Medical test paper cotton pulp and its production method

Abstract

This invention discloses a medical test paper pulp and its production method, belonging to the field of test paper production technology. The method uses a type of short cotton lint, which is mixed with a cooking liquor with an alkali concentration of 65-75 g / L and cooked to obtain a pulp with a degree of polymerization in the range of 400-500. The pulp is then refined using a pulping machine to maintain a fiber length of 2.0-3.0 mm. After bleaching with chlorine dioxide, washing with an acid concentration of 0.8-1.0 g / L, and water washing, the residual acid concentration after washing is <0.05 g / L. The final pulp is then obtained after papermaking. Compared with existing technologies, the cotton pulp prepared by the method provided by this invention has higher water absorption, and the test paper has a fixed weight of 280 g / m³. 2 Filtration time 3s, whiteness 89%–91%, dust-free, cellulose content 98.5%–99.2%, ash content 0.01%, beating degree 28. ° SR can replace imported cotton pulp in the production of rapid medical test strips.

Description

Technical Field

[0001] This invention belongs to the field of test strip production technology, specifically relating to a medical test strip pulp and its production method. Background Technology

[0002] With the development and application of rapid testing technologies, various rapid testing methods are currently popular in the market. However, colloidal gold immunochromatography (CIP) is fast, simple, and easy to perform, making it suitable for widespread screening. CIP detection was first reported by Osikowiez et al., who described a very convenient pregnancy test kit developed and produced by Unipath using dye particles, achieving qualitative detection of human chorionic gonadotropin (hCG) in human urine and serum. Since then, colloidal gold immunochromatography technology has developed rapidly and is widely used in medicine and other fields. A typical colloidal gold immunochromatographic test strip mainly consists of three parts: porous material, reagent, and laminated structure and cartridge. When the sample is added, it is rapidly absorbed by the test strip under the action of siphon, and simultaneously flows laterally to form a complex with the gold-labeled conjugate, continuing to chromatographically. The sample is then captured by the protein substances coated on the test line and control line, resulting in color development, making the results easy to interpret.

[0003] However, rapid test strips require good absorbency, with a fixed weight of 300g / m³. 2 The pulp used in rapid testing strips must have a filtration time of less than 3 seconds for 25 mL of water, be dust-free, have a freeness of 28°SR, and an ash content of <0.05%, while also possessing a certain level of strength. Currently, almost all rapid testing strip pulp is produced from imported pulp, and there is no domestic supply of raw materials for this type of product. Therefore, there is an urgent need to develop a high-quality pulp to replace imports and fill the supply gap for rapid testing strip pulp. Summary of the Invention

[0004] The purpose of this invention is to provide a medical test strip pulp and its production method to solve the problems of poor water absorption and difficulty in large-scale production of rapid test strips.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] 1. A method for producing medical test strip pulp, characterized by comprising the following steps:

[0007] Step a) Mix the cotton linters with the cooking liquor and cook them. The cooking process involves heating to 120℃±2℃ for 60-90 minutes, holding at that temperature for 200-220 minutes, and then releasing the gas to obtain a slurry with a degree of polymerization of 400-500. The concentration of NaOH in the cooking liquor is 65g / L-75g / L, and each 7500-8000L of cooking liquor contains 750-800kg of hydrogen peroxide, 3kg of sodium tripolyphosphate, 3kg of fatty alcohol polyoxyethylene ether, and 7.5kg of octylbenzeneol.

[0008] Step b) The obtained pulp is pulped using a pulping machine to maintain the fiber length at 2.0–3.0 mm;

[0009] Step c) After pulping, bleach with chlorine dioxide, acid wash, and water wash, with residual acid in the water wash <0.05g / L;

[0010] Step d) involves sequentially selecting and removing sand and then papermaking the pulp. The moisture content of the pulp after papermaking is 9-10%, resulting in cotton pulp used for producing medical rapid test strips.

[0011] As a preferred technical solution of the present invention, the cotton linters are a type of cotton linters obtained after opening and removing impurities.

[0012] As a preferred embodiment of the present invention, the pulping process in step b) is as follows: a pulping machine and a refiner equipped with a desander are connected in series for pulping operations, and the desander operates at a pressure of 3 kf / cm². 2 ~3.5 kgf / cm 2 A mortar with a concentration of 0.45% was obtained.

[0013] As a preferred embodiment of the present invention, in step c), the effective chlorine content during the chlorine dioxide bleaching process is 0.19 g / L to 0.21 g / L, the temperature is 60℃ to 65℃, and the bleaching time is 100 min to 120 min.

[0014] As a preferred embodiment of the present invention, the pickling concentration in step c) is 0.8 g / L to 1.0 g / L, and the pickling time is 60 min to 90 min.

[0015] A type of medical test strip pulp, prepared by the above-mentioned production method, has high absorbency and a test strip weight of 280 g / m³. 2 Filtration time 3s, whiteness 89%~91%, dust-free, fiber content 98.5%~99.2%, ash content <0.05%, percussion degree 28oSR.

[0016] The beneficial effects of this invention are:

[0017] This invention provides a medical test strip pulp and its production method, comprising the following steps:

[0018] a) A type of short cotton linter is mixed with cooking liquor and cooked to obtain a pulp with a degree of polymerization in the range of 400-500; the concentration of the alkali solution is 65-75 g / L; b) The pulp from step a) is refined using a pulping machine to maintain the fiber length at 2.0-3.0 mm; c) The pulp from step b) is sequentially bleached with chlorine dioxide, acid-washed, and water-washed, with residual acid in the water washing being <0.05 g / L, to obtain a bleached pulp; the effective chlorine content of the chlorine dioxide bleaching is 0.19 g / L-0.21 g / L; d) The bleached pulp obtained in step c) is sequentially selected, desanded, and paper-made to obtain cotton pulp for the production of medical rapid test strips.

[0019] The cotton pulp prepared by the method provided by this invention has high water absorption, and the test paper has a fixed weight of 280 g / m³. 2 The filtration time is 3 seconds, which can replace imported cotton pulp for the production of rapid medical test strips. Experimental results show that the cotton pulp for medical test strips prepared by the method provided by this invention has a degree of polymerization of 400-500, a whiteness of 89%-91%, is dust-free, has a fiber content of 98.5%-99.2%, an ash content of <0.05%, a tapping degree of 28°SR, and a test strip weight of 280 g / m³. 2 The filtration time is 3 seconds. Furthermore, the preparation method provided by this invention is novel in concept, simple in process, reasonable and controllable, and easy to scale up for production. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1

[0022] This embodiment provides a method for producing medical test strip pulp, including the following steps:

[0023] Step a) Select 1.5 tons of cotton linters, and obtain cotton linters after opening and impurity removal. Prepare the cooking liquor at 55℃, add an appropriate amount of NaOH to make the alkali concentration 70g / L, the alkali solution volume is 7500L, the mass of hydrogen peroxide is 750kg, the auxiliary agents are 3kg of sodium tripolyphosphate, 3kg of fatty alcohol polyoxyethylene ether, and 7.5kg of octylbenzeneol. Spray the prepared cooking liquor onto the impurity-removed cotton linters, and use a screw conveyor to squeeze the liquor to fully penetrate and mix it evenly with the cotton linters. The screw conveyor is then fed into a 25m... 3The balls are steamed and then subjected to a cooking process: the temperature is raised to 120°C for 60 minutes, held for 200 minutes, and the steam is released to complete the cooking process and obtain a slurry; the degree of polymerization of the slurry is 424.

[0024] Step b) The obtained pulp is refined using a polishing machine to maintain a fiber length of 2.0–3.0 mm. Before polishing in the polishing machine, the pulp is first refined using a Dutch polishing machine to ensure smooth entry into the polishing machine. The polishing process involves connecting the polishing machine and a refining machine equipped with a desander in series for polishing operations. The desander operates at a pressure of 3 kf / cm². 2 ~3.5 kgf / cm 2 A mortar with a concentration of 0.45% was obtained.

[0025] Step c) Pump the slurry to the rinsing tank, adjust the pH of the chlorine dioxide aqueous solution to 3-4 by adding sulfuric acid, control the effective chlorine content of the chlorine dioxide aqueous solution to 0.19g / L-0.21g / L, bleach at 60℃-65℃ for 100min, and then wash with water; then acid wash, control the sulfuric acid solution concentration to 0.8g / L-1.0g / L, acid wash for 60min, and then wash with pure water to make the acid concentration less than 0.05g / L;

[0026] Step d) involves sequentially selecting and removing sand and papermaking. The moisture content of the pulp after papermaking is 10%, and it is dried to obtain cotton pulp for the production of medical rapid test paper.

[0027] The test results show that the degree of polymerization of the cotton pulp for the medical test strip provided in Example 1 of this invention is 424, the whiteness is 89%, it is dust-free, the cellulose content is 98.5%, the ash content is 0.01%, the percussion freeness is 28°SR, and the test strip weight is 280 g / m³. 2 The filtration time is 3 seconds. Furthermore, this test strip has good water absorption and a certain strength, and can completely replace imported cotton pulp in the production of rapid medical test strips.

[0028] Example 2

[0029] This embodiment provides a method for producing medical test strip pulp, including the following steps:

[0030] Step a) Select 1.5 tons of cotton linters, and obtain cotton linters after opening and impurity removal. Prepare the cooking liquor at 55℃, add an appropriate amount of NaOH to make the alkali concentration 75g / L, the alkali solution volume is 8000L, the mass of hydrogen peroxide is 750kg, the auxiliary agents are 3kg of sodium tripolyphosphate, 3kg of fatty alcohol polyoxyethylene ether, and 7.5kg of octylbenzeneol. Spray the prepared cooking liquor onto the impurity-removed cotton linters, and use a screw conveyor to squeeze the liquor to fully penetrate and mix it evenly with the cotton linters. The screw conveyor is then fed into a 25m... 3The balls are steamed and then subjected to a cooking process: the temperature is raised to 120°C for 75 minutes, held for 200 minutes, and the steam is released to complete the cooking process and obtain a slurry; the degree of polymerization of the slurry is 460.

[0031] Step b) The obtained pulp is refined using a polishing machine to maintain a fiber length of 2.0m to 3.0mm. Before polishing in the polishing machine, the pulp is first refined using a Dutch polisher to ensure smooth entry into the polishing machine. The polishing process involves connecting the polishing machine and a refining machine equipped with a desander in series for polishing operations. The desander operates at a pressure of 3kf / cm². 2 ~3.5 kgf / cm 2 A mortar with a concentration of 0.48% was obtained.

[0032] Step c) Pump the slurry to the rinsing tank, adjust the pH of the chlorine dioxide aqueous solution to 3-4 by adding sulfuric acid, control the effective chlorine content of the chlorine dioxide aqueous solution to 0.19g / L-0.21g / L, bleach at 60℃-65℃ for 110min, and then wash with water; then acid wash, control the sulfuric acid solution concentration to 0.8g / L-1.0g / L, acid wash for 75min, and then wash with pure water to make the acid concentration less than 0.05g / L;

[0033] Step d) involves sequentially selecting and removing sand and papermaking. The moisture content of the pulp after papermaking is 9%, and it is dried to obtain cotton pulp for the production of medical rapid test paper.

[0034] The test results show that the degree of polymerization of the cotton pulp for the medical test strip provided in Example 2 of this invention is 460, the whiteness is 90%, it is dust-free, the cellulose content is 99.0%, the ash content is 0.01%, the percussion freeness is 28°SR, and the test strip weight is 290 g / m³. 2 The filtration time is 2.9 seconds. Furthermore, this test strip has good water absorption and a certain degree of strength, and can completely replace imported cotton pulp in the production of rapid medical test strips.

[0035] Example 3

[0036] This embodiment provides a method for producing medical test strip pulp, including the following steps:

[0037] Step a) Select 1.5 tons of cotton linters, and obtain cotton linters after opening and impurity removal. Prepare the cooking liquor at 55℃, add an appropriate amount of NaOH to make the alkali concentration 65g / L, the volume of alkali solution is 8000L, the mass of hydrogen peroxide is 800kg, the auxiliary agents are 3kg of sodium tripolyphosphate, 3kg of fatty alcohol polyoxyethylene ether, and 7.5kg of octylbenzeneol. Spray the prepared cooking liquor onto the impurity-removed cotton linters, and use a screw conveyor to squeeze the liquor to fully penetrate and mix it evenly with the cotton linters. The screw conveyor is then fed into a 25m... 3The balls are steamed and then subjected to a cooking process: the temperature is raised to 120°C for 90 minutes, held for 200 minutes, and the steam is released to complete the cooking process and obtain a slurry; the degree of polymerization of the slurry is 435.

[0038] Step b) The obtained pulp is refined using a polishing machine to maintain a fiber length of 2.0m to 3.0mm. Before polishing in the polishing machine, the pulp is first refined using a Dutch polisher to ensure smooth entry into the polishing machine. The polishing process involves connecting the polishing machine and a refining machine equipped with a desander in series for polishing operations. The desander operates at a pressure of 3kf / cm². 2 ~3.5 kgf / cm 2 A mortar with a concentration of 0.46% was obtained.

[0039] Step c) Pump the mortar to the rinsing tank, adjust the pH of the chlorine dioxide aqueous solution to 3-4 by adding sulfuric acid, control the effective chlorine content of the chlorine dioxide aqueous solution to 0.19g / L-0.21g / L, bleach at 60℃-65℃ for 120min, and then wash with water; then acid wash, control the sulfuric acid solution concentration to 0.8g / L-1.0g / L, acid wash for 90min, and then wash with pure water to make the acid concentration less than 0.05g / L;

[0040] Step d) involves sequentially selecting and removing sand and papermaking. The moisture content of the pulp after papermaking is 10%, and it is dried to obtain cotton pulp for the production of medical rapid test paper.

[0041] The test results show that the degree of polymerization of the cotton pulp for the medical test strip provided in Example 3 of this invention is 435, the whiteness is 91%, it is dust-free, the cellulose content is 99.2%, the ash content is 0.01%, the percussion freeness is 28°SR, and the test strip weight is 295 g / m³. 2 The filtration time is 2.95 seconds. Furthermore, this test strip has good water absorption and a certain degree of strength, and can completely replace imported cotton pulp in the production of rapid medical test strips.

[0042] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for producing a medical test paper pulp, characterized by, It comprises the following steps: Step a) mixing the cotton linter with the cooking liquor, cooking, the temperature rising to 120℃±2℃ for 60-90min, keeping temperature for 200-220min, releasing gas, obtaining the pulp, the polymerization degree of the pulp is 400-500; the concentration of NaOH in the cooking liquor is 65g / L-75g / L, 750kg-800kg of hydrogen peroxide, 3kg of sodium tripolyphosphate, 3kg of fatty alcohol polyoxyethylene ether and 7.5kg of octylphenoxypolyethoxyethanol are contained in every 7500-8000L of the cooking liquor; Step b) using the refiner to refine the obtained pulp, keeping the fiber length at 2.0-3.0mm; Step c) after refining, using chlorine dioxide bleaching, pickling, washing, the residual acid in the washing is <0.05g / L; the effective chlorine content in the chlorine dioxide bleaching process is 0.19g / L-0.21g / L, the temperature is 60℃-65℃, the bleaching time is 100min-120min; the pickling concentration is 0.8g / L-1.0g / L, the pickling time is 60min-90min Step d) sequentially performing sand removal and sheet formation, and obtaining a cotton pulp for producing a medical rapid test paper with a water content of 9-10% after sheet formation, and a water absorption: 280 g / m2of test paper basis weight 2 , filtration time 3 s.

2. The method for producing a medical test paper pulp according to claim 1, characterized by, The cotton linter is obtained after opening and removing impurities from a kind of cotton linter.

3. The method for producing a medical test paper pulp according to claim 1, characterized by, The beating process in step b) is as follows: beating operation is carried out by using a refiner and a grinder with a sand remover in series, the operation pressure of the sand remover is 3 kgf / cm 2 ~ 3.5 kgf / cm 2 , and the sand-removed pulp with a consistency of 0.45% is obtained.

4. A medical test paper pulp characterized by, Prepared by the production method in any one of claims 1-3.

5. The medical test paper pulp according to claim 4, wherein Brightness 89-91%, no dust, methylene content 98.5-99.2%, ash content <0.05%, knapping degree 28 o SR.