sheet 5, as shown in Figure 5. Ordinarily the paper is rendered more or less tranparent by the bakelite impregnation, and to prevent the graining of the main sheet 5 from showing through the superimposed strip 6, an intermediate strip 7 is preferably placed between the two, as shown in Figure 6. This intermediate strip is a duplicate of the upper grained strip in shape and size, but is preferably cut from a plain sheet of bakelized paper.
The superimposed layers of paper may be temporarily secured together by a suitable adhesive or by means of thin paper stickers, and the assembled panel sheet applied to the face of the mat and the whole placed between the die plates preparatory to the final pressing operation in a hydraulic press, care being taken that the outer sheet register with the impression in the die plates. The ymore satisfactory method, however, is to first apply the strips 6 and 7 directly to the die plate and in register with the end sections of the irregular marginal portions which form the mitered frame of the panel, fastening them in place as by stickers 8, as shown in Figure 7. Then the all-over grained panel sheet 5 is laid over the die plate, and finally the mat with its covering of kraft paper.
Then the panel l has been nally compressed into the form shown in Figures 1 and 2 and fitted into the stiles and rails to form a complete door, the superimposed strips 6 and 7 are embedded flush with the main panel sheet 5, thus giving the same effect as a mitered frame or moulding, with the grain running crosswise at the top and bottom with the grain in the vertical members of the frame, and the central panel extending lengthwise or vertically of the door. Likewise, the diagonal end edges of the strips by virtue of their perfect registration with the die plate coincide with the lines of mitering and further give the appearance of an actual mitered frame or moulding.
There are other ways of obtaining the same results, namely, by producing sheets bearing an impression printed from a plate prepared from the photographic negative of an actual wood panel. This, however, is a rather costly process, unless a large volume of production is anticipated. Again, the sheets may. be prepared with grainmg rollers, using templets to mask off the areas at the ends for the cross graining and then using a narrow graining roll to fill in these end areas. This recess, however, requires special templets an graining rolls, and therefore is not entirely satisfactory.
The advantage of the present process therefore is the simplicity and cheapness of practice, since no special equipment is required otherl than a. supply of grained paper from which the strips are cut for the cross grained areas at the ends of the panel. Moreover, by fastening these strips directly to the face of the die, the chance of mis-registration is practically eliminated.
I claim as my invention:
1. A process of'manufacturing a panel or the like of a composite material having a base of a compressible fibrous material consisting of covering the surface of the base material with a sheet of fibrous material reproducing a natural wood finish with the grain extending in one direction and coated with a resinous substance, superimposing smaller sheets of the same coated fibrous material upon said first-mentioned sheet to cover predetermined areas with the grain extending transversely thereof, and compressing the base material and sheets of fibrous material.
2. A process of manufacturing a panel or the like of a composite material in imitation of a natural wood nel having a .mitered frame, consisting o preparing a mat of a compressible fibrous material, covering the surface of said mat with sheets of a thin fibrous material coated with a resinous substance and reproducing the natural wood l graining, superimposing strips of the same fibrous sheet material upon the first-mentioned sheets to reproduce mitered frame members along opposite edge portions of the panel with the grain extending transversely to that` in the body thereof, and compressing the mat with its covering sheets in the presence of heat.
3. A process of manufacturing a panel or the like of a composite material in imitation of a natural wood panel having a mitered frame consisting of preparing a mat of a compressible fibrous material, covering the surface of said mat with a sheet of relatively heavy paper coated with a resinous substance, superimposing a thin sheet of resin impregnated fibrous material over the papercovered surface of said mat, the same representing a natural grained wood, superimposing strips of the grained sheet material upon the first sheet to reproduce the mitered frame members along opposite margins of the panel with the grain extending lengthwise thereof,
and compressing the assembled materials between die plates having the impressions ofv the panel surfaces.
4. A process of manufacturing a panel or the like of a composite material havin a base of cellulose libre pulp capable of belng compressed between die plates having the impression of the panel surface inthe opposed faces thereof, consisting of preparing a mat for the base of said panel, covering the surfaces of the mat with thin sheets of grained fibrous material impregnated with a resinous substance with the graining running lengthwise thereof, cutting relatively narrow strips with mitered ends from the same grained fibrous material with the grain running lengthwise thereof, attaching said strips to said diel plates and in register with areas thereof corresponding to the marginal frame members, and compressing the base material and the superimposed layers of brous material between said die plates.
Signed at Dubuque, Iowa, this 7th day of December, 1929.
" EMIL C. LOETSCHER.