US2352444A - Method of preparing newsprint paper for use as pencil sheaths - Google Patents

Description

June 27, 1944. K. MILLER Q 2,352,444

METHOD OF PREPARING NEWSPRINT PAPER FOR USE AS PENCIL SHEATHS Filed Jan. 16, 1942 I 4 Sheets-Sheet l 4 Sheets-Sheet 2 K. MILLER Filed Jan. 16, 1942 June 27, 1944.

METHOD OF PREPARING NEWSPRINT PAPER FOR USE AS PENCIL SHEATHS IIIIIIIIIIIIIIIIIIIIIIIIIII June 27, 1944. K, M|LLER' 2,352,444 METHOD OF PREPARING NEWSPRINT PAPER FOR USE'AS PENCIL SHEATHS Filed Jan. 16, 1942 4 Sheets-Sheet 3 40 I T x 5W June 27, 1944. y K. MILLER 2,352,444

' METHOD OF PREPARING NEWSPRINT PAPER FOR USE AS PENCIL SHEATHS Filed Jan. 16, 1942 4 Sheets-Sheet 4 v the cut surface.

the paper and drying it.

Patented June. 27, 1944 METHOD OF PREPARING NEWSPRINT- PAPER FOR USE AS PENCIL SHEATHS Kay Miller, New Brunswick, N. J., .assignor to Joseph Dixon Crucible Company, Jersey City, N. 1., a corporation of New Jersey Application January 16, 1942, Serial No. 426,945 Claims. (on. 93-1) The invention relates to a method of preparing newsprint paper for use as pencil sheaths, and more specifically to a method of heat treating newsprint paper to render it suitable for use as pencilsheaths in coil form. The heat treated paper produced bythe method of the present invention is primarily intended for use as a substitute for the usual wooden pencil sheath.' The heat treated paper is formed into a pencil sheath by being wrapped around the stick of marking material in tight successive convolutionswhich are caused to adhere together by means of a suitable adhesive applied between the convolutions of the coil. The paper to be treated is unaged, that is, fresh, unprinted newsprint, the paper of which commercial newspapers is composed. A pencil sheath composed of untreated commercial newsprint paper cannot be cut by a rotary pencil sharpener or by I a knife blade as easily as pencil wood. -In fact it is only with dlfiiculty that a coil, of untreated newsprint paper can be cut with a sharp blade, and the rotary cutter of the commercial pencil sharpener leaves fibers projecting from Accordingly it is necessary to treat the newsprint paper in such manner that when it is rolled into a pencil sheath it can be readily cuteither with a knife blade or with a rotary cutter.

The usual-type of newsprint paper consists of cellulose and a rather large proportion of Benin,

that is, impurities of various kinds, some of which are volatilized by heat. Since a newsprint paper composed only of cellulose and lignin deteriorates too rapidly, about 10% sulphide pulp is added to it to make it more stable. But even with the addition of sulphide pulp it is the common observation that ordinary newsprint paper ages relatively quickly, that is to say, becomes brownand brittle. I have found that by coiling newsprint paper which has become The newsprint paper may be ,quickly and artiflcially aged to sufllcient brittleness by subjecting the paper to a bath containing an acid or an alkali, but this method requires a further bath to remove the traces of the acid or alkali, and as a result or these successive wettings the paper has a tendency to wrinkle,

I have discovered that newsprint paper can be quickly and expeditiously artificially aged by bringing it to a proper degree of charred condirequiring ironing of application of the heat to the paper must be carefully controlled in order that the degree of charring obtained will cause the cutting qualities of the charred paper toapproximate .the cutting qualities of the so-called cedar wood, usually used for wooden pencil sheaths. At the same time the charring or brittlizing must not be carried to such extent as seriously to impair the tensile strength of the paper.

When the unaged, unprinted newsprint paper is artificially aged to the proper degree of brittleness to render it suitable for use as pencil sheaths in coil form by means of exposing it to air in a closed chamber, I have found that if the air in the chamber is about 200 C. it requires about three minutes to brittlize the paper properly. If the temperature of the air in the chamber is raised to about 345 C. the proper amount of charting or brittlizing of the paper takes place in about .ii of a minute. '.As the temperature of the air in the chamber is gradually raised the length oi time the paper remains in the chamber to be properly charred or brittllzed proportionately decreases. The paper may be placed in the chamber in festoon-like form or it can be passed to thechaznber as a continuous strip. When .the air treatment is used I prefer to have the temperature of the air in the chamber at about 345 C. so that the paper will pass through the chamber in, about .11 of a minute.

The altcrnative method of my invention is to bring each surface of a travelling strip of unaged, unprinted newsprint paper into contact with a heated metal element, the preferable rate of travel-of the strip of paper being about twenty feet per minute in contact with a smooth heating element of about two feet long heated to about 350 C. The rate of travel of the strip of Paper may be increased, but the temperature of the heating element must be proportionately increased, and this can be done up to a point somewhat below that at which the paper will ignite. One form of machine for carrying out the method of treating newsprint paper to render it In length each plate is about 12 inches.

means for moving a strip of paper past the heat ing elements successively while they are in operative position, so that one surface of the strip of paper will contact with one heating element and the other surface of the strip of paper will contact with the other heating element.

The invention is more fully described hereinafter and is particularly pointed out in the appended claims.

In the accompanying drawings illustrating the preferred form of machine in which one phase of the method of the invention may be practiced, Fig. 1 is a front elevation of the machine for heat treating a continuous strip of newsprint paper, showing the heating elements or plates disengaged from the strip of paper; Fig. 2 is a view similar to Fig. 1, but showing the heating ele-' ments or plates in engagement with the strip of paper, some of the parts being shown in section; Fig. 3 is a front end elevation and section of the machine taken on the line 33 of Fig. 2; Fig. 4 is an enlarged vertical section through the roll of treated paper and its supporting members, taken on the line 44 of Fig. 1; Fig. 5 is an enlarged detail section of the detent for holding the strip of paper away from. the upper heating element, taken on the line 5-5 of Fig. 1; Fig. 6 is a section taken on the line 6-6 of Fig. 2, but showing in top plan view the, roll of untreated paper; Fig. 7 is a section through the idler roll at the top of the machine, taken on the'line: 11 of Fig. 1;' Fig. '8 is an enlarged horizontal section through the detent for holding the lower heating element away from the paper, taken on the line 88 of Fig. 2; Fig. 9 is an enlarged vertical section of the right hand end of the roll of treated paper, shown in the act of being removed from its supporting means;.Fig. 10 is a front elevation of .the slotted washer or diskof the supporting means for the roll of treated paper; Fig. 11 is a vertical longitudinal view through a chamber for heat treating the strip of paper by air heated by electrical elements; and Fig. 12 is a view similar to Fig. 11, but in which the heating elements are infra-red lamps.

with the relay 2!. All these heat controllng parts are of conventional construction and mode of operation.

The roll 30 of fresh or unaged, unprinted newsprint paper is provided at its center with a shaft 31 the outer projecting ends of,which are supported on the upper ends of uprights 32 rising from the right hand end of the base it, viewing Figs. 1 and 2. The free end 33 of the roll of paper on a stud d0 secured to and projecting forwardly I machine.

prises two arc-shaped heating elements or plates,

an upper stationary plate l2 and a lower movable plate i3. The heating plates are somewhat wider than the strip of paper to be treated which is a little wider than the usual lead" pencil is long. Because of its high efliciency as a conductor, the heating elements are preferably composed of copper. The stationary plate I2 is supported by the brackets M from the front side of an upright or standard l5 rising from the rear edge of an elongated box-llke base IS. The movable plate I3 is secured by the brackets I3 on the lower end of an arm I! pivoted at 23 on the front side of the upright 15.

Each heating element or plate l2 and I3 is backed by a block of asbestos 2| inwhich are embedded resistant coils 22 connected by wires 24 with a relay 25. The temperature of the upper heating plate l2 (and therefore of the lower heating plate [3) is controlled by means of a thermostat 23 located at the lower end of the upper heating element l2 and supported by a pocket-shaped and I3 is regulated, the control 29 being connected passesupwardly to an idler pulley 34 which turns from the upper end of the upright 15 (see Fig. 7) The strip of paper then passes downwardly between the heating elements to the under side of the roll 35, thence forwardly under the roll 36 and then backwardly and upwardly to the core 31 on which the treated paper is rolled up.

The roll 35 is secured to the shaft 39, the outer ends of which turn in the journal boxes 4! secured to the upper side of the box-like base it of the The shaft 42 to which the roll 36 is secured is similarly iournaled in a front box 43, the rear Journal box not being indicated.

On the forward ends of each shaft 38 and 42 is I .is connected at its right hand end, facing Fig. l,

with a constant speed motor 48, so that the rolls 35 and 36 are driven at a constant rate of speed.

The core 31 on which is wound the coil of treated paper 43 (see Fig. 4), is mounted on a shaft 49, by an arrangement to be. described later, which is supported at. its forward end on an upright 50 rising from the base l6 and at its rear end by means of a disk 52 loosely mounted on the shaft 49. The periphery of the disk 52 bears upon the peripheries of a disk 53 secured to the rear end of the shaft 39 and a disk 54 fixed on the rear end of the shaft 42. It will be,noted that the shaft 39 which supports the core of the coil of treated paper is located half way between the rolls 35 and 3B and that consequently, as the treated part 55 of the strip of paper passes over the roll 36 it embraces substantially one half of it,

thereby assuring that there is no slippage between the strip of treated paper and the periphery of the roll 36 as the strip of treated paper 35 passes from the roll 36 to the periphery of the coil it being built up on the core 31. This arrangement also assures that there is a steady unslipping pull on the part 55 of the strip of paper as it travels between the heating elements and after it leaves them in treated condition.

The shaft 49 is driven by the friction plate 51 which is held against the front side of the plate 32, loosely mounted on the shaft 49, by means of the adjustable spring 58. Since the peripheries of the disks 53 and 54 on which the disk 52 is supported travel faster than the rolls 35 and 36, and the disk 52 has the same peripheral speed, the

tendency is for the core 31 to have the same speed, through the friction plate 51. The result of this arrangement is that the treated paper is wrapped tightly onto the coil 48 on the core 31, the adjustment of the spring 58 assuring the proper .slippage as the coil 48 increases in size.

When a fresh roll 30 of untreated paper is untreated paper may be delivered to the heating elements with even tension a flexible brake. 60 having a weight 6| at its lower end rests upon the roll 30. The brake 60 is secured at its other end of the hook 62 which passes disengageably over a stud 59 projecting forwardly from the upright I5.

The lower movable heating plate I3 is held in its inoperative position, the position shown in Fig. 1. away from the strip of paper by .means of a flexible detent 62 secured to the front side of the upright IS, the free forward end of the detent being provided with a hump 63 the front side of which takes against the projection 64 on the rear side of the arm I9.

in Fig. 2. the hump 63 is received in a recess 65 in the projection 64. To accommodate the lateral movements of the free end of the detent 62 the upright i5 is slotted at 56.

The upper heating plate l2 being stationary, it is necessary to hold the free end of the fresh roll of untreated paper away from its surface when the paper is being adjusted for treatment, and accordingly there is provided a pin BBcarried by the free end of an arm 69 pivoted on the stud 40 on which the idler roll 34 is mounted. On the rear end of the pin 68 is a handle 6'! by which it is manipulated. The arm 69 is held in its raised position. as shown in Fig. 1, by means of the humpll of a flexible detent 12 secured at one\e nd to the front'side of the upright 15. The movements of the free end of the detent 12 are accommodated by the recess 13 in the upright. When the machine is in operation the pin 68 is received in the arcuate slot 14 in the upper end of the upright.

When the complete supply. of untreated newsprint paper in the roll 30 is exhausted and the last end of it has passed by the heating plates l2 and I3 and been wound up on the roll of treated paper 48, the operator shuts down the motor, and then,-before he leads the free end of a fresh roll of untreated paper over the roll 34 and under the rolls 35 and 36 to the core 37, he pulls outwardly on the arm 9 to bring the lower plate l3to the position shown in Fig. 1, and at the same time raises the pin 68. The free end of the fresh roll may now be led .down between the heating plates without touching either of them, and having been'secured to a fresh core 31, the motor is started and simultaneously therewith the pin 68 is lowered into the slot H while the arm [9 is pushed toward the upright IS, with the result that the parts are in the position shown in Fig. 2, with one surface of the strip of paper fully engaging the arcuate upper heating plate l2 and the other surface of the strip of paper fully engaging the arcuate heating plate l3. The machine now continues to run .until the roll of untreated paper passes as a strip past and is properly charred or brittlized for the intended purpose by the heating plates l2 and I3, and is wound into the roll 48 of treated paper ready for immediate use.

' In aging artificially or brittlizing the newsprint paper to put it into such condition that when it is tightly coiled it can serve as a pencil When the lower heating plate [3 is in operative position, as shown paper between and in contact with the heating elements at a fixed rate of speed, say about twenty feet per minute and to yary the degree of heat to which the paper is subjected. This is done through the control 29 governed by the thermostat 23. By maintaining a constant rate of travel of twenty feet per minute, and with each heating element about twelve inches long,

sheath with cutting qualities comparable to those of the usual wood sheath, the degree of brittlizing depends on two factors, the degree of heat employed and the length of time the paper is exposed to the heat. Although the paper can be fed through the machine at controlled speeds, I have found it more satisfactory to feed the I have found that the paper is "suificiently artificially aged or brittlized for the intended pur-- pose by heating the plates l2 and I3 to about 350 C. A substantially greater heat with the given rate of travel results in seriously affecting .the tensile strength of the paper so that it cannot be properly wound around the stick of marking material. without tearing. By substantially I hausted and has been built up on the core 31 as a roll of treated aper, it is then removed from the shaft 49 so that a fresh core 31 may take the place of the one on which the roll of treated paper has just been wound. The means for supporting the core 31 so that the roll of treated paper may be readily removed from the machine comprises a. roller bearing 15 loosely supported in the upper end of the upright 50 and in which the reduced forward end of theshaft 49 is journaled. Each end of the-core 31 is internally beveled, and on the rear end of the shaft 49 is fixed a disk 16 correspondingly beveled. On the forward end of the shaft 49 is a corresponding .disk or washer 'll held against the forward end of the col-e37 by means of a nut I8. The Washer 17 shown in detail in Fig. 10.is provided with a slot '19. of treated paper $8 from the machine, the motor is stopped and the nut 18 is loosened so that the washer H can be slid forward and removed from in the upper end of the standard 56 and the nut 18 tightened up against the forward end of the washer El.

Upon completion of the treating of the roll of paper 30 the lower movable heating plate 93 is swung outwardly from the standard l5 and the pin 68 moved upwardly the parts now being in the condition shown in Fig. 1, so that when a fresh roll of paper 30 is placed on the standards 32 and the free end of the strip of paper passed over the idler pulley 34, then down to the roll 35 the paper will not contact with the hot plates I2 and H. The free end of the new-roll of paper having been passed under the roll 36 and fastened to the-core 31 and the motor started, the pin 68 is ushed down'into the slot- 18 and the arm l9 moved toward the upright l5 so as to bring these parts into the relation with the strip of paper shown in Fig. 2, whereupon the process continues automatically until the whole of the new roll of untreated paper has been treated in the desired manner.

Vapor rising from the vicinity of the hot plates l2 and I3 is carried away through a hood placed over the top of the upright l5.

When it is time to remove the roll lar box-like structure of about three somewhat wider than the strip when the newsprint paper is. chaired or brittilized to the proper degree ifor'us'e as pencil sheaths in coil form by means of hot air, I pass the strip of newsprint paper through either the heated chamber 02 shown in Fig. 11 or the chamber 04 shown in Fig. 12. The chambers are the same in construction, except as to the heating elements, and the strip of newsprint paper is heat treated in both chambers in exactly the same way. Each chamber is a rectangu- 02 and feet in length. The coil of untreatednewsprint paper 86 is mounted on a shaft shaft SI.

00 corresponding v.to the The-free end o the strip of paper passes over an idler 01 and enters'- the chamber through an opening 00 cut in its rear wall 00.-

The treated end SI of the strip 'of paper as it leaves the chamber through the opening 90 passes under the idler roll 02 and under and over the roll 93, corresponding, respectively, to the rolls 3! and 30, and the free end of the strip of paper is wound up on the core 85. The winding oithe treated paper on the core 95 is effected in the same manner in which the treated paper is wound on the core 31, the disks 08, 81 and 00 corresponding to and functioning like the disks 02, 03 and M.

The part I00 of the strip of newsprint paper treated in the chamber 02 passes between two spaced-apart horizontally arranged, flat platelike electrically heatedelements, an upper heating element iii and a lower heating element I02, of paper and almost as long as the chamber. The part ltd oi the strip of paper treated in the chamber 86 passes between two banks of infra-red lamps, an' upper bank indicated at I05 and a lower bank indicated at I00. The heat from the banks of lamps Ills and I00 is directed toward both sides of the strip of paper by the conventional reflectors I01 Gases are conducted from each chamber through an exhaust pipe I00.

Although newspaper has been successfully treated as to charring or brittlizing to render it when coiled tightly comparable in cutting qualities to the usual wood pencil sheath, by heating the air on both sides of the part of the strip in the chamber to only 200 C., that degree of heat would require the paper to remain in the chamber for about three minutes. So. in orderto bring the heated-air treatment of the paper to an efliciency comparabl with the heat treatment of the'paper obtained in the machine illustrated in Figs. 1 to 10. I prefer to heat the air on both sides of the part or the strip of paper in the chamber to about 345 C. By subjecting the paper to heat or this degree; it requires only about .11 of a minute for the paper topass by the heating elements Ni and I02 or I05 and I08 to be properly charred or brittlizedi for use as pencil sheaths.

It will be understood that the figures given above as to the degree of heat to which fresh newsprint paper is subjected and the length'oi time the paper is ,under the heat treatment although substantially correct, being gathered from various readings of commercial instruments, they are empirical, and can be. varied In considerable degree. without departing from the spirit of the invention. The vital thing is that the fresh unprinted newsprint paper must be brittlized to 'a,ssa,444

such extent by artificial aging, that is, by subjecting the paper to the requisite degree of heat for the proper length of time, that when tightly coiled into a pencil sheath it can be cut by a sharp blade slantingly across the convolutions of the coil as readily and cleanly as can the usual cedar" wood now employed for pencil sheaths. The artificial aging or brittlizing can be accomplished by subjecting the paper to relatively low degrees of heat for relatively long periods of time, or preferably to relatively high degrees of heat for relatively short periods of time. Both methods accomplish the same result and both are conceived to be included within the scope of the invention.

Having thus described the invention, what I claim as new is:

l. The method of heat treating newsprint paper to render it suitable for use as pencil sheaths in coil form which consists in exposing a strip of unaged unprinted newsprint paper to air heated to a degree ranging not less than about 200 C. and notgreater than about 345 C. for a period of time ranging between not greater than about three minutes and not less than about .11 of a minute, the degree of heat to which the paper is exposed and the length of exposure being di rectly proportionate.

2. The method of heat treating newsprint paper to render it suitable for use as pencil sheaths, in coil form, which consists in subjecting a strip of unaged, unprinted newsprint paper to heat of from about 345 C. to about 350 C. for about .11 of a minute.

3. The method of preparing newsprint paper for use as pencil sheaths in coil form, which consists in subjecting a strip of unaged, unprinted newsprint paper to a degree of heat and for a length of time adequate to age or brittlize the paper sufficiently so that when it is wound into a tight coil it can be cut by a knife blade or a rotary pencil sharpener substantially as readily and without leaving uncut fibers on the cut surface as can the usual wood pencil sheath, the degree of heat and length of time :being substantially the equivalent of that obtained by causing each surface of the paper to pass at an approximate rate of speed of twenty feet per minute in contact with a smooth heating element heated to approximately 350 C. and approximately twelve inches long.

4. The method of heat treating newsprint paper to render it suitable for use as pencil sheaths in coil form, which consists in causing each surface of unaged unprinted newsprint paper'to be subjected to substantially the amount of heat obtained by passing the paper at an approximate rate of speed of twenty feet per minute in contact with a. smooth heating element heated to approximately 350 C. and approximately twelve inches long.

5. The method of heat treating newsprint paper to render it suitable for use as pencil sheaths in coil form, which consists in causing a sheet- 'of unaged, unprinted newsprint paper to be subjected to substantially the amount of heat obtained by passing the paper at an approxim'ate rate of speed of twenty feet per minute in c'ontact with approximately two feet in length of heating element heated to approximately 350C.

KAY MILLER.

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