US2562358A - Apparatus for making sheet or web material - Google Patents

Description

y 31, 1951 i w. HUEBNER I f 2,562,358

APPARATUS FOR MAKING SHEET 0R ,WEB MATERIAL Original Filed Feb. 21, 1946 I 3 Sheets-Sheet l HrrunnEYs July 31 1951 w. c. HUEBNER 2,562,358

APPARATUS FOR MAKING SHEET OR was MATERIAL Original Filed Feb. 21, 1946 3 Sheets-Sheet 2 July 31, 1951 w. C. HUEBNEAR r 2,562,358

APPARATUS FOR MAKING SHEET OR WEB MATERIAL Original Filed Feb. 21, 1946 I I5 Sheets-Sheet 5 INVENTOR. WILUHM [1-H UEBNER Patented July 31, 1951 APPARATUS FOR MAKING SHEET OR WEB MATERIAL William C. Huebner, New York, N. Y.

Original application February 21, 1946, Serial No. 649,315. Divided and this application July 7, 1948, Serial No. 37,418. In Canada August 26, 1946 8 Claims. 1

This invention relates to improvements in apparatus for making sheets or webs. The invention contemplates an apparatus for producing sheets or webs similar to paper, cloth, linen, felt, asbestos or other fibrous-like sheets or webs from deposits of compositions in liquid, semi-liquid or mobile liquid particle form and containing electrically chargeable fibrous-like materials and which compositions are then conditioned, dried or set.

The invention also contemplates apparatus for making sheets or webs from cellulose nitrate, cellulose acetate, resins, synthetic resins or other suitable plastic compositions in liquid, semiliquid or mobile liquid particle form and containing electrically chargeable materials by deposits of the compositions and which deposits are then conditioned, dried or set.

The invention further contemplates apparams for producing sheets or webs from any other composition containing electrically chargeable material and which composition can be deposited in liquid, semi-liquid or mobile liquid particle form and then conditioned, dried or set.

The term web as used herein designates a ribbon of the material of substantial length and which can be wound upon a drum while the term sheet as used herein designates a ribbon of the material which is of relatively short length and wherein the separate sheets must be stacked, as distinguished from being able to be continuously wound on a drum.

This application is a division of my copending parent application Serial No. 649,315, filed February 21, 1946, and which parent application is a continuation-in-part of 'my previously filed application Serial No. 533,500, filed May 1, 1944, and now abandoned.

An object of the invention is to provide an improved apparatus for making sheets or webs of the character referred to, rapidly, economically and with controlled uniformity of thickness and texture in accordance with desired characteristics.

Another object of the invention is to provide an improved apparatus for making sheets or webs of the character specified and which apparatus is a unitary structure and can in one continuous operation produce the sheets or webs so that the latter consist either of a single layer of a deposited composition, or of a plurality of laminated layers of the same composition or of different compositions, with the layers being of the same or different thicknesses as desired.

Another object is to provide an apparatus for making sheets or webs and which can be quickly adapted for making sheets or webs of deposited compositions containin electrically chargeable fibrous material or for making sheets or webs of compositions containing electrically chargeable felt material and the like, both of which compositions can be deposited in a thin layer while in liquid, semi-liquid or mobile liquid particle form and then dried orset.

Another object is to provide an apparatus for making sheets or webs and capable of producing the sheets or webs so as to integrate therewith or embed therein simultaneously with their production a reenforcing member or element.- v

Another object is to provide an improved apparatus for forming upon a receiving or reen forcing base material or element a layer or coating of predetermined thickness of a liquid, semiliquid or mobile liquid particle composition containingelectrically chargeable material'and which composition is transferred to and deposited upon the base material or element by the lines of force of an electro field of force and thereafter is conditioned, dried or set. v

Another object is to provide an apparatus for making sheets or webs as specified above and wherein the composition is transferred from a supply source and is deposited on a movable support by the lines of force of an electro field or fields of force created at a predetermined location or locations relative to said movable support.

Another object is to provide an improved apparatus for makin sheets or webs and wherein the composition is deposited on a movable support in such manner as to obtain a uniform and even deposit.

Another and more specific object is to provide an apparatus for making sheets or webs and which includes a movable support upon which the composition is deposited, together with means for varying the rate of movement of said support to obtain different thicknesses or deposits of the composition thereon.

A further object is to provide an apparatus for making sheets or webs such as hereinbefore referred to and wherein in addition to creating an electro field of force to eliect the transfer of the composition from a supply source and the deposit thereof upon a movable support, means is provided for impressing on the composition prior to its transfer and deposit at each transfer .sta-

such polarity as to ionize the electrically chargeable material and facilitate the transfer and deposit of the composition by the lines of force of the electro field of force.

Another object is to provide an apparatus for making sheets or webs as herein referred to in the preceding objects and wherein means is provided for maintaining the composition to be deposited upon the movable support in a liquid, semi-liquid or mobile liquid particle form so that it can be readily transferred and deposited by the electro field of force.

Further and additional objects and advantages not hereinbefore specified will become apparent during the detailed description of embodiments of the invention which are illustrated in the accompanying drawings wherein,

Fig. 1 discloses, partially in front elevation and partially in section, an apparatus embodying the invention and which, in this instance, is shown as comprising three composition deposit stations of such character that the composition can be deposited at only one of the stations or at a plurality of stations as desired, depending upon the character of the sheet or web to be produced, 1. e., if it is to be of a single thickness or of a plurality of layers of the same composition or different compositions.

Fig. 2 is a sectional view taken substantially on line 2-4 of Fig. 1 looking in the direction of the arrows.

Fig. 3 is a view on an enlarged scale of a portion of Fig. 1, i. e., the left hand deposit station of Fig. 1 but showing a different form of movable support upon which the compositionis deposited than the movable support shown in Fig. 1.

Fig. 4 is a fragmentary enlarged view of the belt or movable support of Fig. 3 showing a deposit of a composition containing electrically chargeable fibrous material thereon similar to paper or the like and disclosing the manner in which the suction drums operate to remove moisture from the deposited composition and belt.

Fig. 5 is a view similar to Fig. 4 but illustrates a reenforcing element integrated with the deposited composition, in this instance said element being embedded in the composition.

Fig. 6 is a fragmentary sectional view taken substantially on line l6 of Fig. 3 looking in the direction of the arrows, and

Figs. 7 and 8 are diagrammatic illustrations respectively of the manner in which the composition is deposited on the movable support when the discharge element is stationary and when said element is oscillated transversely of the support.

The apparatus embodying the invention is capable of carrying out a method which employs a novel principle. Inasmuch as there is no adequate term now in use covering this novel principle I have originated a new term therefore and which term is electromigratetics." The term may be defined as follows:

The science of subjecting compositions in liquid. semi-liquid or mobile liquid particle form and containing electrically chargeable material or materials to electric force or forces to ionize said material or materials and cause the migration of said compositions between spaced electrodes under the velocity influence of said electric force or forces and under substantially atmospheric conditions."

The apparatus disclosed in the drawings comprises a base it which is provided adjacent its right hand and and along its longitudinal edges with upstanding side walls II. The upper edges of the side walls II support spaced upwardly extending standards If, there being in the present illustration three pairs of said standards since for purposes of illustration the apparatus will be described as having three composition transfer and deposit stations. However, it will be understood that a difierent number of such stations may be provided as desired.

Each pair of standards i2 supports between its upper end a main or reservoir tank l3 which holds the liquid, semi-liquid or mobile liquid particle composition containing electrically chargeable material and which composition is to be transferred and deposited and formed into a sheet, web, layer or coating. Each tank [3 is provided on its underside with a valved outlet H to which is connected one end of a length of flexible hose l5. Each standard i2 intermediate its top and lower ends is provided with a bayonet slot ii to receive and mount therein trunnions ll formed on the opposite ends of a removable intermediate and smaller supply tank It. The lower end of each flexible hose [5 is connected to the inlet of a supply tank I8, wherefore a regulated amount of the composition can flow from the reservoir ll through the valved outlet l4 thereof, through the hose l5 and into the supply tank [8. The supply tank I8 on its underside is provided with a series of longitudinally spaced vertically extending nozzles 19 while each tank is has its inlet connected to a separate conduit 20 that extends to a regulated source of supply of pressure fluid, wherefore regulated pressure can be created in each tank is to cause a greater or lesser flow of the composition through the nozzles Is. It will be understood that the pressures in the various tanks is may be independently and separately regulated so as to provide for a greater fiow from one of the tanks than from the other. In addition, the composition in one of the tanks may be of a different liquid consistency from the composition in another tank and hence different pressures would be required to produce the desired outward fiows of the two different compositions. A pressure gauge 2| is provided for each supply tank I! so the operator can determine when the desired pressures have been obtained for each of the supply tanks.

Each pair of standards I! supports an inclined plate 22 which extends beneath the row of outlet nozzles I8 and each plate 22 may be provided with suitable means for heating the same as, for instance, an electric heater 23. It will be understood that in some instances the composition will be of such character that it is desirable to heat the same as it fiows along the inclined plate 22 either to maintain the composition in the proper liquid consistency or to facilitate the flow thereof onto a discharge element later to be referred to.

As previously stated, the apparatus embodying the invention effects the transfer of the composition to and the deposit thereof on a movable support by means of the lines of force of an electro field of force. In the present machine there are three units disclosed for creating three separate electro fields of force and each of these units is identical with the others and hence only one need be described in detail.

The standards of each pair of standard I! are provided on their adjacent faces with bossed openings in which an insulator tube 24 is mounted for limited endwise movement, said tube being held against rotation in the openings by pins 2| carried by the tube and located in slots formed in one of the bosses, see Fig. 6.

An angle strip II is secured to'the outer circumi'erence of each tube 24 and said strip is electrically connected by means of one or more connections with an electrical conduit 28 that extends longitudinally within the tube 24 and which is connected to a source of electrical energy as will later be explained. A vertically extending discharge element 29 has its upper end secured and electrically connected to the angle strip 26, while its lower end is, in this instance, in the form of a longitudinal series of comb-like fine pointed teeth 30. The discharge element 29 is spaced slightly from the lower longitudinal edge of the plate 22, wherefore composition on the plate 22 can flow down said plate and onto the discharge element and thence to the comb-like teeth 38 thereof where it will be held by capillary action.

Each unit also includes an attraction element 3| in the form of a blade and vertically aligned with the discharge element 29 with its knife-like upper edge vertically spaced from the lower ends of the pointed teeth 30 of the discharge element. The attraction element 3| is secured to an angle strip 32 similar to the angle strip 26 and attached to the exterior of an insulator tube 33 which is rigidly supported by the walls I I. The angle strip 32 is electrically connected to an electrical conduit 34 extending longitudinally within the tube 33 and connected to the opposite side of the source of electrical energy to which the conduit 28 is connected as will later be explained. A series of electromagnets 35 are mounted on each side of the attraction element 3| and said magnets are provided with field bars 36 shaped to provide sharp edges adjacent to the knife edge of the attraction element 3|. The magnets 35 are connected to a suitable source of electrical energy and when energized will create a magnetic field of force surrounding the electro field of force between the discharge element 29 and attraction element 3| and said magnetic field of force will act as a shield to prevent dispersion of the electro field of force and to concentrate the same within a narrow zone.

The attraction element 3 I, tube 33 and magnets 35 are mounted within a supporting cylinder 31 rotatably supported in and insulated from the side walls I I, with the field bars 36 of the magnets and the knife edge of the attraction element 3| closely adjacent to the inner circumference of the cylinder. Inasmuch as there are three units in the apparatus disclosed three such cylinders 31 are illustrated and such cylinders contact the underside of and support the movable member upon which the composition is deposited to maintain the desired spacing between the member and the discharge element, such member being illustrated as an endless belt. The discharge and attraction elements are of such longitudinal length that they extend substantially the full transverse width of the endless belt or other movable support.

The side walls I adjacent their left hand ends as viewed in Fig. 1 rotatably support a driving roller 38 and an idler roller 39 arranged parallel to each other with the roller 39 spaced vertically above the roller 38. The walls adjacent their right hand ends rotatably support idler rollers 40 and 4| which also are arranged in vertically spaced parallelism and are mounted for adjustment in a horizontal plane. The rollers 38, 39, 40 and 4| are adapted to mount various forms of endless belts later to be referred to and which constitute the movable support for the deposited composition, it being understood that the adjust- 6 ment of the rollers 40 and 4| in the horizontal plane provides the proper tautness to the endless belt.

The roller 38 is driven by a variable speed motor unit 42 which may have a geared reduction embodied therein while the shaft on which said roller 38 is mounted is operatively connected by suitable drive trains indicated generally at 43 and each train includes a clutch and a rotatable cam drum 44 having a cam groove 45 in which travels a follower carried by a rod 46 that is connected to the insulator tube 24. It will be understood that the shaft of the roller 38 is thus operatively connected with each of the insulator tubes 24 and hence when said shaft is rotating and the clutch of each train is engaged, each insulator tube 24 will be given a predetermined limited endwise oscillating movement with a resultant oscillating movement of the discharge element 29. The purpose of this arrangement will be explained later.

As previously stated, the composition is deposited on the movable support which is in the form of an endless belt, the deposit being made either directly on the support or upon a receiving or reenforcing base element traveling over or upon said support.

In Fig. 1 the endless belt is shown as a thin smooth or polished steel or metal belt 41 extending around the rollers 38, 39, 40 and 4| and driven by the roller 38. This form of belt will be employed when the apparatus is producing sheets or webs of film-like composition.

when the apparatus is employed for making sheets or webs from liquid, semi-liquid or mobile liquid particle compositions containing electrically chargeable fibrous or pulp materials a foraminous endless belt is used in place of the steel belt 41 and such foraminous belt is indicated at 48 in Figs. 3, 4 and 5 and consists of a layer of felt or other suitable and similar material interposed between fine screened mesh. It will be understood that the purpose of using such a belt is to allow the moisture to be withdrawn from the composition previously deposited on the belt by the electro field of force between the dischargeand attraction elements so that the fibers of the composition will be felted together when the composition is dried.

The compositions which may be employed in the apparatus are in liquid, semi-liquid or mobile liquid particle form and contain electrically chargeable material in such a proportion that the ionization of said material under electrical influence renders the composition susceptible to migration between the discharge and attraction elements under the velocity influence of the electro field of force and under substantially normal atmospheric conditions. As illustrative of such a composition reference is made to a liquid, semi-liquid or mobile liquid particle composition containing electrically chargeable fibers and wherein the proportion of fibers present in the composition is from sixty to seventy percent while the liquid content of the composition would range from thirty to forty percent. It will be noted that the illustrative composition referred to difiers substantially from ordinary paper pulp as used in the conventional manufacture of paper since such paper pulp contains only ten or less percent of fibrous material and ninety or a greater percent of liquid. The low liquid content of the compositions which it is contemplated using in the apparatus embodying the present invention provides the decided advantage that the deposition of the composition can be quickly dried, conditioned or set, particularly as compared to deposits of ordinary paper pulp.

It is proposed to employ two series of rotatable tubes 49 which are supported by the side walls H and extend transversely of the endless belt with the tubes of one series located intermediate the cylinders 31 and contacting the underside of the upper reach of the belt while the tubes of the other series are positioned to contact the upper side of the lower reach of the belt. Each tube 49 is provided with a plurality of circularly spaced series of longitudinally spaced radially extending ports 50 which are adapted to register as the tubes rotate with longitudinally spaced passages formed in a stationary elongated nozzle 52 that extends longitudinally within the tube as clearly shown in the drawings. The passages 5| in each nozzle 52 communicate with a longitudinally extending bore 53 in the nozzle and said bore 53 is connected to a suitable suction device 53a, wherefore the nozzles and tubes act to withdraw moisture from the belt and particularly from the foraminous belt 48 shown in Figs. 3, 4 and 5 and the composition deposited thereon.

It will be understood that when the metal belt 41 is used as the composition supporting member the suction devices just described need not be operated. A series of air pipes 54 is located beneath the lower reach of the endless belt and said pipes extend transversely of the belt and are provided with a plurality of longitudinally spaced radially projecting outlet nozzles 55. The pipes 54 communicate with a manifold conduit 56 and said manifold conduit 56 is in communication with a suitable source of supply of hot,

warm or cold air under pressure depending upon the type of composition which is being formed into sheets or webs and such air blasts act on the composition on the belt 41 or the belt 48 to condition, dry or set the same as the case may be.

The walls ll just to the left of the roller 58 support a suitable separating device 51 which separates the now conditioned sheet or web from the belt, it being noted that a supporting roller 58 is rotatably carried by the walls ll directly beneath the roller 38 to support the sheet or web as it is separated from the belt.

If sheets are being produced by the apparatus the separated sheets will be carried over a suitable horizontal conveyor and through a drier and thenstacked. However, in the apparatus shown in the drawing a web is illustrated as currently being produced by the apparatus and the separated web W passes through a drier chamber now to be described and is wound upon a drum or reel 59 rotatably supported by suitable standards 60 projecting upwardly from the base l0, it being understood that said reel can be driven in any suitable manner well known in the art and at the proper take-up speed.

The drier chamber through which the web W passes includes side walls Ila extending upwardly from the base II and merging into unwardly projecting standards 8| which rotatably support at their upper ends rollers 82. The walls Ila rotatably support adjacent the base of the standards 6| rollers 63 and the web W is reeved around the rollers 63 and 62 so as to provide a plurality of reaches of the web within the housing 84 of the drier chamber. The walls Ha and the housing 64 support air pipes ll similar to air pipes 54 with the outlet nozzles of said pipes directed to admit blasts of air or other drying medium into the drying chamber and along both sides of the web at each of the reaches thereof. The housing 64 i provided with a stack 66 that communicates with the interior of the housing 64 through the opening 61 to draw away the moisture laden air from the drier. Also, if desired, an air pipe may be so located that the air blasts from the nozzles will engage the upper side of the web intermediate the drive roller 38 and the right hand roller 83 as viewed in Fig. 1.

It will be understood that in place of the air pipes 54 and 65 other suitable drying or conditioning devices might be employed to raise or lower the temperature of the sheets or webs to effect the conditioning, drying or setting thereof to enable the sheets or webs to be handled. It will also be understood that when said sheets or webs are stripped from the belt they will by that time have attained suflicient strength to permit them to be reeved through the drying chamber and wound upon the reel 58 or in the case of sheets to be handled and stacked.

In addition, it will be appreciated that at the start of the operation of producing the web a sufllcient length of the web will first be produced until a short length thereof has been stripped from the belt by the separating element 51 and that such short length can be attached to a suitable lead-in strip which is connected to the reel 59 and is reeved around the rollers of the drying chamber and thus the newly formed web can be reeved around the pulleys of the drying chamber and onto the reel 59.

The left hand upper corner of the walls H as viewed in Figs. 1 and 3 have upwardly extending therefrom supporting arms 68 that rotatably mount at their upper ends a roll 69 of a suitable reenforcing or receiving base material or element as, for instance, open mesh screen or cloth Hi and said screen or cloth extends around a guide roller ll carried by the supporting arms 68 and vertically adjustable by adjusting means indicated at 12. The adjustment of the roller II is for the purpose of providing desired spacing, if any, between the reenforcing or receiving material 1n and the endless belt and said material extends over the upper reach of the endless belt and around the rollers 43 and 4|. The reenforcing or receiving material is utilized when it is desired to have the same integrated or coated with or embedded in the composition containing electrically chargeable material that is deposited on the belt to form a sheet or web including the base material or element and the deposited composition, and this is clearly indicated in Fig. 5. It will be understood that the reenforcing or receiving base material or element can be arranged to lie directly on the belt and to have the composition containing the electrically chargeable material deposited thereon and integrated therewith in the form of a coating or in other instances the reeniorcing material can be spaced from the belt and the composition deposited so as to embed the reenforcing material therein. The adjustment of the pulley ll determines the spacing of the base material or element from the belt at the first deposit station and thereafter the base material is held in proper relationship to the belt by the composition at the first deposit station.

It will be understood that in those instances where the base material or element is employed said material can first be reeved through the drying chamber and onto the reel 59 before commencing to deposit the composition upon the base material and hence the base material will, in

this instance, act as the lead-in for the web.

The left hand discharge element 29, as viewed in Fig. 1, is connected by a lead 13 to the contact 14 of a reversing switch 15. The left hand attraction clement 3| is connected by a lead 16 to the contact 11 of said reversing switch 75 and a suitable adjustable rheostat 18 is included in the lead "5. The contact 14 of the switch .15 is connected to the contact 19 thereof while the contact 1'! is connected to the contact 80. The switch blade 8| is connected to leads 82 and 83 which extend to a source of high potential electrical energy. It will thus be seen that the discharge element 29 and the attraction element 3| can be placed in a high potential circuit and that the polarities of said elements can be selectively changed by means of the reversing switch 15. It will also be seen that the voltage of the high potential current can be regulated by means of the rheostat 18.

It will be understood that a similar and individual arrangement is provided for the sets of discharge and attraction elements of the other two or more stations of the apparatus so that the polarities of said elements can be selectively changed and the voltage of the high potential circuits selectively varied.

An "on and "ofi switch 84 may be located in the main inlet leads 82 and 83 in order to interrupt the high potential circuit to the discharge and attraction elements and thus interrupt the transfer to and the deposit of the composition on the belt. The main on and oil switch can be manually operated or automatically operated at predetermined time intervals and particularly when the apparatus is being employed to produce sheets, it being understood that when the high potential circuit is interrupted no composition will be deposited on the belt and thus the length of the sheets can be controlled.

In order to facilitate the transfer of the composition from the discharge element to the belt or to the base material or element it is proposed to impress on the electrically chargeable material of the composition on the discharge element and to impress on the belt and the base material an electrical precharge of predetermined polarity correlated to the polarities of the discharge and attraction. elements. The precharge impressed on the electrically chargeable material of the composition on the discharge element causes such material to be ionized and renders the composition as a whole susceptible of migration under the velocity influence of the electro field of force between the discharge and attraction elements.

A terminal 85 is located closely adjacent to the discharge element 29 and is connected by a lead 86 to the contact 81 of a reverser switch 88 similar to the reverser switch 15. A terminal 89 is located closely adjacent to the upper surface of the belt in advance of the transfer zone and is connected by a lead 90 to the contact 9| of the reverser switch 88. An adjustable rheostat 92 is located in the lead 90. The contacts 81 and 9| of the reverser switch 98 are connected, respectively, with the contacts 93 and 94 of said switch while the movable switch blade is connected with leads 95 and 96 that extend to a source of high potential electrical energy and in which leads is located a main on and off" switch I80. It will thus be seen that the polarities of the terminals 85 and 89 and the voltages impressed thereon can be selected by the reverser switch 88 and the adjustable rheostat 92 and said polarities and voltages will be correlated to the polarities of the discharge and attraction elements and to the voltages impressed thereon. The terminals 85 and 89 impress precharges on the electrically chargeable material of the composition on the discharge element and on the belt or base material and these precharges ionize the electrically chargeable material and supplement and assist the lines of force of the electro field of force between the discharge and attraction elements to transfer the composition from the discharge element and to deposit the same on the belt or upon the base material.

It will be understood that a similar arrangement is employed for each of the transfer and deposit stations with the understanding that the terminal 89 at those stations beyond the first station will impress a precharge on the composition previously deposited on the belt or base material and also on the belt and base material.

The magnets 35 are connected by leads 9'! and 98 to a suitable source of electrical energy. A main on and off switch 99 is located in the leads 91 and 98 so that the current to the magnets can be interrupted and said switch can be manually operated or automatically operated. It will be understood also that a suitable adjustable rheostat may be arranged in the circiut to the magnets to vary the current to the windings thereof and thus to vary the strength of the magnetic field. v

Assuming that a film-like web is to be produced in the apparatus and that all three deposit stations of the apparatus are to be utilized to i provide the desired thickness in the web the res ervoir tanks |3 will be supplied with a suitable composition in liquid or semi-liquid form and containing electrically chargeable material and the valve means M will be opened until the desired amount of the composition has fiowed into the auxiliary or supply tanks |8, after which the valve means M will be closed and pressure fluid admitted to the conduits 20 to create the desired pressure heads in the tanks "I.

As already stated, the pressure heads established in the tanks l8 are for the purpose of facilitating the fiow of the composition from said tanks through the nozzles l9 and onto the plates 22 and thus the pressure of such pressure heads will vary in accordance with the particular type of composition employed. The composition on the plate-22 flows downwardly of said plates and onto the comb of the discharge elements 29 with the composition being retained on the comb and in the space between the plates 22 and the discharge elements by capillary action. Certain types of composition may require the application of heat to facilitate the flowing of the composition and in such cases the heaters 23 can be utilized.

The operator now causes the motor 42 to function to move the steel belt at the desired speed and adjusts the rheostats I8 and 92 to produce the desired voltages in the circuit to the discharge and attraction elements and in the circuit to the precharging terminals and 89. In addition, the operator positions the reverser switches 15 and 88 to effect the polarities for the discharge and attraction elements and for the terminals 85 and 89 in accordance with the polarities best suited for transferring the particular composition. Likewise, the operator causes air to be supplied to the pipes 54 and, as already stat-ed,

aseasse 11 this air may be cool, warm or hot depending upon the character of the composition.

The electrostatic field of force between the discharge and attraction elements assisted by the ionizing precharges impressed on the electrically chargeable material of the composition on the discharge elements and the precharges on the belt causes the composition to be transferred by electro lines of force from the discharge elements and onto the belt, it being understood that the composition from the discharge element at the first station is deposited directly on the belt while the composition from the discharge elements at the succeeding stations is deposited on the previously deposited composition.

The thickness of the deposits of the composition on the belt can be regulated in three ways. i. e.. by the air pressures in the tanks I! to control the volume of flow of the composition; by the voltages of the electro field of force, and by the speed of travel of the belt.

As the deposited composition moves with the belt to the lower reach thereof said composition becomes dried or set or conditioned by the act-ion of the air blasts from the pipes 54. As soon as the separating device 51 has separated a short length of the deposited and conditioned composition from the belt this length of the composition is quickly attached by the operator to a lead-in which extends from the reel 59 and has been reeved around the rollers in the drying chamber as previously explained. The process then continues and the web as it is formed and preliminarily dried, set or conditioned is separated from the belt by the separating device II and passes through the drier where it is further dried, set or conditioned and is then wound upon the reel I9. During the operation of the apparatus the operator will observe the air gauges II to make sure that the desired air pressures are maintained inthe tanks II.

If the clutches in the drive trains 43 are dis- I engaged the discharge elements 29 will be stationary and the deposits of the composition from the comb teeth of the discharge elements will be straight line deposits, as indicated in Fig. 7, but such deposits are closely spaced and will merge together on the belt. If the clutches in the drive trains 43 are engaged the .discharge elements 29 will be oscillated and the deposits on the belt will be of wavy formation, as indicated in Fig. 8, and will then merge together on the belt.

Assuming that it is desired to produce a web of three difi'erent film-like compositions arranged in three laminated layers, the reservoir tanks I 3 and the respective supply tanks it will be supplied, respectively, with the three different compositions so that the composition from the left hand or first station is deposited directly on the belt, the composition from the intermediate station is deposited on the first deposit of composition while the composition from the third station is deposited on the second deposit of composition. It may be that the three diiferent compositions have different flow characteristics which makes it desirable to have three different pressure heads created in the tanks II and the operator can readily regulate the pressure in the tanks for the desired purpose. It ma also be that the three different compositions will each react to transfer and deposit byelectro fields of force of different voltages or of different polarities and the operator can take care of this situation because of the individual control circuits for each station, whereby the voltages and polarities of the fields of force and of the ionizing percharges can be selectively varied to suit the characteristics of the composition to be deposited. It will be understood that a laminated web with the diiferences above pointed out may be produced in the apparatus in the same way as the web formed of a single composition as above explained.

It will also be understood that in order to concentrate the electrostatic fields of force and to shield the same against dispersion it is preferable to have the magnets 35 energized to create shielding magnetic fields of force when the composition is belng transferred and deposited by the electrostatic fields of force.

The use of the apparatus has been explained above in connection with the making of film-like webs. When it is desired to use the apparatus to make film-like sheets the switch ll can be opened momentarily at predetermined intervals either manually or automatically to interrupt the electro fields of force to momentarily interrupt the transfer and deposit of the composition so as to provide intervals between the successive sheets on the belt 41. As already explained, the sheets thus formed when separated from the belt will be conveyed through a similar drier by a modified form of conveyor.

Assuming that it is desired to produce a fibrouslike web or sheet from a composition in liquid or semi-liquid form and containing electrically chargeable fibers then the metal belt 41 is removed and the belt I of Figs. 3 and 4 is substituted. The composition is introduced into the reservoir tanks II and supply tanks II and the pressure heads for the tanks are regulated to cause the .desired fiow of the composition while the voltages and polarities of the transfer circuits and the precharging circuits also are regulated as required. The composition will then be transferred from the discharge elements 29 onto the belt 48 and the thickness of the deposits can be regulated by regulating the speed of the belt as well as by regulating the pressure heads and the voltages. Inasmuch as the belt 48 is foraminous, being formed of felt interposed between the fine mesh the suction nozzles 82 in the rotatable tubes 49 will act to draw the moisture from the deposited composition to dry said composition and to cause the fibers thereof to become felted together. This drying action is commenced in the upper reach of the belt and is carried on through the lower reach thereof, being facilitated in the latter instance by the air blasts from the pipes 54. Preferably when fibrous-like webs or sheets are being formed the discharge elements 20 will be oscillated to effect the wavy line deposits of Fig. 8, since such wavy deposits of the composition facilitate and strengthen the felting together of the fibers as it tends to cause the same to interlock with each other.

It will be understood that fibrous-like webs or sheets W will be produced similarly to the production of webs or sheets of film as already explained. It will also be understood that laminated fibrous-like webs or sheets can be formed by depositing two or more layers of suitable compositions on the belt similarly to the production of laminated film-like webs or sheets as heretofore described.

It may be desired to produce reenforced filmlike or fibrous-like webs or sheets W. In such case the reenforcing cloth or element II is passed from the rolls 8. over the upper reach of the belt and around the pulleys 40 and ll with the belt and then through the drier to the reel II, the

guide roller 1| being suitably adjusted to rovide the desired space between the reenforci g element and the belt at the first deposit station. The apparatus is then operated in the manner already explained to cause a deposit of a suitable composition to be made On the belt and either on the element 10 or to embed the element I0.

It will be understood that the deposit of the composition occurring at the first deposit station then maintains the reenforcing element in the desired relationship with respect to the belt for the other deposit stations. Thus the reenforcing element will be uniformly embedded or positioned in the webs or sheets produced.

In Fig. the reenforcing element is shown as embedded in a fibrous-like web or sheet W but it will be readily understood that said element can be similarly embedded in a film-like web or sheet.

It will be understood that when reenforced sheets are produced said sheets due to the reenforcing element can be conveyed through the drier as shown in Fig. 1 and wound upon the reel or drum 59 after which the reenforcing element can be severed intermediate the ends of the sheets.

As previously pointed out the composition containing the electrically chargeable material may be deposited on the receiving base material or element in the form of a layer or coating and in such instances the base material or element need not be spaced from the support.

It will also be recalled that a sheet or web of one composition may be deposited or preformed at the first station and then a layer or coating of another or the same composition deposited on the web or sheet at a subsequent station.

The term atmospheric gap as used herein means a gap between the discharge and attraction elements which is subject to the atmospheric conditions and pressures of the room in which the apparatus is located and used, as distinguished from the space between electrodes located in a small confined vacuum chamber or the space between a cathode and an anode located in an electro-chemical bath.

It will be understood that the invention is not to be limited to the specific structural forms herein illustrated but is susceptible of such modifications and adaptations as fall within the scope of the appended claims.

Having thus described my invention, I claim:

1. An apparatus for producing sheets or webs comprising an open top frame having vertically extending spaced side walls, spaced rollers supported by and extending between said side walls, an endless belt extending around said rollers and having a linearly elongated substantially horizontal reach, means carried by said frame for driving one of said rollers to drive said belt, a blade-like discharge element supported by and electrically insulated from said walls and extending transversely of the frame and arranged substantially in a vertical plane above said belt with its lower edge spaced from but adjacent to the upper side of said reach of said belt, an attraction element supported by and electrically insulated from said side walls and extending transversely of said frame and located within the confines of said endless belt and having its uppermost surface spaced from but adjacent to the underside of said reach of said belt and in substantially vertical alignment with the lower edge of said discharge element, a source of high potential electrical energy, means connecting said discharge and attraction elements to the opposite poles, respectively, of said high potential electrical source to produce an electrostatic field of force therebetween and across the gap through which said reach of said belt extends, a container supported by said side walls and adapted to hold a supply of a flowable composi-- tion containing electrically chargeable material, a controlled outlet means carried by said container, and a plate substantially coextensive in length with said discharge element and carried by said side walls and located to receive the com position flowing from said outlet means and inclined downwardly from the horizontal and extending to a position wherein the lower edge of said plate is in predetermined close proximity to one side of said discharge element to provide a flow regulating slot therebetween whereby the composition will flow downwardly of said plate and onto said discharge element and thence through said slot as a film to be held on the discharge element by surface tension until migrated therefrom toward said attraction element by the lines of force of the electrostatic field of force between the elements.

2. An apparatus for producing sheets or webs as defined in claim 1 and wherein means is provided for supporting said discharge element by said walls for oscillating movement transversely of said frame, together with cooperating means carried by said frame and said discharge element for oscillating the latter.

3. An apparatus for producing sheets or webs as defined in claim 1 and wherein means is provided for precharging the composition while held on said discharge element by surface tension to ionize the electrical chargeable material thereof and for precharging said belt, said means including an electrode lo 'ted closely adjacent to said one side of said discharge element and between the lower edge of said plate and said belt and an electrode so located that the upper side of said belt passes closely adjacent thereto prior to passing between said discharge and attraction elements, a second source of electrical energy independent of the first named source, and means electrically connecting said electrodes, respectively, to the opposite poles of said second source.

4. An apparatus for producing sheets or webs as defined in claim 1 and wherein there are electromagnets disposed on opposite sides of and adjacent to the attraction element and which electromagnets are coextensive with the longitudinal length of the attraction element, together with a source of electrical power independent of the first-named source and electrical connections between the second mentioned source and said electromagnets.

5. An apparatus for producing sheets or webs u as defined in claim 1 and wherein there are devices for directing jets of pressure fluid against the outer side of said belt after it has passed between said elements, said devices being supported by said side walls.

6. An apparatus for producing sheets or webs as defined in claim 1 and wherein said side walls are provided with portions mounting a support for a roll of web material, said portions being further provided with means for adjustably mounting a guide roller extending transversely of the frame whereby the web of material can be drawn from said roll and passed around said guide roller and between said discharge and attraction elements in predetermined relation to the upper side of said reach of said belt.

'1. An apparatus for producing sheets or webs as defined in claim 1 and wherein said endless belt is a foraminous belt.

8. An apparatus for producing sheets or webs as defined in claim 7 and wherein suction devices are supported by said side walls and extend transversely of the frame within the confines of said foraminous belt and in close proximity to the latter so as to apply suction to the belt, certain of said devices being located in close proximity to the lower side of said horizontal reach of said belt at a point in the belt's travel after it has passed between said discharge and attraction elements.

WILLIAM C. HUEBNFR.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 16 UNITED STATES PATENTS Name Date Berry May 10, 1927 Collins Feb. 5, 1929 Pugh Apr. 26, 1932 Collins May 30, 1933 Meston Oct. 26. 1937 Formhals Feb. 22, 1938 Burkhardt May 9, 1939 Gladding Aug. 1, 1939 Benner Feb. 27, 1940 Huebner Dec. 10, 1940 Peg'g Aug. 24, 1948 FOREIGN PATENTS Country Date Great Britain 1931

Images