CA2686036C

CA2686036C - Biodegradable laundry bag

Info

Publication number: CA2686036C
Application number: CA2686036A
Authority: CA
Inventors: Kenneth Ohlsson
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-11-23
Filing date: 2009-11-23
Publication date: 2017-05-02
Anticipated expiration: 2029-11-23
Also published as: CA2686036A1

Abstract

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.

Description

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.

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

2 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%

3 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

4 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.

5 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 ,

6 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.

7

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.

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-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.