U.S. patent application number 10/560395 was filed with the patent office on 2006-11-23 for easy open water soluble blister package.
This patent application is currently assigned to Plantic Technologies Ltd.. Invention is credited to Mark Fink, David Macinnes.
Application Number | 20060260973 10/560395 |
Document ID | / |
Family ID | 31954155 |
Filed Date | 2006-11-23 |
United States Patent
Application |
20060260973 |
Kind Code |
A1 |
Macinnes; David ; et
al. |
November 23, 2006 |
Easy open water soluble blister package
Abstract
A blister package consists of a backing sheet (16) of cardboard,
paper or plastic adhered to a blister (17) in which at least one or
both of the backing sheet and the blister is made from a
transparent water soluble thermoformable polymer composition. A
tooth brush, cleaning utensil or garden utensil enclosed in the
water soluble packaging material can be opened by placing it under
running water. The packaging material is a starch or modified
starch based polymer by direct contact with water, and that
biodegrades in waste water. The preferred starch is a high amylose
maize starch. The starch can also be derived from wheat, potato,
rice, oats, arrowroot and pea sources. The backing sheet is adhered
to water and applying the backing sheet with the use of a press
plate (24).
Inventors: |
Macinnes; David; (Victoria,
AU) ; Fink; Mark; (Victoria, AU) |
Correspondence
Address: |
CONNOLLY BOVE LODGE & HUTZ LLP
P.O. BOX 2207
WILMINGTON
DE
19899-2207
US
|
Assignee: |
Plantic Technologies Ltd.
Unit 2/2227-231 Fitzerald Road
Victoria
AU
3026
|
Family ID: |
31954155 |
Appl. No.: |
10/560395 |
Filed: |
June 21, 2004 |
PCT Filed: |
June 21, 2004 |
PCT NO: |
PCT/AU04/00794 |
371 Date: |
December 13, 2005 |
Current U.S.
Class: |
206/528 |
Current CPC
Class: |
B65D 65/46 20130101;
C08L 3/04 20130101; C08L 2205/02 20130101; C08L 31/04 20130101;
C08L 3/08 20130101; Y02W 90/13 20150501; C08L 3/02 20130101; C08L
29/04 20130101; B65D 75/366 20130101; C08L 23/08 20130101; C08L
2205/03 20130101; Y02W 90/10 20150501; C08L 3/06 20130101; C08L
67/00 20130101; Y02W 90/11 20150501; C08L 3/04 20130101; C08L
2666/02 20130101; C08L 3/06 20130101; C08L 2666/02 20130101; C08L
3/08 20130101; C08L 2666/04 20130101; C08L 3/08 20130101; C08L
2666/02 20130101 |
Class at
Publication: |
206/528 |
International
Class: |
B65D 85/42 20060101
B65D085/42; B65D 83/04 20060101 B65D083/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 20, 2003 |
AU |
2003903116 |
Claims
1. A product and package combination in which a significant portion
of the package is sufficiently water soluble that the package can
be disintegrated by exposure to water to allow access to the
product.
2. A blister package comprising a backing sheet adhered to a
blister in which at least one or both of the backing sheet and the
blister is made from a transparent water solublethermoformable
polymer composition.
3. A blister package as claimed in claim 2 consisting of a backing
sheet of cardboard, paper or plastic and the blister is made from a
transparent water solublethermoformable polymer composition.
4. A blister package as claimed in claim 2 in which the adhesion
between the backing sheet and the blister is achieved by wetting
the blister with water.
5. A blister package as claimed in claim 2 in which the water
soluble polymer is partially coated with a water insoluble coating
to expose a portion of the water soluble polymer for easy opening
of the package.
6. A package as claimed in claim 1 in which the water soluble
polymer is selected from water soluble starch or modified starch
polymers water soluble polyesters or polyvinyl alcohol or blends of
these polymers with natural polymers such as starch or modified
starch.
7. A package as claimed in claim 1 in which the water soluble
packaging material is made from a) from 8 to 95% by weight of a
modified starch preferably starch modified to include an
hydroxyalkylC26 group or modified by reaction with an anhydride of
a dicarboxylic acid from b) 0 to 80% of starch c) from 0.5 to 20%
by weight of a water soluble polymer selected from polyesters,
polyvinylacetate, polyvinyl alcohol and copolymers of ethylene and
vinylalcohol which have a melting point compatible with the molten
state of the starch components
Description
[0001] This invention relates to an easy open package particularly
blister type packages for products which can withstand being
wet.
BACKGROUND TO THE INVENTION
[0002] Most manufactured products are presented for sale in
packages. The packaging material usually of paper paperboard and/or
plastics needs to be printable and also to protect the articles.
For personal hygiene products the articles usually are sealed to
ensure the hygiene standards for the product. Consumers usually
like to be able to see what they are purchasing so that it is
common for at least part of the packaging material to be
transparent. Blister packs where a transparent thermoformed polymer
layer is bonded to a paper or card board backing is a common
packaging method for products of this type.
[0003] Tooth brushes are commonly enclosed in a blister pack of
transparent thermoformed plastic material enclosing the brush with
a paper or paperboard panel at the back. The packaging of tooth
brushes has been the subject of a number of patents. U.S. Pat. No.
4,588,089 discloses a disposable brush and paste package. U.S. Pat.
No. 4,890,732 discloses a package for a handle and disposable brush
heads. USA application 2003/0012594 discloses a disposable brush
with paste adhered to the handle. None of these patents address the
problem of easy opening the packages to access the product.
[0004] Blister packages can be difficult to open as the materials
used do not tear easily and it is often necessary to use scissors
to open the package. The package then has to be disposed of and
packaging of this sort adds to the environmental burden of waste
disposal because the materials are not readily biodegradable.
[0005] Other articles are packaged in a similar fashion and present
similar difficulties in opening and the disposing of the packaging
material.
[0006] Soluble packages have been proposed for chemical or food
products that need to be dispersed or mixed with water. U.S. Pat.
Nos. 5,827,586 and 6,484,879 are examples of water soluble
packaging for water dispersible agrichemicals. Patent application
WO02/077354 discloses a water soluble package for laundry
detergent. WO03/016165 discloses a water soluble controlled release
package.
[0007] Japanese abstract 09124804 discloses a hot water soluble
wrapping for raw meat. None of the films disclosed in these patents
are useful in blister packaging and only some are fully
biodegradable.
[0008] It is an object of this invention to provide an easily
opened package that is also easily disposed of in an
environmentally responsible fashion.
BRIEF DESCRIPTION OF THE INVENTION
[0009] To this end the present invention provides a product and
package combination in which a significant portion of the package
is sufficiently water soluble that the portion of the package can
be disintegrated by exposure to water to allow the package to be
easily opened.
[0010] This package combination may be applied to any product but
especially to products that are usually opened in the vicinity of
water such as cleaning utensils, garden utensils and some food
stuffs such as vegetables.
[0011] A tooth brush enclosed in a water soluble packaging material
may be opened by placing it under water or a running tap or faucet
so that the packaging material is disintegrated, exposing the tooth
brush ready for use.
[0012] The packaging material is preferably composed of a
thermoformed transparent water soluble polymer composition
preferably alone or with a paper or other material for the rear of
the package, that is easily disintegrated by contact with water and
biodegrades in waste water systems. Such polymers may be water
soluble starch or modified starch polymers, soluble polyesters or
polyvinyl alcohol or blends of these polymers with natural polymers
such as starch or modified starch.
[0013] The advantage of this invention is that the product is
easily released from its packaging and at the same time is
instantly disposed of as a waste water effluent. In the case of a
tooth brush the consumer usually opens the package in front of a
basin and would turn on the tap or faucet to use the brush. Thus
the combination provides two significant benefits.
[0014] Not all biodegradable materials are water soluble so that
prior art packages made from biodegradable materials could not be
opened by the action of water and would have to be disposed of as
solid house hold waste.
[0015] The packaging method that is most suitable for use in this
invention is blister packaging consisting of a backing or top sheet
and a thermoformed blister adhered to the backing. In a preferred
form of this inventuion the adhesion between the backing sheet and
the blister is achieved by wetting the blister with water and
preferably applying pressure to achieve adhesion.
[0016] The preferred water soluble polymers are those based on
starch or modified starch alone or blended with other water soluble
synthetic polymers such as water soluble grades of polyvinyl
alcohol.
[0017] A preferred biodegradable polymer has the composition
[0018] a) from 8 to 95% by weight of a modified starch preferably
starch modified to include an hydroxyalkyl C.sub.2-6 group or
modified by reaction with an anhydride of a dicarboxylic acid
[0019] b) from 0 to 80% of starch
[0020] c) from 0.5 to 20% by weight of a water soluble polymer
selected from polyesters, polyvinylacetate, polyvinyl alcohol and
copolymers of ethylene and vinylalcohol which have a melting point
compatible with the molten state of the starch components and
optionally
[0021] d) from 0 to 20% by weight of a polyol plasticiser
[0022] e) from 0.1 to 1.5% by weight of a C.sub.12-22 fatty acid or
salt and
[0023] f) from 0 to 15% by weight of added water.
[0024] The composition defined include formulations suitable for
forming films or thermoforming rigid products such as transparent
blister packs. The extruded sheet can be thermoformed into blister
packs for use as biodegradable packaging. Usually the need to vent
the extruder to remove water prior to the product exiting the
extrusion die is not needed with these formulations.
[0025] Other processing methods may be used including injection
moulding, extruded shapes including tubes, cast films for wraps and
thermoformed sheet.
[0026] The modified starch contributes structural benefits to the
resulting material. A preferred component is hydroxypropylated
amylose. Other substituents can be hydroxyethyl or hydroxybutyl to
form hydroxyether substitutions, or anhydrides such as maleic
phthalic or octenyl succinic anhydride can be used to produce ester
derivatives. The degree of substitution [the average number of
hydroxyl groups in a unit that are substituted] is preferably 0.05
to 2.The preferred starch is a high amylose maize starch. A
preferred component is a hydroxypropylated high amylose starch A939
marketed by Penford Australia.
[0027] The other starch component is any commercially available
starch. Dependent on the mechanical and optical properties
required, a preferred concentration range for starch is 50 to
70.6%. This may be derived from wheat, maize, potato, rice, oat,
arrowroot, and pea sources. Generally the water content is about 8
to 15%. The polymer component c) of the composition is preferably
compatible with starch, water soluble, biodegradable and has a low
melting point compatible with the processing temperatures for
starch. Polyvinyl alcohol is the preferred polymer but polymers of
ethylene-vinyl alcohol, ethylene vinyl acetate or blends with
polyvinyl alcohol may be used. A preferred concentration range for
sheet material is 7 to 9%.
[0028] The preferred plasticiser is a polyol particularly glycerol
although ethylene glycol and diethylene glycol are also suitable as
is sorbitol. Cost and for some products food contact, are important
considerations in choosing the appropriate plasticizer. For low
humidity environments it has been found that lower plasticizer
content improves the toughness and long term resilience of the
material. This is partly due to the properties of the starch ether
component and the fact that at low humidity plasticizers such as
glycerol tend to remove water from the starch polymer and make it
more brittle. It is possible to process the formulation with no
plasticizer and the rigid polymer formed is flexible and has good
impact resistance at low humidity. When the plasticiser content is
low additional water is added to improve processing. Thus the
plasticizer content is preferably 0 to 15% and the water content is
15 to 0%. For film processing the plasticizer content is preferably
higher than for rigid sheet products. Higher concentrations of
plasticiser improve flexibility and for flexible packaging films or
other thin films the preferred plasticiser content is 10 to
16%.
[0029] The fatty acid or fatty acid salt component is preferably
present in concentrations of 0.4 to 1%. Stearic acid is the
preferred component. Sodium and potassium salts of stearic acid can
also be used. Again cost can be a factor in the choice of this
component but lauric, myristic, palmitic, linoleic and behenic
acids are all suitable. It is found that the acid tends to
accumulate near to the surface of the composition as it is
extruded.
DETAILED DESCRIPTION OF THE INVENTION
[0030] A preferred embodiment of the invention will be described
with reference to the drawings in which
[0031] FIG. 1 is a side view of blister package to which this
invention is applied.
[0032] FIGS. 2 and 3 illustrate one method of forming a blister
pack according to this invention.
[0033] The package as shown consists of a thermo formed product
tray 12 boded at the peripheral sealing edges 13 to a backing
material 11. The backing material 11 is often of card board or
paper while the blister 12 is a transparent thermoformed tray of
water soluble material. The backing 11 may also be formed from the
same material as the blister tray 12. To facilitate easy opening
only a portion of the tray or backing need be water soluble. For
example the area 14 may be formed of water soluble material and the
remainder of the package could be water insoluble. The water
soluble portion 14 is large enough to allow easy access to the
contents once the film is dissolved away. Such a water soluble
portion can be created by forming the tray from a laminate having
an inner water soluble layer and an outer water insoluble layer
with a hole at area 14 exposing the water soluble inner layer. The
blister material is preferably formed from a thermo formable starch
polymer composition of the formula TABLE-US-00001 A939 % PVOH %
Stearic acid % Water % Glycerol % 81.5 8 0.5 10 0
[0034] A 939 is an hydroxypropylated high amylose starch marketed
by Penford Australia. An alternative and cheaper formulation is to
replace 50% of the A939 with wheat starch.
[0035] Processing conditions depend on the formulations and the
desired properties of the product to be produced. The materials
need to be heated above 130.degree. C. in the extruder to fully
gelatinise the starches. The die temperature needs to be controlled
below 110.degree. C. to avoid foaming.
[0036] The preferred method of carrying out this invention involves
mixing the starch, modified starch, vinylalcohol polymer lubricant
and fatty acid components into a free flowing powder. The premixing
can be carried out in any conventional mixer. The powder is then
introduced into a screw extruder and subjected to an elevated
temperature by the shearing action of the screw and the application
of external heat to the barrel. The temperature equilibrates to an
adiabatic profile ranging 40.degree. C. to 150.degree. C. Any
liquid components including additional water are introduced by
liquid injection or in the premix. The melt that is formed is then
propelled toward the die where the temperature is reduced to a
value in the range of 65.degree. C. to 105.degree. C. A typical
extrusion for rigid products in a single stage process has the
following parameters:
Temperature profile .degree. C.: 60, 70, 90, 110, 130, 145, 130,
120, 110
Screw Speed: 120 rpm
In a two-stage process, where compounding and sheet forming are
separated, the compounding processing conditions are typically:
Temperature profile .degree. C.: 50, 50, 65, 130, 130, 90, 65
Screw Speed: 150 rpm
And sheet forming occurs in a single screw extruder with
Temperature profile .degree. C.: 50, 90, 130, 115
Screw speed: 150 rpm
[0037] Sheet ranging from 10 micron to 800 micron can be extruded
on a cast sheet line. Cooling and drying of the sheet in between
the various rolls of the haul off line, is required to achieve the
final moisture content of the sheet prior to wind-up, such as to
avoid blocking and shrinkage on the wind-up roll. If the film is
formed by the blown tube method some form of drying is also used.
Talc may also be entrained in the air stream to reduce blocking of
the film.
[0038] The films and thermoformed plastics of this invention are
transparent and printable and are ideally suited as packaging items
that need to be seen within the package. The sheets can be produced
in any colour and normal printing processes are able to be
used.
[0039] Table 1 sets out the optical properties of sheet formed from
the preferred water soluble polymer of this invention.
TABLE-US-00002 TABLE 1 Property Value Comment Gloss.sup.1 95%
measured at 60 deg Haze.sup.2 15% Typical 20-30 Transmittance.sup.3
91% Typical 84-90 All material conditioned 24 hrs, 23.degree. C.,
50% RH .sup.1ASTM D2457-97 test method .sup.2ASTM D1003-00 test
method .sup.3ASTM D1746-92 test method
[0040] All material conditioned 24 hrs, 23.degree. C., 50% RH
[0041] 1 ASTM D2457-97 test method
[0042] 2 ASTM D1003-00 test method
[0043] 3 ASTM D1746-92 test method
[0044] The preferred compositions used in this invention are cold
sealable and heat sealable. If transparency is not desired the
package can be made non transparent. The preferred compositions are
not sticky and have no offensive odour on dissolving in water.
[0045] Blisters can be made on standard thermoforming equipment.
When thermoforming the polymer formulations described above the
most important aspect is to use contact heating as compared to the
more traditional radiant heating.
[0046] For pressure forming the general conditions are:
TABLE-US-00003 Heat temp. 130-160.degree. C. Heat time 0.5-1 sec
Form time 1-1.5 sec
[0047] These vary depending on conditions, mould shape, material
gauge etc. The water soluble polymers of this invention are used in
blister packaging because:
[0048] It is a convenient way to display and present goods
[0049] It is tamper evident
[0050] It aggregates small goods which reduces pilfering and makes
economic quantities
[0051] It allows for labels and POS that wouldn't be available on
the good/product
[0052] It protects goods from environment
[0053] A key problem for many packaging types including blisters is
that they are too hard to open for many consumers. This has led to
the advent of "packet rage"--irrational anger at the difficultly of
getting into goods.
[0054] From an environmental perspective blisters are usually not
recyclable. This is because a) the blister is made of many types of
plastic which are hard to separate economically, b) the backing
card is coated with a lacquer to allow the blister to stick making
it unrecyclable and c) the blister and card are rarely fully
separated. Cards for blister pack backing are usually coated with a
polyacrylate lacquer designed to bond with thermoplastics such as
PVC and PET.
[0055] For attaching the polymer of this invention to a backing
card an acrylic polymer that either contains starch or that is
polar is used. An example is Joncryl 624AU from Rhodia. This can be
applied in the usual way as a printing process. The use of this
type of lacquer means the package of this invention is fully
biodegradable.
[0056] A surprising aspect of this invention is the effect of water
on the blister as an attachment option. Water may be used as an
adhesive to simplify the attachment process and make it
significantly more economically and environmentally friendly. This
method is illustrated in FIGS. 2 and 3 of the drawings. A
thermoformed blister 17 made from the polymer described above is
filled with product 18 and the water is applied to the sealing
flange 19 of the blister via an applicator 22 which may be a sponge
or even a shot of water mist. Warm water or steam is also suitable.
The amount of water needs to be sufficient to wet the flange
surface 19 but not to warp or weaken it. The backing sheet 16 which
may be paper card or the same polymer as the blister is then
applied to the flange 19 and pressed by a plate 24 to complete the
sealing and adhesion of the sheet 16 to blister 17. The pressure
can be applied by a pneumatic or hydraulic cylinder. The contact
time sufficient to effect bonding is about 5 seconds.
[0057] A clear printed coating can be applied to make most of the
pack water proof allowing for just a patch to be easy to open. This
can be a benefit where the product needs to be opened from a
particular place or perhaps where a product may be release as a
dose through a hole/orifice. Alternatively the waterproof section
may be over a part of the product that needs to be protected.
Because this water barrier can be added as either a printing
process or as a spray in a post process there is high flexibility
in product design.
EXAMPLE
[0058] A blister pack of a toothbrush was formed using the polymer
described above as a blister attached to a card packing.
[0059] A commercial toothbrush pack was used as a comparative
measured example. TABLE-US-00004 The force required to peel open
the commercial product was 2.415 N The force required to peel open
the blister pack of this 3.180 N invention The force required to
break the commercial product was 0.226 KN The force required to
break the blister pack of this invention 0.115 KN was The force
required to break the blister pack of this invention 0.001 KN after
wetting was
[0060] Effectively no force was required to open the blister pack
of this invention once it was wet.
[0061] Those skilled in the art will realize that this invention
may be implemented in a variety of ways without departing from the
essential teachings of the invention.
* * * * *