U.S. patent application number 15/234738 was filed with the patent office on 2016-12-01 for continuous motion rotating thermoforming of soluble pouches.
The applicant listed for this patent is Rideau Machinery Inc.. Invention is credited to James FOWLER, Boris MAKUTONIN.
Application Number | 20160347521 15/234738 |
Document ID | / |
Family ID | 41565683 |
Filed Date | 2016-12-01 |
United States Patent
Application |
20160347521 |
Kind Code |
A1 |
FOWLER; James ; et
al. |
December 1, 2016 |
CONTINUOUS MOTION ROTATING THERMOFORMING OF SOLUBLE POUCHES
Abstract
A method of producing a water soluble pouch having at least one
compartment containing more than one component includes forming an
open compartment in a base web, adding a component to the
compartment at a sufficiently high temperature to be in a molten
form, and solidifying at least an upper surface of the molten
material. The method further includes adding at least one further
component to the compartment after the upper surface has solidified
to prevent the components mixing with each other and closing the
compartment with a lidding web.
Inventors: |
FOWLER; James; (St. Charles,
IL) ; MAKUTONIN; Boris; (Cincinnati, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rideau Machinery Inc. |
St. Charles |
IL |
US |
|
|
Family ID: |
41565683 |
Appl. No.: |
15/234738 |
Filed: |
August 11, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14151655 |
Jan 9, 2014 |
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15234738 |
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13474493 |
May 17, 2012 |
8662880 |
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14151655 |
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PCT/IB2010/003144 |
Nov 23, 2010 |
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13474493 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65B 2220/14 20130101;
B65B 39/00 20130101; B65B 55/24 20130101; B29K 2029/04 20130101;
B65B 51/026 20130101; B65B 61/08 20130101; B65B 51/16 20130101;
B65B 61/28 20130101; B65B 3/04 20130101; B65B 9/042 20130101; B65B
7/02 20130101; B65B 47/10 20130101; B29C 51/10 20130101; B29K
2105/256 20130101; B65D 65/46 20130101; B65B 61/02 20130101; B29K
2995/0062 20130101; B65B 2230/02 20130101 |
International
Class: |
B65D 65/46 20060101
B65D065/46; B65B 39/00 20060101 B65B039/00; B65B 7/02 20060101
B65B007/02; B65B 47/10 20060101 B65B047/10; B29C 51/10 20060101
B29C051/10; B65B 3/04 20060101 B65B003/04 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 23, 2009 |
GB |
0920445.4 |
Claims
1.-20. (canceled)
21. A method of producing a water soluble pouch having at least one
compartment containing more than one component, the method
comprising: forming an open compartment in a base web; adding a
component to the compartment at a sufficiently high temperature to
be in a molten form; solidifying at least an upper surface of the
molten material; adding at least one further component to the
compartment after the upper surface has solidified to prevent the
components mixing with each other; and closing the compartment with
a lidding web.
22. The method of claim 21 wherein the component having a molten
form is a liquid or a gel.
23. The method of claim 21 wherein the temperature of the component
having a molten form is at least 10 degrees centigrade below the
melting point of the material forming the compartment.
24. The method of claim 21 wherein the at least one further
component is a granular or powder product.
25. The method of claim 21 further comprising adding a three
dimensional solid object to the compartment before the upper
surface of the component having a molten form has solidified.
26. The method of claim 25 wherein the solid object is coated with
a water soluble polymer which is similar or identical to a material
of the pouch.
27. The method of claim 25 wherein the at least one further
component is a granular or powder product added after the upper
surface of the component having a molten form has solidified.
28. The method of claim 25 wherein the at least one further
component is a liquid or a gel product added after the upper
surface of the component having a molten form has solidified.
29. A method of producing a water soluble pouch having at least one
compartment comprising: forming an open compartment in a base web;
adding a three dimensional object to the compartment; and closing
the compartment with a lidding web; wherein the three dimensional
object is coated with a water soluble polymer.
30. The method of claim 29 wherein the water soluble polymer
coating is the same as or similar to the material of the base web
or lidding web.
31. The method of claim 29 wherein the three dimensional object is
a tablet or capsule.
32. A method of filling a compartment of a water soluble pouch, the
method comprising: feeding at least two gels through a nozzle; and
forming the at least two gels in a pattern in the pouch.
33. The method of claim 32 wherein at least one of a composition,
color, or appearance is different between each gel.
34. The method of claim 32 wherein the nozzle is stationary.
35. The method of claim 32 further comprising rotating the
nozzle.
36. Means for producing a water soluble pouch made from at least
two webs comprising soluble polymeric substrates, wherein each web
defines at least two faces, and wherein each face of at least one
web is coated or printed in line.
37. The means for producing a water soluble pouch of claim 36
wherein the at least one coated web forms at least one of a base
web or a top web of the pouch.
38. The means for producing a water soluble pouch of claim 36
wherein the coating is at least one of a color coating, a perfume
coating, an enzyme coating, or an active ingredient coating.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] The present application is a Continuation of U.S. patent
application Ser. No. 14/151,655, filed Jan. 9, 2014, which is a
Divisional of U.S. patent application Ser. No. 13/474,493, filed
May 17, 2012, which is a Continuation of International Application
No. PCT/IB2010/003144, filed Nov. 23, 2010, which claims the
benefit of and priority to United Kingdom Patent Application No.
0920445.4, filed Nov. 23, 2009. The entire disclosures of U.S.
patent application Ser. No. 14/151,655, U.S. patent application
Ser. No. 13/474,493, International Application PCT/M2010/003144,
and United Kingdom Patent Application No. 0920445.4 are
incorporated herein by reference.
BACKGROUND
[0002] This invention relates to soluble packages such as pouches
containing one or more products and to apparatus and method for
producing such pouches. The invention has particular, but not
exclusive, application to thermoformed packages made from two or
more webs comprising polymeric substrates. The webs are soluble or
dispersible in a solvent and may comprise water soluble or water
dispersible films.
[0003] Thermoformed packages comprising a single compartment are
typically made in four steps:
[0004] 1. Forming a pocket in a first web of film (the base
web)
[0005] 2. Filling of the pocket so formed
[0006] 3. Closure of the pocket by means of a second web of film
(the top or lidding web) to form a package.
[0007] 4. Cutting or punching to release the package from the
combined first and second webs of film
[0008] Thermoformed packages are frequently made on intermittent
horizontal machines in which the web is moved through the machine
in intermittent steps allowing each operation described above to be
carried out whilst the web or webs are stationary.
[0009] In such machines, once the base web is moved away from the
forming mould, it begins to cool and unlike many insoluble
polymeric substrates, many soluble webs, including particularly
those comprising substantially polyvinyl alcohol, then experience a
phenomenon known as shrink-back in which the thermoformed film
tries to return to its pre-thermoformed condition thereby reducing
the volume of the thermoformed pocket. This represents a major
problem as the pocket will have reduced in size by the time that it
is filled. To take account of the shrink-back and still maintain
the required fill volume, the thermoformed pocket needs to be made
larger than the fill volume so that it can accept the fill volume
despite the effects of shrinkback. Designing a thermoforming mould
with larger cavities requires either a deeper draw depth, which in
turn often requires a thicker base web provoking slower subsequent
dissolution, or a greater superficial area, known as the footprint,
allowing fewer cavities in either the machine direction or across
the web or both, thereby reducing machine and web material
efficiencies.
[0010] A continuous motion rotary thermoforming machine for making
thermoformed packages is disclosed in U.S. Pat. No. 3,218,776 in
which the base web is heated to a plastic condition and immediately
pressed on to the surfaces of the drum surrounding the pockets. A
heated metal roller is employed to press the web of film against
the surfaces of the drum. The roller is heated to a temperature
sufficient to render the film plastic by the time that it is
pressed against the continuously rotating drum. The actual
temperature will vary depending upon the film, its thickness, and
the length of time that it remains in contact with the heated
roller. The film, by means of the heated roller, may be heated to
about 140.degree. F. (60.degree. C.) but it might be as low as
about 100.degree. F. (37.8.degree. C.) or as high as 300.degree. F.
(148.9.degree. C.). A vacuum is applied to the base of the cavity
in order to draw the web of heated film that covers the cavities
into the cavities and define pockets to receive subsequently the
product to be packaged. The vacuum should be applied instantly
after the cavity is covered with film. In a subsequent operation,
the top web is pressed against the base web, by now containing
filled thermoformed pockets located upon the rotating drum, by
means of a second heated roller which conductively heats the top
web and, by means of a spring, presses the top web over the pockets
containing the packaged product during which both webs are pressed
together on the surfaces surrounding the pockets to achieve a bond.
In the particular case where water-soluble packages are desired,
the top web, prior to arrival at the sealing station, is made
adhesive by moistening with a liquid in which the film of the top
web is soluble, in order that the sealing process can be effected
by a combination of heat and solvent welding.
[0011] In the machine disclosed in U.S. Pat. No. 3,218,776, two
heated rollers provide the sole sources of heat, a first heated
roller heating the base web prior to thermoforming and a second
heated roller heating the lidding web prior to closure of the
pouches. This has a number of disadvantages. Firstly, the base web
begins to cool as soon as it leaves the first heated roller and a
high vacuum is therefore required to hold the base web to the walls
of the cavities and thereby inhibit the occurence of shrink-back.
Secondly, the top web begins to cool as soon as it leaves the
second heated roller, thereby preventing the strongest seal from
being made between the base web and the top web.
[0012] Continuous motion rotating thermoforming offers advantages
compared to intermittent motion horizontal thermoforming,
particularly in respect of higher productivity and reduced
shrink-back. Due to the higher productivity of continuous motion
rotating machines, the time interval between thermoforming and
filling is reduced, thereby allowing the thermoformed web less time
to cool. Nevertheless, shrinkback of soluble webs has remained a
problem, even with continuous motion rotary machines such as
described in U.S. Pat. No. 3,218,776.
SUMMARY
[0013] According to an exemplary embodiment, a method of making a
pouch from two webs comprising soluble polymeric substrates
comprises the steps of rotating a former that comprises a plurality
of cavities around its periphery and one or more heaters around the
former for heating the cavities; heating the cavities; drawing a
base web into the cavities by means of a vacuum to form pockets in
the base web; filling the pockets with at least one component;
closing the pockets with a top web to form a pouch; and heating the
cavities and maintaining the vacuum after the step of drawing the
base web into the cavities in order that, once thermoformed, the
base web is held tightly to a base of the cavities through filling,
sealing and cutting stations until the vacuum is released and the
filled and sealed pouch is ejected from its cavity.
[0014] According to another exemplary embodiment, a method of
making a pouch from three webs comprising soluble polymeric
substrates comprises the steps of rotating a former that comprises
a plurality of cavities around its periphery and one or more
heaters around the former for heating the cavities; heating the
cavities; drawing a micro-perforated or porous base web into the
cavities using a vacuum to form pockets in the base web; filling
the pockets with at least one powder or granular product; closing
the pockets with an intermediate web to create a lower compartment;
evacuating the lower compartment through the micro-perforations or
porosity in the base web; filling the pockets with at least one
powder or granular product or liquid or gel product on top of the
lower compartment; closing the pockets with a top web to create an
upper compartment; and heating the cavities and maintaining the
vacuum after the step of drawing the base web into the cavities in
order that, once thermoformed, the base web is held tightly to a
base of the cavities through filling, sealing, and cutting stations
until the vacuum is released and the filled and sealed pouch is
ejected from its cavity.
[0015] According to another exemplary embodiment, a continuous
motion rotating thermoforming machine for producing pouches made
from two webs comprising soluble polymeric substrates includes a
former having a plurality of pouch forming cavities around its
periphery; a motor configured to continuously rotate the former so
that the cavities follow an endless path in the direction of
rotation of the former through forming, filling, sealing and
cutting stations; one or more heaters disposed around the former
for heating the cavities; and a vacuum configured to apply a vacuum
through the base of each cavity in order that, once thermoformed, a
base web is held tightly to the base of the cavities through
filling, sealing and cutting stations until the vacuum is released
and the filled and sealed pouch is ejected from its cavity.
[0016] According to another exemplary embodiment, a method of
making a pouch from two webs comprising soluble polymeric
substrates includes providing a former having a plurality of
cavities around its periphery; providing one or more heaters around
the former for heating the cavities; continuously rotating the
former; heating the cavities; drawing a base web into the cavities
using a vacuum to form pockets in the base web; filling the pockets
with at least one component; closing the pockets with a top web to
form a pouch; and heating the cavities and maintaining the vacuum
after the step of drawing the base web into the cavities in order
that, once thermoformed, the base web is held tightly to the base
of the cavities through filling, sealing and cutting stations until
the vacuum is released and the filled and sealed pouch is ejected
from its cavity.
[0017] According to another exemplary embodiment, a method of
making a pouch from three webs comprising soluble polymeric
substrates wherein the base web is micro-perforated or porous
comprises providing a former having a plurality of cavities around
its periphery; providing one or more heaters around the former for
heating the cavities; continuously rotating the former; heating the
cavities; drawing a micro-perforated or porous base web into the
cavities using a vacuum to form pockets in the base web; filling
the pockets with at least one powder or granular product; closing
the pockets with an intermediate web to create a lower compartment;
evacuating the lower compartment through the micro-perforations in
the base web; filling the pockets with at least one powder or
granular product or liquid or gel product on top of the lower
compartment; closing the upper compartment with a top web to create
an upper compartment; and heating the cavities and maintaining the
vacuum after drawing the base web into the cavities in order that,
once thermoformed, the base web is held tightly to the base of the
cavities through filling, sealing and cutting stations until the
vacuum is released and the filled and sealed pouch is ejected from
its cavity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic side view of a machine according to a
first embodiment of the invention having external hot air
heaters.
[0019] FIG. 2 is a schematic side view of a machine according to a
second embodiment of the invention having external infra-red
heaters.
[0020] FIG. 3 is a schematic side view of a machine according to a
third embodiment of the invention having internal heaters.
[0021] FIG. 4 is a schematic side view of a machine according to a
fourth embodiment of the invention having two heat sealing
rollers.
[0022] FIG. 5 is a schematic side view of a machine according to a
fifth embodiment of the invention for coating a web.
[0023] FIG. 6 is a schematic side view of a machine according to a
sixth embodiment of the invention for producing pouches having more
than one compartment.
[0024] FIG. 7 is a schematic side view of a machine according to a
seventh embodiment employing an endless belt.
[0025] FIG. 8 is a schematic side view of a machine according to an
eighth embodiment employing an endless belt.
[0026] FIGS. 9.1, 9.2, 9.3, and 9.4 illustrate various pouch
filling operations for use with machines according to the
invention.
DETAILED DESCRIPTION
[0027] The present invention is intended to overcome or at least
mitigate some of the problems and disadvantages aforementioned.
[0028] More especially, this invention seeks to address the problem
of shrink-back of soluble webs in continuous motion rotating
thermoforming machines.
[0029] A preferred aim of this invention is to provide an improved
continuous motion rotating thermoforming machine to make
thermoformed soluble packages containing one or more products and
comprising one or more compartments.
[0030] As used herein, the term "soluble webs" refers to webs of
polymeric substrates which can be dissolved in a solvent. In many
cases, the requirement is for the pouch to dissolve in water or in
an aqueous medium but dissolution in other solvents can be
envisaged where the pouch is required to dissolve in a solvent
other than water.
[0031] As used herein, the term "water soluble" refers to materials
that are capable of being dissolved in water of whatever
temperature to form a homogeneous solution and the term "water
dispersible" refers to materials that are capable of being
dispersed in water of whatever temperature to form a permanent or
temporary suspension. For convenience, where the term "water
soluble" is used hereinafter in the description and claims, it will
be understood this includes "water dispersible".
[0032] As used herein, the term "mould" refers to a constituent
part (containing one or more cavities) of a continuously rotatable
former, the part often being designed to be easily exchanged within
the former in order to produce pouches of different fill volume,
the term "cavity" refers to that part of the mould into which a
base web is drawn during a thermoforming operation, and the term
"pocket" refers to an open container which is formed in a base web
as a result of a thermoforming operation.
[0033] According to a first aspect of the invention, we provide a
continuous motion rotating thermoforming machine for producing
soluble pouches made from two or more webs comprising soluble
polymeric substrates, the machine including a plurality of pocket
forming cavities and means to heat the cavities.
[0034] As used herein, the terms "continuous motion rotating
thermoforming machine" refers to a machine in which thermoforming
is effected by means of cavities in a former that continues to turn
while sequential operations required for the production of soluble
pouches are carried out.
[0035] Preferably, means is provided for rotating the former so
that the cavities follow an endless path in the direction of
rotation of the former through forming, filling, sealing and
cutting stations. The rotating means may comprise a motor, for
example an electric motor, more preferably a variable speed
electric motor.
[0036] The former may comprise a continuously rotating drum with
cavities opening to the outer surface of the drum. Cavities may be
arranged across the width of the drum and/or around the
circumference of the drum. Alternatively, the former may comprise a
continuously rotating endless belt with cavities opening to the
outer surface of the belt. Cavities may be arranged across the
width of the belt and/or along the length of the belt.
[0037] The arrangement and disposition of the cavities across and
along an endless belt can be similar to the arrangement and
disposition of the cavities around a drum. In either case, the
cavities are heated and a vacuum is preferably maintained through
the base of each cavity in order that, once thermoformed, a base
web is held tightly to the base of the cavities through subsequent
filling, sealing and cutting stations until the vacuum is released
and the filled and sealed pouch is ejected from its cavity.
[0038] A rotating endless belt may allow the possibility of greater
space for sequential operations, namely thermoforming, filling, and
sealing, required for the production of soluble pouches from two or
more webs according to this invention. Where the invention is
practiced using a rotating endless belt rather than a rotating
drum, the greater space that may be made available for sequential
operations along that portion of the rotating endless belt that is
disposed horizontally, may be of particular value. The length of
the rotating endless belt that is disposed horizontally can be
varied in order to increase or decrease the space required to carry
out sequential operations. The number of sequential operations will
increase as the number of compartments in the soluble pouch
increases. Thus, a rotating endless belt may be of particular value
in the production of multi-compartment soluble pouches comprising
more than two webs, where successive webs may be thermoformed, and
the successive pockets so formed may be filled and sealed. However
many compartments are contained within the soluble pouch, the top
web that is sealed to the uppermost thermoformed web is not itself
thermoformed.
[0039] The machine has particular application for the manufacture
of water soluble pouches. Depending upon whether they are required
for edible or non-edible applications, water-soluble webs can be
substantially based upon polyvinyl alcohol (PVOH), polyethylene
oxide, modified celluloses such as carboxy-methyl cellulose (CMC)
and hydroxy-propyl methyl cellulose (HPMC), pullulan, certain types
of starch, dextrin, guar gum, gelatine and their derivatives. In
the case where one or more webs is based upon PVOH, their
solubility at a given temperature may be adjusted by selecting a
grade of PVOH with a specific molecular weight and a specific %
saponification. By way of example only, to obtain solubilisation of
a water-soluble film made substantially from PVOH in an aqueous
medium at a temperature at or above 60.degree. C., the PVOH should
preferably be of a fully saponified type i.e. the degree of
saponification ranging from 90-99.5%, and to obtain solubilisation
in an aqueous medium at a temperature of 25.degree. C. and below,
the PVOH should be of a partially saponified type i.e. the degree
of saponification ranging from 71-90%. Hence, the lower the degree
of saponification, the lower the temperature of water required to
dissolve a water soluble film made substantially from PVOH.
[0040] The heating means may be arranged externally and/or
internally of the former and may be of any suitable type for
heating the cavities. The cavities may be heated by convection, for
example hot air heating, or radiation, for example infra-red
heating or conduction, for example electrical heating. Preferably,
the surface temperature of the cavities of the drum or endless belt
is at least 60.degree. C. According to a preferred embodiment of
the invention, the drum or endless belt is heated to a temperature
of between 60.degree. C. and 200.degree. C. (140.degree. F. and
392.degree. F.) in order to reduce or preferably eliminate the
incidence of shrink-back and thereby improve the quality of
thermoforming. This has the benefit of making the complete volume
of the cavity available to receive the product to be filled. A
further benefit is that the reduction or elimination of shrink-back
allows the vacuum within the drum or endless belt to hold the
filled pouches on the drum or endless belt, even after they are
separated by cutting, until the vacuum is removed and the pouches
are released from the drum or endless belt on to a conveyor or
other suitable means for collecting/and or transferring the pouches
away from the machine, for example to a packing unit. It will be
evident that where shrink-back is pronounced, the base web of the
filled pouches can draw itself away from the internal surfaces of
the cavity thereby breaking the vacuum holding the filled pouches
on the drum or endless belt. As a consequence, the filled pouches,
after being separated from each other by cutting knives, will no
longer be held tightly to the drum or endless belt and will fall
away from the drum or endless belt before they arrive at the
conveyor. For effective operation of continuous motion rotating
thermoforming machines, it is essential that the pouches are held
tightly to the drum or endless belt until they are released on to
the conveyor.
[0041] Different levels of vacuum may be provided at different
positions around the drum or endless belt as it rotates according
to the demands of the production being carried out. By way of
example which is by no means limiting, the level of vacuum required
to draw the heated base web into the cavities and hold the base web
in position, thereby avoiding shrink-back, until filling has been
completed will be less than that required to hold the filled and
sealed pouches on the drum or endless belt until they are ejected
from the drum or endless belt by means of air blow off and fall on
to the conveyor transporting the pouches away from the machine.
[0042] The heating of the drum or endless belt may be provided by
precisely placed heaters, some examples of which are described
below:
[0043] Externally mounted hot air heaters (shown at 125 in FIG. 1)
are directed at the cavities in several locations around the
former. An example of a suitable configuration is to locate the hot
air heaters at approximately 4 o'clock, 2 o'clock and 8 o'clock,
i.e. prior to the arrival of the base web over the heated roller
14, after the said roller 14 and after the transverse cutting
knives 22 mounted on a rotating shaft. The number and position of
these locations can be varied. The hot air heaters can be
fabricated to different designs. For example, they can be formed
from a hollow metal bar with a longitudinal bore in which a tubular
heater is installed. Compressed air is supplied from the back and
becomes heated as it moves over the tubular heater, escaping as a
jet of hot air from the narrow slot facing the drum. This is
schematically illustrated in FIG. 1.
[0044] Externally mounted infra-red heaters (shown at 225 in FIG.
2). These can suitably be located at the same points around the
drum as the hot air heaters, although the number and position of
these locations can be varied. This is schematically illustrated in
FIG. 2.
[0045] Internally mounted electrical heaters (shown at 335 in FIG.
3) located within the former itself. These are located near to the
surface of the former in order that heat is easily transferred to
the cavities. This is schematically illustrated in FIG. 3. The air
for ejecting pouches from their cavities on to the conveyor 23 may
be heated by this means in order to provide additional heating to
the drum 10.
[0046] A combination of externally and internally mounted heaters
of the type shown in FIGS. 1 to 3 or any other suitable type.
[0047] The machine may produce soluble pouches made from two or
more water-soluble polymeric substrates. The dissolution
temperature of the two webs may be identical. Alternatively, the
dissolution temperature of the two webs may be different.
Preferably, means is provided for sealing a top web to the base web
(in the case where pouches are made from two webs) or to an
intermediate web (in the case where pouches are made from more than
two webs). Such means may comprise at least one heat sealing
roller. The strength of the seal between the webs may be enhanced
by sequentially mounted heated sealing rollers. According to a
preferred embodiment of the invention, a second heated sealing
roller (shown at 21 in FIG. 4) is installed in such a position that
it presses upon the sealed webs after they have been sealed by a
first heated sealing roller 16. The addition of the second heated
sealing roller has been found to greatly improve the quality of the
seals. This is particularly important where the pouches are filled
with liquids or gels of low viscosity. Liquids having viscosities
between 10,000 and 60,000 centipoise at 20.degree. C. have been
successfully packaged by means of this arrangement.
[0048] Preferably, means is provided to coat or print a web
in-line. For example, a web may be coated or printed in line by a
roller mounted between the web unwind and a heated sealing roller.
A third web may be introduced in order to produce two compartment
pouches. In the case of multi-compartment pouches wherein the webs
comprising polymeric substrates are water-soluble, the compartments
of a pouch may open sequentially as a result of changes in water
temperature or pH.
[0049] A coated web may be required to form the base or top web.
The coating may be a colouring or any other coating that is
sufficiently miscible with the solvent to form a homogeneous
coating medium. This is usually achieved by procuring differently
coated webs from film suppliers, which is costly and may present
logistical problems, especially when there is a requirement to
produce pouches of the same size with different coatings.
[0050] According to a preferred embodiment of the invention,
illustrated schematically in FIG. 5, the top web is coated in-line
by adding a mixing tank 30 that is supplied by a solvent such as
water through inlet tube 32 and by a coating or printing
concentrate through inlet tube 33. The base web may also be coated
as well as or instead of, the top web in a similar manner to that
illustrated in FIG. 5. The coating or printing concentrate and
water proportions are regulated within the mixing tank 30 in order
to achieve the desired coat weight on the web. The coating or
printing medium is then fed to the wetting tank 34 via supply tube
31. An example of a coating that can be applied to the sealing face
of either web according to this aspect of the invention is a
colouring, either as an ink that is miscible with the solvent or as
a pigment suspension in the solvent. It will be evident that whilst
colouring, perfume, or any other concentrate or active ingredient
can be coated on either face of one or more of the webs by this
method, the same cannot be included within the mass of a web by
this method. Where inclusion within the mass of the web is
required, the colouring, perfume, or any other concentrate or
active ingredient must be incorporated into the mix prior to
casting or extrusion of the web.
[0051] The machine may produce pouches made from two or more
polymeric substrates. The polymeric substrates may be
water-soluble. The dissolution temperature of the two webs may be
identical. Alternatively, the dissolution temperature of the two
webs may be different. In the case of multi-compartment pouches
wherein the webs comprising polymeric substrates are water-soluble,
the compartments of a pouch may open sequentially as a result of
changes in water temperature or pH.
[0052] In one preferred embodiment, the present invention provides
a continuous motion rotating thermoforming machine for producing
water-soluble pouches made from two or more webs comprising
water-soluble polymeric substrates including a rotating former
having a plurality of pouch forming cavities around its periphery,
wherein the former has means to be heated and means to apply a
vacuum through the base of each cavity in order that, once
thermoformed, a base web is held tightly to the base of the
cavities through filling, sealing and cutting stations until the
vacuum is released and the filled and sealed pouch is ejected from
its cavity.
[0053] The base web may be micro-perforated or made porous by other
means. Two webs (a base web and a top web) may be employed for
pouches having a single compartment. One or more additional webs
(intermediate webs) may be employed for pouches having two or more
compartments.
[0054] For pouches having two or more compartments, the webs may
dissolve under the same conditions. In this way, the compartments
may open at substantially the same time. Alternatively, the webs
may dissolve under different conditions. In this way the
compartments may open at different times. Preferably, the
compartments of the pouches open sequentially as a result of
changes in water temperature or pH.
[0055] In another preferred embodiment, the present invention
provides a continuous motion rotating thermoforming machine for
producing water-soluble pouches containing two or more compartments
made from a plurality of webs comprising water-soluble polymeric
substrates, including a continuously rotating former having a
plurality of cavities around its periphery, wherein the former has
means to be heated and means to apply a vacuum through the base of
each cavity, in order that, once thermoformed, a base web is held
tightly to the base of the cavities through filling, sealing and
cutting stations until the vacuum is released and the filled and
sealed pouch is ejected from its cavity.
[0056] The base web may be micro-perforated or made porous by other
means. In the case of pouches containing two compartments, a third
web may be provided.
[0057] The machine may produce pouches made from three polymeric
substrates. The polymeric substrates may be water-soluble. The
dissolution temperature of the three webs may be identical. In this
way, the compartments may open at substantially the same time.
Alternatively, the dissolution temperature of the three webs may be
different. In this way the compartments may open at different
times. Preferably, the compartments of the pouches open
sequentially as a result of changes in water temperature.
Alternatively or additionally, the pouches may open as a result of
changes in pH or any other factor affecting solubility of the
polymeric materials employed.
[0058] According to a preferred embodiment, the third web is
mounted on the machine in order to provide pouches having two
compartments as schematically illustrated in FIG. 6. The base web
13 is fed into the machine as described previously. However, in
this embodiment of the invention, the base web is micro-perforated
or made porous by other means either by the supplier or in-line by
means of a perforation unit 25 mounted on the machine or by other
means. As soon as the porous base web has reached the heated drum
or endless belt, the micro-perforations or other porous means allow
air to be drawn through the base web by means of the vacuum within
the former. In the case of micro-perforation, the number, size and
pattern of the micro-perforations should be insufficient to
interfere with effective thermoforming of the base web. The first
product is filled from the first product hopper or injector 18 and
a second web 20 is then sealed to the base web to make a first
lower compartment in a similar manner to that described in earlier
aspects of the invention. However, the presence of
micro-perforations or other porous means in the base web now allow
the lower compartment to be evacuated by the vacuum within the drum
or endless belt as soon as the second web has been sealed to the
base web. As a result of the evacuation of air from the first lower
compartment through the micro-perforations or other porous means,
the second web 20 is drawn down into the cavity thereby creating
space for the second product to be filled from product hopper or
injector 19 on top of the second web thereby creating a second
upper compartment. This second upper compartment is now filled and
then closed by sealing with the third web 21 by means of the heated
roller 17. Preferably, the lower compartment will be filled with a
powder or granular product. The upper compartment can contain
either a second powder or granular product or a liquid or gel
product.
[0059] Other porous means can include the inclusion of mineral
particles of a suitable size in a web thereby making the web porous
due to the creation of minute air channels around the particles,
but this means is by no means limiting. Where mineral particles are
included in a web to create porosity, the particle size is
typically greater than the thickness of the web.
[0060] According to a second aspect of the invention, one or more
novel filling operations may be employed for varying the contents
of the pouch. Examples of these operations can be seen in FIGS.
9.1, 9.2, 9.3 and 9.4, although these illustrations are by no means
limiting.
[0061] In one filling operation, a spherical, hemispherical,
ellipsoidal or any other three dimensional shaped object, for
example a tablet or capsule although these examples are by no means
limiting, may be placed in a thermoformed pocket either prior to,
at the same time as, or following, the filling of a liquid, gel,
granular or powder composition into one or more compartments of a
water-soluble pouch.
[0062] Such a three dimensional shaped object may contain an active
material not present in the liquid or gel. In the case where one or
more of the materials comprised within the three dimensional shaped
object is antagonistic with one or more materials comprised within
the liquid or gel, the three dimensional shaped object can be
coated with a water-soluble polymer, which may for example comprise
the same or similar polymeric materials as comprise one or more of
the webs used to make the pouch.
[0063] The three dimensional shaped object may not necessarily
completely dissolve when the pouch is placed in contact with an
aqueous medium. For example, it can be hollow, insoluble in an
aqueous medium, and perforated such that its contents are released
when placed in contact with an aqueous medium but the perforated
shell of the three dimensional shaped object survives
undissolved.
[0064] In another filling operation, with or without the additional
presence within a compartment of a three dimensional shaped object,
a combination of one or more of a liquid or gel and a granular or
powder product may be present in a compartment of the water-soluble
pouch. In order to prevent the components mixing with each other
thereby destroying the visual identity of each, the liquid or gel
may be filled at a sufficiently high temperature for it to be in
molten form. At least the upper surface of the molten material
solidifies so rapidly within the pocket that a granular or powder
product can be subsequently filled without the components mixing
substantially with each other. The temperature of the molten liquid
or gel must not sufficiently high to cause any distortion of the
thermoformed water-soluble web within the pocket. Where the
water-soluble web within the pocket receiving the molten liquid or
gel comprises substantially poly-vinyl alcohol, the temperature of
the molten liquid on contact with the thermoformed web should not
exceed 10.degree. C. below the melting point of the web if
distortion is to be avoided.
[0065] The base web can be micro-perforated either in-line whilst
mounted on the machine or off line by the film supplier or a
sub-contractor thereof, by mechanical means or by means of lasers
or by any other suitable means such as a needle located in the base
of each cavity. The porosity of the micro-perforated base web can
be adjusted by varying the number and/or pattern of
micro-perforations per square meter, or by varying the diameter of
the micro-perforations. At least one micro-perforation is required
in each portion of the base web that is subsequently thermoformed
to comprise the base of the lower compartment.
[0066] In a third aspect, the present invention provides a
continuous motion rotating thermoforming machine wherein the seal
between a top web and a second web is enhanced by at least one
further heated sealing roller mounted after a first heated sealing
roller.
[0067] In a fourth aspect, the present invention provides a
continuous motion rotating thermoforming machine wherein one or
more webs is coated or printed in line on either face by a roller
mounted between a web unwind and a heated sealing roller.
[0068] Machines according to the third and fourth aspects of the
invention may include any of the features of the machine according
to the first aspect of the invention.
[0069] The invention also provides a method of using a machine
according to any preceding aspect of the invention to produce
soluble pouches from two or more polymeric substrates, preferably,
water soluble pouches.
[0070] The invention also provides a machine as defined in claim 1.
Preferred features of the machine are defined in claims 2 to 15. A
method of using the machine is defined in claims 16 to 23, a pouch
made by the method is defined in claim 24, and a method of forming
a pouch is defined in claim 25.
[0071] In the following description, like reference numerals are
used to indicate the same or similar parts and the arrangement and
operation of these parts in later embodiments will be understood
from the description of earlier embodiments.
[0072] Referring first to FIGS. 1 to 6, embodiments employing a
drum 10 with cavities 11 are shown. The drum is continuously
rotated by any suitable means such as a motor via drive shaft 10a,
preferably an electric motor and more preferably a variable speed
electric motor.
[0073] In each of FIGS. 1 to 3, the drum 10 is heated and in
particular cavities 11 in the drum 10 are heated by different means
as described previously. In FIG. 1, externally mounted hot air
heaters 125 are employed. In FIG. 2, externally mounted infra-red
heaters 225 are employed. In FIG. 3, electrical heaters 325 located
within the drum are employed.
[0074] The drum 10 is rotated in the direction indicated by arrow
12. Soluble pouches are formed from two webs that are drawn
respectively from rolls 13 and 20. The webs preferably comprise
soluble polymeric substrates such as water soluble films which may
dissolve at the same temperature. The first (base) web from roll 13
is guided around a heated roller 14 which presses it tightly over
cavities 11 located around the circumference of the drum into which
the film is drawn by suction from within the drum 10, thus forming
pockets. The surface temperature within the cavities 11 and the
temperature of the heated roller 14 will depend on the type of
film, its thickness, and the speed of rotation of the drum.
Preferably, the surface temperature within the cavities is at least
60.degree. C. The surface of the drum surrounding the cavities
should be smooth, preferably polished. The pockets are filled at
the top (12 o'clock) of the drum 10 from a filling hopper or
injector 18 and in the case of a granular or powder product, the
fill is smoothed by wipers (not shown) which also clean product
from the upper surface of the film surrounding the pockets. The
second (top or lidding) web from roll 20 is made adhesive by
moistening to a sufficient extent by means of a felt roller 15
rotating within a bath of liquid in which the top web is soluble.
It is important that the amount of liquid applied to the surface of
the top web to make it adhesive is controlled very accurately. If
too little liquid is applied, the required adhesiveness will not be
obtained. If too much liquid is applied, the film will be weakened
and in the limit, even dissolved. It has been found that the amount
of liquid can be controlled very accurately by moving the web from
roll 20 along a vertical path, which in FIGS. 1 thru 3 is defined
by roller 16. By maintaining the surface of the liquid in the bath
at a given height with respect to the point of application (or a
given distance between the point of application and the surface of
the bath), the amount of liquid actually applied to the surface of
the film will be accurately controlled. The top web and base web
are then pressed together as the top web passes beneath a heated
roller 16 which is elastically pressed by a spring (not shown)
against the surfaces of the drum 10 surrounding the cavities such
that the periphery around the filled pouches is securely sealed by
a combination of heat and solvent welding. While still held in
their cavities by the vacuum within the drum, the sealed pouches
are then separated from each other by means of transverse knives 22
and longitudinal knives (not shown), after which they are ejected
by means of air blow-off and fall on to the conveyor belt 23.
[0075] Referring now to FIG. 4. The drum 10 may be heated by any
one of the different methods described above with reference to
FIGS. 1 to 3 or it may be unheated, The quality of the seal between
the base web and the top web is enhanced by the addition of a
second heated sealing roller 21 located at between 10 and 11
o'clock. This second heated roller has been found to be
particularly beneficial at enhancing the seal quality of pouches
filled with liquids and gels. The enhanced quality of the seals has
been evidenced by rigorous comparative testing within a vacuum
chamber of sealed pouches made with and without the use of a second
heated roller 21. Other features of the machine will be understood
from the description of previous embodiments.
[0076] Referring now to FIG. 5. The drum 10 may be heated by any
one of the different methods described above with reference to
FIGS. 1 to 3 or it may be unheated. The top web from roll 20 may be
coated or printed prior to its arrival at the drum. Whilst it is
more usual for the top web to be coated or printed on its sealing
surface, this invention allows a web to be coated on either side.
Whilst an obvious application is to apply a colour coating to the
sealing surface of the top web, any type of coating can be imagined
including perfumes, enzymes and active ingredients. The coating may
be conveniently prepared in an adjacently situated mixing tank 30
before being fed to the moistening bath 34 via supply tube 31.
Other features of the machine will be understood from the
description of previous embodiments.
[0077] Referring now to FIG. 6. The drum 10 may be heated by any
one of the different methods described above with reference to
FIGS. 1 to 3 or it may be unheated. Multi-compartment pouches are
produced using additional webs in addition to the two webs
described in previous aspects of the invention. In this embodiment,
the base web from roll 13 is preferably micro-perforated by an
in-line perforation unit 25 or off-line by the film supplier or by
a sub-contractor. The perforations made by the in-line unit 25 may
be made mechanically, by laser, or by any other suitable means. The
base web may also be perforated during the thermoforming process by
means of one or more needles located at the base of each cavity.
The pocket formed by the base web is filled from hopper or injector
18 and closed by the web from roll 20. Once the lower filled
compartment formed by the base web and the second web from roll 20
has been sealed by the first heated roller 16, the presence of
perforations in the base web 13 comprising the thermoformed
substrate of the first compartment, allows the lower compartment to
be evacuated of any air contained within the filled product by
means of the vacuum within the drum. As a result of evacuating the
air from within the product that has been filled and sealed within
the lower compartment, the second web from roll 20 comprising the
lid of the lower filled and sealed compartment may be drawn down by
the vacuum within the drum such that space is created within the
cavity for an upper compartment which can then be filled with
product from the hopper or injector 19. In turn, a top web 21 is
drawn from an unwind, moistened with solvent by means of a felt
roller 24 and then sealed by a heated roller 17 to form an upper
compartment in the pouch. Other features of the machine will be
understood from the description of previous embodiments.
[0078] Other methods of producing multi-compartment pouches may be
used avoiding the need for micro-perforation of the base web. The
base web may be made porous by means other than micro-perforation
such as by impregnating the base web with particulate matter
providing minute path ways through the web, although this example
of how the base web may be rendered porous is by no means limiting.
By whatever method the base web is rendered porous, the second web
may be pulled down into the cavity by means of the vacuum within
the drum in a similar manner to that described above where the base
web was perforated. Alternatively, the base web may not be rendered
porous and instead of using the vacuum within the drum or endless
belt to pull down the second web into the cavity, the second web
may be pressed into the base of the cavity by mechanical means or
by means of air jets placed externally across the web immediately
prior to the filling station.
[0079] In this embodiment of the invention, when the base web has
been rendered porous by whatever means, the product contained
within the lower compartment is preferably granular or powdery in
nature in order to prevent escape of product through the porous
web. In the case of pouches comprising two or more compartments, in
which at least the lower compartment contains either a liquid or a
gel, the base web is typically not rendered porous.
[0080] Referring now to FIGS. 7 and 8. The drum 10 is replaced by
an endless belt 100 having cavities 11 The belt 100 is illustrated
in side elevation rotating in an almost elliptical path which
nevertheless contains horizontal sections. This allows greater
space for filling more than one product in a single compartment
pouch. The belt 100 is continuously rotated by any suitable means,
for example by a motor via gear wheel 100a, preferably an electric
motor and more preferably a variable speed electric motor.
[0081] In FIG. 7 two filling operations are shown with two filling
equipment's 18 and 194 filling different products before the single
compartment pouch is closed by a top web 20 being sealed to the
thermoformed base web by means of a heated sealing roller 16.
[0082] In FIG. 8, three filling operations are shown with three
filling equipment's 18, 194 and 195, each capable of filling
different products in a single compartment before the single
compartment pouch is closed by a top web 20 being sealed to the
thermoformed base web by means of a heated sealing roller 16.
[0083] It will be understood that the cavities contained within the
endless belt 100 in FIGS. 7 and 8 can be heated by any of the means
described previously. It will also be understood that the endless
belt may be used to produce pouches having a single compartment or
multiple compartments as described previously.
[0084] Referring now to FIGS. 9.1, 9.2, 9.3 and 9.4. Various
options for filling pouches made by the above described machines
are shown.
[0085] FIG. 9.1 illustrates how a single compartment pouch can
contain two different products which do not mix together and
thereby become potentially antagonistic. This is achieved by
filling first a molten gel, and then by providing cooling means to
the upper surface of the gel such that it cools sufficiently to
form a skin, a granular or powder product is subsequently filled
directly upon the solidified upper surface of the gel, such that
the two products do not mix together.
[0086] FIG. 9.2 illustrates a single compartment pouch containing
three different products which are filled such that they do not mix
and thereby become potentially antagonistic. This is achieved by,
in addition to what has been illustrated in FIG. 10.1, providing a
three dimensional solid object, here shown as a sphere which is
inserted into the molten gel before the molten gel has formed a
solid skin on its upper surface. In order to prevent chemical or
physical interaction between the three dimensional solid object and
the molten gel, the three dimensional solid object is coated,
either in-line by means of the machine of this invention or
off-line using a separate process, with a polymeric material which
is similar or identical to the material of either or both of the
webs used to produce the pouch. The filling of the pouch is
completed with a granular or powder being filled upon the by now
solidified upper surface of the molten gel.
[0087] FIG. 9.3 illustrates a single compartment pouch containing
three different products similar to that illustrated in FIG. 10.2
except that here, the filling of the pouch is completed with a
liquid or a second type of gel being filled upon the by now
solidified upper surface of the molten gel.
[0088] FIG. 9.4 illustrates a single compartment pouch containing a
multiple gel fill using either stationary or rotating nozzles, each
gel having a different composition, colour and/or appearance in
order to create an attractive pattern within the pouch.
[0089] It will be understood that the invention in its various
aspects is not limited to the embodiments above-described which are
provided by way of example only and that features of any of the
embodiments may be employed separately or in combination with
features of any other embodiments.
[0090] List of references used in the drawings:
TABLE-US-00001 10 A rotating drum 10a Drive shaft 11 Pocket forming
cavities contained around the circumference of the rotating former
12 Arrow denoting the direction of rotation of the former 13 Unwind
of a first web 14 Heated roller imparting heat to a base web as it
arrives at the former 15 Felt roller imparting solvent to a web 16
Heated sealing roller 17 Heated sealing roller 18 Filling device,
hopper or injector, filling the cavities as they pass beneath 19
Filling device, hopper or injector, allowing filling of a second
compartment within a pouch 20 Unwind of a second web 21 Heated
sealing roller 22 Transverse cutting knives mounted on a rotating
shaft 23 Conveyor transporting sealed and filled pouches away from
the machine 24 A second felt roller imparting solvent to a web 25
An in-line perforating device 26 Unwind of a third web 30 Mixing
tank 31 Supply tube from mixing tank to wetting tank 32 Solvent
supply tube 33 Coating or printing medium supply tube 34 Moistening
bath 100 A rotating endless belt 100a Gear wheel 125 Externally
mounted hot air jets 194 Filling device, hopper or injector,
allowing filling of a second product within a pouch comprising a
single compartment 195 Filling device, hopper or injector, allowing
filling of a third product within a pouch comprising a single
compartment 225 Externally mounted infra-red heaters 325 Internally
mounted electrical heaters
* * * * *