US2415625A - Method of making containers - Google Patents

Description

Feb. 11, 1947. g COKER, 30 2,415,625

METHOD OF MAKING CONTAINERS Filed 001;. 15, 1942 2 Sheets-Sheet 1 Feb. 11, 1947. K R, 3

METHOD OF MAKING CONTAINERS Filed Oct. -15, 1942 2 Sheets-Sheet 2 Patented Feb. 11, 1947 2,415,625 Mn'rnon or MAKING CONTAINERS James Lisle Coker, HI, Hartsviile, S. 0., assignor to Sonoco iroducts Company, Hartsville, S. 0., a corporation of South Carolina 1 7 Application October 15, 1942, Serial No. 462,184

7 Claims. 1

The present invention relates to containers and particularly to paper containers designed and intended for use in the packaging, transportation and dispensing of granular or pulverulent material.

Because of its low cost and light weight paper has been heretofore employed to a very considerable extent in the fabrication of boxes, cartons, containers or other envelopes for goods and commodities of various kinds but, for one reason or another, for instance its lack of durability when subjected to the severe impacts incident to handling or its failure, in the average case, to present a finished ornamental appearance, paper has not been so widely employed in the manufacture of containers intended for use in the storage, transportation and distribution to the ultimate consumer of costlier grades-0f granular pulverulent material, such for instance as talcum powder. Manufacturers of such materials have, as a rule, chosen to employ metallic containers of relatively high cost rather than to economize, accept less decorative packages, or run an increased risk of container failure due to rough handling.

It is the purpose of the present invention to provide a paper container well suited for use in the packaging, transportation and dispensing of various commodities, particularly granular or pulverulent materials which, while retaining the full advantages of low cost and light weight which result from the use of paper as a starting material, nevertheless has the attributes of durability or serviceability and attractiveness in appearance which have been heretofore usually obtained in the highese degree only where materials other than paper are employed. The improVed container, as an article of manufacture, is strong and form-retaining to an extent not realized even in containers fabricated of light gauge metal and is so constructed that the shock and wear due to transportation and daily use has no destructive efiect, thus making the container particularly suitable for use in the storage and dispensing of materials which are consumed intermittently in small quantities, or batches, over substantial periods of time, for instance, in the packaging of materials such as talcum powder, minor amounts of which are shaken from the container from time to time as needed.

Essentially the container comprises a tubular body initially formed by convolutely winding a sheet of paper on a conical mandrel. The body thus formed is further shaped so that it ultimately comprises a major portion which is frustoconical and a minor portion which is cylindrical,

end and constituting a cap-receiving material discharge neck. At the small end of the container body, 1. e., at the outer end of the neck just referred to, is secured a perforated closure and the container body at its large end is closed by an imperforate disc or bottom member, the perforated closure at the top or small end and the imperforate bottom member likewise being fabricated of paper. The cap fits rather snugly over the cylindrical neck of the container body so as to be normally frictionally retained in position but is readily removable in order to permit the consumer to effect the discharge of a desired quantity of the contents of the container through. the

perforations of the top closure. Preferably the cap is of paper likewise but in its fabrication other materials may also be employed, a decorative plastic cap being preferred in some instances. In order to protect the paper wall of the container body against the penetration of moisture, which would normally tend to weaken it, this wall may be either coated witlra moisture excluding substance such as enamel paint or the like, or it may be covered with a varnished paper, this paper covering all areas of the outside of the body, including the cylindrical neck, and extending around the upper edge of the neck and around the lower edge of the body, such paper having moisture-excluding properties and constituting a moisture-protective shield for the'body which is particularly serviceable in the event that the body is made of relatively inexpensive and porous paper, which is generally the case. The paper covering thus employed may be decorated prior to application in such manner that the resulting container. presents a most attractive appearance.

A novel method is employed in the fabrication of the container. The frusto-conical paper body is first formed as aforesaid by winding a suitably formed blank upon a conical mandrel, the ends of the tube thus formed being trimmed so that the edge surfaces lie in parallel planes normal to the axis of the container The closure for the small end of the container body is then inserted, this closure preferably comprising-a cup-shaped paper member the central disc of which is provided with perforations and the skirt or attached fiange'being frusto-conical. The end closure just described is preferably inserted into the container body promptly after that body is discharged from the conical mandrel on which it has been formed and trimmed and before the paste or adhesive which is used to secure the several convolutions of the blank together has had opportunity'to dry.

The closure member is so dimensioned that, when the perforated disc portion thereof is flush with the annular edge surface of the small end of the r body, the outer surface of the skirt thereof will be in close engagement with an area of the inner wall surface of the container body at that end, the adhesive remaining on the surface of the container body being sufiicient in amount to cause the end closure to adhere to the body in such position, no additional adhesive being in the average case necessary. Following the positioning of the closure for the small end the label or sheet covering for the outer surface of the body is applied and following this operation the small end of the container body is subjected to the action of a shaping tool, preferably a rapidly rotating die provided with a cylindrical recess into which the small end of the body is forced.

By the action of this tool the shape of the small end of the container body is transformed from conical to cylindrical, the wall being inwardly deflected and circumferentially contracted by the action of the die. While this shaping operation' is proceeding the skirt of the perforated closure member which has previously been placed Within the container body is circumferentially contracted. As a result this closure is firmly gripped and Securely locked in position within the container body, being gripped so firmly that it is no longer essential that the adhesive previously relied upon to retain the closure in this position continue to function, the closure being thus mechanically secured in such manner that it may not become dislodged even when the container is subjected to repeated use, allowed to fall, or experiences severe jarring incident to transportation.

During the operation of forming the cylindrical neck at the small end of the container body, and causing the closure at that end to be-mechanically gripped, the previously applied protective and decorative sheet is also deformed, but is not broken, the'applied sheet being of such character that it will not be ruptured by the action of the shaping die. The edge of the sheet will be turned over the exposed annular end surface of the container body by the die during the neck-shaping operation, this operation thus effecting three objectives at one time, i. e., rendering the small end of the container body cylindrical, contracting the wall of the body to cause it to mechanically grip the end closure, and deflecting and crushing down upon the annular end surface of the body. at its small end a protective sheet which will prevent the entrance of moisture into the body through that surface. By the process thus described an extremely strong neck or small end construction is obtained, the neck remaining integral with and firmly attached to the frustoconical body of the container and it is also clear that the operation of closing and shaping the small end of the body, covering the end surface, and gripping the closure, can be performed with great rapidity and at very slight cost.

The protective sheet also extends beyond the annular endsurface of the container body at the larger end and by any suitable means this projecting edge is deflected inwardly and around this large end, to give it the desired protection against the penetration of moisture. The imperforate disc which comprises the bottom is inserted after the container has been charged with material and is preferably simply snapped into an annular groove previously formed in the inside surface of the container body close to the larg end thereof. This groove I prefer to create by compressing the container wall with the aid of a narrow rolling implement either just after formation of the body and before the adhesive which has been employed has had opportunity to dry or set or later on, after the adhesive has dried. The groove may also be formed by a grinding operation if the container body is quite dry.

The paper employed in the fabrication of the body may be of low grade but adequate body strength nevertheless obtained by winding it into a cone several plies or convolutions in thickness. Despite the thickness of the wall of such a body, however, its weight is slight and the addition of the top and bottom closures and protective and decorative sheet causes but little increase in weight.

In the accompanying drawings a preferred embodiment of the invention is illustrated and this will now be described in detail, together with the novel method of fabrication employed. It will be appreciated by one skilled in the art that the container shown has been set forth by way of example, and that the method of manufacture may likewise be changed somewhat in the fabrication of containers of slightly different types, all without departure from the invention.

In the drawings:

Figure 1 is a side elevation, partly broken away, of a frusto-conical tubular member from which a container body may be fabricated;

Figure 2 shows in perspective, partially broken away, the cup-shaped closure for the small and of the container;

Figure 3 shows in perspective the disc-like bottom closure of the container;

Figure 4 is a plan view of the protective and decorative sheet which is applied to the outer surface of the container body;

Figure 5 is an axial section through a partially completed container, the container body havin been grooved for the reception of the bottom closure and the top or mall end closure having been inserted;

Figure 6 shows in section the container body end closure, as shown in Figure 5, the outer protective and decorative sheet having been p0sitioned;

Figure '7 shows the container of Figure 6, after the lower-edge of the protective sheet has been inturned, a rotating die being diagrammatically illustrated in axial alignment with the container body and in position to act upon the container small end;

Figure 8 shows in section the container of Figure 7 after the completion of the small end shaping operation, the bottom closure disc being shown just below the container;

Figure 9 is a side elevation of the container in its completed form, partially broken away to show the completed bottom construction, and a protective cap being shown in section, upon the cylindrical neck of the container; and

Figure 10 shows in perspective the aligned portions of a two-part cap of suitable type Which may be used to close or seal the container.

The container body, indicated at H) in the drawings, is several plies in thickness, the number of plies 0r convolutions being optional and depending upon the nature of the paper employed and the, resulting wall strength which is to be obtained. The closure II for the small end of the container comprises a central disc-likeportion [lo and a frusto-conical skirt Hb. Preferably, this closure is formed by drawing or pressing a simple paper disc, by known methods, into the form substantially as shown, the perforations H in the disc Ha being, if desired, formed during the drawing or pressing operation. Closure I i is preferably assembled with the body it shortly after the body has been formed and its ends trimmed, and prior to the hardening or setting of the adhesive with which the blank sheet was coated just prior to the winding operation. The assembled body and end closure are shown in Figure 5, the outer surface of the frusto-conical skirt portion Nb of the closure closely engaging the frusto-conical inner surface of the small end of the body Ii], with the annular end surface of the body it and the outer surface of the disclike end lie of the closure lying in a common plane.

The closure is preferably retained in position by the adhesive used in the formation of the body ill but, in the event that that adhesive has been allowed to set or harden before assembly of the end closure a small quantity of additional adhesive may be placed upon the outer surface of the frusto-conical skirt Nb of the end closure prior to its assembly with the body. In Figure there is also illustrated, interiorly of the body Iii and adjacent its larger end, a groove la and this groove may be formed in the wall of the body shortly after the body is discharged from the mandrel upon which it is formed, by a rolling operation which results in the compaction of the fibrous wall of the body beneath the base of the groove. If the container body is allowed to dry before such groove is formed, however, the groove may still be formed in the same manner, i. e., by the application of a narrow rolling tool to the inner wall of the body. Alternatively, the groove 1611 may be formed by a grinding operation, performed after the container body has thoroughly dried.

In the next operation a protective and decorative sheet such as indicated at l2 in Figure 4 is applied to a partially completed container such as shown in Figure 5, this sheet being wrapped about so as to smoothly cover the frusto-conical outer surface of the container body, one margin of the sheet projecting beyond the small end of the container body and the opposite margin of the sheet projecting beyond the large end of the container body IE, as shown in Figure 6. means of any suitable tool that margin of the protective sheet I 2 which extends beyond the large end of the container body is inturned while the adhesive which has been applied to the sheet to cause it to adhere to the container body is still moist, the end of the sheet being tucked into the interior of the body as indicated in Figure '7.

Following this the small end of the body may be shaped and I prefer to employ, in effecting such shaping operation, a rotating die such as that diagrammatically illustrated at I3 in Fig ure '7, the die having a cylindrical recess I300 of a diameter substantially the same as the diameter of the container body at its small end. The container body and die are disposed in coaxial relationship and are relatively revolved about their common axis, the die being preferably rotated, at high angular velocity. Either by moving the die toward the container body, or the container body toward the die, or by moving both simultaneously toward each other, the small end of the container is caused to enter the recess In of the rotating die and the action of the die upon the wall of the container body is conform to the shape of the recess in the die, the small end eventually becoming truly cylindrical as shown in Figure 8, the upwardly projecting margin of the covering protective sheet l2 being inwardly and downwardly deflected upon the annular end surface of the body id as the end of the body reaches the bottom of the recess 13a of the rotating die, and the frusto-conical skirt portion I lb of the closure i I being inwardly contracted or compressed during the same operation. The covering and protective sheet !2 is of relatively high quality paper which preferably has been subjected to a coating of lacquer or varnish after having been printed and does not break under the action of the die i3, being somewhat distorted by the action of the die but preserving its continuity.

At the base of the cylindrical neck thus formed there will naturally result a substantial shoulder, as indicated at S in Figure 8, the several plies or convolutions of the paper of the body here curving reversely and rather sharply, likewise the covering sheet l2, but both body and sheet being, as aforesaid, unbroken, and the junction between the cylindrical neck thus formed and the remaining frusto-conical portion of the body It being entirely stiff or rigid and amply strong despite the shaping or deformation to which the paper has been subjected in this zone. Preferably, the shaping operation is carried out prior to the drying or setting of the adhesive used in the fabrication of the conical body and prior to the setting of the adhesive employed in attaching the sheet l2 to the conical body if additional adhesive is necessary. The small end of the container body is more easily shaped while the fibers of the paper of which it is composed are slightly moist, and the operation is not so drastic that straightening of the distorted fibers will cause the neck to resume its original shape after the operation has been concluded. The shaping operation may be performed after the container body and the applied protective sheet have dried, with satisfactory results, but it is preferred to effect the shaping while the container is somewhat moist.

The container shown in Figure 8 is completed save for the application of a cap and the insertion of the bottom closure, which is indicated at G5 in Figures 8 and 3. Bottom closure i5 is not inserted until the container has been charged with the material to be dispensed, charging being effected by insertion of the powder or pulverulent material while the container body is inverted, larger end open and uppermost, a seal being preferably placed under the disc-like end surface Ha. of the small end closure ii to prevent escape of material through the perforations 8 lo during charging. Following the charging operation, the paper or cardboard disc 55 is pressed into position by a force applied centrally, the disc being flexible so that it may be readily forced into the position in which it is shown in Figure 9, with its edge within the annular groove ifia, straightening of the disc after removal of the applying force resulting in its edge deeply entering into the groove iila, the bottom being thus firmly secured in position.

A previously stated a protective cap of any suitable type may be employed. That shown in Figure 10 may advantageously be used, this cap comprising a tube i6 which may be fabricated by convolutely winding 9. paper blank into tubular form and inturning one end (from the position 7 which is indicated in dotted lines in Figure 10 to the position in which it is shown in full lines in that-figure). A closure disc '17 may then be thrust into the tubular member 1 9 until it contacts with the annular edge of the inturned portion of the tube 16 and a suitable adhesive employed, if thought necessary, to firmly retain the disc I! in this position, as shown clearly in Figure 9. Disc 11, therefore, comprises a closure disc and the tube it comprises a means for frictionally holding this closure disc in position upon the container body. The protective cap is held frictionally in the position in which it is shown but may be readily removed and readily replaced from time to time in order 'to permit unsealin'g and rescaling of the container.

Under some circumstances it may be desired to omit the use of the protective sheet 12; When this sheet is not to be employed the sequence of operations performed are exactly as before, the end closures being applied and the small end of the container body shaped in the manner previously described. The container body 19, however, is coated with enamel paint or lacquer to protect it against the penetration of moisture and to improve its appearance. In the average case, however, a protective sheet such as 12 will be applied in the manner previously described.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. The method of fabricating a rigid self-supporting paper container which comprises forming a frusto-conical open-ended tubular body, attaching to the inner surface of said body, at the small end thereof, a closure for that end, and thereafter shaping said small end and imparting a permanently altered form thereto by applying external forces, the outer surface thereof being rendered substantially cylindrical by such action as to be adapted to serve as a seating surface for a cap or closure which has a cylindrical inner surface.

2. The method of fabricating a rigid self-supporting paper container which comprises forming a frusto-conical open-ended tubular body, closing the small end of the body by attaching an end closure to said body at that end, and thereafter permanently deforming saidsmall end to form a cap or closure-receiving portion with a substantially cylindrical cap receiving portion.

3. The method of fabricating a rigid self-supporting paper container which comprises forming a i'rusto-conical open-ended tubular body, at-

taching to the inner surface of said body, at

the small end thereof, a closure for that end, and thereafter rendering the exterior surface of the small end of the body permanently cylindrical by means of an externally applied tool, the closure being compressed and more tightly engaged by the wall of the body when the small end of the body is rendered cylindrical in shape.

4. The method of fabricating a rigid self-supporting paper container which comprises forming a frusto-conical open-ended tubular body, inserting into the interior of said body a closure for the small end thereof, securing the closure in position by attaching it to the inner face of the body by means of an adhesive, and simul- 8 taneously permanently shaping the small end of the body for cooperation with a cap and compressing the said closure and causing the same to be firmly gripped by the small end of the body by means of a die.

5. Thefmethod of fabricating a rigid, self-supporting container which comprises forming from a paper blank a multi-ply open-ended frustoconical body portion, applying to the outer surface thereof a relatively tough smooth surfaced paper label with the margin of the label projecting slightly beyond the small end of the body, and simultaneously rendering said small end permanently cylindrical exteriorly, and inturning the projecting margin of the label, by pressing said small end axially into a rotating die.

6. The method of fabricating a paper container which comprises applying adhesive to a suitable paper blank, convolutely winding the blank on a mandrel to form an open-ended frusto-conical tubular body, and thereafter imparting to the smaller end of said body a substantially cylindrical shape by pressing against the outer surface thereof, the smooth surface or a tool rapidly rotating about the axis of said body, the fibers of such end being thereby inwardly displaced and permanently distorted, and a smooth substantially cylindrical outwardly facing cap-receiving surface created.

7. The method of fabricating a paper container which comprises forming a frusto-conical openended container blank by convolutely winding onto a mandrel an adhesive coated sheet and thereafter imparting to the smaller end of said body a substantially cylindrical shape by advancing the blank, small end foremost and while the adhesive is still moist, axially of and into a cylindrical recess formed in a die, and rapidly rotating the die about the axis of said recess as the blank enters the same whereby the paper fibers at the small end of the blanl: are progressively inwardly displaced and permanently distorted,

and a smooth outwardly facing permanent capreceiving surface created.

JANES LIDE COKER, III.

REFERENCES CITED 0 The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 940,310 Greenfield Nov. 10, 1909 1,161,795 Starr Nov. 23, 1915 1,346,827 Jennings -July 20, 1920 2,125,415 Baker Aug. 2, 1938 2,207,003 Dunlap July 9, 1940 2,104,344 Heymann Jan. 4, 1938 1,587,544 Moore June 8, 1926 1,922,854 Klein Aug. 15, 1933 1,967,931 Fox July 24, 1934 2,064,189 Bodor Dec. 15, 1936 2,276,577 Hahn Mar. 17, 1942 2,288,896 Fink July 7, 1942 FOREIGN PATENTS Number Country Date 435,898 British Oct. 1, 1935 451,698 British Nov. 7, 1934

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