A process for the production of packaging material for a wound dressing product

Abstract

The present application relates to the technical field of medical packaging, in particular to a packaging material production process for wound dressing products, comprising the following steps: S1: selecting a high-barrier polymer material comprising purified terephthalic acid and ethylene glycol, and performing pretreatment to obtain a processing material; S2: processing the processing material through an extrusion molding process to form a single-layer film; S3: uniformly coating the inner surface of the single-layer film with functional glue to form a packaging film; S4: placing the packaging film in a drying machine for drying treatment; S5: taking out the dried packaging film, cutting it, and cutting it into small rolls; S6: placing the wound dressing on the inner surface of the packaging film; the present application uses nano-silver particles and a specific water-blocking agent in the functional glue, which enhances the antibacterial and moisture-proof ability of the packaging, so that the adhesive plaster can maintain its sterile state even during long-term storage, effectively prolonging the service life of the product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical packaging, in particular to a packaging material production process for wound dressing products. BACKGROUND

[0002] With the development of the medical industry, the packaging requirements of medical products such as adhesive bandages are becoming increasingly stringent. As a common external medicine, adhesive bandages are usually used for the care and protection of small wounds. Therefore, the packaging not only needs to have the ability to prevent moisture and bacteria, but also needs to ensure that the adhesive bandage is not contaminated during long-term storage. Traditional adhesive bandage packaging mostly uses paper boxes or ordinary plastic packaging. Such packaging is prone to moisture in a high humidity environment, especially in humid weather conditions such as the plum rain season in the south. Moisture may penetrate the packaging, causing the adhesive bandage to lose its original sterile properties, affecting the use effect and safety. In addition, the sealing and airtightness of the packaging are insufficient, which cannot effectively prevent the intrusion of external moisture and microorganisms, further affecting the storage quality of the adhesive bandage.

[0003] The packaging materials for adhesive bandages in the prior art still have deficiencies in moisture prevention, bacteria prevention, and airtightness, especially during long-term storage. The humidity control inside the packaging is difficult to maintain stable. The current packaging technology cannot ensure the dryness and sterility of the adhesive bandage in a high humidity environment. Moreover, the existing sealing process often cannot provide sufficient airtightness, causing the humidity level inside the packaging to exceed the safe range. Therefore, there is an urgent need to develop a new packaging process that can effectively solve the moisture prevention and antibacterial problems of adhesive bandages during long-term storage, ensuring their quality and safety in various environmental conditions. SUMMARY

[0004] Based on the above purpose, the present application provides a packaging material production process for wound dressing products.

[0005] A packaging material production process for wound dressing products, characterized in that it comprises the following steps:

[0006] S1: selecting a high-barrier polymer material including purified terephthalic acid and ethylene glycol, and pretreating to obtain a processing material;

[0007] S2: processing the processing material through an extrusion molding process to form a single-layer film;

[0008] S3: uniformly coating functional glue on the inner surface of the single-layer film to form a packaging film;

[0009] S4: placing the packaging film in a drying machine for drying treatment;

[0010] S5: taking out the dried packaging film and cutting it into small rolls;

[0011] S6: placing the wound dressing on the inner surface of the packaging film;

[0012] S7: rolling the packaging film of the wound dressing product, so that the film covers the wound dressing and forms a sealed package;

[0013] S8: quality testing of the sealed package to ensure that its sealing performance and moisture-proof performance meet the predetermined standards.

[0014] Preferably, the ratio of the polymer material is that the molar ratio of terephthalic acid to ethylene glycol is 1:1.2.

[0015] Preferably, S1 specifically comprises:

[0016] S11: mixing terephthalic acid and ethylene glycol according to a predetermined ratio, and adding a catalyst and a stabilizer to obtain a mixture A;

[0017] S12: heating the mixture A to 260°C under a pressure of 0.4 MPa for 50 min to completely melt the mixture A and generate an oligomer through esterification;

[0018] S13: the oligomer is subjected to a polycondensation reaction under vacuum to generate a polyester resin with high molecular weight.

[0019] Preferably, S2 specifically comprises:

[0020] S21: putting the polyester resin into an extruder, and setting the temperature of the extruder to 200°C;

[0021] S22: controlling the extrusion pressure at 8 MPa;

[0022] S23: setting the extrusion speed at 1.5 m / min;

[0023] S24: adjusting the thickness of the discharged material through a die to finally form a single-layer film with a thickness of 75 μm;

[0024] S25: cooling the film to room temperature through a cooling roller after the film is formed;

[0025] S26: longitudinally stretching the preliminarily cooled film through a group of rollers to increase its length;

[0026] S27: feeding the film stretched in the longitudinal direction into a transverse stretching machine to increase its width through air pressure or mechanical stretching;

[0027] S28: feeding the film stretched in both directions into a heat setting zone to rearrange the molecular chains through high-temperature heating.

[0028] Preferably, in S5, the functional glue is composed of water-based chlorobutyl, nano-silver particles and water-blocking agent, wherein the mass ratio of water-based chlorobutyl, nano-silver particles and water-blocking agent is 98:0.5-1.5:0.5-1.5; the thickness of the functional glue is 3 silk; the water-based glue contains glue content of 4 g / m or more; and the fluorescent substance does not show strong blue fluorescence when observed at 365 nm and 254 nm wavelengths.

[0029] Preferably, in S11, the catalyst is diantimony trioxide, the mass of diantimony trioxide is 0.01%-0.05% of the mass of purified terephthalic acid, and the stabilizer is orthophosphate, the mass of orthophosphate is 0.001%-0.01% of the mass of purified terephthalic acid.

[0030] The beneficial effects of the present application are:

[0031] In the present application, the use of nano-silver particles and specific water-blocking agent in the functional glue enhances the antibacterial and moisture-proof ability of the packaging, so that the band-aid can maintain its sterile state even during long-term storage, effectively prolonging the service life of the product.

[0032] By adding a catalyst, the mass of the catalyst is set to 0.01%-0.05% of the mass of purified terephthalic acid, which can promote the esterification reaction to be more complete, further improve the regularity of polyester molecular chain, reduce the free volume, and improve the intrinsic barrier property by 15%-20%. Further, by setting the temperature of the extruder to 200℃, the melt viscosity of the polyester resin is reduced by 12%-15%, which is beneficial to eliminate the melt rupture phenomenon, and further reduces the surface porosity of the single-layer film formed.

[0033] The improved sealing technology not only ensures the stable preservation of the band-aid in a humid environment, but also greatly reduces the product waste caused by packaging failure, thereby improving the economic benefits and market competitiveness of the product. The comprehensive application of these technologies ensures the safe use of the band-aid under various climate conditions, which is of great significance to improve the use experience and reliability of consumers. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only a part of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0035] Figure 1 The flow chart of the packaging production process of the drug of the present application. DETAILED DESCRIPTION

[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more comprehensive, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0037] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0038] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0039] Example 1

[0040] like Figure 1 As shown, a manufacturing process for packaging materials of a wound dressing product includes the following steps:

[0041] S1: Select high-barrier polymer materials, including purified terephthalic acid and ethylene glycol, and pretreat them to obtain the processed material;

[0042] S2: The material is processed through an extrusion molding process to form a single-layer film;

[0043] S3: A functional adhesive is uniformly coated on the inner surface of a single-layer film to form a packaging film;

[0044] S4: Place the packaging film into the dryer for drying;

[0045] S5: Take out the dried packaging film and cut it into small rolls;

[0046] S6: Place the wound dressing on the inner surface of the packaging film;

[0047] S7: roll the packaging film of the wound dressing product, so that the film covers the wound dressing and forms a sealed package;

[0048] S8: quality detection is performed on the sealed package to ensure that its sealing performance and moisture-proof performance meet the predetermined standards.

[0049] The ratio of the polymer material is that the molar ratio of purified terephthalic acid and ethylene glycol is 1:1.2.

[0050] S1 specifically includes:

[0051] S11: mix purified terephthalic acid and ethylene glycol according to a predetermined ratio, and add a catalyst and a stabilizer to obtain a mixture A;

[0052] S12: heat the mixture A to 260℃ under a pressure of 0.4MPa for 50min, so that the mixture A is completely melted and an esterification reaction occurs to generate an oligomer;

[0053] S13: the oligomer is subjected to a polycondensation reaction under vacuum conditions to generate a high-molecular-weight polyester resin.

[0054] S2 specifically includes:

[0055] S21: put the polyester resin into an extruder, and set the temperature of the extruder to 200℃;

[0056] S22: control the extrusion pressure at 8MPa;

[0057] S23: set the extrusion speed to 1.5m / min;

[0058] S24: adjust the thickness of the discharged material through a die to finally form a single-layer film with a thickness of 75μm;

[0059] S25: cool the film to room temperature through a cooling roller after the film is formed;

[0060] S26: longitudinally stretch the preliminarily cooled film through a group of rollers to increase its length;

[0061] S27: the film stretched in the longitudinal direction is sent into a transverse stretching machine and is stretched in the transverse direction through air pressure or mechanical means to increase its width; wherein, through sufficient stretching, the polyester molecular chain is highly oriented along the biaxial direction, and a more compact lamellar structure is formed.

[0062] S28: the film stretched in the biaxial direction enters a heat setting zone, and the molecular chain is rearranged through high-temperature heating.

[0063] In S3, the functional glue is composed of waterborne neoprene, nano-silver particles and water blocking agent, wherein the mass ratio of waterborne neoprene, nano-silver particles and water blocking agent is 98:0.5:1.5; the functional glue has a thickness of 3 silk; the water-based glue has a glue content of ≥4 g / m; and the fluorescent substance does not show strong blue fluorescence at 365 nm and 254 nm wavelengths.

[0064] Further, the coating of the functional glue described above adopts gradient coating, and first, the waterborne neoprene is used for the first layer of coating to form an initial adhesion layer. Then, the nano-silver particles and the water blocking agent are used for the second layer of coating to form a conformal layer, thereby enhancing the antibacterial property and the water blocking property.

[0065] In S11, the catalyst is antimony trioxide, and the mass of the antimony trioxide is 0.01%-0.05% of the mass of the purified terephthalic acid; the stabilizer is a phosphonate, and the mass of the phosphonate is 0.001%-0.01% of the mass of the purified terephthalic acid;

[0066] The air tightness test is performed on the packaged body in a sealing test device, the test pressure is set to 80 kPa, and the duration is 10 minutes; the pressure difference in the test is 0.2 kPa, which meets the sealing standard ISO 11607-1;

[0067] The moisture resistance test is performed on the packaged body in an environment with a humidity of 95%, and the humidity inside the packaged body is tested after the packaged body is stored for 48 hours. The specific humidity is 5%, which meets the moisture resistance requirement of the ASTM D3079 standard.

[0068] Example 2

[0069] S1: Select a high-barrier polymer material including purified terephthalic acid and ethylene glycol, and perform pretreatment to obtain a processing material;

[0070] S2: Process the processing material through an extrusion molding process to form a single-layer film;

[0071] S3: Uniformly coat the functional glue on the inner surface of the single-layer film to form a packaging film;

[0072] S4: Place the packaging film in a drying machine for drying treatment;

[0073] S5: Take out the dried packaging film, and slit the packaging film into small rolls;

[0074] S6: Place the wound dressing on the inner surface of the packaging film;

[0075] S7: Roll the packaging film of the wound dressing product to cover the wound dressing with the packaging film to form a sealed package;

[0076] S8: Quality detection is performed on the sealed package to ensure that the sealing property and moisture-proof property meet predetermined standards.

[0077] The polymer material is prepared by mixing purified terephthalic acid and ethylene glycol in a molar ratio of 1:1.2.

[0078] S1 specifically comprises:

[0079] S11: Purified terephthalic acid and ethylene glycol are mixed in a predetermined ratio, and a catalyst and a stabilizer are added to obtain a mixture A;

[0080] S12: The mixture A is heated to 260℃ under a pressure of 0.4 MPa for 50 min to completely melt the mixture A and generate an oligomer through esterification;

[0081] S13: The oligomer is subjected to a polycondensation reaction under vacuum to generate a polyester resin with a high molecular weight.

[0082] S2 specifically comprises:

[0083] S21: The polyester resin is fed into an extruder, and the temperature of the extruder is set to 200℃;

[0084] S22: The extrusion pressure is controlled at 8 MPa;

[0085] S23: The extrusion speed is set to 1.5 m / min;

[0086] S24: The thickness of the discharged material is adjusted through a die to finally form a single-layer film with a thickness of 75 μm;

[0087] S25: After the film is formed, it is cooled to room temperature by a cooling roller;

[0088] S26: The preliminarily cooled film is stretched longitudinally by a set of rollers to increase its length;

[0089] S27: The film stretched longitudinally is sent into a transverse stretching machine and is stretched transversely by air pressure or mechanical means to increase its width;

[0090] S28: The film stretched in both directions enters a heat setting zone and is heated at a high temperature to rearrange the molecular chains.

[0091] In S5, the functional glue is composed of water-based neoprene, nano-silver particles and water-blocking agent, and the mass ratio of the water-based neoprene, nano-silver particles and water-blocking agent is 98:1:1; the functional glue has a thickness of 3 silk; the water-based glue has a glue content of ≥4 g / m; and the fluorescent substance does not show strong blue fluorescence under observation at wavelengths of 365 nm and 254 nm.

[0092] In S11, the catalyst is antimony trioxide, the mass of the antimony trioxide is 0.01%-0.05% of the mass of the purified terephthalic acid, the stabilizer is orthophosphate, and the mass of the orthophosphate is 0.001%-0.01% of the mass of the purified terephthalic acid;

[0093] The air tightness test is performed by placing the packaging body in a sealing test device, setting the test pressure to 80 kPa, and testing for 10 minutes, during which the pressure difference is 0.3 kPa. At the same time, the moisture resistance test is performed by placing the packaging body in an environment with a humidity of 95% for 48 hours, and testing the internal humidity change. The specific humidity is 7%, which ensures the moisture resistance and long-term stability of the adhesive tape.

[0094] Example 3

[0095] S1: Select a high-barrier polymer material, including purified terephthalic acid and ethylene glycol, and perform pretreatment to obtain a processing material;

[0096] S2: Process the processing material through an extrusion molding process to form a single-layer film;

[0097] S3: Uniformly coat the inner surface of the single-layer film with functional glue to form a packaging film;

[0098] S4: Place the packaging film in a drying machine for drying treatment;

[0099] S5: Take out the dried packaging film and cut it into small rolls;

[0100] S6: Place the wound dressing on the inner surface of the packaging film;

[0101] S7: Roll the packaging film of the wound dressing product to cover the wound dressing with the film, forming a sealed package;

[0102] S8: Perform quality detection on the sealed package to ensure that its sealing property and moisture resistance meet the predetermined standards.

[0103] The ratio of the polymer material is that the molar ratio of purified terephthalic acid to ethylene glycol is 1:1.2.

[0104] S1 specifically includes:

[0105] S11: Mix the purified terephthalic acid and ethylene glycol according to the predetermined ratio, and add the catalyst and stabilizer to obtain a mixture A;

[0106] S12: Heat the mixture A to 260°C under a pressure of 0.4 MPa for 50 minutes to completely melt the mixture A and generate an oligomer through esterification;

[0107] S13: The oligomers are subjected to a polycondensation reaction under vacuum to form a high molecular weight polyester resin.

[0108] S2 specifically comprises:

[0109] S21: The polyester resin is put into an extruder, and the temperature of the extruder is set to 200°C;

[0110] S22: The extrusion pressure is controlled at 8 MPa;

[0111] S23: The extrusion speed is set to 1.5 m / min;

[0112] S24: The thickness of the discharged material is adjusted through a die to finally form a single-layer film with a thickness of 75 μm;

[0113] S25: After the film is formed, it is cooled to room temperature by a cooling roller;

[0114] S26: The preliminarily cooled film is stretched longitudinally by a set of rollers to increase its length;

[0115] S27: The film stretched longitudinally is sent into a transverse stretching machine and is stretched transversely by air pressure or mechanically to increase its width;

[0116] S28: The film stretched bidirectionally enters a heat setting zone and is heated at a high temperature to rearrange the molecular chains.

[0117] In S5, the functional glue is composed of water-based neoprene, nano-silver particles and water-blocking agent, and the mass ratio of the water-based neoprene, nano-silver particles and water-blocking agent is 98:1.5:0.5; the functional glue has a thickness of 3 silk; the water-based glue has a glue content of ≥4 g / m; and the fluorescent substance does not show strong blue fluorescence at 365 nm and 254 nm wavelengths.

[0118] In S11, the catalyst is antimony trioxide, and the mass of the antimony trioxide is 0.01%-0.05% of the mass of the purified terephthalic acid; the stabilizer is a phosphoric acid ester, and the mass of the phosphoric acid ester is 0.001%-0.01% of the mass of the purified terephthalic acid;

[0119] The air tightness test is performed by placing the packaging body in a sealing test device, setting the test pressure to 80 kPa, and testing for 10 minutes, with a pressure difference of 0.5 kPa during the test. At the same time, the moisture resistance test is performed by placing the packaging body in an environment with a humidity of 95% for 48 hours, and testing the change in internal humidity, with a specific humidity of 10%, to ensure the moisture resistance and long-term stability of the adhesive plaster.

[0120] Table 1: Comparison of performance parameters of finished products of various embodiments

[0121]

[0122] From Table 1 above, it can be seen that the air tightness of Example 1 is best at 99.5%, followed by Example 3 at 98%, while the standard packaging is 90%; the moisture resistance of Example 1 and Example 3 performs close, at 95% and 94% respectively, Example 2 is slightly lower at 92%, but all significantly better than the standard packaging of 80%; the antibacterial property of Example 1 is the highest at 98%, Example 2 and Example 3 are 95% and 96% respectively, also significantly better than the standard packaging of 85%; the material strength of Example 1 is 90%, Example 2 is 88%, and Example 3 is 89%, slightly higher than the standard packaging of 85%; the packaging tightness of Example 1 and Example 3 is 97% and 96% respectively, Example 2 is 95%, all better than the standard packaging of 90%; the production cost of Example 1 is the highest at 85%, Example 3 is 82%, Example 2 is 80%, and the standard packaging is 70%, indicating that the new process cost is slightly higher; the service life of Example 1 is 24 months, Example 3 is 22 months, Example 2 is 20 months, and the standard packaging is 12 months, extending the preservation time of the product.

[0123] Table 2 Comparison of performance parameters in other aspects

[0124]

[0125] From Table 2 above, it can be seen that the processing time of Example 1 is longer, at 120 minutes, but compared with the standard packaging of 90 minutes, its processing technology is more complex, and the performance optimization is significant; the energy consumption of Example 1 is 50 kWh, although slightly higher than the standard packaging of 40 kWh, but considering its better performance, this level of energy consumption is acceptable; the material utilization rate of Example 1 is 95%, significantly better than the standard packaging of 85%, indicating that Example 1 performs outstanding in the efficient use of materials, reducing waste; Example 1 produces the least waste, only 0.5 kg, while the standard packaging is 1.0 kg, indicating that the new process is more environmentally friendly; the finished product weight of Example 1 is 10 g, slightly higher than the standard packaging of 8 g, which may be due to the additional weight of its composite structure, but this is also the result of improving performance; the production efficiency of Example 1 is 500 pieces / hour, compared with the standard packaging of 460 pieces / hour, although the process is complex, but it does not significantly reduce the production efficiency; the environmental index of Example 1 is 85%, significantly higher than the standard packaging of 70%, indicating that this process has advantages in reducing pollution and reducing carbon emissions.

[0126] In summary, Example 1 exhibits better performance in many aspects, especially in material utilization, waste generation and environmental index, although the processing time and energy consumption are slightly higher, but these sacrifices bring higher quality of finished products and lower environmental impact, suitable for long-term popularization and application.

[0127] The present application encompasses any alternatives, modifications, equivalent methods and solutions made to the essence and scope of the present application. In order to make the public have a thorough understanding of the present application, specific details are described in the following preferred embodiments of the present application, and the present application can also be fully understood without the description of these details to those skilled in the art. In addition, in order to avoid unnecessary confusion to the essence of the present application, well-known methods, processes, procedures, elements and circuits, etc. are not described in detail.

[0128] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can also be made, which should be considered as the protection scope of the present application.

Claims

1. A packaging material production process for a wound dressing product, characterized in that, The application relates to a packaging film for wound dressings, and a preparation method thereof. S1: selecting a high-barrier polymer material including purified terephthalic acid and ethylene glycol, pretreating the polymer material, and obtaining a processing material; S2: processing the processing material through an extrusion molding process, so that the processing material forms a single-layer film; S3: uniformly coating a functional adhesive on an inner surface of the single-layer film to form a packaging film; S4: placing the packaging film into a drying machine for drying treatment; S5: taking out the dried packaging film, and slitting the packaging film into small rolls; S6: placing a wound dressing on an inner surface of the packaging film; S7: rolling the packaging film of the wound dressing product, so that the packaging film covers the wound dressing to form a sealed package; S8: performing quality detection on the sealed package. The step S1 specifically comprises the following steps. S11: mixing the purified terephthalic acid and the ethylene glycol according to a predetermined proportion, and adding a catalyst and a stabilizer to obtain a mixture A; S12: heating the mixture A to 260 DEG C under a pressure of 0.4 MPa for 50 min, so that the mixture A is completely melted and an esterification reaction is generated to form an oligomer; S13: performing a polycondensation reaction on the oligomer under a vacuum condition to form a polyester resin with a high molecular weight; The step S2 specifically comprises the following steps. S21: feeding the polyester resin into an extruder, and setting the temperature of the extruder to 200 DEG C; S22: controlling the extrusion pressure to be 8 MPa; S23: setting the extrusion speed to be 1.5 m / min; S24: adjusting the thickness of the material through a die head, and finally forming a single-layer film with a thickness of 75 mu m; S25: cooling the formed film to room temperature through a cooling roller; S26: longitudinally stretching the preliminarily cooled film through a group of rollers to increase the length of the film; S27: feeding the film after the longitudinal stretching into a transverse stretching machine, and performing transverse stretching on the film through air pressure or mechanical methods to increase the width of the film; S28: feeding the film after the bidirectional stretching into a heat setting area, and re-arranging the molecular chains through high-temperature heating; In the step S5, the functional adhesive is composed of water-based neoprene, nano-silver particles and water-proof agents, and the mass ratio of the water-based neoprene, the nano-silver particles and the water-proof agents is 98:0.5-1.5:0.5-1.

5. In the step S11, the catalyst is antimony trioxide, and the mass of the antimony trioxide accounts for 0.01%-0.05% of the mass of the purified terephthalic acid.

2. A process for producing a packaging material for a wound dressing product according to claim 1, characterized in that, The ratio of the polymer material is that the molar ratio of the purified terephthalic acid to the ethylene glycol is 1:1.

2.

3. A process for producing a packaging material for a wound dressing product according to claim 1, characterized in that, The functional adhesive has a thickness of 3 silk, a water-based adhesive coating, a glue content of greater than or equal to 4 g / m, and no strong blue fluorescence of a fluorescent substance is observed at 365 nm and 254 nm wavelengths.

4. A process for producing a packaging material for a wound dressing product according to claim 1, characterized in that, In the step S11, the stabilizer is orthophosphate, and the mass of the orthophosphate accounts for 0.001%-0.01% of the mass of the purified terephthalic acid.

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