Reusable cleaning socks for GMP (good manufacturing practice) medicine cleaning workshop

Abstract

The invention discloses a reusable clean sock for a GMP (good manufacturing practice) medicine clean workshop, which is characterized in that for particles with the particle size of more than or equal to 0.5 micron, the dust generation amount in air does not exceed 500 counts per sock; the clean sock capable of being used repeatedly is formed by weaving covering yarn, and the covering yarn comprises polyester filaments and polyurethane stretch yarn. According to the covering yarn capable of being repeatedly used for the clean socks, the polyester filaments and the polyurethane stretch yarn are adopted, the production process of the polyester filaments and the polyurethane stretch yarn is continuous in the aspect of material selection, the filaments large in length are directly produced from a spinning machine, compared with short fibers, the filaments are smooth in surface, less in hairiness and small in dust generation amount, and the covering yarn is suitable for being used for the clean socks. And the fibers are continuous, so that the fibers are less broken or dropped, and the breaking strength is high.

Description

Technical Field

[0001] The invention relates to the technical field of socks, and in particular to a pair of reusable clean socks used in a GMP pharmaceutical clean workshop. Background Art

[0002] In August 2022, the new GMP (Good Manufacturing Practice) regulations were introduced to further regulate the production environment and product quality to ensure higher hygiene standards and product safety. Clean socks are a new concept and new application product born with the new GMP regulations. The purpose is to prevent the contamination of the environment and products by blocking the flow of contaminants from the feet of people entering the dust-free clean area.

[0003] Clean socks are a product with a new concept and new application field. Ordinary civilian sock manufacturers are unaware of this regulation and this application field, and do not have the relevant conditions such as production technology, qualifications, environment and facilities for clean socks. They are unable to produce such products and have no corresponding sales channels.

[0004] The socks currently sold on the market are basically woven from polyester staple fibers, cotton staple fibers or spandex staple fibers, which are materials with lower costs and better comfort. However, such socks made of staple fibers often have a lot of hair on the surface, generate a lot of dust, and have low cleanliness, and cannot meet the use requirements of GMP pharmaceutical clean workshops at all. Summary of the invention

[0005] In order to overcome the above technical defects, the present invention provides a reusable clean socks for use in a GMP pharmaceutical clean workshop.

[0006] In order to solve the above problems, the present invention is implemented according to the following technical solutions:

[0007] The present invention discloses a reusable clean sock for use in a GMP pharmaceutical clean workshop. The reusable clean sock generates no more than 500 counts of dust in the air for particles with a particle size of ≥ 0.5 microns. The reusable clean sock is woven with core-spun yarn, which includes polyester filaments and polyurethane stretch yarns.

[0008] Preferably, the fabric structure of the reusable clean socks is a plain weave structure.

[0009] Preferably, the fabric structure of the reusable clean socks is a plain weave structure with plain needles of 132-200G.

[0010] Preferably, the sock body comprises a sock barrel, a sock surface, a sock sole, a sock heel and a sock toe, and the fabric thickness of the sock sole, the sock heel and the sock toe is greater than the fabric thickness of the sock barrel and the sock surface of the sock body.

[0011] Preferably, the reusable clean socks are prepared by the following method:

[0012] Knitting socks: using core-spun yarn to weave in a plain weave structure to obtain semi-finished socks, wherein the core-spun yarn includes polyester filaments and polyurethane stretch yarns;

[0013] Cleaning: The semi-finished socks are cleaned several times with deionized EDI ultrapure water;

[0014] Drying: Dry the semi-finished socks after multiple washings;

[0015] Shaping: Use a thermal setting machine to shape the semi-finished socks to obtain clean socks that can be used multiple times;

[0016] Sterilization:

[0017] All the above processes are completed in a clean room that meets ISO 4-7 standards. The temperature of the clean room is 22℃±2℃ and the humidity is 55%±15%. For particles with a diameter of ≥0.5 microns, the environmental cleanliness value of the clean room is APC≤

[0018] 100Counts / 2.83L.

[0019] Preferably, in the cleaning step, the resistivity of the deionized EDI ultrapure water is 17.6 MΩ±0.6 MΩ, LPC<20 counts / mL, IC<0.01 ug / mL, and NVR DIW<5.0 ug / mL.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The invention provides a reusable clean sock for a GMP pharmaceutical clean workshop. The reusable clean sock generates no more than 500 counts of dust in the air for particles with a particle size of ≥0.5 micron. The reusable clean sock is woven with core-spun yarn, which includes polyester filaments and polyurethane stretch yarns.

[0022] The core-spun yarn of the reusable clean socks of the present invention adopts polyester filament and polyurethane stretch yarn. In terms of material selection, the production process of polyester filament and polyurethane stretch yarn is continuous, and long filaments are directly produced from the spinning machine. Compared with staple fibers, the filaments have a smooth surface, less hairiness, and less dust generation. Because the fibers are continuous, they are less likely to break or fall off, and have a high breaking strength.

[0023] The socks of the present invention have high cleanliness, can effectively protect the environment of the GMP pharmaceutical clean workshop from pollution, and can be widely used to meet the use requirements of the GMP pharmaceutical clean workshop. In addition, the clean socks of the present invention can be used repeatedly and are not disposable products, which effectively reduces the use cost of the enterprise and reduces the generation of waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 It is a schematic structural diagram of the reusable clean socks of the present invention;

[0026] Figure 2 It is a structural schematic diagram of the plain weave structure of the present invention;

[0027] Figure 3 It is the spinning principle diagram of the present invention;

[0028] In the figure:

[0029] 10-sock body, 11-sock tube, 12-sock heel, 13-sock surface, 14-sock bottom, 15-sock toe;

[0030] 1-spandex filament, 2-PLA yarn, 3-tension disk, 4-guide wheel, 5-polyester filament, 6-drafting device, 7-composite core-spun yarn. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0032] like Figure 1-2 As shown, the preferred structure of the reusable clean socks for GMP pharmaceutical clean workshop according to the present invention.

[0033] Embodiment 1

[0034] like Figure 1 As shown, the reusable clean socks for GMP pharmaceutical clean workshops include a sock body 10, which is woven from core-spun yarn. For particles with a particle size of ≥0.5 microns, the dust emission in the air of the reusable clean socks does not exceed 500 counts / piece.

[0035] In the present invention, the sock body at least comprises a sock toe 15, a sock bottom 14, a sock surface 13, a sock heel 12, a sock tube 11 and a sock opening, that is, the whole sock is woven with the same core-spun yarn.

[0036] In a preferred embodiment, the core-spun yarn includes polyester filaments and polyurethane elastic yarns. Combined with the preparation process with specific requirements, the dust emission of the sock body in the air for particles with a particle size of ≥ 0.5 microns does not exceed 500 counts / piece, that is, the clean socks of the present invention release low particulate matter in a clean environment, ensuring that the cleanliness of the GMP pharmaceutical clean workshop meets the GMP standard.

[0037] In the present invention, polyester filaments are also called polyester filaments. Such fibers have the advantages of wear resistance, high strength, chemical corrosion resistance, etc., and are used to provide good physical properties for socks. In terms of material selection, the production process of polyester filaments and polyurethane stretch yarns is continuous, and long filaments are directly produced from the spinning machine. Compared with staple fibers, the filaments have a smooth surface, less hairiness, and less dust generation. Because the fibers are continuous, they are less likely to break or fall off, and have a large breaking strength.

[0038] Combining the two filaments, polyester filament has high cleanliness, high strength (each monofilament fiber is continuous and uninterrupted), good wear resistance, smooth surface and not easy to produce hairiness, so it can produce clean socks with high cleanliness, low dust generation, smooth surface, no hairiness and high tensile strength. The material cost is equivalent to that of common polyester staple fibers. Polyurethane stretch yarn has the advantages of high strength, high elastic recovery ability, firmness, durability, wrinkle resistance, ironing-free, good light resistance and chemical resistance.

[0039] In summary, the present invention achieves the excellent characteristics of smooth surface, low dust generation, high strength, wear resistance, good barrier properties and comfortable wearing of socks. The design is simple and practical, especially suitable for workplaces requiring high cleanliness, and meets the use needs of GMP pharmaceutical clean workshops.

[0040] In a specific implementation, the polyester filament is a polyester filament of 75D / 36F specification.

[0041] It should be noted that for 75D / 36F polyester filament, 75D means the yarn thickness is 75 denier, D is denier, which is the weight of 9000 meters of yarn at the standard moisture regain, which can be used to quantify the thickness of the yarn; "36F" means that each strand of yarn is composed of 36 polyester fibers.

[0042] Preferably, in the core-spun yarn, the polyurethane elastic yarn is used as the core yarn and the polyester filament is used as the covering yarn. The core-spun yarn is composed of polyester filament and polyurethane elastic yarn.

[0043] In the present invention, the core-spun yarn is a yarn with a special structure, which is composed of a core fiber (core yarn) and a covering fiber (covering yarn). The core fiber has high elasticity, while the covering fiber gives the desired properties to the yarn surface. For this reason, the polyester filament provides the strength and wear resistance of the socks, and the polyurethane stretch yarn increases the elasticity and comfort of the socks. The use of elastic fiber makes the core-spun yarn products more elastic and have deformation recovery ability, meeting the needs of multiple uses.

[0044] Specifically, the woven sock-shaped structure can be short socks, middle socks or long socks, which can effectively prevent pollutants from flowing out of people's feet and causing pollution to the clean workshop.

[0045] Preferably, the fabric structure of the sock body is a plain weave structure with plain needles of 132-200G.

[0046] It should be noted that plain stitch is a basic stitch for knitwear, usually also called single-sided knitting or single-sided plain stitch. Its characteristics are that the front side of the fabric is smooth, while the back side has raised small circles. Plain knitted fabrics have good stretchability and comfort.

[0047] Specifically, the parameter is 132-200G, where "G" represents the needle density of the knitting machine, also known as "needle length" or "needle number". 132G means that the number of needles in one horizontal circle of the socks is 132. This parameter determines the density and fineness of the fabric. The higher the value, the denser the fabric, the finer the surface of the fabric will be, and it will usually be softer and smoother. The present invention adopts a flat needle of 132-200G, which can obtain a sock fabric with a higher density and a fine surface.

[0048] In a preferred embodiment, the sock body adopts a single-layer plain weft knitted structure with plain needles of 132-200G.

[0049] It should be noted that if Figure 2 As shown, the plain weft knitted structure is a basic structure of knitted fabrics. It has become an important structure in knitted fabrics due to its simple weaving process, good elasticity and comfortable wearing experience.

[0050] In a preferred embodiment, the sock body includes a sock barrel, a sock surface, a sock sole, a sock heel and a sock toe, and the fabric thickness of the sock sole, the sock heel and the sock toe is greater than the fabric thickness of the sock barrel and the sock surface of the sock body. The purpose of thickening the weaving is to increase the local strength and wear resistance of the stress-bearing parts of the socks during wearing, as well as the number of washing times.

[0051] In a specific implementation, the present invention also provides a method for preparing recycled and environmentally friendly disposable clean socks, the method comprising:

[0052] Knitting socks: core-spun yarn is used for weaving in a plain weave structure to obtain semi-finished socks, wherein the core-spun yarn includes polyester filaments and polyurethane stretch yarns; the sock body of the semi-finished socks adopts a single-layer plain weft knitted structure with a plain needle of 132-200G.

[0053] Cleaning: The semi-finished socks are cleaned several times with deionized EDI ultrapure water;

[0054] Drying: Dry the semi-finished socks after multiple washings;

[0055] Shaping: Use a thermal setting machine to shape the semi-finished socks to obtain clean socks that can be used multiple times;

[0056] Sterilization:

[0057] Among them, all the above processes are completed in a dust-free clean room that meets ISO 4-7 standards. The temperature of the dust-free clean room is 22℃±2℃ and the humidity is 55%±15%. For particles with a particle size ≥0.5 microns, the environmental cleanliness value of the dust-free clean room is APC≤100Counts / 2.83L.

[0058] Specifically, the present invention provides a specific implementation method of reusable clean socks, comprising:

[0059] 1. Sock structure: The socks are woven with a bottom yarn frame to make the socks more elastic, more comfortable, and tighter on the surface, so that they can more effectively block stains on the user's feet and reduce the risk of hair loss. The toe, sole, and heel of the socks are thickened to increase the local strength and wear resistance of the stress-bearing parts during the wearing process of the socks, as well as the number of washing times.

[0060] 2. Base material: The socks are knitted with composite core-spun yarn made of high-quality, high-cleanliness polyester filament and polyurethane elastic yarn through special processing. Since chemical fiber filament has high cleanliness, high strength (each monofilament fiber is continuous and uninterrupted), good wear resistance, smooth surface and not easy to produce hairiness, it can produce clean socks semi-finished products with high cleanliness, low dust generation, smooth surface, no hairiness and high tensile strength, and its material cost is equivalent to that of common polyester staple fibers. Polyurethane elastic fiber has a series of advantages such as high strength, high elastic recovery ability, firmness, durability, wrinkle resistance, ironing-free, good light resistance, good chemical resistance, etc.

[0061] 3. Sock weaving process: high-speed plain needle 132-200G plain weave, high weaving efficiency, tight fabric, the socks shaped structure woven out is short socks, mid-tube socks or long socks, which can effectively block the outflow of pollutants from the feet of personnel and cause pollution to the GMP workshop (medical clean workshop environment). Special sock weaving equipment is used to weave the surface of the socks with polyester chemical fiber filaments and the inner layer of the socks with polyurethane elastic fibers, so as to achieve the excellent characteristics of smooth surface, low dust generation, high strength, wear resistance, good barrier properties and comfortable wearing.

[0062] 4. Production environment: All manufacturing processes are completed in a strictly controlled dust-free clean room area ISO 4-7 (10-10000 grade). The personnel and environment in the clean room area are strictly controlled in accordance with the ISO 14644-1:2015 standard. Therefore, the socks produced in such a controlled environment have ultra-high cleanliness and ultra-low dust generation.

[0063] 5. Washing and drying process: In a strictly controlled dust-free clean room area ISO 4-7 (10-10000 level), the socks are washed multiple times with deionized EDI ultrapure water and then dried to obtain semi-finished socks with ultra-high cleanliness and ultra-low dust generation.

[0064] 6. Shaping process: In a strictly controlled dust-free clean room area ISO 4-7 (10-10000 grade), an ultra-clean thermal shaping machine is used to shape the socks to obtain finished socks with ultra-high cleanliness and ultra-low dust generation.

[0065] 7. Packaging / quality inspection: In the strictly controlled dust-free clean room area ISO 4-7 (10-10000 grade), the socks are fully inspected for appearance quality and physical specifications after shaping. In the laboratory of the strictly controlled clean area certified by ISO / IEC 17025:2017, the cleanliness (APC) test and analysis are carried out before packaging. The result is a GMP pharmaceutical clean workshop clean sock with guaranteed quality and performance that can be used repeatedly.

[0066] 8. Sterilization (sterilization) treatment: The packaged socks are sterilized using high-tech gamma ray irradiation sterilization technology or high-temperature moist heat sterilization technology to kill all microorganisms, pathogenic bacteria, viruses and fungi, etc., so that all socks reach a sterile level (10 to the negative 6th power level).

[0067] 9. Sterility testing: The sterilized socks are sent to a third-party testing agency for sterility testing, and a test result report is issued to ensure that the sterilized socks can reach the sterility level (10 to the negative 6th power), providing safety protection for users.

[0068] Specifically, the performance of the present invention is compared with that of ordinary civilian socks on the market, and the comparison results are as follows:

[0069]

[0070]

[0071] Through the above effective technical solutions, a kind of clean socks that can be used repeatedly in GMP pharmaceutical workshops is formed, which is sterile, does not lint or shed after multiple washings, has low dust emission, high cleanliness, high strength, high wear resistance, smooth surface and no hairiness. It can meet the requirements of being used again after multiple washings after the first wear, can reduce the consumption of socks for the majority of GMP pharmaceutical industry customers, can effectively supervise the cleanliness and replacement frequency of each employee's socks, and prevent the pollution of pharmaceutical clean workshops by unclean socks due to ineffective supervision of cleanliness and replacement frequency caused by employees wearing private socks. It can provide better comfort for each user and protect the user's feet from harm by chemicals. Sterilization treatment and sterility testing can make users safer, make the environment more effectively controlled, and produce safer and more secure quality drugs.

[0072] Embodiment 2

[0073] The second embodiment provides a reusable clean socks for GMP pharmaceutical clean workshops, and the materials used and the product principle are exactly the same as those of the first embodiment. Specifically, the second embodiment is an optimization and improvement of the core-spun yarn.

[0074] like Figure 3 As shown, the core-spun yarn is made of polyester filaments, PLA yarns and polyurethane stretch yarns, wherein the polyester filaments are actually polyester filaments and the polyurethane stretch yarns are spandex filaments.

[0075] In the present invention, the materials of the polyester filament include PHBV particles, biomass graphene and recycled polyester PET particles, and the recycled polyester PET particles are obtained by processing and granulating waste recycled polyester bottles. In a specific implementation, the polyester filament includes the following raw material PHBV particles 2.5%, biomass graphene 2% and recycled polyester PET particles 95.5% calculated by weight percentage.

[0076] Specifically, the PHBV particles, biomass graphene and recycled polyester PET particles are mixed evenly, placed in a twin-screw extruder for melt blending to obtain a masterbatch, and the melt extrusion temperature is 150° C. The masterbatch is added to a melt spinning machine, the spinning temperature is 275° C., the heat setting temperature is 150° C., and the recycled polyester filament is produced.

[0077] 1. Degradation experiment

[0078] Take the recycled polyester filament and bury it in the soil. To ensure that the soil moisture, microbial species, quantity and activity are high, the embedding depth of the composite filament is set to 20 cm. Take out some samples every 30 days, rinse them with deionized water and ethanol several times, put them in the oven, and seal them after drying for testing.

[0079] After 60 days of soil degradation, deep grooves appeared inside the fibers of the regenerated polyester filaments, and large gaps were formed between the filaments, indicating that the regenerated polyester filaments were eroded by microorganisms and water molecules in the soil, resulting in changes in the internal structure of the fibers; the microorganisms in the soil interacted with the macromolecular segments of the regenerated polyester filaments, causing the macromolecular chains to break and decompose, thereby causing changes in the fiber structure.

[0080] According to GB / T14344-2022 "Test Method for Tensile Properties of Chemical Fiber Filaments", a yarn tensile tester was used to test the mechanical properties of regenerated polyester filaments. The sample length was 50 cm, the tensile speed was 250 mm / min, each sample was tested 10 times, and the average value was taken. The fiber breaking strength of the regenerated polyester filament was 5.3 cN / dtex; the elongation at break was 32.1%; the dyeing was uniform; the appearance of hair was very small, ≤1 / bit.

[0081] In the present invention, the PLA yarn is a wrapped yarn of PLA filaments and PLA / PHBV filaments. One PLA / PHBV filament wraps two PLA filaments, and the PLA / PHBV filament wraps the two PLA filaments under the action of twist (Z twist), wherein the linear density of the wrapped yarn is 18.5tex.

[0082] In one specific implementation, the PLA / PHBV filaments used have a linear density of 3.33 tex, a breaking strength of 104.9 cN, a breaking tenacity of 34.2 cN / dtex, and a breaking elongation of 33.25%.

[0083] It should be noted that PHBV is an aliphatic polyester synthesized by microorganisms, which is biodegradable and has good biocompatibility. It is produced by bacteria and can be digested by bacteria. It is completely decomposed into carbon dioxide, water and biomass under soil or composting conditions, and will not cause pollution to the environment. PLA / PHBV filament is a blended filament formed by PLA filament and PHBV filament, with a blending ratio of 80:20.

[0084] After testing, the actual twist of PLA yarn is 79.12 twists / 10cm, the breaking strength is 301.51cN, and the breaking elongation is 12.5%. According to GB / T20944.3-2008 "Evaluation of antibacterial properties of yarns Part 3: Oscillation method", the antibacterial properties of the spun PLA yarn are tested. If the antibacterial rate of the yarn against the bacteria is ≥70%, the yarn is considered to have antibacterial properties.

[0085] The test results show that the antibacterial rate of PLA yarn against Escherichia coli is 97.21%, the antibacterial rate against Staphylococcus aureus is 98.32%, and the antibacterial rate against Candida albicans is 98.11%.

[0086] In a preferred embodiment, the PLA yarn is modified by using chitosan to modify the PLA filaments and PLA / PHBV filaments in the PLA yarn. The specific method is as follows:

[0087] The twisted PLA yarn was immersed in 80°C hot water for 1 h for heat setting.

[0088] Weigh chitosan, put it into a soaking container, add 1% glacial acetic acid by mass, stir until chitosan is completely dissolved, and prepare a modified solution. The ratio of chitosan to glacial acetic acid is 200g chitosan per 1L glacial acetic acid. Then, 2% glutaraldehyde by mass is added dropwise to the modified solution, and the addition ratio of glutaraldehyde is 0.2L glutaraldehyde per 1L glacial acetic acid.

[0089] The heat-set PLA yarn was immersed in the modification solution for 1 hour, then taken out and 2% by mass glutaraldehyde was evenly dripped on the PLA yarn, and then placed in a fume hood for drying.

[0090] The invention adopts chitosan and appropriately cross-links it with glutaraldehyde to modify the polylactic acid filaments in the PLA yarn. The high crystallinity of the polylactic acid fiber makes it have morphological stability and heat setting ability. After heat setting, the surface of the polylactic acid filament is smoother, the hairiness is reduced, the surface friction coefficient is greatly reduced, and the wrapped yarn after heat setting is more compact.

[0091] Through experiments, it was found that after the above modification treatment, the surface morphology of PLA yarn is better and smoother, which can improve the comfort of wearing and reduce discomfort. The elongation at break and elongation at break of PLA yarn are significantly increased, and the mechanical properties are better than those of unmodified yarn. This makes the mechanical properties of socks better and more comfortable to wear.

[0092] On the other hand, by adding PLA yarn, the socks have antibacterial properties to better meet the use needs of GMP pharmaceutical clean workshops, and cooperate with the wear resistance and other properties of the socks to better achieve the purpose of multiple reuse.

[0093] For other structures of the reusable clean socks for GMP pharmaceutical clean workshop described in this embodiment, refer to the prior art.

[0094] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A reusable clean socks for GMP pharmaceutical clean workshop, characterized by: For particles with a diameter of ≥0.5 microns, the amount of dust generated in the air by reusable clean socks shall not exceed 500 counts / piece; The reusable clean socks are woven from core-spun yarns, which include polyester filaments and polyurethane stretch yarns.

2. The reusable clean socks for GMP pharmaceutical clean workshop according to claim 1, characterized in that: The fabric structure of the reusable clean socks is a plain weave structure.

3. The reusable clean socks for GMP pharmaceutical clean workshop according to claim 2, characterized in that: The fabric structure of the reusable clean socks is a plain weave structure with a plain needle of 132-200G.

4. The reusable clean socks for GMP pharmaceutical clean workshop according to claim 1, characterized in that: The sock body comprises a sock barrel, a sock surface, a sock sole, a sock heel and a sock toe, and the fabric thickness of the sock sole, the sock heel and the sock toe is greater than the fabric thickness of the sock barrel and the sock surface of the sock body.

5. A reusable clean socks for GMP pharmaceutical clean workshop according to any one of claims 1 to 4, characterized in that: The reusable clean socks are prepared by the following method: Knitting socks: using core-spun yarn to weave in a plain weave structure to obtain semi-finished socks, wherein the core-spun yarn includes polyester filaments and polyurethane stretch yarns; Cleaning: The semi-finished socks are cleaned several times with deionized EDI ultrapure water; Drying: Dry the semi-finished socks after multiple washings; Shaping: Use a thermal setting machine to shape the semi-finished socks to obtain clean socks that can be used multiple times; Sterilization: All the above processes are completed in a clean room that meets ISO 4-7 standards. The temperature of the clean room is 22℃±2℃ and the humidity is 55%±15%. For particles with a diameter of ≥0.5 microns, the environmental cleanliness value of the clean room is APC≤ 100Counts / 2.83L.

6. The reusable clean socks for GMP pharmaceutical clean workshop according to claim 5, characterized in that: During the cleaning step, the resistivity of deionized EDI ultrapure water was 17.6 MΩ ± 0.6 MΩ, LPC < 20 counts / mL, IC < 0.01 ug / mL, and NVR DIW < 5.0 ug / mL.

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