Composite end closure member for composite containers

An improved composite container is disclosed in which a composite end closure member having a horizontal generally disk-shaped central portion and an annular flange portion is bonded to one end of a tubular cylindrical composite body member, preferably by the use of radio frequency or dielectric energy. Preferably, the body member end portion is reversely inwardly curled to define an upwardly extending curled portion the free extremity of which is contiguous with the end member, thereby to structurally reinforce the container and to more securely hold the end member in place.

BRIEF DESCRIPTION OF THE PRIOR ART 
Composite containers having composite ends are well known in the art, as 
evidenced by the patents to Griese, Jr., U.S. Pat. No. 3,151,765, Betner 
U.S. Pat. No. 3,317,068, Sternau U.S. Pat. No. 3,348,358, Christine et al 
U.S. Pat. No. 3,391,847, and Smith et al U.S. Pat. No. 3,949,927. Such 
containers have utility in the packaging of frozen citrus juices, dough, 
dry powders, cleansers, motor oil and the like. In such containers, by 
avoiding the use of conventional metal end closure members, the cost of 
the resulting container is significantly reduced. One problem in the known 
composite containers is that of effecting a positive, leak-free rugged 
seal between the body and end closure members in a relatively short period 
of time. 
SUMMARY OF THE INVENTION 
The present invention relates to an improved composite container including 
a composite body member and a composite end closure member, wherein the 
members are connected in a positive leak-free manner, preferably by means 
of a thermal bond produced by a radio frequency or dielectric energy. The 
composite end and body members of the subject invention each have at least 
one fibrous layer. The composite end closure member, which is mounted at 
one end of the composite body member, has a horizontal, generally 
disk-shaped central portion, and a peripheral flange portion. The 
peripheral flange portion is preferably heat sealed to the container inner 
liner layer using radio frequency or dielectric energy. When using radio 
frequency energy, a metal such as aluminum foil must be present in 
combination with a heat sealable material to effect proper sealing of the 
heat sealable material. When using dielectric energy, moisture which is 
present in the fibrous layer of the composite material is heated to effect 
a proper heat seal bond between the composite end member and the composite 
body member. It is also possible to use a thermoplastic bonding material 
that contains a polarized molecule material, including polyvinyl chloride, 
nylon or the like. The end of the body member may be reversely inwardly 
curled to structurally reinforce the container and to more firmly secure 
the composite end closure member to the composite body member. In some 
embodiments, a reinforcing disk is placed between the end closure member 
and the reversely inwardly curled end of the body member to further 
reinforce the end closure structure. 
Accordingly, a primary object of the present invention is to provide an 
improved composite container having a composite end member thermally 
bonded, for example, by radio frequency or dielectric energy, to a 
composite body member, which container is suitable for use in the 
packaging of frozen citrus juice, dough, motor oil and the like, thereby 
eliminating the need for more expensive metal ends.

DETAILED DESCRIPTION 
Referring first more particularly to FIGS. 1 and 2, the helically-wound 
cylindrical tubular composite body member 2 includes an outer label layer 
2a (of paper or foil), a fibrous body wall layer 2b (normally of paper), 
and an inner liner layer 2c (preferably of a heat sealable material, such 
as polyethylene.) The lower end of the vertically arranged body member is 
closed by a composite end closure member 4 having an inner layer 4a formed 
of heat sealable material, such as polyethylene, a fibrous layer 4b 
(formed of paper), and an outer layer 4c, preferably formed of a heat 
sealable material, such as polyethylene. The end closure member includes a 
disk-shaped central portion 4d extending horizontally across and spaced 
from the lower end of the body wall member, and a downwardly depending 
annular flange portion 43. The lower end of the body wall member includes 
a reversely inwardly curled terminal portion 2d that extends upwardly into 
abutting engagement with the lower surface of the disk portion 4d of the 
end closure member 4. 
In accordance with the present invention, the outer surface of the flange 
portion 4e is bonded to the inner liner layer 2c of the body member, 
preferably by a heat sealed bond produced by high frequency or dielectric 
energy. In the former case, the inner layer 2c of the body wall layer 
and/or the outer layer 4c of the end closure member is formed of metal, 
such as aluminum foil. Furthermore, the seal can be improved by also 
bonding the inner surface of the end closure flange portion 4e to the 
adjacent surface of the curl portion 2d. To this end, the outer layer 4c 
of the end closure member may be formed of a material (such as 
polyethylene) that is heat sealable to the inner liner layer 2c of the 
body wall. 
In the embodiment of FIG. 1, the disk portion 4d is generally planar, and 
in the modification of FIG. 3, the central part of the disk portion 4d is 
deformed downwardly, thereby to increase the volume and/or strength of the 
container. 
Referring now to the embodiment of FIG. 4, a rigid composite reinforcing 
disk 8 is supported by the reversely curled portion 2d for extending in 
reinforcing supporting relation beneath the central disk portion 4d of the 
end closure member. The reinforcing disk includes an upper layer 8a (of 
paper, foil, or synthetic plastic material, such as polyethylene), a 
fibrous (paper) central layer 8b, and an outer layer 8c (preferably of 
foil). 
In the modification of FIG. 5, the end closure member 4 includes a further 
fibrous layer 4f, and an outer protective layer 4g (of foil, paper or 
synthetic plastic material), which further fibrous layer 4f serves to 
strengthen the center of the end closure member 4. The flange portion 4e 
of the end closure member is bonded to the inner surface of the body wall, 
and preferably, the reversely curled body portion is bonded to the outer 
peripheral surface 4c of the flange portion 4e. 
Referring now to the embodiment of FIG. 6, the flange portion 104e of the 
end closure member 104 extends upwardly, the disk portion 104d being 
supported by the reverse curl portion 2d. In this embodiment, only the 
outer circumferential surface of the flange portion 104 of the end closure 
member is bonded to the inner liner layer 2c of the body member. 
Consequently, the outer layer 104c of the end closure member is formed of 
a material (such as paper, polyethylene or the like) that is heat sealable 
to the inner liner layer 2c. 
In the modification of FIG. 7, a composite reinforcing disk 108 is 
supported by the curl portion 2d for supporting the central part of 
central disk 104d. The central layer 108b of the reinforcing disk is 
formed of fibrous material such as paper, and the upper and lower layers 
are formed of paper, foil, or synthetic plastic material, such as 
polyethylene. 
During assembly, the end member is punched and inserted in one end of the 
preformed helically wound composite container body. After assembly, 
aligning, and folding are completed, the end closure member is heat sealed 
to the container body member using radio frequency or dielectric heating 
apparatus. In radio frequency sealing, the container liner layer 2c is 
preferably formed of a heat sealable material, such as polyethylene, while 
the end member inner and/or outer layers are formed from metal foil. 
Alternatively, the container liner layer 2c may be metal foil and the 
closure inner and/or outer layers may contain the heat sealable material. 
The heat sealable material may be polyethylene, polypropylene, ethylene 
vinyl acetate, surlyn, polyvinyl chloride or any other conventional heat 
sealable synthetic plastic material. It is not necessary for the heat 
sealable material to be included as one of the composite material layers 
as previously described, but may be added to the end structure during 
assembly. When dielectric energy is used, it is not necessary for a metal 
material to be included, but a substance to be heated such as water which 
is present in the fibrous layers is necessary to effect a proper heat seal 
of the closure member to the body member. 
While the preferred forms and embodiments have been illustrated and 
described, various changes and modifications may be made without deviating 
from the inventive concepts set forth above.