US1615393A - Method for coating cores - Google Patents

Description

J. S. LITTLE Jan. 25 1 927.

MET HOD FOR COATING CORES Original Filed May 30, 1924 6 Jam 521222? yaw/21m fig,

Patented Jan. 25, 1927.

UNITED STATES PATENT OFFICE.-

Jomi sHInLEY LITTLE, or LA GRANGE, ILLINOIS, ASSIGNOR TO wnsrnmInLEc'rRIo COMPANY, moonronarnn, or new YORK, N. Y., A conronn'non on NEW YORK.

METHOD FOR COATING CORES.

I Application filed May 30, 1924, Serial No. 716.842. Renewed October 20, 1926.

This invention relates to a method for coating cores and more particularly to a method for coating cores with pulpous material.

A feature of the invention is the manner in which the pulpous material is dried upon the cores by subjecting it to air of predetermined temperature and predetermined relative humidity.

The pulpous material is preferably applied to the cores by apparatus of the type disclosed vin the co-pending application of H. G.. lValker, Serial N 0. 569,751, filed June 20, 1922, which apparatus is adapted to subject a core in strand form to liquid containing pulp, the pulp being subsequently treated to form a homogeneous coating for the core.

In practice itis necessary to dry the pulpous material thoroughly after it has been applied to the core. This should be. done so that the pulpous material will be retained upon the core and, where the core is an electrical conductor, so that the core will be properly insulated. a

If the pulpous material is dried by subjecting it to a high temperature which tends to withdraw the surface moisture from the pulp very rapidly and no provision is made to control the relative humidity of the air in contact with the pulpous material, the moisturein the innermost portions "of the pulp coating will not pass readily to the surface of the coating; the thin shell of dry pulpous material which the inner layer of moist pulpous material from the high temperature. The temperature must be kept suflici'ent-ly low sothat'the pulp coating will not be injured or destroyed, but e en if the pulp coating is subjected to a proper temperature and no provision is made to regulate the relative humidity of the air Into which the moisture of the pulp coating is evaporating, it is exceedingly diflicult to produce a uniform article. Under proper conditions the pulpous material may be thoroughlydried upon the core in ajpredetermined period of time. This insures a uniform'product.

The drawing illustrates the' improved method as employed for coating :1 core in strand form. In this instance the core is coated with unfinished paper ofwhich the fabrication is completed while it is on the core. The core is first brought into intimate contact with a liquid containing pulp Wherems P p is formed tends to protectwhich a core in strand form by pulp is applied thereto. The core is then removed from the pulp mixture, a ribbon of pulp adhering to the core as it is withdrawn from the mixture. The free liquid is removed from the pulp adhering to the core and this pulp is then worked or formed into a uniform coating for the core, which coating contains an undesirable amount of moisture. The-coating is then dried in circulating air of predetermined temperature and predetermined relative humidity.

'The objects of the invention will become more apparent as the detailed description progresses, reference being had to the ac companying drawings wherein Fig. 1 is a plan elevation partly in section of a preferred apparatus for performing the method embodying the invention,

Fig. 2 isa side elevation, partly in section of the apparatus shown in Fig. 1,

, Figs. 3 and t are enlarged transverse sections showing the forming of a pulp coat-' ing as it is delivered from the liquid containand certain squeeiingrolls respectively, and,

Figs. 5 and 6 are enlarged transverse sections showing the forming of a pulp coating during the'forming operation and after the completion of the forming operation respectively.

It is believed that a complete understanding of the improved method Will be procured from a description ofthe apparatus by which it may be performed. i

Referring to the drawing, the reference character 10 designates a supply roll from is drawn over an idler roll 11 and thence around a drum 12 which is partly submerged in a liquid containing pulp within a tank 13.

The drum 12 preferably comprises a pair of sides 14 and a peripheral portion 15 interposed between thesides. The portion 15 is provided with a plurality of relatively large perforations .(not shown) which are 1 covered with a strip of fine wire mesh 17. The drum has a tubular -axle 18 which is rotatably mounted in suitable bearings 19 in a framework which supports'the tank 13..

The tank is adapted to hold a quantity of 1 maintained at a level lower than that of the pulp in the tank A continuous circulation 11.9

of the pulp mixture is maintained by suitable means (not shown) which insuresthatpulp in the tank liquid will pass from the 13 into the drum 12 through the wire mesh 17 thus straining pulp onto the surface of the wire mesh and onto the core which is trained around the drum. The apparatus is so arranged that some pulp is first strained onto the wire mesh, before the core is brought into contact therewith. Then when the core contacts the initial layer of pulp on the mesh and the drum continues to revolve in the tank, an additional amount of pulpous material will be deposited on the core and the wire mesh. The core and the pulp deposited thereon are brought into contact with a felt covered roll 24 adapted to remove free liquid, from the pulp adhering to the core and to aid in picking off the pulp from the mesh. A'roll25 co-operates with the roll 24to impart a contour to the pulpous material substantially as shown in vFig. 3. The core and its pulpous material are then drawn between a pair of squeezing rolls 26 which impart a contour to the pulp substantially as shown in Fig. 4 and remove additional moisture from the pulp. The core with its ribbon of pulp is then passed through a forming mechanism 30 which wraps the ribbon around the core as illustrated in Fig. 5 until the pulpous material is worked into a uniform coating conforming to the shape of the core (Fig. 6).

The above described apparatus resembles that shown in the aforementioned co-pending application wherein the apparatus is more fully illustrated and is described. in

detail. The apparatus delivers the core with apulp coating having the required form but the coating retains an undesirable amount of moisture which must be removed therefrom to insure that the coating will remain upon the core and will be of a uniform quality, it beingunderstood that the Wet pulpous material is easily stripped from the core and that it is undesirable to have different portions of the coating vary as to moisture content. It is obvious that if the core is to be employed asan electrical conductor, the coating should be thoroughly dried to prevent failure thereof I as insulation.

In the preferred embodiment of the invention the pulp coating delivered from the forming mechanism 30 is thoroughly dried by being subjected to air of predetermined temperatur and predetermined relative humidity for a predetermined length of time. The core with its coating is led from the forming mechanism 30, through a honilurality of sheaves 33 disposed in the housing 31 lead the coated core through a circuitous path, the length of which is determined by the speed at which the coated core travels and by conditions maintained within the housing. These conditions, the temperature and relative humidity of the air within the housing, are held substantially constant with respect to certain 'predetermined values.

Any suitable air conditioning apparatus may be employed for holding the temperature and the relative humidity of the air within the housing substantially constant. Thus in the drawing, air conditioning apparatus of a well known type is shown an comprises a fan 35 adapted'to establish a circulation of air through the housing. The fan 35 is disposed outside the housing and, when in operation, blows air into the housing byway of a conduit 36 which terminates in a plurality of nozzles 37 within the housing. The fan 35 draws this air from an auxiliary housing 38 which is provided with a conduit'39 communicating with the housin 31, a shutter 40 being provided to control the flow of air from the housing 31 into the conduit 39. The auxiliary housing 38 is also provided with an aperture 42 through which a supply of fresh air is admitted to the auxiliary housing, the flow of air through the aperture shutter 43. The shutters 40 and 43 are preferably connected by suitable mechanism which causes the shutter 40 to open as the shutter 43 is closed and to close as the shutter 43 is opened,- the shutter 43 being manually controlled. The mechanism which connects the shutter 40 with the shutter 43 is indicated at 45.

A hygrostat 46 and a thermostat 47 are positioned in the path of the air'flowing from the housing 31 into the auxiliary housing 38 by way of the conduit 39. The hygrostat 46 controls the relative humidity of the air circulating through the system as it is adapted to control the admission of steam into the auxiliary housing 38 through the medium of a pipe 48 projecting into the auxiliary housing and provided with a plurality of nozzles 49. The pipe 48 is connected to any suitable supply of steam (not shown) and the hygrostat 46 is adapted to control the flow of steam through the pipe, the hygrostat being operatively connected by a well known means (not shown) to a Valve 50 in the pipe.

The thermostat 47 controls th e flow of steam to a plurality of heaters 01. and 52 disposed in the auxiliary housing 38. The

.heaters 51 and 52 are connected to a suitable supply of steam not shown) and the thermostat 47 is operatively connected by a well known means (not shown) to valves 53 disposed in pipes 54. which connect the heaters 51 and 52 with the supply of steam.

The housing 31 is provided with an aperture 56 whereby air may escape from "the system, a plurality of shutters 57 being piv- I housing 31 below the desired value.

otally mounted in the aperture and being adapted to swing open when the pressure within the housing 31 exceeds the atmospheric pressure.

Inthe operation of the apparatus for drying the pulp coating, the shutter 43 is opened to admit fresh air into the system, the shutter being so positioned that 'suflicient air is added continually to the system to keep the relative humidity of the air in the air is continually added to the system, the

pressure in the housing 31 tends to rise above the atmospheric pressure then obtaining and the shutters 57 swing open,

thus allowing air to escape from the housing 31 by way of the aperture 56. The escaping air serves as a medium for removing moisture from the system, it being necemary to provide some means for discharging the moisture evaporated from the pulp coating. It is for this reason that air' is continually added to and discharged from the system. The temperature of air in the housing 31 is held substantially constant by the thermostat 47 which co-operates with the hygrostat 46 to maintain the desired conditions in the system.

In practice, it has been found advantageous to maintain a temperature of approximately 160 within the housing 31, the relative humidity of the air circulating through the housing 31 being maintained at approximately 20%. This allows the ulp coating to become thoroughly dry in a period of substantially four minutes.

What is claimed is:

1. A method ofcoating a core with ulpous material which\ consists in app ying moist ulpous material to the core and in subjecting the pulpous material to a predetermined temperature.

2. A methodot coating a core in strand form with. pulpous material which consists inapplying moist pulpous material to the core while it is in motion and in subjecting the pulpous material to a predetermined temperature.

3. A method of coating a core with pulpous material which consists in applying moist pulpous material to a core and in drying the pulpous material in air-of predetermined relative humidity.

4. A method of coating a core in strand" form with pulpous material which consists .This

in applying moist pulpous material to the core while it is in motion and in drying the pulpous material in air of predetermined relative humidity.

5. A methodof coating a core with pulpous. material which consists in applying moist pulpous material to the core and in drying the pulpous material in air of predetermined temperature and predetermined relative humidity.

6. A method of coating a core in strand form with pulpous material which consists in applying moist pulpous material to the core while it is motion and then drying the pulpous material in air of predetermined temperature and predeterminedrelative humidity.

7. A method of coating a core with pulpous material which consists in applying moist pulpous material to the core and then subjecting the ulpous material for a predetermined perlod of time, to air of pie determined temperature and predetermined relative humidity.

8. A method of coating a core' with pulpous material which consists in applying liquid containing pulpous material to the core, removing free liquid from the pulpous material, and then drying the pulpous material by subjecting it to a predetermined ten'iperature. i

9. A method of coating a core, with pulpous material which consists in applying liquid containing pulpous material to the core, removing free liquid from the pulpous material, and then drying the pulpous material in air of predetermined relative, humidity. p 10. A method of coating a core with pulpous material which consists in subjecting the core to liquid containing pulpousn'iatorial so that said pulpous material adheres to the core, removing free liquid from said pulpous material, and then drying the pulpous material in air ofpredetermined temperature and predetermined relative humidity.

11. A methodof coatin a core in strand form with pulpous material which consists in subjecting the core while it is in motion to liquid containing pulpous material so that said pulpous material adheres to, the core, removing free liquid from the core, and then drying the pulpous material in air of predetermined temperature and predetermined relative humidity.

12. A method of coating a core in strand nae ing the fabrication including the dryin thereof in air of predetermined relative humidity.

14. A method of coating a core in strand form which consists in applying unfinished paper to the core and subsequently completing the fabrication of the paper on the core including the drying thereof in air of predetermined tempe'rature and predetermined relative humidity.

, 15. A method of coating a core with pulpous material which consists in applying moist pulpous material to the core and in subjecting the pulpous material to circulating air of a predetermined temperature.

16. A method of coating a core with pulpous material which consists in applying moist pulpous material to the core and in subjecting the pulpous material to circulating air of a predetermined relative humidity.

17 A method of coating a core with pulpous material 'which consists in applying moist pulpous material to the core and in subjecting the pulpous material to circulating air of (predetermined temperature and predetermined relative humidity. .\'18. A method of coating \a core which consists in applying unfinished paper to the core and 1n completing the fabrication of the paper on the core including dryingthereof in air of a predetermined temperature.

19. A method of coating a core which consists in applying unfinished paper to the core and in completmg'the fabrication of the paper on the core including drying thereof in air of a predetermined relative humidity.

20. A method of coating a core which consists in applying unfinished paper to the core and in completing the fabrication of the paper on the core including drying thereof in air at a predetermined temperature and predetermined relative humidity.

21. A' method of coating a core with ulpous material which consists in app ying of the paper on the core;

moist pulpous material to the core, and in subjecting the pulpous material to air held at a predetermined temperature which is between 140 F. and 180 F.

22. A method of coating a core with pulpous material which consists in applying moist pulpous material to the core, and in subjecting the pulpous material to air held at a predetermined constant temperature above 100 F.

23. A method of coating a core with pulpous -material which consists in applying moist pulpous material to the core, and in subjecting the pulpous material to air having a predetermined relative humidity of not less than 5% nor more than 24:. A method of coating a core with pulpous material which consists in applying moist pulpous material to the core, and in subjecting the pulpous material to air of substantially constant relative humidity of not more than 70%.

25. A method of coating a core with pulpous material which consists in applying moist pulpous material to the core, and in subjecting the pulpous material for from 1 to 8 minutes to air conditioned to have a predetermined characteristic.

26. A method of coating a core With pulpous material which consists in applying moist pulpous material to the core, and in subjecting the pulpous material to air-for more than 1 minute, the air being held at a substantially constant temperature which is more than'90 F.

27. A method of coating a core which consists in applying moist pulpous material to the core, and in subjecting the pulpous material to air of substantially constant relative humidity, the pulpous material being subjected to the air from 1 to 10 minutes.

In witness whereof, I hereunto subscribe my name this 22nd day of May A. D., 1924.

JOHN SHIRLEY LITTLE.

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