US 3208192 A
Description (OCR text may contain errors)
P 28, 1965 J. E. SCHAEFER 3,208,192
FORMATION OF FIRM FLAT PACKETS OF GRANULAR SUBSTANCE Filed Sept. 6, 1962 2 Sheets-Sheet 1 INVENTOR. E6 5 JEAN E. Samsmz BYaauoviw-p AT TORN EYS.
P 1965 J. E. SCHAEFER 3,208,192
FORMATION OF FIRM FLAT PACKETS OF GRANULAR SUBSTANCE Filed Sept. 6, 1962 2 Sheets-Sheet 2 INVENTOR. JEAN E. SCHAEFER,
BY g WM Fwh/ ATTORNEYS.
United States Patent Oflice 3,208,192 Patented Sept. 28, 1965 3,208,192 FORMATION OF FIRM FLAT PACKETS F GRANULAR SUBSTANCE Jean E. Schaefer, Cincinnati, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio Filed Sept. 6, 1962, Ser. No. 222,768 3 Claims. (CI. 53-30) This application is a continuation-in-part of applicants co-pending application, Serial Number 59,083, filed September 28, 1960, now abandoned.
This invention relates to the packaging of granular materials in film-like substances. It is applicable generally to this field; but it will be described in connection with the formation of packets of granular detergent substances in polyvinyl alchol or other water soluble films to provide packages containing measured quantities of detergent suitable for introduction as such into a washing machine or the like where the films dissolve in the wash water.
The invention will be described in connection with that type of packeting operation in which a first stretchable film strip is led onto a moving member configured to present pockets and intermediate lands. The film strip is caused to adhere to the lands; and vacuum is drawn in the pockets through one or more connections between the bases of the pockets and a vacuum source. The film strip, being in a distortable condition, is drawn into the pockets so as to form pockets in the strip. The strip pockets are then filled with the granular material to be packaged, after which a second film strip in undistorted condition is led onto the moving member and is sealed to the first strip on the lands. The packet composite may be separated into individual packets along lines of severance intermediate the width of the lands. Apparatus and a procedure for accomplishing this type of packaging operation is generally described and claimed in the co-pending application of Virgil E. Gex and Robert L. Kramer entitled Sealing Soluble Film Packets, Serial Number 61,509, filed October 10, 1960 and commonly owned by the assignee of the present application. The cited application has issued as U.S. Patent 3,057,127, dated October 9, 1962. The utility of the present invention, however, is not confined to the specific apparatus and method to which reference has just been made.
In the formation of packets as above described, and in other ways, air is likely to be entrapped with the contents in the packets. The result is that the packets appear not to be full. Moreover, they are not fiat and firmly packed; and it becomes difficult to handle them during the packaging operation when they are assembled in an outer box or carton to provide a unit for sale.
It is an object of this invention to provide packets and a method of making them which avoid these difliculties.
It is an object of the invention to provide packets which are flat, firm and suitable for handling and cartoning with automatic machinery.
In the apparatus and method described in Gex et al. Patent 3,057,127, the fill is usually volumetric. The granular product being filled and packaged may from time to time exhibit variations in density. When this occurs the volumetric fill is varied to compensate for the variations in density. Consequently, some compromise must be made to assure the ability to fill a packet with minimum density product. This means that the amount of air entrapped in the packets is of necessity variable from time to time. It is an object of this invention to provide a means and a method for forming fiat firm packets despite variations in the volume of the fill.
These and other objects of the invention which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications are accomplished by that construction and arrangement of parts of which certain exemplary embodiments will now be described.
FIGURE 1 is a partial sectional view of the moving member above referred to, showing a means by which the invention may be practiced.
FIGURE 2 is a partial plan view of the moving member showing the pockets formed in the first film strip.
FIGURE 3 is again a partial sectional view of the moving member showing another form of means with which the invention may be practiced.
FIGURE 4 is a partial side elevation of a packet forming apparatus showing still another form of means with which the invention may be practiced.
FIGURE 5 is a detailed cross section of the electrodes and the film shown schematically in FIGURE 4.
FIGURE 6 is a schematic diagram of a circuit that can be used in energizing the electrodes illustrated in FIG- URE 5.
FIGURE 7 is a plan view of the first film strip showing the apertures made therein by means of the apparatus and circuit illustrated in FIGURES 4, 5 and 6.
Hitherto various suggestions have been made looking toward the vacuumizing of packets. In following these suggestions the packets are sealed excepting for a narrow passageway. A vacuumizing means is caused to act upon the packets through the passageway, and after the internal air has been withdrawn the passageway is sealed. However, this requires an elaboration of apparatus and process steps, including a double sealing operation and does not always produce a positive effect.
If a sealed packet is formed containing excess air, it is possible to prick the packet as with a pin. This will allow the excess air to escape, particularly if the packet is subjected to compression on its upper and lower sides. But the action occurs too slowly to be of any commercial significance.
On the other hand it is possible to form minute holes in one film strip ahead of the filling station in the packaging operation. If the first film strip is punctured with extremely small apertures by electrical means, it can be drawn down and held in the vacuum pocket of the moving member. Mechanical puncturing is also possible but only after the film is drawn into the vacuum pocket as the mechanical puncturing means give the apertures a ragged edge, thereby causing splitting and tearing when the film is drawn into the vacuum pocket. It the second film strip is punctured, there will be no tendency for excess air to escape from the packets until after their discharge from the machine.
Briefly, in the practice of this invention, it has been found that the first film strip can be punctured either before or after it is drawn down into the pockets of the moving member. This puncturing is done so that the holes in the film lie over the vacuum ports in the moving member. The holes are extremely small so that the film can be drawn into the pockets if punctured beforehand and, also, to permit the film to be held in the pocket by the vacuum acting on its undersurface whether it is punctured before or after being drawn into the pocket. The punctures in the film are made to fall within the area of the vacuum port so that air will be withdrawn from the packet as it is being formed. This also prevents transmission of stress to this area and consequently prevents splitting or tearing of the film material, especially when mechanical puncturing means are employed.
The film pocket may then be filled with the desired contents, and the second film strip lead against it and sealed to it on the lands. A partial vacuum is drawn on the interior of the packet through the puncture opening. This exhausts excess air, and external atmospheric pressure forces the top covering strip inwardly against the granules, compacting them into a mass of greater density.
present within the packet.
The packet thus becomes temporarily a relatively rigid body of uniform shape which is readily handled by automatic machinery even though atmospheric pressure is The exertion of slight pressure on edge portions of the packets relieves this rigidity so that as an incident to the cartoning of the packets they are capable of being slightly reshaped so as to fit better in the receiving structure.
. Needless to say, the size of the puncture in the first film strip will be less than the granule size so as to prevent loss of contents. Otherwise, the size of the opening is not critical. Excellent results have been attained by puncturing means of a diameter of ordinary pins such as are used for holding cloth together.
In FIGURE 1 the numeral 1 indicates a moving member which in this instance may be a drum. The moving member is configured to provide pockets 2 separated by intermediate transverse lands 3. The moving member will also have longitudinal lands 4 and 5; and if pockets are formed abreast in the moving member there will be intermediate lands 6. A first thermoplastic film strip 7 will be led onto the moving member in a distortable or heat softened condition and caused to adhere to the lands as is known in this art. The portions of the film strip between the lands will be drawn down into the pockets of the moving member 1 because of the evacuation of the pockets through one or more vacuum ports indicated at 8, 9, and 10.
A form of puncturing device is illustrated in FIGURE 1 as comprising a spider having arms 11 ending in points or pricking means 12. The spider is mounted on a shaft 13 which is driven in timed sequence with the moving member 1 in such a way that one of the points 12 will puncture the film in a preformed film pocket 14 and in a postion over one of the vacuum ports. The film pocket will be maintained in shape within the corresponding pocket of the moving member 1, the size of the puncture in the film being insufficient to relieve the vacuum. While three vacuum openings or ports have been illustrated for each pocket more or fewer may be provided as desired, and in particular excellent results have been obtained with only one vacuum opening or port per pocket.
In FIGURE 3 where like parts have been given like index numerals, a somewhat modified structure is shown. Here a hollow pricking means 15 is supported by a spider 16 in an annulus 17 threaded or otherwise engaged in the vacuum port 9. The use of the spider prevents the closing off of the vacuum port 9. The location of the parts is such that the pocket 14 will be formed in the lower film strip 7 before the film is punctured by the point 15. The pocket will be maintained by a continuation of the vacuum as aforesaid. When the second film strip 18 is led onto the filled pocket 14 and sealed to it on the lands of the moving member 1, excess air in the packet will be withdrawn through the hollow in the pricking means 15. The atmospheric air pressure will draw the portion 18a of the second strip down tightly against the granular contents of the packet, compacting the film. In FIGURE 3, the portion 18a of the second film strip is shown concaved, a condition which will obtain when the film is somewhat slack. For the sake of clarity in FIGURE 3 the granular contents of the packet have not been illustrated.
The film strip may also be electrically perforated prior to drawing the film into the pocket by means of the apparatus and circuit illustrated in FIGURES 4, 5 and 6. Referring first to FIGURE 4, there is shown a portion of the apparatus which is illustrated in greater detail in the previously cited US. Patent 3,057,127 issued to Virgil E. Gex et al. A portion of the moving member in the form of a drum 1 is journaled in bearings (not shown) on the frame 19 of the machine. The first film strip 7 is withdrawn from a roll 20 journaled in the frame of the machine and is applied to the surface of the moving 4 member 1 by a roller 21. The undersurface of the film 7 may be moistened as at 22 as it is led onto the surface of the moving member 1; and the roller 21 will be heated so as to soften the film and to cause it to adhere to the lands.
FIGURE 4 also illustrates the position of a pair of electrodes 23 and 24 which are mounted on the frame in opposed relation to the film 7 passing therebetween. The details of the electrodes are illustrated in greater detail in FIGURE 5. Each electrode is composed of an insulating member 25 and 26 respectively. The insulating members are each provided with an electrical conducting screw member 27 and 28 made of brass or like material as illustrated. The inner end of each screw member has a tungsten wire electrode 29 and 30 secured thereinto. The screw members are held by the lock nuts 31 and 32 which, in turn, hold the wire terminals 33 and 34 in place. The ends of the electrodes 29 and 30 are approximately in line with the surfaces 35 and 36 so that the film 7 passing between the electrodes, will not catch on the electrodes. An electrode spacing of about .015" has been found generally satisfactory in the perforation of film for the purposes described herein.
The electrodes can be energized by means of the circuit illustrated in FIGURE 6. The circuit is energized by a volt alternating current source. It includes a high voltage continuous duty ignition transformer 37 in which the primary circuit is provided with a micro switch interrupter 38. The secondary circuit has a resistor 39 in series with the electrodes 29 and 30. The interrupter 38 is mechanically actuated in timed sequence with the drum 1 so that groups of spaced perforations 40 (FIGURE 7) are made in the film 7. Most but not necessarily all of the perforations 40 overlies the vacuum openings in each successive pocket. The interrupter pre vents formation of a continuous line of holes in the film 7 which would make it very difficult to maintain the film in the pockets 2 since some of the perforations in the film would be at some distance from the vacuum ports and would provide leakage paths.
The resistor 39 causes an intermittent arc across the electrodes 29 and 30 and consequently the film 7 is provided with a spaced series of aligned holes 40 again as illustrated in FIGURE 7. When the interrupter 38 is closed to energize the circuit, the potential in the secondary circuit is increased sufficiently to cause a momentary are between the electrodes 29 and 30. This causes a hole 40 to be burned through the film 7. The value of the resistance 39 is such that it will impede current flow across the electrodes almost instantly after arcing has begun so that arcing is stopped momentarily until the electrical potential is once again suflicient to form an arc. The result of this circuit operation is the series of side-by-side holes illustrated in FIGURE 7.
One major advantage of the perforations made by electric arcing is that they are heat formed so that no jagged edges remain around the holes. In fact, the edge of each perforation is cauterized by the melted film material. The result is that the film can be drawn into the successive pockets on the drum without splitting and tearing of the film as might occur when the film is punctured mechanically.
Modifications may be made in the invention without departing from the spirit of it. The invention having been described in certain exemplary embodiments, what is claimed as new and desired to be secured by Letters Patent is:
1. A method of packaging granular materials in filmlike substances comprising the steps of deforming a first film into a pocket and maintaining it in said pocket by means of a vacuum opening in said pocket, puncturing the film with at least one pinhole size aperture in an area that will lie over said vacuum opening, said puncture being smaller than said vacuum opening and of such size as to prevent the granular material from sifting therethrough while permitting the maintenance of a sufficient vacuum on the first film to keep it deformed into the pocket, filling the film pocket with granular material, leading a second film over said pocket and sealing its edges to the edges of the first film to form a packet of granular material, drawing a partial vacuum continously on the interior of the packet through the said puncture opening to exhaust excess air from the packet and to permit external atmospheric pressure to force the said second film inwardly against the granules to form a firm, flat and relatively rigid packet in which the granules are compacted into a mass of greater density, removing the finished packet from the said pocket, allowing atmospheric pressure to build up within the packet through said aperture without any substantial change in the firm, fiat and relatively rigid character of the packet.
2. A method of packaging granular materials as claimed in claim 1 including the step of puncturing the first film after it is deformed into the pocket, said puncture being References Cited by the Examiner UNITED STATES PATENTS 1,387,805 8/21 Roberts 53184 X 2,116,995 5/38 Bickford 531l2 X 2,387,812 10/45 Sonneborn et al 53--ll2 X 2,750,719 6/56 Wandelt 53-22 2,888,787 6/57 Cloud 53-l 12 FRANK E. BAILEY, Primary Examiner.
TRAVIS S. MCGEHEE, Examiner.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 208 ,192 September 28 1965 Jean E. Schaefer It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.
Column 4, line 47, for "are" read arc Signed and sealed this 3rd day of May 1966.
ERNEST W. SWIDER Attesting Officer Commissioner of Patents EDWARD J. BRENNER