US1344180A - Defiberizing redwood-bark - Google Patents

Description

U. S. McM|LLAN.Q-

nEHBEmzlNG REDwooD BARK.

Patented J une 22, 1920. l 2 SHEETS-SHEET `2.

wm A M 45 act upon the bark longitudinally of the UNITED i sTATEs PATENT oEFlcE.

UEL S. MQMILLAN, OF SAN FRANCISCO, CALIFORNIA,

DEFIBERIZIN G REDWOOD-BARK.

Specification of Letters Patent. Patented June 22 1920 Application filed November 26, 19.19. SerialiNo. 340,772.

T o ZZ wlw/1L t may concern.'

Be it known that I, Uni. S. MeMiLLAN, a citizen of the United States, residing at San Francisco, in the`county of San F'rancisco `and State of ialifornia, have invented new r and useful Improvements in .Defiberizing Redwood-Bark, of which the following is a specification.

T his invention relates to the defiberizing of the bark of California redwood.y .California redwood orSeguoza Semper-virent is indigenous to the Pacifieslope. This bark is sui generis and is characterized by the presence of long loose fibers in layers alternating with., layers of bast-fiber. The long loose fiber, if properly preserved in defiberization, is admirably suited for paper pulp making, as amply proven by many laboratory tests conducted by the forestry department of the United States Government.

In the present invention, I provide a method and apparatus for defberizing redwood bark in a manner to' remove the fiber without at the same time crushin and 2b grinding it into small particles. n the present form of my invention, this is accomplished by the use of a movable combing i element, preferably in the form of a wire brush which acts uponthe bark longitudi- 30j nally of the grain or fiber.

In the accompanying drawings:

Figure 1 shows a vertical elevation, partly in section, of a suitable form of apparatus for practising my method.

Fig. 2 shows an enlarged or exaggerated -view'in perspective of a'piece of redwood bark, the.. edge or thickness of the bark `appearing at the front of the view.

Fig.' 3 `shows a diagram of a modified element.

Fig. 4 shows t e application of my invention to the bark as'contain'ed on a log, the log being assed beneath the combing eleli element is suitably mounted to show in F ig. 1 a conventional apparatus for performing my method. In a general way this apparatus comprises a combineP element 10, in the form of a rotary wire brus powerdriven at the desired speed, a guide member 11 for feeding the ,bark .to the brush .is

a manner to present the bark so that the brush will act longitudinally of the fiber or grain-of the bark. A receptacle or conveyer 12 1s positioned beneath the brush to catch the defiberized material.

In Fig. 2 I show an enlarged vertical cross section of a kslab of redwood bark wherein A indicates in exaggerated form the layers of bast-fiber, and B the intermediate layers of long loose fiber. The bast-fiber is hard and brittle. Therefore, I may feed the bark to the combing element in such a way that the wire brush will act on the longitudinal edge face of the bark rather than the longitudinal side face, since in so doing the wires of the brush will get in between the bast-fiber layers and tear away the other fibers without breaking upl and crushing the long fiber. I may also feed the bark so that the brush will act on the side face longitudinally of the fibers, as when working on a log. The important requisite is that the brush acts longitudinally of the fibers at all times.` The long fiber will not thereby be ground up or broken into small particles land will thus be better suited for paper pulp USBS- In Figf' I show a modified form of combing elementcomprising an endless belt 13,

on the outer` surface of which are arranged 10 may be mounted on a frame 15, beneath which the log is conveyed by suitable means 16. Thereby the bark is removed from the log and at the same time defiberized. This method of employing my invention saves the expense and labor of stripping the bark from the log.

Heretofore the bark of redwood has been peeled off in the woods or at the mills, inasmuch as the vlogs cannot be successfully sawed with the bark thereon. This is because the stringy fiber of the bark quickly dulls the teeth of the saw and being drawn into the pathway of the saw often causes the saw to spring out of its course. The bark, therefore, is generally pulled from the log by hand means and thereafter burned as waste. Therefore, by my invention I not onl eliminate the expense and labor .of peeling the bark from the logs but convert this bark into a4 valuable by-product.

By the foregoing described'invention, the (leberizing of redwood bark is made comparatively simple and easy Lind the long fiber is not crushed or broken up, and hence it will produce a better andl stronger peper.

IVhile I have shown a carrier 16 for bringing the l'og into position beneath the brush, it will be understood that the brush muy be applied to the log as the' latter passes through a fiume on its way to the mill. The bark need not necessarily be dry, and, in fact, I find that dampened bark is more easy to. lefiberize than dry berk.`

Various changes in the construction und arrangement of the several parts may be employed Without departing from the spirit of my invention as disclosed in the appended elaims.

Having thus described my'invention, what I claim und desire to secure by Letters Pntent is:

l. The process of defiberizing Wood whielf consists in subjecting the solid wood to zt yielding combing action in line with the length of the ibers of the sume.

2. A wood defiberizing machine comprising a hopper having front and rear walls, the rear wall extending below the Jfront tvull and a rotary Wire brush detiberizer, the periphery of which extends into seid hopper below said upper Wall und backwzu'dly udjucent the rear wall above the bottom of said rear Wall.

In testimony whereof I have hereunto set my hand in the presence of two subscribing Witnesses.

UEL S. MCMILLAN. Witnesses WM. HEALEY, M. E. EWING.`I t

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