1. Field of the Invention
The present invention relates to biodegradable compositions utilized in the manufacture of biodegradable containers and method of manufacture. More specifically, the present invention relates to a biodegradable resin composition utilized in the manufacture of biodegradable bottles and other biodegradable containers, and the method of manufacturing such containers via injection molding and ultrasonic welding.
2. Description of Related Art
With the ever-increasing awareness of the depletion of Earth's non-renewable resources and the resulting increase in the need to protect same, a dramatic push for the manufacture and use of environmentally friendly products has been made. Products which are now considered “harmful to the environment”, which may be deemed as such due to the type(s) of materials in such product, the process in which such products are manufactured, or a combination of both, are now being replaced with more eco-friendly products, including biodegradable products.
Traditionally, plastics or resins have been petroleum-based and the manufacture of same consumes much energy, thereby classifying traditional plastics or resins as harmful to the environment or, at the very least, to be non-eco-friendly. To such end, more and more research has been performed in an attempt to manufacture resins that are biodegradable. For example, polyactic acid (PLA) plastic resins are marketed as biodegradable, as such resins are manufactured from corn and other vegetation. Microorganisms transform the sugars from the corn (and/or other vegetation) into lactic acid and the molecules of the lactic acid are chemically linked into chains of plastic. However, although the materials originally utilized in creating PLA are environmentally friendly, the method of treating the materials in order to produce the end result require chemical alteration.
Moreover, although there is a greater push towards biodegradable resin products, there are limited venues in which an end user may send the biodegradable resin product for recycling, as most recycling facilities are not equipped to process biodegradable resin.
Further, if an end user deposits the biodegradable resin product for recycling with conventional resins, such as polyethylene terephthalate, s/he ultimately contaminates the conventional resin for reuse.
The present invention is directed to a biodegradable resin composition utilized in the manufacture of biodegradable bottles and other biodegradable containers, and the method of manufacturing such containers via injection molding and ultrasonic welding.
A biodegradable resin composition includes the following in percent by weight: 1 to 80% starch; 1 to 8% cellulose; 1 to 5% sodium stearate; and 1 to 2% oleic acid.
Another biodegradable resin composition includes the following in percent by weight: 1 to 70% starch; 1 to 8% cellulose; 1 to 12% hydroxyl-polypropylene; and 1 to 5% calcium carbonate.
Another biodegradable resin composition include the following in percent by weight: 1 to 30% starch; 1 to 40% poly(butylene adipate-co-terephthalate) (PBAT); 1 to 20% poly(lactic acid) (PLA); and 1 to 5% hydrated magnesium silicate.
The method of manufacturing biodegradable containers includes forming components of the container via injection molding and ultrasonically welding the components to one another.
A description of the preferred embodiments of the present invention will now be presented.
The present invention relates to biodegradable resin bottles and other biodegradable containers, such as, but not limited to, pharmaceutical containers, shampoo containers, mouthwash containers, and any other type of container, comprising a biodegradable resin composition having a softening point of approximately 257 degrees Fahrenheit, a melting point of approximately 313 degrees Fahrenheit, extended heating capabilities that last for approximately one hour at 250 degrees Fahrenheit, a specific density of approximately 1.2, and a flow rate of between approximately 0.5 and 2.0 g/10 minutes.
The present invention also relates to a method of manufacturing biodegradable resin bottles and other containers having the aforementioned composition.
A biodegradable resin composition includes approximately eighty percent (80%) starch, approximately eight percent (8%) cellulose, approximately five percent (5%) sodium stearate, approximately two percent (2%) oleic acid, and approximately five percent (5%) other ingredients. This biodegradable resin composition naturally biodegrades in compost, wet soil, fresh water, seawater and activated sludge where microorganisms exist, is compostable, is recyclable, and is renewable.
Another biodegradable resin composition includes the following in percent by weight: 1 to 70% starch; 1 to 8% cellulose; 1 to 12% hydroxyl-polypropylene; 1 to 5% calcium carbonate; and the balance being other ingredients. This biodegradable resin composition naturally biodegrades in compost, wet soil, fresh water, seawater and activated sludge where microorganisms exist and is renewable.
Another biodegradable resin composition include the following in percent by weight: 1 to 30% starch; 1 to 40% poly(butylene adipate-co-terephthalate); 1 to 20% poly(lactic acid); 1 to 5% hydrated magnesium silicate; and the balance being other ingredients. This biodegradable resin composition naturally biodegrades in compost, wet soil, fresh water, seawater and activated sludge where microorganisms exist and is compostable.
The starch may be selected from a corn starch, wheat starch, potato starch, sweet potato starch, or tapioca starch.
Over time, products manufactured from the biodegradable resin composition of the present invention naturally biodegrade without non-environmental chemical, heat, or other forms of treatment.
The use of the term “biodegradable” herein is intended to include those compositions and the containers made therefrom that may result in a certain amount of biodegrading over a course of time and is not specifically limited to those compositions and containers made therefrom that do not completely biodegrade.
Similarly, use of the term “renewable” herein is intended to include those compositions and the containers made therefrom that may result in a certain amount of replacement or replenishing over a course of time and is not specifically limited to those compositions and containers made therefrom that do not result in complete renewal.
To manufacture bottles and other containers utilizing the biodegradable resin composition, a combination of injection molding and ultrasonic welding is utilized. The main components of a biodegradable bottle include a body, a base, and cap. Each of the components of the biodegradable bottle can be manufactured, for example, via conventional injection molding techniques and in accordance with the additional/alternative specifications set forth below. After each component is manufactured, the body and the base can be ultrasonically welded to one another. The cap can be of a conventional screw-on style, but may be of any other shape or style so long as it permits a user to seal an open end of the bottle body.
The particles of the biodegradable resin composition may be mixed with other biodegradable resin compositions, additives, and dyes to manufacture bottles and other containers.
To manufacture bottles and other containers utilizing the biodegradable resin composition identified above, traditional injection molding practices can be utilized with additional/alternative specifications. Traditional injection molding includes the utilization of at least one injection molding machine and commonly includes the following steps: feeding a resin composition into the injection molding machine via a hopper, entering the resin composition into an injection barrel by gravity via a feed throat, heating and melting the resin composition upon entrance into the barrel, and injecting the melted resin composition into a mold by a reciprocating screw or a ram injector. The mold, which is the component of the injection molding machine that receives the melted resin composition and shapes it, is formed of two plates that are held together by mechanical or hydraulic force. The resin composition enters the mold through a sprue in the first plate, branches out between the two sides through channels called runners, and enters each part cavity through at least one gate. Within each cavity, the resin composition flows around protrusions and conforms to shape of the cavity so as to form the desired shape. The mold is then cooled to a temperature that permits the melted resin composition within the cavity to solidify.
With specific respect to the manufacture of the biodegradable resin composition of the present invention into bottles and other containers, the sprue and runners of the mold design should be larger as compared to the sprues and runners of conventional mold designs so as to accommodate the biodegradable resin composition's lower flow rate as compared to traditional resins.
In addition, the mold plate's thickness should also be greater as compared to the thickness of traditional mold plates. For example, the percentage increase in thickness of the mold plates utilized in the manufacturing method of the present invention as compared to traditional mold plates could be thirty percent (30%).
If the mold cavity is large, a padding block should be added to the bed die to ensure that the mold plate will not distort under injection pressure. Pinpoint gates and fan gates should be utilized so as to ensue smooth flow of melting materials. Special attention should be taken when monitoring the flow of melting materials around corners so as to avoid or minimize the effects associated with back-up of the melting materials.
After completion of the injection molding phase, the biodegradable resin composition may be dried. Ideally, the resin should be dried at 85 degrees Celsius for approximately four hours. Upon completion, the biodegradable resin composition should contain no more than one percent (1%) moisture.
The biodegradable resin composition compounds easily with polypropylene. The extruder should be completely purged with polypropylene prior to introduction of the biodegradable resin composition. While purging the biodegradable resin composition, ideally one should begin with the biodegradable resin composition mixed with polypropylene and slowly increase the biodegradable resin composition percentage incrementally, thereby slowly reducing the polypropylene percentage.
The temperature setting for injection molding should be set between approximately 170 and 205 degrees Celsius, dependent upon the weight of the resulting injection molded products and the size of the injection molding machine. The temperature of the adjusted dies should range between approximately 50 and 80 degrees Celsius. Runners having a temperature of approximately 60 degrees Celsius assist in maintaining an ideal flow rate of the biodegradable resin composition.
To process the biodegradable resin composition, compression and speed of the injection molding should be determined according to molding area and weight and will most likely result with the compression and speed of the injection molding being greater than that of other resins, such as polyethylene, polypropylene, and general purpose polystyrene.
In the course of processing, white mineral oil, coconut oil, or other comparable oils may be added to the biodegradable resin composition and pre-blended so as to improve fluidity of the biodegradable resin composition during injection molding. Additionally or in the alternative, polyethylene and/or polypropylene may be added to the biodegradable resin composition to improve fluidity and shock resistance of the biodegradable resin composition. The addition of such other resins should be limited to a range of between approximately five percent (5%) and twenty percent (20%).
During blending and dyeing of the biodegradable resin composition, organic or inorganic dyestuff may be added to the particles of the biodegradable resin composition. The dyestuff should be blended for approximately 15 to 20 minutes.
Once the biodegradable resin bottles or other containers are manufactured via injection molding, the components of the bottles or holding containers that should be permanently sealed to one another are done so via ultrasonic welding.
For instance, in manufacturing a biodegradable container of the present invention as shown in the form of a biodegradable bottle in
In
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At least one rib 15 may extend vertically along the internal wall 13 of the biodegradable bottle 6 so as to increase the rigidity of the biodegradable bottle 6. Optional joints 12 and saw teeth 16 may extend upwardly from the base 2 of the biodegradable bottle 6.
After the body 1 and the base 2 are formed via injection molding and are cooled, the body 1 and the base 2 are permanently joined together via ultrasonic welding along the saw teeth 16 and the joints 12. The joints 12 to permit a greater and longer-lasting seal between the body 1 and the base 2. Examples of such types of joints include, but are not limited to, dovetail joints, biscuit joints, box joints, dado joints, domino joints, dowel butt joints, finger joints, and lap joints. Thus, the joints 12 may be manipulated so as to interlock with the body 1 prior to ultrasonically welding the base 2 to the body 1, thereby permitting a stronger seal to be created between the base 2 and the body 1.
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In manufacturing a biodegradable container of the present invention as shown in the form of a biodegradable bottle in
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The body 1 includes a plurality of saw teeth 16 on a top face 18 of an upper end 21 of the body 1, which aid in creating a stronger bond between the top 20 and the body 1 when ultrasonically welded to one another. After the top 20 and body 1 are formed via injection molding and are cooled, the top 20 and the body 1 are twist-fit to one another, interlocked with one another via the joints 12, and permanently joined together via ultrasonic welding along saw teeth 16 and the joints 12. Although saw teeth 16 are shown, other types of edging along the top 20 and/or body 1 may be envisioned, including, but not limited to, jagged edging, curved edging, linear edging, etc.
In manufacturing a biodegradable container of the present invention in the form of a biodegradable bottle 6 as shown in
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The body 1, base 2, and top 20 may be opaque, translucent, or a combination thereof.
Additionally, the biodegradable bottle or other biodegradable container may be of varying shapes and sizes, dependent upon the dimensions of the body 1, base 2, and top 20. For instance, the body 1 and base 2 may be of the same length or differing lengths, thereby resulting in varying locations of the base 2 to body 1 weld in relation to the overall height of the biodegradable bottle or other biodegradable container and different overall heights of the biodegradable bottle or other biodegradable container. Similarly, the body 1 and the top 20 may be of the same length or differing lengths, once again resulting in varying weld locations relative to the height of the biodegradable bottle or other biodegradable container and different over heights of same. Lastly, the base 2 and the top 20 may be of the same length of differing lengths, once again resulting in varying weld locations relative to the height of the biodegradable bottle or other biodegradable container and different over heights of same.
Finally, although the biodegradable container of the present invention is shown in the form of a biodegradable bottle, this invention is not limited to a biodegradable bottle only, but includes other biodegradable containers including, but not limited to, pharmaceutical containers, shampoo containers, mouthwash containers, and any other type of biodegradable container.
Having now described the invention, the construction, the operation and use of preferred embodiments thereof, and the advantageous new and useful results obtained thereby, the new and useful constructions, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.
This application claims priority to provisional application Ser. No. 61/159,174, filed on Mar. 11, 2009, entitled “Biodegradable Resin Composition utilized in the Manufacture of Biodegradable Containers, Biodegradable Containers, and Method of Manufacture.”
Number | Date | Country | |
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61159174 | Mar 2009 | US |