US1887691A

US1887691A - Method of veneering

Info

Publication number: US1887691A
Application number: US567748A
Authority: US
Inventors: Emil C Loetscher
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-10-08
Filing date: 1931-10-08
Publication date: 1932-11-15
Anticipated expiration: 1949-11-15

Description

i Patented Nov. 15, 1932 UNITED STATES PATENT caricamm. c. Lomscnna, or nostrana, Iowa muon or vmmname Application nled October 8, 18781. Serial 10.507376.

The object of this invention is to provide an improved method of veneering a base with wood veneer whereb in the finished product the veneer will practically vdent and scratch proof and not subject to disigurement under ordinary conditions of use by burns from matches, cigarettes and the'like laid thereon. y

With the above and other objects in view,

reference will be had to the accom anying drawin diagrammatically illustrating the parts o? one product of the invention juxtaosed for consolidation into a unitary body y a suitable press in the presence of heat.

Referring to the drawing, reference numerals l and 2 designate the lower and upper platens respectively of a press such as is usually employed in producing laminated synthetic resin products. The product itself comprises a base 3 which may be solid wood, compound lumber, laminated paper or any other material. In certain products this base is not employed. Upon the base, two layers 4 of paper treated with phenolic condensation. roduct are applied. A single layer may sudice for certain products while others may require three or more layers. A

metal plate 5 is next applied and may be aluminum, copper, steel or other metal ci high heat conductivity. A layer 6 of paper treated with phenolic condensation product is applied to the metal, and in some instances more than onel of these layers may be employed. Wood veneer layer 7, thoroughly saturated with phenolic condensation product is next applied and this wood veneer is preferably a very thin one of approximately 1/100 in thickness. A sheetl of tissue or vcellophane 8 treated with phenolic conden- 0 sation product is finally applied, though more than one sheet thereof may be used in certain instances, while in others the tissue or cellophane may not be employed.

Wood veneers have been found to be very susceptible to denting and applicant has discovered that this is due to the fact that under present methods of treating the veneer with phenolic condensation product, many, 50 and probably most, of the microscopic cells or tubes of the wood veneer were not completely filled with the synthetic product, ence they collapse under pressure and the surface of the wood veener shows dents. Likewise a sharp ob'ect readily digs into the wood veneer an results in scratches. By impregnating the wood veneer under pressure, virtual y allof the microscc ic cells and tubes thereof are thoroughly ed with phenolic condensation product so that when the latter is reacted the wood of the veneer cannot be compacted or readil penetrated to cause dents or scratches since its cells are completel filled with the hard synthetic product, w ich in addition to filling the cells of the wood su plies a hard. varnishlike surface coating br the wood veneer. These results are not obtainable with wood veneer that has been brush or immersioncoated with the synthetic resin, since in neither of these methods will the synthetic product penetrate much more than the surface portion or cells of the wood veneer.

Pressure impregnation of the wood veneer is accomplished by placing the wood veneer in an air-tight chamber, opening up 75. the cells of the veneer by drawing a vacuum and then flowing the phenolic condensation product into the evacuated chamber without reaking the vacuum. When the chamber is entirely filled with phenolic condensation product, air pressure from 500 to 2,000 pounds per square inch is applied on top of the phenolic condensation product .and this, in producing hydrostatic-v pressure of the same amount on the condensation product, forces the latter into practically all of the cells of the veneer. When such high hydrostatic pressure is used, as 1,000 unds or more per square inch, the vacuum eature may be dispensed with. In either case, when the air pressure is released, the chamber is opened and the veneer taken out. The wood veneer now has a very different appearance than when merely brush coated or immersed in phenolic condensation product. It has become practically transparent showing that the condensation product has thoroughly penetrated and filled the pores and cellular spaces of the veneer. Y 100 Wood veneers, while highly desirable-,for

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table and counter tops and the like, because of the natural beaut of the wood grains, have hadto be aban oned in many cases on account of the same not being able to resist disfigurement from such degrees of heat Ias may bev encountered in ordinary use as from hot dishes, lighted matches, cigarettes or the` like laid thereon.

Applicant has found that pressure impregnation of the woodv veneers, in addition to rendering them dent and scratch proof under ordinary conditions of use, is materially 4an advance step in making them burnproof under ordinary conditions of use. In certain cases, pressure 'impregnation alone answers the purpose, but in others veven that failed to make the wood veneers resistant to disligurement from the effects of certain higher temperatures. Nevertheless, such treatment proved itself to be an advanced step toward perfectionin rendering the wood veneer disigurement proof from the effects of certain high degrees of heat.

Applicant, during the course of experimentation, discovered that if heat is conducted rapidly away from the point of concentra.

tion, the pressure impregnated wood veneer would withstand such high temperatures as may be caused by burning matches, cigarettes and hot food dishes laid thereon, without disfigurement. The metal plate 5 lends itself perfectly to the purpose because of its high heat conductivity though it is within the purview of this invention to substitute any other material, as a backing for the phenolic condensation product pressure impregnatedA wood veneer, that has sufficient heat conductivity as to cause it to disperse, from the point of concentration, heat of a degree that would otherwise injure the wood veneer and damage its surface iinish.

Applicant makes no claim to having produced a -product that cannot be dented by an excessive blow, as one from a hammer, nor does he claim a product that will be disiigured by excessive heat as that from a blow torch. His product will, however,resist finger pres-` sure without denting, ordinary scratches, and disigurement from burning matches, cigarettes and even hot dishes. In other words, products made under applicantsmethod meet all the requirements demanded of furniture,

building trim and the like under ordinary usage.

Applicant has further discovered that phenolic condensation product treated tissue, and cellophane when applied to wood veneer increases the burn-resisting qualities of the product and while the same may be adopted, is not essential to the production of a satisfactory burn proof wood veneered article.

As stated, the base 3 may be dispensed with in products calling for decreased thickness. In eliminating the base 3, a metal plate 5 of increased thickness is adopted,` the plate in the surface of the wool veneer.

ed with phenolic condensation product in any desired manner, the essential being that under the infiuenceof' heat the paper, due to the fusing of the condensation product with which it is impregnated, will become plastic and adjust itself to the irregularities in the metal plate or layers\3 and 7. If the .base 3 is not employed the paper layer or layers 4 on the bottom surface will conform to the contour of the upper face of the press platen 1, or if the base 3 is employed, will conform to that of the upper surfaceof the base. The upper and lower faces of the paper layers 4 and 6 respectively will conform to the lower and l upper faces respectively of the metal plate, and the upper face of the paper layer 6 will conform to the lower face of the wood veneer, permitting the upper veneer to conform to the lower faceof the upper press platenQ. In some cases the paper layer 4 as well as the base 3 may be eliminated.

It will be observed that even though the pressure impregnated wood veneer is itself dent-proof, that if backed by a compressible foundation, a severe blow would in certain instances compress the foundation material producing a dent in the same rather than in the wood veneer itself, but since the latter is axed to the foundation material it would be distorted into the dent made in the foundation material, producing in effect a dent in the wood veneer, though the dent is in the foundation -material rather than in the wood veneer. To overcome this, the metal plate 5 as well as the paper layers 4 and 6,

which become extremely hard ipon the phenolic condensation product therein becoming reacted, provide an armour for the base 3 and prevents the wood veneer from being forced by a' severe blow, `as may ordinarily be encountered, from forcingthe wood veneer into the base 3 and producing in eEect a dentin It will be apparent that the hard backings 4, 5 ,6 if used with wood veneers that'are not pressure impregnated, but treated by brushing with or immersing in synthetic resin, will enable the wood veneer itself yto be more readily dented since the fibres of the latter being confined between the hard backing-and the striking object will readily be compacted and show surface disfgurement whichg would not be the case were all the cells of the wood ien llC

veneer completely filled with the synthetic resin as under applicants method.

In filling the pores or cells of the wood veneer completely with phenolic condensation product by pressure impregnation, the grain of the wood veneer will not rise under certain degrees of heat, and in the case of higher' degrees of heat, the grain of the wood veneer will not be raised if the heat, in excess of what pressure impregnation will cause the veneer to withstand, is rapidly carried away from the point of concentration. Raising of the grain of the wood veneer may probably be due to the evaporation of the volatile oil in the natural resins of the wood under the action of heat.

Applicant lays no claim to the production of a product that cannot be dented with a Sledge hammer blow or disfigured from the effects of a blow torch flame, but he does claim the production of a product that will withstand the abuses of usage to which furniture, doors, building trim are ordinarily subjected, such as impacts, scratching, and the elfects of lighted matches and cigarettes laid thereon.

' Obviously both sides of the base 3 may be built up alike, or if the base 3 is not used, a sheet of wood veneer similar to the one 7 may take its` place with or with,or without the employment of a tissue orl cellophane layer similar to the one 8. ,A Having described the invention, what is claimed as new and useful and desired to be secured by Letters Patent is:

1. The method of making compound lumber having a surface that is dent proof under pressures corresponding to linger nail pressure and proof against burns from heat corresponding to the heat imparted from a lighted cigarette or match when laid thereon, consisting in impregnating the wood veneer in a manner to fill virtually all of the cells thereof with phenolic condensation product, providing for the treated wood veneer a heatdispersing backing, and subjecting the pack to heat and pressure to react the phenolic condensation product.

2. The method of preventing the raising of the grain of wood veneer of compound lumber from the effects of lighted cigarettes or matches laid thereon, consisting in imregnating the wood veneer in a manner to fill virtually all the cells thereof with phenolic condensation product, providing a metal backing for the treated wood veneer, and in subjecting the pack to heat and pressure to react the phenolic condensation product.

3. The method of preventing the raising of the grain of wood veneer of compound lumber from the effects of lighted cigarettes and matches laid thereon, consisting in pressure impregnating the Wood veneer with synthetic resin, and in providing a backing there-