US3159515A - Method and apparatus for making composite oil containers of spirally wound strips - Google Patents

Description

c. K. DUNL'AP, JR. ETAL- 3,159,515

Dec. 1, 1964 METHOD AND APPARATUS FOR MAKING COMPOSITE OIL. CONTAINERS OF SPIRALLY WOUND STRIPS Flled March 19, 1962 3 Sheets-Sheet 1 INVENTORSI gHARLEfi K. bum.

AP, J12. Avu C. ALEXANDER, BY PHI LAP G. HART and.

/ Q Wok/fir JAMEs P. HAL

Dec. 1, 1964 c. K. DUNLAP, JR.. ETAL 3,159,515

' METHOD AND APPARATUS FOR MAKING COMPOSITE OIL S OF SPIRALLY WOUND STRI 3 Sheets-Shee CONTAINER Filed March 19, 1962 INVENTORSI CHARLES K.DUNLAP,J2.,

.5 bAvn C. ALEXANDER, BY PH\L.\\ G. HART and JAMEE: P. HAx L 7 W ATTORNEY c. K. DUNLAP, JR. ET AL 3,159,515 D AND APPARATUS FOR MAKING COMPOSITE OIL Dec. 1, 1964 METHG Filed March 19, 1962 CONTAINERS OF SPIRALLY WOUND STRIPS 3 Sheets-Sheet 3 m i Y M H iv m M y 52 M T /5/ KL.. A w w m i P N V\ C P I I United States Patent METHOD AND APPARATUS FOR MAKING COMPOSITE OIL CONTAKNERS 0F SPI- RALLY WOUND STRlPS Charles K. Dunlap, Jr., David C. Alexander, and Philip G. Hart, Hartsville, and James P. Hall, Darlington, S.C., assignors to Sonoco Products Company, Hartsville, S.C., a corporation of South Carolina Filed Mar. 19, 1962, Ser. No. 180,666 3 Claims. (Cl. 156-190) This invention relates to containers and more particularly to tubular containers for liquid materials such 'as oil and the like.

In the packaging of liquid and semiliquid materials, containers or cans of metal are generally employed due to the obvious advantages of metal over many other materials for such containers. For instance, engine oil packaged for sale to the typical motorist is packaged in a tubular metal container in relatively small quantities, the onequart capacity oil can being the most popular.

The use of metal for the construction of containers used for materials such as oil imparts numerous highly desirable features to such containers including strength and ruggedness so as to resist denting, weathering, puncturing and other damaging effects to which such a container is subjected during handling, shipment and the like. Metal containers are also generally characterized by ready printability of the metal outer surface so as to provide an attractive and readily marketable product. Most importantly, metal is impermeable to the penetrating action of oil and other liquid materials and can be treated to be relatively inert to chemical attack by the packaged material.

However, the high cost of metal and metal fabrication has inspired considerable development work searching for less expensive substitute materials for metal to be used in the construction of such containers. Many substitute materials for metal have been proposed including fibrous materials such as paper impregnated or laminated at least on the side forming the inner surface of the container with a suitable material to render it impervious to oil and other penetrating packaged materials. It is generally accepted that some sacrifice in strength cannot be avoided with theuse of materials other than metal for the oil container but the impermeability feature of a metal can is required to be present in containers made firom other materials.

It has been generally proposed that paper is the most suitable substitute material for metal for containers and many efforts have been made to perfect a wound paper tube either convolutely or spirally wound in which liquid materials such as oil can be packaged and which is impermeable to the penetrating action of the oil. The relatively low cost of paper and the highly developed techniques for winding paper tubes from which the container bodies can be made have brought about considerable development work leading up to such a container. However, even though coated papers, laminated papers and the like provide a high degree of impermeability for the inner surface of the wound paper container bodies, the seam onthe inner wall of the container body is a source of leaking or wicking generally and efforts to produce an inexpensive impermeable container acceptable for the packaging of liquid and semiliquid materials have not met with .the desired degree of success.

It has been found that while the use of a plastic coating or a metal foil laminate on the inner surface of such containers provides considerable leakproofing, the slightest pinhole or exposed fiber on inner surface produces a wicking and attendant leaking of oil through the container wall. This wicking and leaking is particularly prevalent along the seam of the container even with overlapping plies and the like as a result of the difiiculty of producing a seam completely closed by oil impermeable material.

The use of metal for containers has other disadvantages in addition to high cost as disposal of empty metal oil containers has always posed somewhat of a problem due to the non-combustibility of the metal and the difiiculity of collapsing the metal container. Furthermore, the weight of the metal container is always a cost factor to consider when freight costs (are involved.

Accordingly, a primary object of this invention is to provide a new and novel method for making a leakproof container body using fibrous material such as paper.

Another object of this invention is to provide a new and novel method of forming a leakproof container body for an oil container utilizing fibrous material such as paper which is completely impermeable to penetrating liquids such as oil and which is inexpensive and rugged in construction.

A further object of this invention is to provide a new and novel method of spirally winding strip material including paper and metal foil into a tubular body for an oil container in which the spiral seam is completely sealed so as to prevent wicking or leaking of the liquid such as oil packaged in the container.

A still further object of invention is to provide a new and novel apparatus for making a leakproof body for the packaging of materials such as oil and the like.

Still another object of this invention is to provide a new and novel apparatus for spirally winding paper and metal foil strip material into a le-akproof composite oil container tubular body.

This invention further resides in the provision of a new and novel apparatus and method for spirally winding paper strips and foil laminated paper strips together to form a composite oil container tubular body in which the inner spiral seam is completely sealed against oil wicking and leaking and which tubular body may be readily closed at either end with metal ends or the like to provide a rugged, leakproot container of inexpensive construction utilizing readily available material and provided with a pleasing outward appearance.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings.

The objects stated above and other related objects in this invention are accomplished by spirally winding a plurality of strips on anelongated rnandrel with adhesive therebetween to form a spiral tube severable into tubular container bodies. The inner strip comprises oil impervious material such as foil laminated paper with the edges of adjacent convolutions in abutting relationship to form a spiral seam. A relatively narrow strip of oil impervious material such as foil coated on its outwardly facing side with a thermoplastic adhesive is spirally wound between the inner strip-and the mandrel across the spiral but-t seam. A portion of the mandrel adjacent the spiral tube forming end is heated to activate the thermoplastic adhesive on the narrow strip and adhesively secure the narrow strip to the inner strip to completely seal the seam. The spiral tube is then cooled to set the thermoplastic adhesive and form an oil impervious ply for the container body.

The novel features which are believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 is an isometric view of a composite oil container incorporating the tubular body formed in accordance with the invention;

FIGURE 2 is a plan view of a spiral tube winding ap paratus illustrating the carrying out of the novel method of the invention;

FIGURE 3 is an enlarged isometric view of a portion of the winding apparatus of FIGURE 2;

FIGURE 4 is an enlarged sectional view taken substantially along line 4-4 of FIGURE 3 in the direction of the arrows;

FIGURE 5 is a sectional view taken substantially along line 5-5 of FIGURE 3 in the direction of the arrows;

FIGURE 6 is a sectional view of a portion of the men drel incorporated in the apparatus of FIGURE 2;

FIGURE 7 is a sectional view similar to FIGURE 6 of another portion of the mandrel;

FIGURE 8 is a sectional view similar to FIGURE 6 illustrating still another portion of the mandrel; and

FIGURE 9 is an enlarged sectional view taken substantially along line 99 of FIGURE 1 in the direction of the arrows.

As referred to above, the novel method and apparatus of the invention is employed in the production of tubular bodies for containers such as oil cans or the like and one such container for oil is shown in FIGURE 1 and is identified generally by the numeral 10. It should be understood that the invention is suitable for the production of bodies for containers used to package liquid materials, semiliquid materials or any other type of materials which is prone to cause container leakage but references hereinafter will be made to a container used for the packaging of oil.

The container 10 comprises a spirally wound tubular body 11 having an exterior spirai seam I2 which body is formed from a plurality of strips of suitable material such as paper and the like as will be described hereinafter adhesively secured together in overlapping relationship. Prior to filling, the container 10 is first sealed at one end with a suitable circular disk or end 13 preferably formed from metal with an edge seam 14- and after filling with oil or the like is sealed at its other end with an end 16 utilizing a similar edge seam 17 to form a completely closed container.

Referring now to FIGURE 2, there is shown spiral tube winding apparatus similar generally to conventional tube winding apparatus having certain components constructed in accordance with the invention. As is well known, the spiral tube winding apparatus of FIGURE 2 includes a bed 18, a head 19 to which is secured at one end a mandrel 21 constructed in accordance with the invention. A continuous belt 22 is provided which advances over pulleys 23 and which is looped around the mandrel in the conventional manner as shown to advance a spiral tube 24 being formed in accordance with the invention and advanced in the direction of the arrow I. As will be explained hereinafter the tube 24- is severed into uniform lengths to form the container bodies 11.

In accordance with the novel construction of the invention, the mandrel 21 is provided with a heated section A adjacent its tube forming end and a cooled section B as shown in FIGURES 6, 7 respectively. As can be seen, the left hand end of mandrel section B is arranged to be threadedly connected to the right hand end of mandrel section A as viewed in FIGURES 6, 7. The mandrel 21 is also provided with a section C (FIGURE 8) forming an extension the left hand end of which is arranged to be threadedly connected to the right hand end of mandrel section B as viewed in FIGURES 7, 8.

Referring now to FIGURES 1-8, the mandrel 21 contains a tubular inner shell 31 and an outer shell designated generally by the numeral 32 the three sections of which are identified as 32a, 32b and 320 in FIGURES 6-8 respectively. The tubular inner shell 31 which extends throughout mandrel sections A, B is supported in coaxial relationship with the outer shell 32 by means such as an end plate 33 as shown best in FIGURE 3, a coupling collar 34 as shown in FIGURE 6 and an end collar 36 as shown in FIGURE 7 to form an annular hot cavity 37 in mandrel section A and a cold cavity 38 in mandrel section B.

The coupling collar 34 is fixed to the outer shell section 32a and inner shell 31 by means such as welding and the like and is externally threaded at 41 for a threaded connection with an internally threaded end 42 on mandrel section B of FIGURE 7. The other end of mandrel section B is internally threaded at 43 for a threaded connection with an externally threaded portion 44 on the mandrel section C of FIGURE 8. The externally threaded portion 44 is formed on an enlarged portion 46 of an inner tube 47 threadedly connected at one end to the outer shell section 320 as shown and at its other end by means of an annular spacer 48 for supporting the tube 47 within the mandrel outer shell section 32c.

When the mandrel portions A-C shown in FIGURES 6-8 respectively are assembled together as described above, the outer shell sections 32a, 32b and 32c form a continuous outer mandrel surface along which the spiral tube 24 advances.

The mandrel 21 has associated therewith an elongated shaft 51 which is supported for reciprocating movement within the mandrel inner shell 31 on bushings 52-54 and 56 positioned as shown in FIGURES 6-8. The shaft 51 is arranged to be connected to a cut-off device for the spiral tube 24 and as it forms no part of this invention, the cut-ofi? device is neither shown nor described.

The annular hot cavity 37 is sealed at its ends by means of the plate 33 and collar 34 and is arranged to be supplied with steam from a suitable steam source 57 (FIG- URE 2) by means of a conduit or hose 58 threadedly connected by means of a fitting 59 to a threaded opening 61 in the plate 33 which opening is in communication with the hot cavity 37. Condensate is arranged to be removed from the lower portion of the hot cavity 37 by means of an outlet conduit or hose 62 connected by means of a fitting 63 to a threaded opening 64 within the plate 33. Thus by injecting steam into the cavity 37 of the mandrel section A, the mandrel shell section 32a is heated.

Mandrel section B is arranged to be cooled by cold water from a cold water source identified in FIGURE 2 by the numeral 66 which has connected thereto an inlet conduit 67 entering the mandrel 21 through an opening 63 in the mandrel end bushing 52. The conduit 67 communicates with the annular cavity 38 in mandrel section B by extending through an opening 69 in the wall of the mandrel inner shell 31. In the upper portion of the cavity 38 in the mandrel section B, an outlet conduit 71 is provided having an inner end extending through an opening 72 in the wall of the mandrel inner shell 31. The outlet conduit 71 similarly passes through an opening 73 in the mandrel end bushing 52.

The tubular body 11 of the container 10 wound by means of the apparatus of FIGURE 2 is formed from a plurality of strips of material with an inner strip 81 of oil impervious material such as foil laminated paper unwound from a supply roll 82 suitably supported adjacent the apparatus of FIGURE 2. In order to insure that the foil-paper strip 81 is completely impervious to oil, the foil laminate is preferably coated on its exposed surface with an oil impermeable material such as a clear plastic material or the like. The strip 81 is fed onto the mandrel 21 with the foil side adjacent the mandrel, sections A, B having been heated and cooled by the steam and cold water from the sources 57, 66 respectively.

Two additional strips 83, 34 of fibrous material such as paper are then spirally wound in overlapping relationship with the inner strip 81 as shown. Strip 83 is unwound from a suitably supported supply roll 86 and is passed through an adhesive applicator 87 of conventional construction with the strip immersed in the adhesive bath for thorough coating. The strip 84 is unwound from a suitably supported supply roll 88 so that the strips 81, 83, 84 are all adhesively secured together by means of the adhesive on opposite sides of the strip 83. It will be noted that the hot section A of mandrel 21 extends substantially up to the point at which a tube is formed with the strips 81, 83, 84 as shown in FIGURE 2.

As shown best in FIGURE 4, the adjacent edges of the convolution of the inner strip 81 are wound in abutting engagement to form a butt seam 91. In accordance with the novel method of the invention, a relatively narrow strip 92 of oil impervious material preferably foil is unwound from a supply roll 93 and is spirally wound together with the strip 81. The strip 92 has a thermoplastic adhesive coating 94 and is wound onto the mandrel 21 between the inner strip 81 and the outer surface of the mandrel with thermoplastic coating in contact with the foil side of strip 81. Thus the narrow foil strip 92 extends across the butt seam 91 of strip 81. Any suitable thermoplastic adhesive may be used for the coating 94 on the strip 92.

The heat of the mandrel outer shell section 32a, as the narrow coated sealing strip 92 and foil laminated paper strip 81 are wound thereon softens and activates the thermoplastic adhesive coating 94 so that a bond develops between the sealing strip 92 and the inner foilpaper strip 81, and the butt seam 91 is completely sealed.

As the formed spiral tube is advanced in the direction of the arrow I by means of the belt 22, it passes over the cold section B of the mandrel 21 chilling the thermoplastic adhesive 94 setting it in a permanent bond. The resulting tube leaving the mandrel cold section B is a spiral tube formed of the strips 81, 83, 84 and the narrow sealing strip 92 in seal-ing relationship across the inner ply butt seam 91.

In the preferred embodiment, an outer foil laminated paper strip 96 is wound in overlapping relationship with the ply formed by strip 84. The outer surface of strip 96 is preferably printed with suitable indicia for advertising and identification purposes or the like. The strip 96 is preferably spirally Wound with the other strips down from the belt 22 to avoid damage to the foil layer. The foil-paper strip 96 is shown being unwound from a supply roll 97 whereupon it is passed through a glue applicator 98 having a glue applicator roll 99. The resulting tube 24 is therefore a multi-ply tubular structure forming the body 11 for an oil container which after filling can be sealed with the metal ends 13, 16 to form a leakproof container.

It can be seen with the novel arrangement of this invention that a tubular body for a container may be constructed in a simple and easy manner using fibrous material such as paper as a substitute for metal which container is suitable for the packaging of highly pentrative liquid and semi-liquid materials such as oil or the like. The method of the invention permits the use of conventional spiral tube winding techniques and apparatus characterized by ease of operation and low cost and at the same time permits a continuous tube to be formed which can be severed into suitable lengths for container bodies having an inner surface which is completed impermeable to oil and the like. The novel method of sealing the internal spiral seam is accomplished inexpensively utilizing conventional spinal winding techniques so that the internal spiral seam is completely closed to the packaged material. The apparatus of the invention incorporates a novel spiral tube winding mandrel which while serving as does the mandrel presently used in conventional machines additionally performs a heating and cooling function on the novel wound tube of the invention so as to permanently bond together strips employed in winding the novel tubular body of the invention.

While there has been described what at present is considered to be the preferred embodiment of the invention, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the invention and, therefore, it is the aim of the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Having thus described the invention, what is claimed is:

1. A method of making a composite oil container body comprising the steps of, spirally winding a plurality of strips adhesively secured together on an elongated mandrel to form a container body, said strips including an inner strip of leakproof material wound with the edges of adjacent convolutions in abutting relationship to form a spiral seam, simultaneously spirally winding a relatively narrow strip of leakproof material, coated on its outwardly facing side with a thermoplastic adhesive, across said seam and adjacent to said mandrel, heating a portion of said mandrel beneath said wound narrow strip and said inner strip to activate the thermoplastic adhesive on said narrow strip and adhesively secure said narrow strip to said inner strip and cooling said heated narrow strip to set said thermoplastic adhesive and form a leakproof inner ply for said container body.

2. A method of making a composite oil container body comprising the steps of, spirally winding a plurality of strips adhesively secured together on an elongated mandrel to form a container body, including a plurality of paper strips and an inner strip of foil laminated paper wound with the foil of said foil laminated paper adjacent said mandrel and with the edges of adjacent convolutions in abutting relationship to form a spiral seam, simultaneously spirally winding a relatively narrow strip of foil, coated on its outwardly facing side with a thermoplastic adhesive, across said seam and adjacent to said mandrel, heating a portion of said mandrel beneath said wound inner strip of foil laminated paper and said wound narrow foil strip to activate said thermoplastic adhesive and adhesively secure said narrow strip to said inner strip and cooling a portion of said mandrel adjacent said heated portion to set said thermoplastic adhesive and form a leakproof inner ply for said container body.

3. In a spiral tube winding apparatus, the combination of an elongated mandrel for winding a plurality of spirally wound overlapping strips adhesively secured together into a spiral tube, said strips including an inner strip wound with the edges of adjacent convolutions in abutting relationship to form a spiral seam and a narrow strip, having an outwardly facing thermoplastic adhesive coating wound across said spiral seam and adjacent said mandrel, means in said mandrel for heating a longitudinally extending portion of said mandrel to heat said thermoplastic adhesive coating and adhesively bond said narrow strip to said inner strip, and means in said mandrel for cooling a longitudinally extending portion of said mandrel adjacent said heated portion to cool and set said thermoplastic adhesive to thereby maintain said strips in a bonded relationship.

References Cited by the Examiner UNITED STATES PATENTS 1,944,970 l/ 34 Ditfenbach 93-80 XR 2,131,343 9/ 38 Cordiano 93-94 XR 2,411,542 11/46 Ilch.

2,555,380 6/51 Stuart et a1 229-45 XR 2,766,160 10/56 Bentov 156-461 XR FOREIGN PATENTS 683,206 11/52 Great Britain. 825,304 12/59 Great Britain.

EARL M. BERGERT, Primary Examiner.

Claims (2)

1. A METHOD OF MAKING A COMPOSITE OIL CONTAINER BODY COMPRISING THE STEPS OF, SPIRALLY WINDING A PLURALITY OF STRIPS ADHESIVELY SECURED TOGETHER ON AN ELONGATED MANDREL TO FORM A CONTAINER BODY, SAID STRIPS INCLUDING AN INNER STRIP OF LEAKPROOF MATERIAL WOUND WITH THE EDGES OF ADJACENT CONVOLUTIONS IN ABUTTING RELATIONSHIP TO FORM A SPIRAL SEAM, SIMULTANEOUSLY SPIRALLY WINDING A RELATIVELY NARROW STRIP OF LEAKPROOF MATERIAL, COATED ON ITS OUTWARDLY FACING SIDE WITH A THERMOPLASTIC ADHESIVE, ACROSS SAID SEAM AND ADJACENT TO SAID MANDREL, HEATING A PORTION OF SAID MANDREL BENEATH SAID WOUND NARROW STRIP AND SAID INNER STRIP TO ACTIVATE THE THERMOPLASTIC ADHESIVE ON SAID NARROW STRIP AND ADHESIVELY SECURE SAID NARROW STRIP TO SAID INNER STRIP AND COOLING SAID HEATED NARROW STRIP TO SET SAID THERMOPLASTIC ADHESIVE AND FORM A LEAKPROOF INNER PLY FOR SAID CONTAINER BODY.

3. IN A SPIRAL TUBE WINDING APPARATUS, THE COMBINATION OF AN ELONGATED MANDREL FOR WINDING A PLURALITY OF SPIRALLY WOUND OVERLAPPING STRIPS ADHESIVELY SECURED TOGETHER INTO A SPIRAL TUBE, SAID STRIPS INCLUDING AN INNER STRIP WOUND WITH THE EDGES OF ADJACENT CONVOLUTIONS IN ABUTTING RELATIONSHIP TO FORM A SPIRAL SEAM AND A NARROW STRIP, HAVING AN OUTWARDLY FACING THERMOPLASTIC ADHESIVE COATING WOUND ACROSS SAID SPIRAL SEAM AND ADJACENT SAID MANDREL, MEANS IN SAID MANDREL FOR HEATING A LONGITUDINALLY EXTENDING PORTION OF SAID MANDREL TO HEAT SAID THERMOPLASTIC ADHESIVE COATING AND ADHESIVELY BOND SAID NARROW STRIP TO SAID INNER STRIP, AND MEANS IN SAID MANDREL FOR COOLING A LONGITUDINALLY EXTENDING PORTION OF SAID MANDREL ADJACENT SAID HEATED PORTION TO COOL AND SET SAID THERMOPLASTIC ADHESIVE TO THEREBY MAINTAIN SAID STRIPS IN A BONDED RELATIONSHIP.

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