WAXER FOR COATED EMBOSSED CONTAINERS

DISPOSITIF D'ENDUCTION A LA CIRE DE CONTENANTS ALVEOLES

English Abstract

ABSTRACT OF THE DISCLOSURE

The invention is a method for making a paperboard blank
for pan block frozen fish. The interior surface of the container
being formed with spaced apart depressions embossed therein for
the purpose of assisting the escape of air forced from the fish as
it is compressed within the container in the packaging operation
by the steps of cutting a quantity of container blanks and coating
and embossing the said blanks by continuously feeding them through
a waxer and roll embosser serially set up so that the embosser
accepts the output of the waxer on a continuous basis.

Claims

The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:

1. A method of making a paperboard blank for a contain-
er adapted to contain pan block frozen fish, the interior surface
of the container being formed with spaced apart depressions embos-
sed therein for the purpose of assisting the escape of air forced
from the fish as it is compressed within the container in the
packaging operation comprising the steps of:
cutting a quantity of container blanks;
coating and embossing the said blanks by continuously
feeding them through a waxer and roll embosser serially set up so
that the embosser accepts the output of the waxer on a continuous
basis.
2. A method of making a paperboard blank for a contain-
er adapted to contain pan block frozen fish, the interior surface
of the container being formed with spaced apart depressions embos-
sed therein for the purpose of assisting the escape of air forced
from the fish as it is compressed within the container in the
packaging operation as claimed in Claim 1 in which said roll em-
bosser is a steel roll embosser with synchronized matched embos-
sing rolls.
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Description

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This invention relates to a method for making a paper-
board blank for a container of the type described in Canadian
Patent No. 726,545 dated January 25, 1966 to Fletcher Mayo. Con-
tainers of this type have been used extensively at least since
1965 for packaging frozen fish.
Generally speaking, the container blank is made from
paperboard that is waxed and then embossed with spaced apart de-
pressions that are adapted to relieve the fish packed therein of
air that is driven out as the fish is compressed prior to Ereez-

ing. This invention is concerned with a method of making thesecontainers and detailed reference to the manner of using the con-
tainers will not be made in this specification. In any event, it
is very well known in the trade and is described generally in
Canadian Patent No. 725,545.
The method used heretofor to make these containers is
to cut the blank, apply wax to the blank and then stack the waxed
blanks. The waxed blanks are transported to a cut and crease
press, the flat bed of which i5 fitted with an embossing matte
that has raised portions that form the depressions in the blank.
The blanks are fed to the press and the cylinder presses the
blanks against the embossing matte to form the depressions in the
paperboard.
This method of forming the depressions in the blanks
has been successful as evidenced by its extensive and continuous
use over the past seventeen years. It is, however, relatively ex-
pensive because it involves the waxing and stacking of the blanks
and the transport of the stacked blanks to another location for
the distinct and separate operation of forming the depr~ssions in
the container.




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Consideration to other methods Eor forming the depres-
sions in the blank may well have been given by various persons
over the past sixteen years, but no material modiEication in the
general method ~or producing these blanks has occured, notwith-

standing the disadvantage noted. Persons in the art may wellhave had the idea cross their mind to Eoem the spaced apart de-
pressions in the con-tainer by passing the blank between a pair of
matched embossing rolls and performing the operation on the
blanks as they are delivered from the waxer. The two steps in
combination would avoid stacking and transporting the waxed
blanks to another location for embossing.
Whether the idea was conceived or not is not known but
if it was it was apparently not given any credibility by those in
the art. Some persons involved with the machinery prior to the
invention felt that matched embossing rolls of -this type would
not work because the freshly waxed carton blanks would give up
wax to the rolls and plug the embossing depressions. E'or what-
ever reason it was not considered practical and was not used not-
withstanding the obvious advantages that can be achieved with it
from a labour saving point of view.
It has been found that one can form the spaced apart de~
pressions of these containers with a roll embosser se-t up to ac-
cept the output of the waxer on a continuous basis. The rolls of
the embossing machine do not tend to plug up with wax and the
time cost with which the opera-tion can be performed is materially
improved. This results in reduced manufacturing costs.
According to the invention; the method of making a
paperboard blank for a container adapted to contain pan block


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~rozen fi,sh, the interior surface oE the container being formed
with spaced apart depressions embossed therein for the purpose of
assisting the escape of air forced from -the fish as it is compres-
sed within the container in the packaging operation comprises
5 the steps oE cutting a quantity of container blanks, coating and
embossiny the said blanks by continiuously feeding them through a
waxex and roll embosser serially set up so that the embosser ac-
cepts the output of the waxer on a con-tinuous basis.
The invention will be clearly understood after refer-

ence to the following detailed specification read in conjunction
with the drawings.
In the drawings:
Figure 1 is an illustration of a container oE the gen-
eral type to which this invention relates;
Figure 2 is an enlargement of a portion of the surface
of the container showing the depressions that are embossed there-
in; and
Figure 3 is a schematic illustration of the production
method of the invention.
In the drawings the numeral 10 generally refers to a
paperboard container according to this in~ention. It is made
from chipboard waxed on both sides and then embossed wi-th depres-
sions 12 illustrated in Figure 2 of the drawings.
Detailed reEerence will not be made to the very well
known con-tainer or to its manner of use~ This invention is con-
cerned with a method of making such a container.
The container is made from a lay-flat blank folded into
the forma-tion illustrated in Figure 1.




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The method of this invention i5 concerned with the wax-
ing and embossing oE the flat blank fxom which the containe is
made in a more ef~icient manner than has hereto~ore been pos-
sible. Figure 3 is a schematic illustration of the method.
The container blank 14 is fed from a stack o~ blanks 15
to a conventional waxer 16. One pair only oE waxing rolls is
schematically indicated by the numerals 17 and 18. The standard
waxer of the type manufactured by Interna-tioinal Paper Box
Machine Company is very well known. It has four sets of waxing
rolls. The bottom roll of each set extends into a sump o~ hot
wax. ~he hot wa~ is circulated by a pump and sprayed over the
blank and the top rollO The waxer also includes a chill water
tank 19. The ~lanks covered with hot wax are conducted down-
wardly into the chill water to set the wax. This machine and its
operation is so well known that only brief schematic reference to
one set of rolls is reEerred to in the drawings. The blanks are
then fed from the water cooler 19 o~ the waxer to a tape feeder
20 of conventional design and thence to the input table of a pair
of rotating cooperating steel notched embossing dies 24 and 26.
The top embossing die has projections having the con-
figuration of the depressions 12 and the bottom embossing die 26
has corresponding depressions. The embossing dies 24 and 26 are
sychronized so that as they rotate the projections engage in the
depressions to form the depressions 12 over the sur~ace o~ the
blank as it passes therethrough. Numeral 30 is a drive roll that
projects the blanks 1~ into the embossing rolls 2~ and 26. It is
driven through a slip clutch and insures that the blanks are fed
into the rolls as they are delivered fro~l the tape conveyor 2~.




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The speed of tape feeder 20 is synchronized with the speed of the
waxer to deliver the output of the waxer to the embossing rolls.
The embossing rolls deliver their output on-to a slow
moving stacking conveyor 32 that is designed to shingle the embos-

sed blanks prior to manual stacking for shipment as at 3~. Theoperation of a shingle spacer is conventional and not referred to
in detail.
The design of the embosslng rolls and their operation
is not of itself novel. Embossing rolls similar to the rolls 24
and 26 are of known design. The important thing about this inven-
tion is the concept in its entirety of taking the waxed blanks as
they come from the waxer on a continuous basis and feeding them
to embossing rolls. It is the unexpected success with which this
configuration operates in the manufacture of freshly waxed con-

tainer blanks that is of importance in this invention.
It has been found that containers can be continuouslyfed through the system at a speed of about 750 feet per minute.
This speed represents a speed of about 6000 containers per hour.
The invention has worked well with solid steel embos-

sing rolls with no provision for internal cooling and hardened to55 Rockwell C and hard chrome plated. The wax coating is a con-
ventional wax or equivalent coating.
Modifications in the roller arrangement, the wax or
coating composition or feed system within the skill of the art
are contemplated and it is not intended that the description of
the equipment given herein should be read in a limiting sense.
It will be understood that the term "wax" includes any coating
useable for this application. The i-mportant thing is that embos-





sing rolls have successfully worked on an in line con-tinuous sys-
tem from the output of a waxing machine to wax and emboss con-
tainer blanks.




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