Dialyzer microparticle removal production process based on membrane inside and outside pressure regulation

Abstract

The application discloses a kind of based on membrane inside and outside pressure regulation and control dialyzer microparticle removal production process, comprising the following steps: step S1, dialyzer pretreatment;Step S2, low-pressure pre-wetting, bubble and loose microparticle are discharged;Step S3, bidirectional pressure difference flushing, remove membrane inside + membrane outside deep microparticle;Step S4, section microparticle directional high-pressure micro-pulse;Step S5, negative pressure emptying + drying, prevent microparticle secondary attachment;Beneficial effect, low consumption water saving: single dialyzer total water consumption≤120mL, adaptation injection molding-washing continuous production;Domain removal: through membrane inside and outside bidirectional pressure difference + section pulse flushing, synchronous removal membrane inside, membrane outside, both ends section all microparticle, no cleaning dead angle;Protect membrane silk: accurate control transmembrane pressure, avoid high pressure to cause hollow fiber breakage, aperture deformation;Mass production adaptation: process step is simple, pressure, flow rate can be automatically controlled, adaptation dialyzer scale production line, microparticle removal rate>99.5%, substantially reduce clinical microparticle risk.

Description

Technical Field

[0001] This invention relates to the field of hemodialysis machine manufacturing technology, and in particular to a dialyzer particulate removal process based on intra- and extra-membrane pressure regulation. Background Technology

[0002] Hollow fiber dialyzers are injection molded from hollow fiber membranes, outer shells, end caps, and polyurethane potting compound. During production, the cutting process generates slit particles, injection molding generates plastic particles, membrane fiber cutting debris, and potting compound dust, which can easily remain inside the membrane (blood side), outside the membrane (dialysis fluid side), and in the slits at both ends of the dialyzer. Existing cleaning processes have problems such as: high water consumption, lack of pressure control leading to particle residue, inability to clean dead corners, low efficiency of separating and cleaning particles inside and outside the membrane, and damage to the hollow fiber membrane by high-pressure rinsing. Particles entering the human body can easily cause micro-inflammation, vascular damage, and first-time user syndrome. There is an urgent need for a production cleaning process that uses low water consumption, has precise and controllable pressure, and can completely remove particles inside / outside the membrane and from the slits. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a dialyzer particulate removal process based on intra- and extra-membrane pressure regulation, comprising the following steps: Step S1: Dialyzer pretreatment; Step S2: Low-pressure pre-impregnation to remove air bubbles and loose particles; Step S3: Two-way pressure differential flushing to remove deep particles inside and outside the membrane; Step S4: Oriented high-pressure micro-impact on the cut surface microparticles; Step S5: Negative pressure evacuation + drying to prevent secondary adhesion of particles.

[0004] As a further supplement to this technical solution, in step S1, the dialyzer completes polyurethane potting, end-face cutting, shell assembly, and sealing of the shell side holes, leaving only the blood inlet, blood outlet, dialysate inlet, and dialysate outlet intact.

[0005] As a further supplement to this technical solution, a micro-gap of 0.5-1mm is reserved at the cutting surface in step S1; the cleaning water is purified water for injection molding with a resistivity ≥18.2MΩ. cm, the total water consumption of a single dialyzer is ≤120mL.

[0006] As a further supplement to this technical solution, in step S2, the water pressure inside the membrane is controlled at 0.02-0.04 MPa, and the water pressure outside the membrane is controlled at 0.01-0.02 MPa, with the water pressure inside the membrane being greater than that outside the membrane, thus forming a positive transmembrane pressure of 0.01-0.02 MPa; A small amount of injection-grade water is introduced through the blood inlet at a flow rate of 10-15 mL / min for 20-30 seconds to wet all hollow fiber membrane fibers and remove air bubbles, loose cutting debris, and injection dust from the membrane. Simultaneously, a trace amount of water seeps out from the cut surface gaps, carrying away surface particles. Waste liquid is discharged from the blood outlet and dialysate outlet.

[0007] As a further supplement to this technical solution, step S3, bidirectional pressure differential flushing, includes the following steps: S3-1 Forward Transmembrane Pressure Deep Cleaning: Intramembrane pressure: 0.05-0.07 MPa; Extramembrane pressure: 0.02-0.03 MPa; Transmembrane pressure: 0.03-0.04 MPa; Blood side is flushed with water for 30-40 seconds. The water flow passes through the inner wall of the membrane fibers, flushing away residual particles inside the membrane. Some particles enter the outside of the membrane through the membrane pores. S3-2 Reverse Transmembrane Pressure Osmosis Cleaning: Switching pressure: external membrane pressure 0.06-0.08 MPa, internal membrane pressure 0.02-0.03 MPa, reverse transmembrane pressure 0.04-0.05 MPa; Water is passed through the dialysate side for 25-35 seconds. The water flow penetrates the membrane fibers in the opposite direction, flushing the particles on the outside of the membrane and the inner wall of the outer shell. At the same time, it pushes the particles embedded in the membrane pores back into the membrane and carries them out. Pressure is strictly controlled to avoid damage to the hollow fiber membrane caused by transmembrane pressure greater than 0.06 MPa.

[0008] As a further supplement to this technical solution, step S4 closes the blood inlet and dialysate inlet, and opens the blood outlet and dialysate outlet; Pulsed injection water at 0.08-0.10 MPa is introduced into the outer jacket of the dialyzer, with a pulse frequency of 2-3 times / s and each pulse lasting 3-5 seconds; High-pressure pulsed water directly impacts the gaps at both ends of the cutting surface, flushing out the potting compound debris, fiber cutting particles, and outer plastic particles. The microparticles are discharged from both ends with the water flow, and the pulse pressure is controlled to be <0.12MPa to prevent the potting compound from falling off.

[0009] As a further supplement to this technical solution, in step S5, a negative pressure of -0.02 to -0.03 MPa is applied simultaneously inside and outside the membrane for 15-20 seconds to drain residual moisture and suspended particles from the membrane. The particles are removed by purging with clean, dry nitrogen gas at a temperature of 25-35℃, and then the product enters the sterilization process.

[0010] A dialyzer particulate removal production device based on intramural and extramural pressure regulation includes a main housing, a blood inlet disposed on one side of the main housing, a blood outlet disposed on the other side of the main housing, a dialysate outlet disposed below the main housing and located on the side of the blood inlet, and a dialysate inlet disposed below the main housing and located on the side of the blood outlet. A dialysis membrane is disposed inside the main housing near the blood outlet.

[0011] As a further supplement to this technical solution, the main housing is provided with symmetrical blood caps, which are threadedly connected to the main housing.

[0012] Its beneficial effects are low consumption and water saving: the total water consumption of a single dialyzer is ≤120mL, using only injection-grade purified water, which is suitable for continuous production of injection molding and cleaning. Complete cleaning: Through bidirectional pressure difference between inside and outside the membrane and sectional pulse flushing, all particles inside the membrane, outside the membrane, and at both ends of the sectional surface are removed simultaneously, leaving no cleaning dead corners; Protective membrane fibers: Precisely control transmembrane pressure to prevent high pressure from causing damage to hollow fibers and deformation of pore size; Mass production compatibility: The process steps are simple, and the pressure and flow rate can be automatically controlled, making it compatible with large-scale dialyzer production lines. The particulate removal rate is >99.5%, which significantly reduces the risk of particulate matter in clinical settings. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a dialyzer particulate removal production device based on intra- and extra-membrane pressure regulation according to the present invention. In the diagram, 1. Main shell; 2. Blood inlet; 3. Blood outlet; 4. Dialysis fluid outlet; 5. Dialysis fluid inlet; 6. Dialysis membrane; 7. Blood cap; 8. Mounting cap; 9. O-ring; 10. Sealing adhesive. Detailed Implementation

[0014] To facilitate a clearer understanding of this technical solution for those skilled in the art, the following will be described in conjunction with the appendix. Figure 1 The technical solution of the present invention is described in detail below: A dialyzer particulate removal process based on intra- and extra-membrane pressure regulation includes the following steps: Step S1: Dialyzer pretreatment; Step S2: Low-pressure pre-impregnation to remove air bubbles and loose particles; Step S3: Two-way pressure differential flushing to remove deep particles inside and outside the membrane; Step S4: Oriented high-pressure micro-impact on the cut surface microparticles; Step S5: Negative pressure evacuation + drying to prevent secondary adhesion of particles.

[0015] In step S1, the dialyzer undergoes polyurethane potting, end-face cutting, and outer shell assembly. The side holes of the outer shell are sealed, leaving only the blood inlet, blood outlet, dialysate inlet, and dialysate outlet. A 0.5-1mm micro-gap is left at the cut surface in step S1 to allow for the discharge of microparticles. The cleaning water is purified water used for injection molding, with a resistivity ≥18.2MΩ. cm, the total water consumption of a single dialyzer is ≤120mL.

[0016] In step S2, the water pressure inside the membrane is controlled at 0.02-0.04 MPa, and the water pressure outside the membrane is controlled at 0.01-0.02 MPa, with the water pressure inside the membrane being greater than that outside, thus forming a positive transmembrane pressure of 0.01-0.02 MPa. A small amount of injection-grade water is introduced through the blood inlet at a flow rate of 10-15 mL / min for 20-30 seconds to wet all hollow fiber membrane fibers and remove air bubbles, loose cutting debris, and injection dust from the membrane. Simultaneously, a trace amount of water seeps out from the cut surface gaps, carrying away surface particles. Waste liquid is discharged from the blood outlet and dialysate outlet.

[0017] Step S3, bidirectional pressure differential flushing, includes the following steps: S3-1 Forward Transmembrane Pressure Deep Cleaning: Intramembrane pressure: 0.05-0.07 MPa; Extramembrane pressure: 0.02-0.03 MPa; Transmembrane pressure: 0.03-0.04 MPa; Blood side is flushed with water for 30-40 seconds. The water flow passes through the inner wall of the membrane fibers, flushing away residual particles inside the membrane. Some particles enter the outside of the membrane through the membrane pores. S3-2 Reverse Transmembrane Pressure Osmosis Cleaning: Switching pressure: external membrane pressure 0.06-0.08 MPa, internal membrane pressure 0.02-0.03 MPa, reverse transmembrane pressure 0.04-0.05 MPa; Water is passed through the dialysate side for 25-35 seconds. The water flow penetrates the membrane fibers in the opposite direction, flushing the particles on the outside of the membrane and the inner wall of the outer shell. At the same time, it pushes the particles embedded in the membrane pores back into the membrane and carries them out. Pressure is strictly controlled to avoid damage to the hollow fiber membrane caused by transmembrane pressure greater than 0.06 MPa.

[0018] In step S4, the blood inlet and dialysate inlet are closed, and the blood outlet and dialysate outlet are opened. Pulsed injection water at 0.08-0.10 MPa is introduced into the outer jacket of the dialyzer, with a pulse frequency of 2-3 times / s and each pulse lasting 3-5 seconds; High-pressure pulsed water directly impacts the gaps at both ends of the cutting surface, flushing out the potting compound debris, fiber cutting particles, and outer plastic particles. The microparticles are discharged from both ends with the water flow, and the pulse pressure is controlled to be <0.12MPa to prevent the potting compound from falling off.

[0019] In step S5, a negative pressure of -0.02 to -0.03 MPa is applied simultaneously inside and outside the membrane for 15-20 seconds to remove residual moisture and suspended particles. The particles are removed by purging with clean, dry nitrogen gas at a temperature of 25-35℃, and then the product enters the sterilization process.

[0020] Positive transmembrane pressure: inside the membrane > outside the membrane, water flows from the inside to the outside, clearing particles from the blood side of the membrane; Reverse transmembrane pressure: outside the membrane > inside the membrane, water flows from the outside to the inside, removing microparticles from the dialysate side outside the membrane + microparticles embedded in the membrane pores; Cutting pulse pressure: Directional impact cuts into the dead corners of the cutting end face, eliminating specific microparticles on the cutting surface; The maximum transmembrane pressure throughout the process shall not exceed 0.06 MPa, and the pulse pressure shall not exceed 0.12 MPa, to prevent damage to the hollow fiber membrane and potting compound.

[0021] The entire process uses a small amount of water for injection molding, with pressure controlled in stages to avoid high pressure damaging the membrane fibers. The water consumption is only 1 / 3 to 1 / 4 of that used in conventional rinsing.

[0022] A dialyzer particulate removal production device based on intra- and extra-membrane pressure regulation includes a main housing 1, a blood inlet 2 disposed on one side of the main housing 1, a blood outlet 3 disposed on the other side of the main housing 1, a dialysate outlet 4 disposed below the main housing 1 and located on the side of the blood inlet, and a dialysate inlet 5 disposed below the main housing 1 and located on the side of the blood outlet 3. A dialysis membrane 6 is disposed inside the main housing 1 near the side of the blood outlet 3, and an O-ring 9 is disposed on the side of the main housing 1 near the blood outlet 3 for sealing. A sealing adhesive 10 is also disposed between the dialysis membrane 6 and the main housing for sealing.

[0023] The main housing 1 is symmetrically provided with blood covers 7, which are threadedly connected to the main housing 1 and can play a protective role.

[0024] The dialysate outlet 4 and dialysate inlet 5 are equipped with mounting covers 8 to provide protection.

[0025] The above technical solutions only embody the preferred technical solutions of the present invention. Any modifications that may be made by those skilled in the art to certain parts thereof embody the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. A dialyzer particulate removal process based on intra- and extra-membrane pressure regulation, characterized in that, Includes the following steps: Step S1: Dialyzer pretreatment; Step S2: Low-pressure pre-impregnation to remove air bubbles and loose particles; Step S3: Two-way pressure differential flushing to remove deep particles inside and outside the membrane; Step S4: Oriented high-pressure micro-impact on the cut surface microparticles; Step S5: Negative pressure evacuation + drying to prevent secondary adhesion of particles.

2. The dialyzer particulate removal process based on intra- and extra-membrane pressure regulation according to claim 1, characterized in that, In step S1, the dialyzer is filled with polyurethane, cut at both ends, assembled with the outer shell, and the side holes of the outer shell are sealed, leaving only the blood inlet, blood outlet, dialysate inlet, and dialysate outlet.

3. The dialyzer particulate removal process based on intra- and extra-membrane pressure regulation according to claim 2, characterized in that, In step S1, a 0.5-1mm micro-gap is left at the cut surface; the cleaning water is purified water for injection molding with a resistivity ≥18.2MΩ. cm, the total water consumption of a single dialyzer is ≤120mL.

4. The dialyzer particulate removal process based on intra- and extra-membrane pressure regulation according to claim 1, characterized in that, In step S2, the water pressure inside the membrane is controlled at 0.02-0.04 MPa, and the water pressure outside the membrane is controlled at 0.01-0.02 MPa, with the water pressure inside the membrane being greater than that outside, thus forming a positive transmembrane pressure of 0.01-0.02 MPa. A small amount of injection-grade water is introduced through the blood inlet at a flow rate of 10-15 mL / min for 20-30 seconds to wet all hollow fiber membrane fibers and remove air bubbles, loose cutting debris, and injection dust from the membrane. Simultaneously, a trace amount of water seeps out from the cut surface gaps, carrying away surface particles. Waste liquid is discharged from the blood outlet and dialysate outlet.

5. The dialyzer particulate removal process based on intra- and extra-membrane pressure regulation according to claim 1, characterized in that, Step S3, bidirectional pressure differential flushing, includes the following steps: S3-1 Forward Transmembrane Pressure Depth Cleaning: Intramembrane pressure: 0.05-0.07 MPa; Extramembrane pressure: 0.02-0.03 MPa; Transmembrane pressure: 0.03-0.04 MPa; Blood side is flushed with water for 30-40 seconds. The water flow passes through the inner wall of the membrane fibers, flushing away residual particles inside the membrane. Some particles enter the outside of the membrane through the membrane pores. S3-2 Reverse Transmembrane Pressure Osmosis Cleaning: Switching pressure: external membrane pressure 0.06-0.08 MPa, internal membrane pressure 0.02-0.03 MPa, reverse transmembrane pressure 0.04-0.05 MPa; Water is passed through the dialysate side for 25-35 seconds. The water flow penetrates the membrane fibers in the opposite direction, flushing the particles on the outside of the membrane and the inner wall of the outer shell. At the same time, it pushes the particles embedded in the membrane pores back into the membrane and carries them out. Pressure is strictly controlled to avoid damage to the hollow fiber membrane caused by transmembrane pressure greater than 0.06 MPa.

6. The dialyzer particulate removal process based on intra- and extra-membrane pressure regulation according to claim 1, characterized in that, In step S4, the blood inlet and dialysate inlet are closed, and the blood outlet and dialysate outlet are opened. Pulsed injection water at 0.08-0.10 MPa is introduced into the outer jacket of the dialyzer, with a pulse frequency of 2-3 times / s and each pulse lasting 3-5 seconds; High-pressure pulsed water directly impacts the gaps at both ends of the cutting surface, flushing out the potting compound debris, fiber cutting particles, and outer plastic particles. The microparticles are discharged from both ends with the water flow, and the pulse pressure is controlled to be <0.12MPa to prevent the potting compound from falling off.

7. The dialyzer particulate removal process based on intra- and extra-membrane pressure regulation according to claim 1, characterized in that, In step S5, a negative pressure of -0.02 to -0.03 MPa is applied simultaneously inside and outside the membrane for 15-20 seconds to remove residual moisture and suspended particles. The particles are removed by purging with clean, dry nitrogen gas at a temperature of 25-35℃, and then the product enters the sterilization process.

8. The apparatus for producing dialyzer particulate matter removal based on intra- and extra-membrane pressure regulation according to any one of claims 1-7, characterized in that, It includes a main housing (1), a blood inlet (2) disposed on one side of the main housing (1), a blood outlet (3) disposed on the other side of the main housing (1), a dialysate outlet (4) disposed below the main housing (1) and located on the side of the blood inlet, and a dialysate inlet (5) disposed below the main housing (1) and located on the side of the blood outlet (3). A dialysis membrane (6) is provided inside the main housing (1) near the side of the blood outlet (3).

9. A dialyzer particulate removal production device based on intra- and extra-membrane pressure regulation according to claim 8, characterized in that, The main housing (1) is symmetrically provided with blood caps (7), and the blood caps (7) are threadedly connected to the main housing (1).

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