JP2009535163A - Degradable medical sharps and waste containers and method of making the same - Google Patents

Abstract

Methods and apparatus for medical sharps and waste disposal containers made from polypropylene and additive compositions are provided. The container has a puncture resistance of at least about 2.8 lbf. The additive is present in an amount sufficient to accelerate the degradation of the polypropylene after a predetermined shelf life. The container has an average puncture resistance of at least about 3.4 lbf and includes a wall having a thickness of about 0.050 inch to 0.075 inch, wherein the medical sharps or medical waste is from the container. Has sufficient impact strength to prevent it from coming off.

Description

  The present invention relates to degradable medical sharps and waste containers and methods of forming degradable medical sharps and waste containers.

  Plastics have become an important part of modern life and are used in a variety of applications such as packaging, building materials, and consumer products. Plastic is very versatile. Some plastics are shrinkable, rigid, flexible, impermeable, or selectively permeable. One characteristic of plastic is that it does not decompose rapidly over time and is relatively inexpensive to manufacture.

  An example of products made from plastic are medical sharps and waste disposal containers. Medical sharps and waste disposal containers are a convenient and safe way to dispose of contaminated needles, syringes, glass tubes, scalpel blades, and any other sharps and medical waste. Such disposal containers are used to safely store, transport and ultimately destroy sharps that may be infected. Filled medical sharps and waste disposal containers are biomedical / biological hazardous waste and should be disposed of in accordance with strict federal and state guidelines. For example, medical sharps and waste disposal containers can be incinerated by the facility or off site, or the facility can render the container harmless by various sterilization techniques.

  When medical sharps and waste disposal containers are rendered non-infectious by sterilization, most landfills consider sterilized medical sharps and waste disposal containers as municipal solid waste. Thus, sterilized medical sharps and waste disposal containers follow only the same requirements as household waste and can be disposed of in an authorized and contained landfill. Although plastic medical sharps and waste disposal containers are a safe and efficient way to collect contaminated or consumed medical sharps and medical waste, these containers can be used as medical sharps and medical waste. The properties of plastics that make it suitable for disposal, i.e. impervious to heat and moisture, have sufficient rigidity and fracture resistance, and the ability to maintain its integrity over time is also It causes a difficult problem for the disposal. Even though infectious substances contained within medical sharps and waste disposal containers are destroyed (ie, sterilized), the filled containers still pose a problem occupying a large amount of space in the landfill .

(Summary of Invention)
In accordance with one exemplary embodiment, the medical sharps and waste disposal containers of the present invention are made from a polypropylene and additive composition and have a puncture resistance of at least about 2.8 lbf. The additive is present in an amount sufficient to accelerate the degradation of the polypropylene after a predetermined shelf life.

  In accordance with another exemplary embodiment, the medical sharps and waste disposal container of the present invention is made from a composition of polypropylene and additive and has sufficient impact strength to prevent sharps from escaping from the container. Have The additive is present in an amount sufficient to accelerate the degradation of the polypropylene after a predetermined shelf life.

  An exemplary method for manufacturing degradable medical sharps disposal and waste containers according to embodiments of the present invention is to accelerate polypropylene and degradation / biodegradation of polypropylene within the composition after a predetermined shelf life. Forming a container from the composition with a sufficient amount of the additive. The formed container has a puncture resistance of at least about 2.8 lbf.

  In accordance with an exemplary embodiment of the present invention, another method of manufacturing medical sharps and waste disposal containers includes forming pellets containing polypropylene and additives. The pellets are melted and medical sharps and waste disposal containers are formed by the molding process. The formed container has a puncture resistance of at least about 2.8 lbf and an impact strength sufficient to prevent sharps from escaping from the container.

  A method for disposing of medical sharps and medical waste, according to an exemplary embodiment of the present invention, comprises a composition of polypropylene and an amount of an additive sufficient to accelerate the degradation of the polypropylene after a predetermined shelf life. Including receiving medical sharps in the container made. The container has a minimum puncture resistance of at least about 2.8 lbf. Once medical sharps and / or waste is received by the disposal container, the container is exposed to irritation and begins degrading / biodegrading the container.

  The invention is best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Included in the drawings are the following figures.

(Detailed description of the invention)
Degradation is the process by which very large molecules break into smaller molecules or fragments. Decomposition generally occurs when oxygen is mixed into these molecular fragments. This type of degradation is called oxidative degradation. In general, as a result of oxidative degradation, a strong plastic thin film is weak and brittle. Plastic “decomposes”. This is because usually the long polymer chains forming the plastic break into shorter, smaller chains. Oxidative degradation can be initiated by mechanical pressure, heat, or exposure to ultraviolet light or sunlight. The term “degradable plastic” is defined by the American Society for Testing and Materials (ASTM D883-99) as the following plastic: That is, during the period that determines the classification of a plastic, it can be subject to significant changes in chemical structure under certain environmental conditions, as measured by standard test methods appropriate for that plastic and application. It is a plastic that is designed to cause loss of part properties.

  According to an exemplary embodiment, the degradation process of the medical sharps and waste disposal container of the present invention is accelerated in a manner that facilitates degradation while maintaining an acceptable shelf life of the container. In other words, degradation is accelerated while allowing the container to retain its integrity and performance characteristics for an acceptable period of time. For example, this period (ie, shelf life) can be set to about 30 months. That is, approximately 30 months after the production of medical sharps and waste disposal containers (during this period the containers can be stored, transported or used), the containers still retain their structural integrity. However, when measured by standard test methods appropriate to the container, it undergoes significant changes in its chemical structure and begins to cause some loss of properties that can fluctuate.

  Biodegradation, which is distinct from degradation, is the process by which microorganisms (ie, bacteria, fungi or algae) found naturally in the soil change materials into biomass, carbon dioxide, inorganic substances, and water. Biomass is understood to include energy resources derived from organic matter and includes any carbon source from which microorganisms can grow. The term “biodegradable plastic” is defined by the American Society for Testing and Materials (ASTM D883-99) as the following degradable plastic. That is, biodegradable is a degradable plastic that results from the action of naturally occurring microorganisms, ie, bacteria, fungi, and algae.

Once accelerated degradation is facilitated (eg, as a first step), the medical sharps and waste disposal containers of the present invention can undergo biodegradation (eg, as a second step). In accordance with exemplary embodiments, medical sharps and waste disposal containers are rendered biodegradable when exposed to microorganisms (ie, bacteria, fungi or algae) that are naturally found in the soil.

  FIG. 1 illustrates exemplary medical sharps and waste disposal containers that may be configured for accelerated degradation and made biodegradable in accordance with aspects of the present invention. For example, the container 10 has a base and an upper part and is composed of a plurality of walls 15. The container 10 can also have a lid 17 that can have various configurations. Wall 15 and lid 17 have a thickness of about 0.050 inch to 0.075 inch, and more preferably have a thickness of 0.060 inch to 0.065 inch. The container 10 is adapted to receive medical sharps and medical waste. Wall 15 is made from a composition of polypropylene and an additive that accelerates degradation after a predetermined shelf life. The lid 17 is also preferably made from a composition of polypropylene and an additive that accelerates degradation, but it does not have to be made from such a composition. According to an exemplary embodiment, the composition that also forms the wall 15 and possibly the lid 17 of the container 10 contains from about 90% to about 100% polypropylene, based on the weight of the container.

The additive is provided in a container such as container 10 in an amount sufficient to accelerate the degradation of the polypropylene in the composition. One exemplary additive is EPI Environmental Technologies Inc. of Vancouver, British Columbia, Canada under the trademark TDPA® (Totally Degradable Plastic Additive). Manufactured by. Another exemplary additive is ECM Biofilms, Inc. of Painsville, Ohio under the trade name ECM Masterbatch Pellets. Manufactured by. Yet another exemplary additive is manufactured by Symphony Plastic Technologies, UK, and under the trademark d ₂ w®, Degradable Plastic Products Inc. of Toronto, Ontario, Canada. Sold by. Additives of this type are described in US Pat. No. 5,854,304, US Patent Application Publication No. 2004/0062884, and PCT International Application Publication No. WO 2005/017015, each of which is incorporated by reference. These patent document additives are generally described for use in thin film structures such as, for example, plastic bags.

  If the additive is added to various concentrations of plastic resin (ie, polypropylene, polyester, or polystyrene), the manufactured plastic product can be accelerated in degradation and finally biodegradable. Once degradation and biodegradation are complete, all that remains of plastics and additives is carbon dioxide, water, inorganic materials and biomass. By varying the concentration and type of additive in the plastic composition, the plastic product formed by the composition can begin to accelerate its degradation and be made biodegradable within a desired time frame. An exemplary time frame in which the medical sharps disposal container of the present invention begins to accelerate its degradation (so as to lose some of its integrity and performance characteristics) is at least about 20-40 months, preferably at least about 25- Includes 35 months, most preferably at least about 30 months. Additives according to exemplary embodiments of the invention may be up to about 10%, preferably about 1-10%, based on the total weight of the container, as described in PCT International Application Publication No. WO 2005/017015. More preferably it is present in an amount of about 3-5%.

  The degradation process is accelerated by the additive and is generally initiated by the breakdown of large polymer chains having an average molecular weight of up to 300,000 daltons into smaller polymer chains by oxidative degradation. Decomposition continues by oxygenating the exposed ends of the smaller polymer chains to form aldehydes, ketones, carboxylic acids, and alcohols. The degradation process is initiated when exposed to heat, ultraviolet light (eg, sunlight), moisture and mechanical pressure. One of any combination of these irritants initiates the degradation process of the product having the composition of the present invention. Biodegradation begins when the microorganism consumes the oxygenated end resulting from the degradation process and reduces the end of the polymer chain by two carbon atoms at a time. As the microorganism consumes the oxygenated end, the polymer backbone end is again exposed, oxygenated (ie, degraded) and consumed (ie, biodegraded) by the microorganism, thus degrading. / Repeat the biodegradation cycle. Degradation can occur without biodegradation, or degradation and biodegradation can proceed simultaneously as described above.

  The medical sharps and waste disposal container of the present invention can be made biodegradable by accelerating the degradation process, but maintains structural characteristics that make it suitable as a container for the disposal of medical sharps and medical waste To do. One such structural characteristic is fracture resistance. ASTM-F2132 defines test procedures and performance requirements for the fracture resistance of materials used in the construction of containers for discarded medical waste, needles and other sharps. This test specification establishes (1) the average destructive force and (2) the minimum destructive force that the container material must withstand when following the test procedure. In accordance with one exemplary embodiment, the medical sharps and waste disposal containers of the present invention have an average puncture resistance of at least about 3.4 lbf, preferably at least about 5.0 lbf, any one time The minimum requirement for this measurement is at least about 2.8 lbf.

  Another structural property is impact strength. The test procedure for measuring impact strength is ASTM-D5628, which crushes or smashes a rigid plastic sample under flattened impacts of various specified conditions. The relative order of the materials is determined according to the energy required for the process. Another test for impact strength is to drop filled medical sharps and waste disposal containers from a predetermined height (height depends on container size and weight) onto a hard surface. If a medical sharp or other medical waste escapes from a container due to a drop impact, the container fails this impact strength test. For example, a filled 2 gallon medical sharps disposal container weighing approximately 1.0 pound was dropped from a height of 36 inches. A container has sufficient impact strength if it does not allow any medical sharps or medical waste to fall out of the container after the container has been dropped from a predetermined height due to the destruction of either the container wall or lid. Then it is decided.

  Degradable sharps and medical waste disposal containers according to the exemplary method of the present invention are plastic vacuum molding, thermosetting injection molding, blow molding, rotational molding, thermoforming, structural foam molding, compression molding, resin injection. Manufactured by conventional plastic fabrication processes including but not limited to molding (RTM), coating and dipping. For example, FIG. 2 illustrates an exemplary method 20 for forming the medical sharps and waste disposal containers of the present invention. In accordance with exemplary method 20, a composition of polypropylene and an amount of additive sufficient to accelerate polypropylene degradation is provided in step 22. According to another exemplary embodiment, the polypropylene and additive composition is pelletized and provided in the form of pellets. The composition is then injected into the mold at step 24. In step 26, a container is formed that has sufficient fracture resistance and impact strength to prevent medical sharps and medical waste from escaping from the container.

  An exemplary method of disposing of medical sharps and medical waste according to an embodiment of the present invention is illustrated in the flowchart of FIG. Disposal method 30 includes receiving 32 medical sharps and / or medical waste in a container containing polypropylene and a sufficient amount of additive to accelerate the degradation of the polypropylene after a predetermined shelf life. To dispose of the medical sharps container, the spent medical sharps and / or medical waste is sterilized as shown in step 34. Suitable sterilization techniques include non-infectious medical sharps and waste that may be infected. Exemplary methods include steam (autoclaving), gravity displacement, dynamic air removal (pre-vac), dry heat, convection heating, ethylene oxide, plasma (hydrogen peroxide plasma or gas) Plasma) and peracetic acid treatment.

  As shown in step 36, accelerated disintegration of medical sharps and waste containers is facilitated after sterilization. The promotion of degradation is initiated upon exposure to mechanical and / or chemical stimuli including mechanical breakage, heat or exposure to ultraviolet light (eg, sunlight) or moisture. As shown in step 38, biodegradation of medical sharps and waste disposal containers is facilitated after accelerated degradation is facilitated. The promotion of the biodegradation process is initiated when exposed to microorganisms (ie bacteria, fungi or algae) found naturally in the soil.

  While preferred embodiments of the invention have been shown and described herein, it is understood that such embodiments are provided by way of example only. Numerous variations, modifications and alternatives will occur to those skilled in the art without departing from the spirit of the invention. Accordingly, the appended claims are intended to cover all such modifications as fall within the spirit and scope of the invention.

FIG. 1 is an illustration of exemplary medical sharps and medical waste containers that may be made disassembleable in accordance with aspects of the present invention. FIG. 2 is a flowchart of an exemplary method for manufacturing medical sharps and waste containers in accordance with aspects of the present invention. FIG. 3 is a flowchart of an exemplary method for treating medical sharps and medical waste in an exemplary container in accordance with aspects of the present invention.

Claims (29)

  A disposal container adapted to receive medical sharps or medical waste, the container comprising polypropylene and a sufficient amount of additive to accelerate degradation of the polypropylene after a predetermined shelf life A disposal container having a puncture resistance of at least about 2.8 lbf.   The disposal container of claim 1, wherein the container has an average puncture resistance of at least about 3.4 lbf.   The disposal container of claim 1, wherein the container has an average puncture resistance of at least about 5.0 lbf.   The disposal container of claim 1, wherein the container includes a wall having a thickness of about 0.050 inch to 0.075 inch.   The disposal container of claim 1, wherein the container comprises a wall having a thickness of about 0.060 inches to 0.065 inches.   The disposal container of claim 1, wherein the container has sufficient impact strength to prevent the medical sharps or medical waste from falling out of the container.   2. The lid further comprising a polypropylene and an amount of an additive sufficient to accelerate the degradation of the polypropylene after a predetermined shelf life, the lid having a puncture resistance of at least about 2.8 lbf. Disposal container as described in.   A disposal container adapted to receive medical sharps or medical waste, the container comprising polypropylene and a sufficient amount of additive to accelerate degradation of the polypropylene after a predetermined shelf life The disposal container, wherein the container has sufficient impact strength to prevent the medical sharps or medical waste from falling out of the container.   9. The disposal container of claim 8, wherein the container has a puncture resistance of at least about 2.8 lbf.   The disposal container of claim 8, wherein the container has an average puncture resistance of at least about 3.4 lbf.   9. The disposal container of claim 8, wherein the container has an average puncture resistance of at least about 5.0 lbf.   9. The disposal container of claim 8, wherein the container includes a wall having a thickness of about 0.050 inch to 0.075 inch.   The disposal container of claim 8, wherein the container includes a wall having a thickness of about 0.060 inches to 0.065 inches.   Further comprising a lid comprising polypropylene and an amount of an additive sufficient to accelerate degradation of the polypropylene after a predetermined shelf life, the lid withdrawing the medical sharps or medical waste from the container or lid 9. A disposal container according to claim 8, having a sufficient impact strength to prevent this. A method of manufacturing a medical sharps or waste disposal container,
Injecting a composition comprising polypropylene and an amount of an additive sufficient to accelerate degradation of the polypropylene after a predetermined shelf life;
Forming a container having a fracture resistance of at least about 2.8 lbf.   The method of claim 15, wherein the forming comprises forming a container having an average puncture resistance of at least about 3.4 lbf.   The method of claim 15, wherein the forming comprises forming a container having an average puncture resistance of at least about 5.0 lbf.   16. The method of claim 15, wherein the injecting step comprises injecting a composition having polypropylene and additives to define a wall having a thickness of about 0.050 inches to 0.075 inches. .   16. The method of claim 15, wherein the injecting step comprises injecting a composition having polypropylene and additives to define a wall having a thickness of about 0.060 inches to 0.065 inches. .   The method of claim 15, wherein the forming step includes forming the container with sufficient impact strength to prevent the medical sharps or medical waste from escaping from the container.   16. The method of claim 15, further comprising forming a lid from a composition comprising polypropylene and a sufficient amount of additive to accelerate degradation of the polypropylene after a predetermined shelf life. A method of disposing of medical sharps or waste,
Medical sharps and / or medicals in a container comprising polypropylene and a sufficient amount of additives to accelerate degradation of the polypropylene after a predetermined shelf life and having a minimum fracture resistance of at least about 2.8 lbf Receiving the waste,
Initiating disassembly of the container;
Initiating biodegradation of the container.   23. The method of claim 22, further comprising sterilizing the container and the medical sharps and / or medical waste.   23. The method of claim 22, wherein initiating the disassembling comprises mechanically crushing the container and the medical sharps and / or waste.   24. The method of claim 22, wherein initiating the degradation comprises exposing the container to moisture.   23. The method of claim 22, wherein initiating the degradation comprises exposing the container to ultraviolet light or sunlight.   23. The method of claim 22, wherein initiating the biodegradation comprises exposing the container to soil.   23. The method of claim 22, wherein initiating the biodegradation comprises exposing the container to a stimulus selected from the group consisting of microorganisms, bacteria, fungi and algae, or combinations thereof. A method of manufacturing a medical sharps or waste disposal container,
Forming a pellet comprising polypropylene and additives;
Form pellets into medical sharps or waste disposal containers with a minimum fracture resistance of at least about 2.8 lbf and sufficient impact strength to prevent the medical sharps or medical waste from escaping from the containers A method comprising:

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