US2081324A - Machine for waxing paper - Google Patents

Description

I May 25, 1937 Original Filed Oct. 12, 1952 L. L. DODGE MACHINE FOR WAXING PAPER 2 Sheets-Sheet 1 May 25, 1937. L. DODGE MACHINE FOR WAXING PAPER Original Filed Oct. 12, 1932 Z-Sheets-Sheet 2 m ,6 Dodye. Q 5%; Q:

Patented May 25, 1937 UNITED STATES MACHINE FOR WAXING PAPER Lloyd L. Dodge, Rhinelander. Wis., assignor to Rhinelander Paper Company, Rhinelander, Wis., a, corporation of Wisconsin Original application October '12, 1932, Serial No. 637,421. Divided and this application March 9,

1935, Serial No. 10,227

.6 Claims. (01. ill-46)- This invention relates to a machine for waxing paper. More particularly the invention relates to an apparatus for preparing waxed paper of increased transparency.

5' This application is a division of my co-pending in order to increase the amount of penetration I of the wax into the paper.

My present invention contemplates a machine 30 for waxing paper, whereby the transparency of the waxedpaper is still further enhanced. In my machine or apparatus, the paper is subjected to a pre-waxing step, wherein the wax is caused to penetrate into and thoroughly impreg- 5 mate the fibers of the paper. This step is followed by a second waxing step carried outin the usual manner.

It is therefore an important object .of this invention to provide a machine for preparing wax n paper of increased transparency.

It is a further important object of this invention to provide a converter apparatus that is simply and efiiciently operated to form waxed sheets of increased transparency and flexibility.

:5 Other objects of this-invention will become apparent from the following description and appended claims. I

This invention (in a preferred form) is illustrated on the drawings and hereinafter more fully l described. l

On the drawings:

I Figure l is a side elevational view of appara- 'tus embodying the principles of myinvention.

Figure 2 is a top'plan view of the apparatus shown in- Figure l.

Figure 3 is an enlarged sectional viewt'aken substantially along the line"III- II I"of Figure 2,

:with parts in elevation. r v Figure '4 is an enlarged broken sectional view taken substantially along the line Ive-IV of Fig-- .ure 3.

figure 5 is an .enlarged broken fragmentary sectional, view taken substantially .along.the line V .-V Of'Figure l' j wi nder shaft 26 is mounted above the bath "compartment i. Adjustable end flanges 3i and As shown on the drawings: I Reference numeral l indicates generally a housing supported on a flooring 2, for enclosing elements of a machine for pre-waxing paper. Said housing I comprises an L-shaped compart- 5 ment 3 having top and side walls and an open bottom and a closed compartment 4. Both compartmen'ts 3 and 4 are'provided with hinged covers such as the covers 5, 6 and 1 respectively. An unwinding stand 8 for supporting a roll of paper 9 is mounted in the open space In defined by the L-shaped compartment 3, so as to be readily accessible at its ends through the opening II]. It should be understood that the unwinding stand 8 is of any conventionalconstruction, and-may 15 be provided with suitable means for tensioning the paper web as it is unwound from the roll 9. A chilled roll or sweat roll H is supported on pedestals l2 in the compartment 3 adjacent the short leg thereof. The roll ll comprises a hollow shell communicating through a hollow trunnion, as at I3, with a source of cold water or brine that is circulated through the shell and out through the other hollow trunnion M. The hollow trunnions I3 and I l are suitably journaled in bearing brackets 15 and I6 respectively supported from the side walls of the compartment 3. A steam spray pipe I! is mounted parallel to and closely adjacent to the periphery of the sweat roll III and is provided with a plurality ofperfo rations l8 (Fig. .4) through which steam may be directed toward the surface of the roll H.

The compartment 6 constitutes a tank having a false bottom It (Fig. 3) and four side walls 20, 2|, 22 and 23. Beneath the false bottom i9 is a space for heating elements such as steam coils M (Fig. 3). The heating coils serve to keep molten the wax .in the bath 25 maintained above the false bottom 59 at asuitable level. A

with ,its ends suitably journaled in bearings 21 and 28 (Fig. 4). Said bearings 21 and 28 are supported on side extensions 29 and 30, respectively; formed on the side walls 20 and 22 of the 32' areheld'in position by means of collars 33 and 34, respectively, at the ends of the roll portionof saidwinder shaft 26 to insure an even winding of the web of paper on the roll porsome. l 1--= As the .web is unwound from the roll 9, it

passes around the sweat roll H and then over a small'idler roller 35, mounted in the compart- -mentili adjacentto and slightly above the upper -edge-of= the-wall '23. In adjustable roller it (Figs. 3, 4 and 5) ismounted at its ends in bearlugs 31 secured to vertically movable racks 38 extending along the side walls 20 and 22 of said compartment 4. Said racks 38 are movable within guideways 39 afflxed to the side walls 20 and 22 and are adapted to be moved up or down by means of pinion gears 40, mounted on a transverse shaft 4|. One end of said shaft 4| extends through the wall 20 (Fig. 4) and is provided with a wheel or handle 42 for manual operation.

In threading the paper through the apparatus, above described, the web of paper 43 is drawn from said roll 9 around the sweat roll II and over the idler roller 35. The roller 36 is adjusted to lie above the surface of the bath 25 to permit the end of "the web 43 to be passed under it and then the roller 36 is lowered into the bath so as to lie completely beneath its surface. The end of the web 43 is then started around the winder roll 26. Any suitable source of power such as the motor 44, belt 45 and pulley 46, may be used to drive the winder shaft 26a on which the roll 26 is mounted (Fig. 2).. The rotation of the" roll 26 in a counter-clockwise direction draws the web 43 through the bath of molten wax. In. operation, the wax in the bath 25 is kept at a temperature sufilciently above its melting point to insure thorough penetration of the wax into the fiber of the web.

No means are provided for removing the excess wax from the web as it passes out of the bath other than the effect of gravity in causing any large excess carried up with the web out of the bath to flow back into the bath. The wax coated web is wound up into a roll on the winder shaft 26 while the wax is still in a molten condition, and because of the fact that the compartment 4 is entirely enclosed, the roll of coated paper on the winder shaft 26 is maintained so long as it remains in said compartment 4 at a temperature above the softening point, and preferably substantially above the melting point of the wax. The purpose of this is to permit the wax to penetrate and thoroughly impregnate the individual fibers of the web 43. To fully accomplish this purpose, the roll of coated paper on the winder shaft 26 is allowed to remain within the heating compartment 4 until substantially complete penetration and impregnation of the wax into the paper has taken place.

After the wound, coated web of paper has remained for a suflicient length of time within the compartment 4, it is removed and immediately subjected to the usual waxing step on any suitable conventional type of waxing apparatus such as is indicated at A in Figures 1 and 2. As there illustrated, the roll 50 of the pre-waxed paper is mounted on an unwinding stand and the coated web 52 is led through a bath of molten wax held in a container 53 where it receives an additional coating of wax. From the container 53 the waxed web is passed between squeeze rolls 54 and 55 and around a plurality of cooled drums 56 to a winder shaft 51. Inasmuch as the apparatus A may be of standard or conventional construction, it is deemed unnecessary to give-any further description of it. Itwillbe understood, of course. that instead of passing the paper through a bath of molten wax, the waxmay be sprayed or otherwise applied to the traveling web 52.

The converter apparatus of this invention provides for a pre -waxing step which gives enhanced transparency to the final waxed sheet because it insures a thorough penetration of the wax into the paper and a full impregnation of the fibers of the paper to give a continuity of the wax substantially free from fissures and cleavages therein. The absence of such fissures and cleavages is believed to be responsible for the increased transparency of the sheet, since the presence of planes of cleavage in the crystalline wax structure would naturally bring about a refraction and diffraction of light passing through the waxed sheet.

The purpose of the sweat roll I i and the steam pipe I! is to increase the moisture content of the web of paper prior to the pre-waxing step. so as to increase the flexibility of the waxed sheet. As paper ordinarily comes from a paper machine, in the manufacture of sulphite or glassine paper, it contains between 4% and 8% moisture. Quite generally the moisture content is nearer the lower limit. Subsequently, as the paper web passes into contact with the chilled surface of the roll II on which moisture from the steam projected through the pipe l1 has condensed, the web of paper picks up additional moisture to bring the moisture content up to between 8% and 15%. Since the parafiine waxes which are generally employed for the waxing of paper have melting points considerably below the boiling point of water (being generally in the neighborhood of between 50 and 60 C.) a considerable amount of moisture that is thus introduced into the sheet-is retained in the paper during and after the waxing operation. The coating of the wax applied to the paper serves to aid the fibers in retaining the moisture and thus keep the fibers pliable and flexible. Cellulose fibers are hydroscopic in character and normally absorb, when exposed to a moist atmosphere, a fairly definite quantity of moisture, in the neighborhood of 10% by weight. On the other hand, if the fibers are dried out excessively on the machine and no moisture is subsequently added, they are relatively brittle, and after being coated with the wax are unable, under ordinary circumstances, to re-acquire a sufiicient moisture content to render them flexible and pliable. The step of moistening the paper as provided by my converter apparatus prior to the pre-waxing step is, therefore, an important feature of my invention.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as follows:

1. A converter apparatus for'conditioning and waxing paper, comprising, in combination, a closed compartment having a cover permitting access to the interior thereof, means at the bottom of said compartment adapted to receive a bath of molten wax, means for maintaining said wax in molten condition and for heating said compartment, a roll wholly within said compartment in spaced relation from the bottom thereof, means for driving said roll, guide tracks mounted on the side walls of said compartment adjacent one end thereof, racks slidable in said tracks, a guide roll rotatably mounted on said racks, means to raise and lower said racks to thereby vertically adjust said guide roll in the compartment, a hood adJacent said compartment, means for creating a moist atmosphere within the hood, and means for mounted on said racks, pinion gears enmeshed with said racks to raise and lower the same thereby adjusting the guide roll vertically in the compartment, a hood adjacent said compartment,

means for guiding a web of paper through said hood, means for mOistening said web of paper as it enters the hood and means for guiding the paper passing through the hood into said compartment. 3. A converter apparatus for conditioning and waxing paper comprising a hood having top and side walls, a chill roll mounted in one end of said hood, means for moistening the periphery of said chill roll, a closed compartment at the other end of said hood, said compartment being adapted to receive a wax bath in the bottom thereof, means for heating said compartment and maintaining the wax bath in a molten condition, a winder roll in said compartment above the wax bath, means for driving said roll, and means for feeding a web of paper through said hood to b'e moistened there in, and into said compartment to be thoroughly impregnated with wax. e

4. A converter apparatus for conditioning and.

waxing paper comprising an elongated tunnellike hood, means for supplying a moist atmosphere within said hood, means for directing a web of paper through said hood, a closed compartment at the other end of said hood, said compartment having a wax bath therein, means for directing the web of paper from said hood into said wax bath, a driven roll above said wax for receiving the web of paper from the bath and means for heating said compartment.

5. A converter apparatus for conditioning and waxing paper comprising a closed compartment for receiving a wax bath therein, means for heating said compartment and maintaining the wax bath in a molten condition, a winder roll in said compartment above the wax bath, means for driving said roll, a vertically'adjustable guide roll in said compartment adjacent one end thereof adapted to be lowered into the wax bath, an L-shaped hood adjacent said compartment having top and side walls, a chill roll in said hood adjacent the short leg thereof, means for moistening the periphery of said roll and a reel stand mounted below the hood for supplying a web of paper for travel over the chill roll through the hood to the heated compartment.

6. A converter apparatus for conditioning and waxing paper comprising a closed compartment for receiving a wax bath therein, means for heating said compartment and maintaining the wax bath in a molten condition, a winder roll in said compartment above the wax bath, means' for driving said roll, a vertically adjustable guide roll in said compartment adjacent one end thereof, said roll adapted to be lowered into the wax bath. an L-shaped hood adjacent said compartment having top and sidewalls, a hollow roll mounted in said hood adjacent the short leg thereof, means for circulating a cooling medium through said roll, a perforated roll extending axially in spaced relation in front of said hollow roll, means for supplying steam through said perforated rol1tomoisten the periphery of said hollow roll and means for feeding a web of paper over said hollow roll and through said tunnel to the heated compartment.

- LLOYD L. DODGE.

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