Horizontal Heat-seal Liner For Fibre Drums

Abstract

A fibre container having a tubular body, a bottom member closing one end and a metal chime securing the bottom member to said tubular body, said container having an improved tubular flexible liner therein. The flexible liner may comprise a thin film of a polymeric material having the desired barrier or protection characteristics for the bulk material to be stored, and is divided into two portions by a horizontal heat seal. An upper portion provides an inner container for the bulk material, while the lower portion is integrally connected to the bottom of the fibre container through an interlock between the metal chime and the bottom member.

Description

BACKGROUND OF THE INVENTION

This invention relates to plastic lined containers. More particularly, it relates to plastic lined fibre drums and a method for their manufacture whereby liquids, semi-liquids, and bulk materials can be effectively stored or transported therein.

Fibre drums having plastic liners are desirable for packaging many materials because they are relatively inexpensive to manufacture, are of a relatively light weight, and usually have substantial vertical stacking strength.

Containers of this nature which are currently being manufactured may include a molded liner which is integrally and mechanically interlocked with a fibre drum such as that illustrated by U.S. Pat. No. 3,158,311. In this instance the liner is specially manufactured for use with the drum and thus requires specific methods and apparatus for its manufacture. On the other hand, some liquids, semi-liquids or bulk materials are merely placed in a loose flexible bag within a fibre drum. In the latter instance, after the material has been placed within the liner, it is sealed at its upper end and is ready for transport or storage. This design, although relatively expensive, is troublesome to the user of the package in that he must separately purchase two components, e.g. the fibre drum and the liner and assemble the same prior to filling thereof. Additionally, when the drum is to be emptied, it is merely turned up-side-down and the liner flows out of the drum with the material therein, the liner, having to be subsequently separated from such material.

In an effort to improve lined containers, the invention includes a fibre drum having a bottom member and a thin tubular liner locked thereto by a chime. The liner is divided into an upper container portion and a lower portion which is mechanically and frictionally interlocked to the bottom member, the two portions being separated by a horizontal seal.

Accordingly, it is an object of this invention to provide a simple economical drum for fibre containers having a liner therein which is also rigidly attached to the interior of the drum. Additionally, it is an object of the invention to provide a convolute wound fibre drum having a liner which will retain the fluid and vapor characteristics of the packaged product with a minimum amount of packaging costs. Finally, it is object of this invention to provide a container with a flexible liner which avoids the traditional sealing problems associated with such liners and which will permit the filling thereof with the product to be packaged without entrapping any air within the container which might otherwise effect a loss of storage volume.

DESCRIPTION OF THE DRAWINGS

The manner in which the objects of this invention is attained will be made clear by consideration of the following specification and claims when taken in conjunction with the accompanying drawings in which:

FIG.1 is a perspective view of a preferred embodiment of the instant invention;

FIG. 2 is a side elevational view of a preferred embodiment of the inner liner of the instant invention; and

FIG. 3 is an elevational view taken in section through a vertical section line of the preferred embodiment of this invention.

DETAILED DESCRIPTION

As shown in FIG. 1, the preferred embodiment of my invention may be represented by a fibre drum container 10 having a flexible bag 40 therein which contains a bulk material to be stored or transported. This preferred embodiment is very similar in external appearance to the conventional fibre drum and includes a tubular body 12 preferably formed of fibre or container board which is convolutely wound about a mandrel with appropriate adhesives being placed between the various layers thereof, such being a conventional manner of manufacture of the tubular body 12. At the bottom of the tubular body 12 is a metal chime 16 which is utilized to re-enforce the lower most portion of the tubular body and to engage and mechanically interlock a bottom member or header 14 thereto in a manner subsequently to be described. The upper portion of the tubular body 12 also carries a metal chime 30 whidh is clamped to the container board by way of a groove 34, with the upper portion of the chime and the extremity of the tubular body 12 being curled in a manner more thoroughly depicted in FIG. 3. Within the container 10 is placed a tubular bag 40 having a closed bottom end at 44 and which is adapted to receive a bulk material, liquid or solids and to be bound at the top in the manner shown in FIG. 1.

The details of the finished container depicted in FIG. 1 may be better understood with reference to FIG. 2 which depicts the structure of the liner, and by FIG. 3 which depicts a cross-sectional view of the final construction of the lined container of FIG. 1.

With reference to FIG. 2, the preferred embodiment of the liner utilized in the instant invention initially takes the form of a section of tubular stock of an extruded polymeric material, which is selected from various polymers such as polyethylene, polypropylene, etc., according to the barrier and protection properties desired for the product which is to be shipped. This tubular liner 40 has a longitudinal dimension substantially in excess of the height of the container and a diameter subsequently equal to that of the drum 12. Prior to insertion of the liner into the drum it is divided into an upper portion or compartment 42 and a lower portion or compartment 48 by a horizontal heat seal 44. Apertures 50 are placed in the lower portion for purposes hereinafter described.

After the tubular liner or insert has been formed in this manner by providing the horizontal heat seal 44 and the apertures 50, the liner 40 is placed within the tubular body member 12 between the bottom member 14 or header and the tubular body 12 with the metal chime 16 being placed thereover. Subsequently, a groove 18 is placed in the chime as indicated by a conventional rolling or press operation, with the lower end portion of the tubular member 12, the chime 16, the header 14, and the lower extremity of the lower member 48 of the tubular liner being curled so as to provide a mechanical interlock between these four members. Simultaneously with, or perhaps prior to the forming of the mechanical interlock between four members at the bottom portion of the tubular member 12, the upper chime is placed upon the tubular body 12, with the curl 32 and the groove 34 being placed therein in a similar fashion.

Thus as depicted in FIG. 3, the fibre container is provided with an integral liner comprising the upper portion 42 of the tubular film material. With the heat seal 44 at the lower portion of the upper compartment 42, it should be apparent that the bottom portion of the upper compartment 42 is sealed so as to preclude the escape of fluids which might be transported therein. Through this construction the conventional problems of forming a seal at the joinder of the metal chime 16 and the bottom member 14 are eliminated.

After the container has been formed in this manner, it is ready for filling with the material to be stored or transported. As such material is placed within the liner 40 of the container 10, its weight will urge or force this liner to take shape of the tubular body 12. However, to preclude the formation of an air pocket between the lower portion 48 of the liner 40, and the bottom member 14, the apertures 50 will permit the transmission of air out of this bottom compartment whereby it may pass up the walls between the upper portion of the liner 42 and the tubular container 12. Upon complete filling of the upper compartment 42, it is obvious that such will take the form of the container and the excess material which was provided at the top may be utilized to close the liner by a conventional banding or tying operation. Subsequently, a top formed either of metal, or of container board may be placed over the top of the liner in a conventional manner.

From this disclosure, it should be clear that applicant has provided a very inexpensive lined container of fibre board material having a liner with a minimum amount of sealing problems, and one which is mechanically interlocked with the bottom of the container. Obvious advantages include the fact that no labor is required to maintain separate liners for the containers or to insert such a liner within the container prior to the filling thereof. Too, in the event of bulk dumping of such material from the container, there is little possibility that the inner liner will pass into a hopper or a bin with the material so as to present subsequent retrieval problems.

The invention may take various forms. For example a complete circumferential mechanical interlock between the lower portion 48 of the tubular liner 40 may not be necessary to obtain all the advantages of the instant invention. However, it should be noted that the mechanical interlock is in many cases quite superior to an adhesive type interlock between the bottom member 14 and a bag placed within the fibre drum since such adhesives normally require curing time, if water based, or in the alternative, if solvent based adhesives are utilized, they may emit undesirable odors.

Claims

We claim:

1. In a fibre container having a tubular body, a bottom member closing one end and a chime securing said bottom member to said tubular body, an improved liner comprising:

a. a tubular flexible bag within said tubular body having an upper compartment and a lower compartment, said upper and lower compartments being separated by a horizontal seal;

b. said upper compartment being open and forming an inner container within the fibre container; and

c. said lower compartment being secured to the bottom member and the tubular body by said chime.

2. An apparatus as recited in claim 1 in which said lower compartment is provided with means for permitting the escape of air from the space defined by the lower compartment and the bottom member.

3. An apparatus as recited in claim 1 in which said lower compartment is secured to the bottom member and tubular body by a mechanical frictional engagement effected by the chime.

4. In a container having a body portion and a bottom portion attached thereto, an improved liner comprising:

a. a tubular flexible bag within said body portion having an upper compartment and a lower compartment, said upper and lower compartments being separated by a horizontal seal;

b. said upper compartment being open and forming an inner container within the container; and

c. said lower compartment being secured to the bottom portion and the body portion by a mechanical interlock.