SAC A LINGE BIODEGRADABLE

BIODEGRADABLE LAUNDRY BAG

Abrégé français

Un procédé de fabrication dun sac à lessive biodégradable. Le procédé comprend la formation dune ou de plusieurs pellicules biodégradables ayant une épaisseur calibrée variant entre 20 et 30 microns. La ou les pellicules biodégradables peuvent être formées en mélangeant une combinaison de résine polyéthylène basse densité linéaire avec jusquà 5 % en rapport poids/poids dun additif oxodégradable. La résine polyéthylène basse densité linéaire peut avoir un indice de fluidité à chaud variant entre 1 g/10 min et 160 g/10 min et une plage de densité variant entre 0,910 g/cm3 et 0,930 g/cm3 de manière que, lorsquelles sont combinées, la ou les pellicules biodégradables présentent un étirement prolongé sous charge.

Abrégé anglais

A method of producing a biodegradable laundry bag. The method includes forming one or more biodegradable films having a caliper thickness of between 20 - 30 microns. The one or more biodegradable films may be formed by blending a combination of linear low-density polyethylene resin with up to 5% weight-to-weight ratio of an OXO-degrading additive. The linear low-density resin may have a melt flow rate of between 1g/10 min - 160g/10 min and a density range of between 0.910g/cm3 - 0.930g/cm3, such that when combined, the one or more biodegradable films exhibit prolonged elongation under load.

Revendications

CLAIMS
What is claimed is:
1. A method of forming one or more biodegradable films having a caliper
thickness of between 20 ¨ 30 microns, said one or more biodegradable
films formed by blending a combination of linear low-density polyethylene
resin with up to 5% weight-to-weight ratio of OXO-degrading additive, said
linear low-density resin having a melt flow rate of between 1g/10 min ¨
160g/10 min and a density range of between 0.910g/cm3 ¨ 0.930g/cm3,
such that when combined, said one or more biodegradable films exhibit
prolonged elongation under load.
2. The method of claim 1 wherein said one or more biodegradable films is
formed through a blown film extrusion process.
3. The method of claim 1 wherein said one or more biodegradable films is
formed to have the caliper thickness of 23 microns.
4. A biodegradable laundry bag being formed from one or more
biodegradable films having a caliper thickness of between 20 ¨ 30
microns, said one or more biodegradable films comprising a blended
combination of linear low-density polyethylene resin with up to 5% weight-
to-weight ratio of OXO-degrading additive, said linear low-density resin
having a melt flow rate of between 1g/10 min ¨ 160g/10 min and a density
range of between 0.915gm/cm3 ¨ 0.925gm/cm3, such that said one or
more biodegradable films exhibit prolonged elongation under load.
5. The biodegradable laundry bag of claim 4 wherein said one or more
biodegradable films are formed from a blown film extrusion process.
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6. The biodegradable laundry bag of claim 4 wherein said one or more
biodegradable films have the caliper thickness of 23 microns.
7. The biodegradable laundry bag of claim 4 in the form of a die cut bag.
8. The biodegradable laundry bag of claim 4 wherein a bottom of the
biodegradable bag comprises connected fold lines to form a reinforcing
star-patterned bottom.
9. The biodegradable laundry bag of claim 4 having a length of between 30
inches to 50 inches.
10. The biodegradable laundry bag of claim 4 having a length of 38 inches.
11. The biodegradable laundry bag of claim 9 having a width of between 25
inches to 35 inches.
12. The biodegradable laundry bag of claim 10 having a width of 29 inches.
13. A method of forming one or more biodegradable films having a caliper
thickness of 23 microns, said one or more biodegradable films formed by
blending a combination of linear low-density polyethylene resin with up to
5% weight-to-weight ratio of OXO-degrading additive, said linear low-
density resin having a melt flow rate of between 1g/10 min ¨ 160g/10 min
and a density range of between 0.910g/cm3 0.930g/cm3, such that when
combined, said one or more biodegradable films exhibit prolonged
elongation under load.
14. A biodegradable laundry bag being formed from one or more
biodegradable films having a caliper thickness of 23 microns, said one or
more biodegradable films comprising a blended combination of linear low-
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density polyethylene resin and up to 5% weight-to-weight ratio of OXO-
degrading additive, said linear low-density resin having a melt flow rate of
between 1g/10 min ¨ 160g/10 min and a density range of between
0.915gm/cm3 ¨ 0.925gm/cm3, such that said one or more biodegradable
films exhibit prolonged elongation under load, wherein a bottom of the
biodegradable laundry bag comprises connected fold lines to form a
reinforcing star-patterned bottom, wherein the biodegradable laundry bag
has a length of between 30 inches to 50 inches and a width of between
25 inches to 35 inches.

Description

CA 02686036 2015-11-25
TITLE OF THE INVENTION
A BIODEGRADEABLE LAUNDRY BAG
FIELD OF THE INVENTION
The invention relates to the field of biodegradable materials generally, and
more
particularly to a biodegradable laundry bag made of a resin blended with a
biodegradable additive into a biodegradable film that has enhanced strength
and
stretch properties.
BACKGROUND OF THE INVENTION
Plastic is a very familiar component of modern living, used in all sorts of
packaging and household and commercial applications. While the benefits of:
low-cost, light weight, strength, relative imperviousness to gas and water,
transparency, and printability are highly regarded, the very properties that
make
plastic such a useful and economic material become a major problem when
disposal is required. However, it is now possible to manufacture a plastic
material that will degrade to a number of harmless elements - typically water
and
carbon dioxide.
Biodegradable materials have long been studied for their applicability in
commonly-used products. Recently, increased emphasis has been placed on
developing products made from biodegradable materials as replacements for
existing, non-biodegradable products. In fact, some governmental regulations
call for the phasing out of certain non-biodegradable products in lieu of
biodegradable counterparts.
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The changeover to the utilization of biodegradable materials in such products,
however, has been met with both implementation challenges, as well as
decreased performance issues.
Furthermore, products fabricated from
biodegradable materials have typically been more expensive than conventional
non-biodegradable products. Such issues have limited the extent to which
products fabricated from biodegradable materials have been widely accepted in
residential or industrial applications alike.
A particular example of a product that is well suited for the use of
biodegradable
material is a laundry bag, such as those commonly used in hospitals. Recently,
certain municipalities have required the use of biodegradable bags. To qualify
as
"biodegradable", materials forming the biodegradable product must have at
least
a 90% conversion rate of starting material to CO2 and water within six months
of
disposal thereof. Bags and other containers fabricated from biodegradable
materials that have been utilized to date, however, do not perform as well
strength wise as conventional products, and are typically more expensive than
such conventional products.
A specific drawback to currently available containers, more particularly bags,
fabricated from biodegradable materials is the low strength characteristics
associated with such materials. Accordingly, currently available biodegradable
containers are undesirably weak, in that such products are substantially
stretchable under relatively low forces.
To date, efforts in creating viable and economical fully biodegradable
materials
have focused primarily on blending known biodegradable polymeric resins such
as polyesters with starch derived from maize to reduce the cost. However,
these
materials predominantly require an active microbial environment such as a
landfill
or composting before they will degrade. Some will totally degrade in such an
environment but others will only perforate, and the plastic component will not
degrade. The remaining plastic particles can be harmful to soil birds and
other
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wildlife. Also, if genetically-modified crops are used in the manufacture of
these
products, this may jeopardize their use in organic systems. Moreover, starch-
based degradable plastics degrade by a process of HYDRO-degradation, which
emits carbon dioxide rapidly into the atmosphere.
Another type of degradable plastic uses aliphatic polyesters. However, in the
same manner as starch-based plastics, they rely on microbial activity
typically in
a compost or landfill, before they will degrade. Still another type of
degradable
plastic uses photo-degradable materials. However, these will only degrade when
exposed to sunlight and will not degrade in a landfill or sewer or other dark
environment.
Two primary problems to be overcome in order to increase acceptance and use
of biodegradable products are strength and price. Polyethylene, one of the
most
commonly used polymeric resins base for non-biodegradable films used in the
manufacture of, for example, bags, is a low cost resin that is versatile
enough to
handle the physical requirements of any disposal bags. Polyethylene bags are
also typically less expensive than their biodegradable counterparts. Such
characteristics of polyethylene represent a marketing barrier to the
acceptance of
similar biodegradable products.
Accordingly, a need exists for a biodegradable bag which overcomes the limits
of
strength, durability and stretch of current bags. Other objects of the
invention
will be apparent from the description that follows.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method of producing a
biodegradable laundry bag. The method includes forming one or more
biodegradable films having a caliper thickness of between 20 ¨ 30 microns,
preferably 23 microns. The one or more biodegradable films may be formed by
blending a combination of linear low-density polyethylene resin with up to 5%
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CA 02686036 2015-11-25
weight-to-weight ratio of an OXO-degrading additive. The linear low-density
resin
may have a melt flow rate of between 1g/10 min ¨ 160g/10 min and a density
range of between 0.910g/cm3 ¨ 0.930g/cm3, such that when combined, the one
or more biodegradable films exhibit prolonged elongation under load.
The biodegradable films may be formed through a blown film extrusion process
and a biodegradable laundry bag may be formed from a die cut of the
biodegradable films.
The bottom of the biodegradable laundry bag may formed to include connected
fold lines to form a reinforcing star-patterned bottom and the biodegradable
laundry bag may be formed to have a length of between 30 inches to 50 inches
(preferably 38 inches) and a width of between 25 inches to 35 inches
(preferably
29 inches)
In accordance with another aspect of the present invention there is provided a
biodegradable laundry bag. The biodegradable laundry bag may be formed from
one or more biodegradable films having a caliper thickness of between 20 ¨ 30
microns, preferably 23 microns. The one or more biodegradable films may
include a blended combination of linear low-density polyethylene resin and up
to
5% weight-to-weight ratio of an OXO-degrading additive. The linear low-density
resin may have a melt flow rate of between 1g/10 min ¨ 160g/10 min and a
density range of between 0.915gm/cm3 ¨ 0.925gm/cm3, such that the one or
more biodegradable films exhibit prolonged elongation under load.
Other aspects of the invention will be appreciated by reference to the
detailed
description of the preferred embodiment and to the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
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The preferred embodiment of the invention will be described by reference to
the
drawings thereof in which:
Fig. 1 is a side view of a biodegradable laundry bag of the present invention;
Fig. 2 is a side view of the biodegradable laundry bag of Fig.1 in a folded
position
off of a roll or bags;
Fig.3 is a top plan view of the biodegradable laundry bag of Fig.1; and
Fig. 4 is a bottom plan view of the biodegradable laundry bag of Fig.1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
OF THE INVENTION
The most useful and economic of the new biodegradable technologies produces
plastic which degrades by a process of OXO-degradation. This technology is
based on a small amount of additive being introduced into the conventional
manufacturing process, thereby changing the behaviour of the plastic.
There is little or no additional cost involved in products made with this
technology
as the plastic bags and sheets made with the oxo-biodegradable plastic uses
the
same machinery as currently used for conventional plastic. There is therefore
no
need to re-equip factories or retrain the workforce.
The degradation of the plastic starts immediately after manufacture and will
accelerate when exposed to heat, light or stress. This process is irrevocable
and
continues until the material has reduced to nothing more than CO2 and water.
It
does not therefore leave fragments of petro-polymers in the soil.
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The plastic will be consumed by bacteria and fungi after the additive has
reduced
the molecular structure to a level (sub 40,000 Daltons) that permits living
micro-
organisms access to the carbon and hydrogen within. The material has then
ceased to be a plastic and has become a food source. It can therefore be
properly described as "biodegradable" or even "omni-degradable."
The length of time it takes for oxo-biodegradable plastic to degrade can be
"'programmed" at the time of manufacture and can be as little as a few months
or
as much as a few years.
The present invention utilizes the new OXO-degradation technology in the
formation of a biodegradable laundry bag that is programmed to begin
degradation within 12 to 24 months from exposure to air and sunlight and end
degradation within 36-60 months from exposure to air and sunlight.
In the present invention, up to 5% weight-to-weight ratio of the OXO-degrading
additive is added to a linear-low density polyethylene to form a blended
biodegradable combination. The blended combination is then formed into a
biodegradable film through a conventional blown film extrusion process. A
biodegradable laundry bag is then formed from the film through a conventional
die cut process.
To achieve the necessary programming requirements while maintaining certain
strength, stretch and durability requirements, the biodegradable film is
formed to
have a caliper thickness of between 20 ¨ 30 microns. In a preferred
embodiment, the film thickness is 23 microns. Additionally, the linear low-
density
resin has a melt flow rate of between 1g/10 min ¨ 160g/10 min and a density
range of between 0.910g/cm3 ¨ 0.930g/cm3.
To increase the strength of the laundry bag, the bottom is formed during the
conventional die cut process to include connected fold lines to form a
reinforcing
,
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star-pattern as best depicted in Figures 3 and 4. As those skilled in the art
will
appreciate, the fold lines are formed in the die cut process using
conventional
means.
A particular application for the biodegradable laundry bag of the present
invention
is in the packaging and storing of hospital laundry. In a hospital, laundry
must be
packaged and stored for transportation under a variety of circumstances. These
bags must be strong and durable while at the same time resistant to punctures
to
prevent soiled laundry from coming into contact with the immediate
environment.
Additionally, these bags must be dimensioned to accommodate volumes of
laundry while at the same time dimensioned to enable an average individual to
carry them. As such, the present biodegradable laundry bag is formed to have a
length of between 30 inches to 50 inches (preferably 38 inches) and a width of
between 25 inches to 35 inches (preferably 29 inches).
It will thus be seen that a new and novel biodegradable laundry bag has been
illustrated and described and it will be apparent to those skilled in the art
that
various changes and modifications may be made therein.
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Dessin représentatif