US2649034A - Pulp wood product and method of manufacturing - Google Patents

Description

Aug. 18, 1953 c. u. GRAMELSPACHER 2,649,034

PULP WOOD PRODUCT AND METHOD OF MANUFACTURING 2 Sheets-Sheet 1 Filed Sept. 17, 1949 mven'ron CLARENCE U. GRAME \LSPACHER ATTORNEYS Aug. 18, 1953 c. u. GRAMELSPACHER 2,649,034

PULP WOOD PRODUCT AND METHOD OF MANUFACTURING Filed Sept. 17, 1949 4 2 Sheets-Sheet 2 D IO \D /ID 3 3 up}; 6 i5 2 J1; I110 "l l 8 3M m INVENTOR CLARENCE U. GRAMELSPACHER ATTORNEYS Patented Aug. 18, 1953 UNITED; STAT as; ore-icev PULP-WOOD mow ANDMEIEHQQQF.

M N ACTURING;

Clarence -U.=Gramelspacher, Jasper, Ind;

Application September 17, 1949, Seria1 No, 11fi,g9 gl 3 Claims.

This invention. relates to a woodproduct veneer sheet'or a wood roduct board and a method for makingthe same.

It ,isgeneraHy recognized that the existence of first-class. logsfor. the manufacture of wood veneer is rapidly decreasing. Such wood species as ,poplar, gum, birch, maple. and others, which are commonly used in the manufacture, of wood veneer, arebecoming difficult to obtain infirstclass .logs thatvcan be-usedin machine-turning of; veneer.

However, there is much second. and third class wood of-the above-mentioned species that is unsatisfactoryfor the manufacture of wood veneer, yet thecharacteristics-of the second and third class logs are the same as those of the first-class logs, bu-t due either to size or slight imperfections in the wood, they cannot be used in making machine-cut .veneer.

Itis therefore anobject of-this invention to provide'a method of making a wood-product.

veneer sheet, and anew product of manufacture of ,a veneer sheet by which second and third class.

hard wood logs, scraps and sawdust as well, as softwoods such as, pine and others, can be incorporated intoa Wood product that simulates, wood veneer, and which can be'used in the manufacture of plyboard. as well as in the manufacture of articles producedin molds.

It is another object of the invention to. provide a WOOd product consisting of sawdust, woodohipswood-chipsandwood pulp bonded together with a binding agent in which a grain'is imparted to the product;

Another object ofthe invention is tar-provide wood product like that set forth in the foregoing objects that can be formed or shaped after its initial? manufacture to alter the form or shape of; the product, for example, die-forming wood product sheets.

It;is still another object of the invention to provide a method of roducing a wood product or-v a Wood product veneer sheet, having characteristics referred to in the foregoing ob'ects.

Further. objects and advantages will become apparent from the drawings and the following.

description.

21' In thedrawings; Figure 1 is a wood product-made in accordance with this invention;

Figure 2 isa-grained woodproduct-madein.

Figured isa, view of a die-formed product made i from the wood product of this invention; I

Eigure '7 illustrates. j diagrammatically a machine for carrying forwa-rda methodoft-produc ing the: products of Figuressl and" 3;

Figure illustrates diagrammatically. a ma? chine i01 carryingforwardaimethod -ofmaking,

the-products,illustrated insEigures 2- and +4.

The manufacture. of high uality-.wood veneer is becoming more difficult each year asaresult of, an increasingsscarcity of; first-classlogfi. that cante sedinmac newu ti adv n Ho ever, thereisa large quantitynflower grade logs,

and. limbs as well; as, scrap, materials of. the.

veneer species, snchaspop lalt, gum,. b irch,, mama. magnoliaretcothat arelsound as farz. as,the ir od, characteris ics a e, c hce hed o ha hew od. haracte stics could he arri d rward, to. W099 heets. made. these heer. pecie n er uit blecondii hs n. his nventloh. he. QW-smfle oss of he neer. species a ,w ll. s. .mb cr p. and. a dust are utilized inthe making of a wood product heeri h t.,can ehser1. h h same a heme chine cut ,veneer, and in fact will have improved hara t cs. hat he WOQd, n er. o s

heth r. it. be. when. h e or a ct o With inerent peci s. .5,. o d hszq q -e d be obtained by the rate at which the wood species absorb color stains, thus giving to the wood product a color variation which enhances its decorative effect.

The wood product of this invention can be made either as a grained or a non-grained product depending upon the particular nature of its manufacture under certain circumstances. The grained product is particularly useful when incorporating the wood product into plywood so as to increase the strength of the plyboard.

Primarily, this invention consists of making a wood product either in veneer sheet form or in formed products of manufacture from sawdust, wood chips and wood pulp that is bonded together by a suitable resin which may be either thermoplastic or thermosetting in character. The use of wood chips in the wood product gives a mottled appearance to the surface of the sheet or wood product made from the materials. If this mottled effect is not desired, the wood chips can be omitted and the product made from sawdust and wood pulp bonded with a resin binder.

Also, depending upon the final use of the wood product, either a thermosetting or a thermoplastic resin can be used in bonding the sawdust wood chips and wood pulp together. If it is desired to die-form sheets of the wood product into articles of manufacture after the sheet has been given its initial manufacture, then it would be desirable to use a thermoplastic resin to bond the materials together in the wood product so that the sheet could be formed under heat and pressure to any desired configuration. On the other hand, if such subsequent forming is not desired, then preferably a thermosetting resin would be used to bond the materials of the wood product together since such thermosetting resins are unaffected by normally encountered temperatures.

In the group of resins satisfactory as thermosetting resins there are the phenolformaldehyde resins, phenolfurfural resins, and others such as ureaformaldehyde which would be satisfactory for use in bonding the materials of the. wood product of this invention. If thermoplastic resins are desired for use, such resins as polystvrene are satisfactory as well as the vinyl chloride acetate resins and the various cellulose resins which can be used according to the heat conditions under which they will finally be used since most of these resins soften in temperature ranges of from about 150 F. to 300 F.

In Figure 1 there is illustrated a wood product board that is composed of sawdust particles 10, wood chips H and wood pulp fibers I2. These materials are bonded together byeither a thermosetting or thermoplastic res-in of a suitable type, depending upon the service to which the board will be placed. The sawdust, wood chips and wood pulp fibers are bonded together under heat and pressure until the bonding resin sets, and cools if the bonding resin is a thermoplastic material. The plyboard product of Figure 1 is one that does not present any grain structure since the wood pulp fibers I2 are interspersed at random throughout the body of the wood product in all directions.

In Figure 3 there is illustrated a wood product veneer sheet [3 that is made like the product illustrated in Figure 1 except that the veneer sheet may be as thin as thus presenting a wood product veneer sheet of a thickness similar to that of machine-cut veneer so that it can be 4 used in the same way and in the same places as machine-cut veneer.

In either of the products of Figures 1 and 3, the Wood chips may be omitted if the mottled effect in the surface of the product is not desired.

In Figure 2 there is illustrated a wood product in the form of a board that is made in the same manner as the product illustrated in Figure l, but the wood pulp fibers l2a are arranged substantially parallel to one another whereby a definite grain is established in the product of Figure 2. This graining of the product can be obtained by correct handling of the wood pulp and of the mixture of sawdust, wood chips and wood pulp during the manufacture of the Wood product, which will be hereinafter described.

In Figure 4 there is illustrated a Wood product veneer sheet [5 that is grained in the same manner as the product of Figure 2, and is made in the same way and incorporates the same materials of sawdust, wood chips and wood pulp bonded with a suitable resin.

In Figure 5 there is illustrated a sheet of plyboard 20 that has the individual plys 2|, 22 and 23 each made from a wood product veneer sheet such as that illustrated in Figure 4. It will be noted, however, that the grained wood product veneer sheet constituting the plys of the plyboard 253 are laid so that the grain of the respective sheets is angular to the grain of adjacent sheets. Thus, by utilizing grained wood product veneer sheets, a plyboard of increased strength can be obtained in much the same manner as that now obtained in the use of machine-cut Wood veneers that are plied in a like manner.

In Figure 6 there is illustrated an article of manufacture in the form of a U-shaped product 25. The U-shaped product of Fig. 6 can be formed from a Wood product plyboard such as that illustrated in Figs. 1 and 2 or from a wood product veneer sheet, such as that illustrated in Figs. 3 and 4,, or from a plyboard such as that illustrated in Fig. 5 when the bonding resin of the wood product is a thermoplastic material. Under these circumstances, the wood product board, or veneer, or plyboard can be heated to a temperature at which the bonding resin again softens to re-form the sheet into the U-shaped product of Fig. 6, whereupon the sheet will be allowed to cool so that the resin will set and the sheet will retain its formed shape.

It has been found that the use of wood pulp fibers in the wood product produces a structure that is superior to a product in which sawdust or wood chips alone are used. The wood pulp fibers, even when incorporated in a wood product in percentages as low as 5 to 10% increase the strength of the wood product. This is believed to be the result of the longer wood pulp fibers projecting across the granules formed by the sawdust or the sawdust and wood chips when used together, and the matting effect produced by the pulpwood fibers throughout the mass of the wood product board or veneer.

The increase in strength of the wood product board or veneer is even more noticeable when the product is grained, as when the mixture is collected on an endless wire belt as in a Fourdrinier type paper-making machine. When the grained wood product veneer is plied, a plyboard is produced which is even more resistant to warping than plyboard produced from machined wood veneer as a result of the lack of continuity of fibers and particles over any substantial length of the veneer.

sheet, and/or to set a thermoplastic resin, if such has been used as a bonding agent. Pressure is also retained on the mix during the cooling to prevent shrinkage of the material, and in fact the cooling chambers 42 and 43 can be set in spaced relationship that is slightly less than the spaced relationship of the steam chambers 40 and 4| if any shrinkage takes place in the material due to the particular materials used in the mix.

In Fig. 8 there is illustrated a machine for performing a method of producing a Wood product veneer that contains a decided grain.

In the machine and method disclosed in Figure 8, wood particles consistin of wood pulp and sawdust or sawdust and wood chips are supplied to the pulp box 50 in which an agitator retains the wood particles and wood fibers in uniform distribution in the percentages in which they were added to the pulp box. Overflow from the pulp box across the feeding ledge 52 causes the mix floated with a water carrier to be delivered upon an endless wire web 53, such as that as can be found in any conventional Fourdrinier type of papermaking machine. The wire web 53 in picking up the overflow from the pulp boX 59 causes the wood pulp fibers to establish a definite grain in the mix which is parallel to the forward direction of movement of the wire web 53. Suitable-deckle straps 54 control the width of the mix as it is applied to the wire Web 53.

A suction box 55 is positioned near the forward end of the web 53 to remove the major portion of the water from the mix. As the mix forms a web, it is picked up by the fabric belt 56 and is carried over the surface of a drying cylinder 69 to dry the wood particles and wood fibers contained in the web 65.

The dried web leaving the drying cylinder 60 may then pass between spray-heads 6 I, that may be positioned on one or both sides of the web 65 to apply a bonding agent to the web of dried wood particles and wood fibers.

The web 65 with the bonding agent added is then carried to between belts 32a and 31a. of a machine like that described in Figure 7 to thereafter compress the web 65 to a desired thickness and cure the resin to bond the wood particles and wood fibers together.

It will thus be seen that the machine and method of making a Wood product veneer as disclosed in Figure 8 will produce a veneer sheet in which there is a decided grain in that a large percentage of the wood pulp fibers will lie relatively parallel with one another.

It will be understood that various modifications of the invention can be made without departing from the basic concept of the invention, and that the modifications that fall within the scope of the appended claims are intended to be included herein.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A rigid wood product veneer sheet consist- 8 ing of a mixture of sawdust, wood chips and at least 5% wood pulp fiber with the wood pulp dispersed in the sheet to establish a grain therein extending in one direction throughout the sheet and bonded together with a synthetic resin.

2. A rigid wood product veneer sheet consisting of Wood chips, sawdust, at least 5% pulpwood fibers and a resin binder, all bonded together under heat and pressure, said wood pulp fibers being dispersed in said sheet in such a manner as to establish a determined grain extending in one direction throughout the sheet by substantially parallel arrangement of the fibers.

3. The method for producing a rigid grained artificial wood veneer sheet that consists of, mixing together wood particles and wood pulp fibers in a liquid vehicle, floating the mixture onto a moving carrier in a manner causing rearrangement of the wood pulp fibers in the mixture into substantially parallel arrangement relative to each other to establish a flexible web grained longitudinally of the direction of movement of the web as deposited on the moving carrier, removing the liquid vehicle from the web and drying the same while flexible, applying a bonding agent to the web after drying thereof, moving the web thereafter in a planar condition while applying pressure to the web to compress the same to a predetermined thickness while wet with the bonding agent, and setting the bonding agent with the web in planar condition while pressure is maintained on the web until the bonding agent is set to retain the predetermined thickness.

CLARENCE U. GRAMELSPACHER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,500,207 Shaw July 8, 1924 1,511,475 Howell et a1 Oct. 14, 1924 1,892,873 Darrah Jan. 3, 1933 1,899,768 Nevin Feb. 28, 1933 1,959,375 Loetscher May 22, 1934 1,969,291 Antoni Aug. 7, 1934 2,066,734 Loetscher Jan. 5, 1937 2,167,440 Mason July 25, 1939 2,381,269 Elmendorf et a1 Aug. 7, 1945 2,480,851 Goss Sept. 6, 1949 2,503,407 Perry Apr. 11, 1950 FOREIGN PATENTS Number Country Date 559,974 Great Britain Mar. 14, 1944 571,786 Great Britain Sept. 10, 1945 OTHER REFERENCES Ser. No. 369,752, Schweizer (A. P. C.) published Apr. 27, 1943.

Continuous Structural Board From Sawdust, Modern Plastics Sept. 1947, pages 89 to 91.

Resins Bond Wood Waste Board, vol. 26, No. 6 Modern Plastics Feb. 1949, pages 59-62.

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