Cleanroom packaging materials

Abstract

Described are methods for making a bio-based cleanroom grade packaging material. The method includes providing a resin mixture comprising about 5% to about 40% by volume of a biodegradable material and about 60% to about 95% of a polymer resin, extruding a bio-based film from the resin mixture, cleaning the bio-based film, and converting the bio-based film into the bio-based flexible packaging material inside of a cleanroom. The method may further include winding the bio-based film onto a master roll after the extrusion step. The method may yet further include laminating the bio-based film with a recyclable film after the cleaning step.

Description

JARRT.001WO PATENT CLEANROOM PACKAGING MATERIALS RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 556657, filed on February 22, 2024, the entire contents of which are incorporated by reference herein and made part of this specification. BACKGROUND Field

[0002] The disclosure generally relates to a method of producing bio-based cleanroom grade packaging materials that degrade faster than traditional thermoplastic products. Description of the Related Art

[0003] Cleanroom materials, including bags and films, are utilized in industries like pharmaceuticals, electronics manufacturing, semiconductor production, biotechnology, and other sensitive manufacturing processes where even small particles can cause problems. In recent years, sustainability has become more and more important for packaging materials. Cleanroom packaging materials require specialized materials and manufacturing processes to meet the stringent quality control requirements. For safety reasons, recycled materials cannot be used for making cleanroom packaging materials as they are used to store and transport sensitive devices and products (e.g., life science products) without the risk of potential contamination. Thus, there is a need to find a sustainable solution for providing cleanroom packaging materials that also meet the requirements for use in cleanrooms. SUMMARY

[0004] The present disclosure provides for a method of producing sustainable cleanroom packaging materials that degrade faster than traditional packaging materials for cleanroom use. The sustainable cleanroom packaging materials are bio-based and, in some embodiments, may be flexible. The method for producing a bio-based cleanroom grade packaging materials comprises providing a resin mixture comprising about 5% to about 40% by volume of a biodegradable material and about 60% to about 95% by volume of a polymer resin; extruding a bio-based film from the resin mixture; cleaning the bio-based film; andconverting the bio-based film into the cleanroom grade packaging material inside of a cleanroom. In some embodiments, the method for producing the bio-based cleanroom grade packaging materials can further comprise winding the bio-based film onto a master roll after the extruding step. In some embodiments, cleaning the bio-based film comprises cleaning the bio-based film on the master roll.

[0005] Also disclosed herein is a method for producing bio-based cleanroom grade packaging materials comprises providing a resin mixture comprising about 5% to about 40% by volume of a biodegradable material and about 60% to about 95% by volume of a polymer resin; extruding a bio-based film from the resin mixture; cleaning the bio-based film; laminating the bio-based film with a recyclable film thereby forming a laminated film; and converting the laminated film into the cleanroom grade packaging material inside of a cleanroom. In some embodiments, the method for producing the bio-based cleanroom grade packaging materials can further comprise winding the bio-based film onto a master roll after the extruding step. In some embodiments, cleaning the bio-based film comprises cleaning the bio-based film on the master roll.

[0006] In some embodiments, the polymer resin can comprise one or more of the following materials: nylon (PA), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), aluminum, and ethylene vinyl alcohol copolymer (EVOH).

[0007] In some embodiments, the biodegradable material can include plant-based resins. In some embodiments, the plant-based resins can include polyhydroxyalkanoate (PHA), polylactic acid (PLA), starch blend, cellulose-based plastic, lignin-based polymer composite, polyglycolic acid (PGA), polybutylene succinate (PBS), and polycaprolactone (PCL). In some embodiments, the plant-based resins is a starch blend. In some embodiments, the starch blend can include hydrolyzed starch.

[0008] In some embodiments, the recyclable film may include, for example, polyethylene (LLDPE, MDPE, HDPE), nylon, polyester, polyethylene terephthalate glycol, polyethylene terephthalate, ethylene vinyl alcohol copolymer, and aluminum.

[0009] In some embodiments, the bio-based cleanroom grade packaging material is flexible.

[0010] The bio-based packaging materials manufactured from the methods above can include cleanroom tubings, cleanroom bags, or cleanroom films. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG.1 is a flow chart illustrating one embodiment of the method of making a bio-based cleanroom grade packaging material.

[0012] FIG. 2 is a flow chart illustrating another embodiment of the method of making a bio-based cleanroom grade packaging material. DETAILED DESCRIPTION

[0013] The present disclosure provides various embodiments of bio-based cleanroom grade packaging materials that degrade faster than traditional plastic materials and the methods of making them. Compositions of the bio-based cleanroom packaging materials can comprise about 5% to about 40% by volume of a biodegradable material and about 60% to about 95% by volume of a polymer resin. The polymer resin portion of the material may act as a composite matrix, housing the biodegradable material. The polymer resin may further provide the bio-based material with the specific physical properties the user may desire. Even after the biodegradable material has been incorporated in the polymer matrix, it retains physical properties that are nearly the same or the same as traditional plastics made by the polymer resin. For example, some embodiments of the bio-based cleanroom grade packaging materials may have similar transparency, puncture resistance, temperature resistance, strength, and toughness compared to traditional plastics.

[0014] Furthermore, the biodegradable material may provide the bio-based cleanroom grade packaging material with an additional property of enhanced degradability. When the bio-based material is exposed to microbes, such as when placed into a landfill, the microbes can quickly break down the portion of the bio-based material formed by the biodegradable resin, and cause the bio-based packaging material to degrade much faster compared to the traditional cleanroom grade packaging material and plastics.

[0015] The amount of time required for the bio-based material to degrade in landfill conditions can be varied by changing the ratio of the polymer resin to the biodegradable material. In some embodiments, when under landfill conditions, the bio-based cleanroom grade packaging material disclosed herein can have at least about 90% of the bio-based materialbroken down in 0.5 to 15 years. For example, when the ratio of the biodegradable material to the polymer resin is 1:3, at least about 90% of the bio-based cleanroom grade packaging material can be broken down in 1-2 years, and in some embodiments, 1 year. When the ratio of the biodegradable material to the polymer resin is 1:19, at least about 90% of the bio-based cleanroom grade packaging material can be broken down in 12-15 years, and in some embodiments, 15 years. When the ratio of the biodegradable material to the polymer resin is anywhere in between 1:2.5 and 1:20, the degradation rate may fall within any ranges between 0.5 and 15 years. However, the degradation rate may be less than 0.5 years, or extend beyond 15 years depending on a variety of factors, including, for example, the thickness of the material, the condition of the bag or film, and the environment the bag or film is placed.

[0016] The transparency of the bio-based cleanroom grade packaging material may also be affected by the amount of biodegradable material in the bio-based packaging material. The lower the amount of biodegradable material, the more transparent the bio-based packaging material would be.

[0017] The present disclosure provides a method for producing bio-based cleanroom grade packaging materials, as illustrated in FIG. 1. The method 100 begins at step 110 providing a resin mixture. The resin mixture comprises about 5% to about 40% by volume of a biodegradable material and about 60% to about 95% by volume of a polymer resin. In some embodiments, the resin mixture comprises about 5% to about 35%, about 5% to about 30%, about 5% to about 25%, about 5% to about 20%, about 5% to about 15% by volume of a biodegradable material. In some embodiments, the resin mixture comprises about 65% to about 95%, about 70% to about 95%, about 75% to about 95%, about 80% to about 95%, about 85% to about 95%, about 60% to about 85%, or about 70% to about 85% by volume of a polymer resin.

[0018] In some embodiments, the biodegradable material in the resin mixture can include a plant-based resin. In some embodiments, the plant-based resin can include one or more of the following: polyhydroxyalkanoate (PHA), polylactic acid (PLA), starch blend, cellulose-based plastic, lignin-based polymer composite, polyglycolic acid (PGA), polybutylene succinate (PBS), and polycaprolactone (PCL). In some embodiments, the plant- based resin can include a starch blend. In some embodiments, the starch blend may contain a hydrolyzed starch. Other materials not specifically mentioned above may be used as thebiodegradable material such as materials derived from natural sources and natural by-products from the production of the plastic used as a polymer resin. In some embodiments, the resin mixture comprises about 5% to about 20%, about 5% to about 15%, or about 10% to about 15%by volume of a starch blend.

[0019] In some embodiments, the polymer resin can include one or more of the following: nylon (PA), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), aluminum, and ethylene vinyl alcohol copolymer (EVOH).

[0020] In some embodiments, providing a resin mixture may include a mixing step. The resin mixture can be prepared by placing the biodegradable material and the polymer resin into a mixer. The mixing step can be used to ensure that the biodegradable material and the polymer resin are thoroughly mixed within the resin mixture. In some embodiments, thoroughly mixed resin mixture may provide a bio-based packaging material with a more consistent degradation rate.

[0021] The resin mixture can be prepared in various types of mixers. In some embodiments, the mixing step can be performed in a tilting or non-tilting drum mixer. The drum mixer can include a drum with a height, at least one mixing blade, and a motor. Both the resin mixture and the biodegradable material can be placed inside the drum where the mixing may take place. The drum may have an inner surface. The at least one mixing blade may be positioned on the inner surface of the drum. In embodiments where there is a single mixing blade, the mixing blade can be threaded on the inner surface of the drum, descending the height of the drum in a spiral shape. In embodiments where there is a plurality of mixing blades, the mixing blades can be positioned equidistant from each other along the inner surface of the drum. In embodiments where there is no mixing blade positioned on the inner surface of the drum, the drum mixer may include at least one agitator. After the polymer resin and the biodegradable material are placed inside the drum, the motor can activate rotating the drum about a horizontal axis. If at least one mixing blade is present in the drum mixer, the mixing blades lift and tumble the polymer resin and the biodegradable material onto itself. The motor can rotate the drum in a single direction, or the motor can be configured to rotate in one direction then reverse the rotation motion to enhance the mixing of the polymer resin andbiodegradable material. Various methods of mixing can be used to create the consistency, including for example, agitation mixing, kneading, and tumble mixing. In some embodiments, the resin mixture may be prepared inside of a cleanroom. In some embodiments, the resin mixture may be provided premixed.

[0022] Step 120 of the method includes extruding a bio-based film from the resin mixture. In some embodiments, the resin mixture may be gravity dropped into an extruder. Alternatively, the resin mixture may be transported from the mixer to the extruder by a person or a machine. The extruder is configured to allow an operator to control the temperature and pressure inside the extruder. In some embodiments, the extruding step can occur inside a cleanroom.

[0023] In some embodiments, a screw extruder may be used to complete the extruding step. The screw extruder may include screw and a shaft with a first end, a second end, and a length extending from the first end to the second end. The resin mixture can be placed into the shaft of the extruder proximate to the first end. The screw of the extruder may include a rod and a blade threaded on the rod. The threaded blade is configured to transport the resin mixture from the first end to the second end. The extruder may also include heaters positioned along the length of the shaft. The heaters allow heat to be applied to the resin mixture inside the extruder and melt the resin mixture. When the molten resin mixture reaches the second end of the extruder, it engages a shaping die of the extruder, and the resin mixture takes the shape of the shaping die. Common shapes include, for example, sheets, films, structural parts, tubings, and pipes. When the molten resin exits the shaping die of the extruder, the molten resin begins to cool, becoming the bio-based film. In some embodiments, the bio- based film may take the shape of a film / sheet, a tubing, or a structural part. Although the extruding step was illustrated using a screw extruder, various types of extruders may be used to extrude the bio-based film, including, for example, ram extruders. The composition of the extruded bio-based film may be similar to the composition of the resin mixture.

[0024] After the bio-based film is extruded, the method moves to step 130, which includes cleaning the bio-based film. In some embodiments, the cleaning step can be performed by a contact cleaning systems. The contact cleaning system may include at least one contact cleaning roller, which is configured to engage with the bio-based film. The at least one contact cleaning roller can extract dust and other contaminants from the surface of the bio-based film.

[0025] In some embodiments, the cleaning of the bio-based film can also be accomplished through web cleaning, by taking the bio-based film to an autoweb for example. The autoweb cleans the outside of the film by removing particles off the film. Although the cleaning step is illustrated as using a contact cleaning system, other methods for cleaning films like non-contact cleaning systems, for example, are also contemplated. Further, although the cleaning step is described as occurring outside a cleanroom, the cleaning step can occur inside a cleanroom.

[0026] In some embodiments, after the bio-based film is extruded in step 120, the bio-based film can optionally be subject to a cooling step. The bio-based film may be sent vertically up on rollers to initiate the cooling period. In some embodiments, the cooling step may include exposing the bio-based film to chill rollers. The chill rollers may act as a heat transfer and finishing device. The temperature of the chill rollers is less than the temperature of the bio-based film exiting the extruder. In some embodiments, the cooling step may include exposing the bio-based film exiting the extruder to an environment with a lower temperature than the temperature of the extruded bio-based film. However, it should be understood that these are only a few examples of ways to cool the extruded bio-based film, and other methods of cooling the film are also contemplated. The cooling period may allow the shape and form of the bio-based film to set. After the optional cooling step, the bio-based film may be sent back down to proceed with the method’s subsequent steps.

[0027] In some embodiments, the method can further include an optional step of winding the bio-based film onto a master roll. Winding the bio-based film onto the master roll allows for the film to be easily handled, stored, or transported to a new location. The master roll may be used to transport the bio-based film into a cleanroom environment. In some embodiments, the width of the master roll can depend on the extruder or on the width of the film needed to make the packaging material. Although the winding the bio-based film onto a master roll step is described as occurring outside a cleanroom, the winding step can also occur inside a cleanroom. In some embodiments, the bio-based film on the master roll can then be cleaned in step 130 as discussed above. Thus, the cleaning step 130 can include cleaning the bio-based film on the master roll.

[0028] After the bio-based film is cleaned in step 130, the bio-based film, if formed outside of the cleanroom can now be introduced into a cleanroom using standard cleanroomprocedure. The method moves to step 140, which includes converting the bio-based film into the bio-based cleanroom grade packaging material inside the cleanroom. In some embodiments, a conversion machine can be configured to convert the bio-based film into sheets or tubings. In some embodiments the bio-based films can be converted into a bag. The bio-based or laminated film can be fed through the conversion machine through rollers, feeders, and tensioners to keep the films from wrinkling and to ensure that the films are moving through the conversion machine at a suitable speed . In embodiments where the bio-based film is in tubular form, the conversion machine can be set to a desired bag length. The conversion machine can then place a seal at the set length, and an autoblade can make a cut across the length of the films just after the seal to form bags. Other configurations may be used to form bags. In some embodiments, the bio-based film may itself be used as a cleanroom grade packaging material.

[0029] In some embodiments, the cleanroom grade packaging material may be a flexible material.

[0030] The present disclosure also provides a method for producing bio-based cleanroom grade packaging materials as illustrated in FIG.2. The cleanroom grade packaging material includes a laminated film, which is made by laminating the bio-based film with a recyclable film. The laminated film may offer some advantages over non-laminated packaging materials. Laminating the bio-based film with a recyclable film can protect the bio-based film from puncture and other destructive factors, thus provides a better protection for the objects in such packaging material. Further, laminated film may provide a better barrier against outside agents such as light, moisture, pathogens, and gases.

[0031] The method 200 begins at step 210 providing a resin mixture. The resin mixture comprises about 5% to about 40% by volume of a biodegradable material and about 60% to about 95% by volume of a polymer resin. The method 200 continues to step 220, which includes extruding a bio-based film from the resin mixture. After the bio-based film is extruded, the method moves to step 230 cleaning the bio-based film. The steps 210, 200, and 230 correspond to steps 110, 120, and 130 in the method 100 described herein, including various options for the equipment and materials used.

[0032] The method 200 may also optionally include the cooling step, winding the bio-based film onto a master roll step as described herein.

[0033] After the bio-based film is cleaned, the method moves on to step 240, which include laminating the bio-based film with a recyclable film thereby forming a laminated film. In some embodiments, the recyclable film includes, for example, polyethylene (including LLDPE, MDPE, and HDPE), nylon, polyester, polyethylene terephthalate glycol, polyethylene terephthalate, ethylene vinyl alcohol copolymer, and aluminum. Although the laminating step is described as occurring outside a cleanroom, the laminating step can occur inside a cleanroom. The lamination step can be performed by any equipment known in the art to laminate two or more substrates together.

[0034] The laminated film can then be converted into the cleanroom grade packaging material inside of a cleanroom in step 250 of the method. Similarly, step 250 is the same as step 140 in method 100. The bio-based film may be introduced or transferred into the cleanroom prior to performing a step that occurs in the cleanroom. In some embodiments, the cleanroom grade packaging material is flexible.

[0035] Currently, laminated structures with at least a non-recyclable film cannot be recycled. Once a non-recyclable film and a recyclable substrate are laminated together, it can be expensive to separate the layers. The present laminated film includes a bio-based film that can decompose / degrade relatively quickly, leaving the recyclable substrate that can then be recycled.

[0036] In order for materials to be “Cleanroom grade,” they must be produced in controlled environments called cleanrooms. Whereas many non-cleanroom grade materials can be produced in environments without the strict control of particulate matter or environmental conditions, cleanrooms have stringent control over airborne particles, humidity, and other environmental factors to minimize contamination. In some instances, cleanrooms may have high efficiency particular air filters (HEPA), ultra low particulate air filters (ULPA), or other filter systems. The HEPA and ULPA filters can intake air that would naturally pass into the cleanroom without the filter, and process the air according to certain specifications, cleaning and decontaminating the air. The filters can then reintroduce the processed air into the controlled environment. Further, there is positive pressure inside the cleanroom. The positive pressure inside the cleanroom creates airflow out of the room, flushing out contamination generated by internal activities.

[0037] Cleanroom bags and other packaging materials may use specialized materials configured to minimize particulate generation and may be made from low-particulate materials like polyethylene or polypropylene for example. The cleanroom manufacturing may have specific requirements regarding the material used, and recycled material is generally not allowed. Specific requirements for cleanroom packaging may include no silicon, no amide, and / or no amine in the packaging material made for cleanroom use. Thus, the resins used for making cleanroom packaging material should be substantially free of silicon, amide, and / or amine. Further, the machinery used to manufacture cleanroom packaging materials may be designed to minimize particle generation as well. Moreover, regular and thorough cleaning and maintenance of equipment are performed in cleanroom settings to prevent any particle buildup or contamination that could affect the production of cleanroom packaging materials. The disclosed resin mixture utilizes a combination of the biodegradable material and the traditional polymer at disclosed ratios to achieve a base-based film that is more environmentally friendly or more sustainable. At the same time, the bio-based films and cleanroom packaging materials made from said bio-based films also maintain a high level of the physical and mechanical properties of traditional cleaning packaging material. The disclosed process allows for producing a cleanroom packaging material that uses less virgin material made from fossil fuels.

[0038] Cleanroom packaging materials may further undergo rigorous handling and packaging procedures to maintain cleanroom cleanliness standards. Cleanroom packaging materials are often double or triple bagged and sealed to prevent contamination. Furthermore, workers in cleanroom environments typically follow strict gowning procedures, including wearing specific cleanroom garments like suits, gloves, hairnets, and shoe covers, to prevent contamination from human sources. Because of the specialized materials, manufacturing processes, and stringent quality controls required to produce cleanroom packaging materials, cleanroom packaging materials are often more expensive and packaging materials produced outside cleanrooms.

Claims

WHAT IS CLAIMED IS:

1. A method for making a cleanroom grade packaging material comprising: providing a resin mixture comprising about 5% to about 40% by volume of a biodegradable material and about 60% to about 95% of a polymer resin; extruding a bio-based film from the resin mixture; cleaning the bio-based film; and converting the bio-based film into the cleanroom grade packaging material inside of a cleanroom.

2. The method of Claim 1, further comprising winding the bio-based film onto a master roll after the extruding step.

3. The method of Claim 2, wherein cleaning the bio-based film comprises cleaning the bio-based film on the master roll.

4. The method of Claim 1, wherein the polymer resin comprises one or more of nylon (PA), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), aluminum, and ethylene vinyl alcohol copolymer (EVOH).

5. The method of Claim 1, wherein the biodegradable material comprises plant- based resin.

6. The method of Claim 5, wherein the plant-based resin comprises polyhydroxyalkanoate (PHA), polylactic acid (PLA), starch blend, cellulose-based plastic, lignin-based polymer composite, polyglycolic acid (PGA), polybutylene succinate (PBS), or polycaprolactone (PCL).

7. The method of Claim 6, wherein the plant-based resin comprises a starch blend.

8. The method of Claim 7, wherein the resin mixture comprises about 10% to about 15% by volume of the starch blend.

9. The method of Claim 7, wherein the starch blend comprises hydrolyzed starch.

10. The method of Claim 1, wherein the cleanroom grade packaging material comprises cleanroom tubing, cleanroom bag, or cleanroom film.

11. The method of Claim 1, wherein the cleanroom grade packaging material is flexible.

12. The method of Claim 1, wherein the resin mixture comprises about 5% to about 25% by volume of the biodegradable material.

13. A method for making a cleanroom grade packaging material comprising: providing a resin mixture comprising about 5% to about 40% by volume of a biodegradable material and about 60% to about 95% of a polymer resin; extruding a bio-based film from the resin mixture; cleaning the bio-based film; laminating the bio-based film with a recyclable film thereby forming a laminated film; and converting the laminated film into the cleanroom grade packaging material inside of a cleanroom.

14. The method of Claim 13, wherein the polymer resin comprises one or more of nylon, linear low density polyethylene (LLDPE), high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), aluminum, or ethylene vinyl alcohol copolymer.

15. The method of Claim 13, wherein the biodegradable material comprises plant- based resin.

16. The method of Claim 15, wherein the plant-based resin comprises polyhydroxyalkanoate (PHA), polylactic acid (PLA), starch blend, cellulose-based plastic, lignin-based polymer composite, polyglycolic acid (PGA), polybutylene succinate (PBS), or polycaprolactone (PCL).

17. The method of Claim 15, wherein the plant-based resin comprises a starch blend.

18. The method of Claim 17, wherein the resin mixture comprises about 10% to about 15% by volume of the starch blend.

19. The method of Claim 17, wherein the starch blend comprises hydrolyzed starch.

20. The method of Claim 13, further comprising winding the bio-based film onto a master roll after the extruding step.

21. The method of Claim 20, wherein cleaning the bio-based film comprises cleaning the bio-based film on the master roll.

22. The method of Claim 13, wherein the recyclable film comprises polyethylene, nylon, polyester, polyethylene terephthalate glycol, polyethylene terephthalate, ethylene vinyl alcohol copolymer, or aluminum.

23. The method of Claim 13, wherein the cleanroom grade packaging material comprises cleanroom tubings, cleanroom bags, or cleanroom films.

24. The method of Claim 13, wherein the resin mixture comprises about 5% to about 25% by volume of the biodegradable material.

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