Glue pouring system and glue pouring process for hollow fiber ends

Abstract

The invention belongs to the field of glue filling, and particularly relates to a glue filling system and a glue filling process for hollow fiber ends. The glue filling system comprises a glue injection unit, a to-be-filled glue unit, a vacuumizing unit, a pressure regulating unit, a heating unit and an optional weight monitoring and oscillating unit. The process comprises the steps of system assembling, preheating, glue filling and in-situ secondary curing. Through vacuum-positive pressure collaborative glue injection, segmented temperature control and weight real-time monitoring, the problems of many bubbles, abnormal curing and poor adaptability in the prior art are solved, full-specification assembly adaptation is achieved, glue is free of bubbles, penetration is deep, the yield is high, and the method is suitable for the fields of water treatment, biological medicine and the like.

Description

Technical Field

[0001] This invention belongs to the field of glue dispensing, specifically relating to a glue dispensing system and process for hollow fiber ends. Background Technology

[0002] In the production and application of hollow fiber membrane modules (such as ultrafiltration membranes, microfiltration membranes, and reverse osmosis membrane modules), end-capping sealing is a core process that determines the module's performance, service life, and safety. Its quality directly affects the membrane module's separation efficiency, antifouling ability, and pressure resistance. Currently, hollow fiber end-capping sealing is widely used in water treatment, biomedicine, food processing, and other fields. Different scenarios place varying requirements on the sealing performance, adhesive strength, and process adaptability of the sealant. Existing technologies are insufficient to meet these diverse needs, specifically presenting the following key issues: 1. Significant limitations in process adaptability: Mainstream potting processes exhibit a "scenario-bound" characteristic, making it difficult to be compatible with hollow fiber modules of different specifications and types. Manual syringe or stepper motor-driven potting methods are only suitable for small-sized modules with low fiber density. When dealing with large filters (such as industrial-grade water treatment membrane columns) with diameters exceeding 100mm, uneven potting and localized missing potting are prone to occur. Although centrifuge potting processes can improve the potting efficiency of small-volume modules, they are only suitable for fast-curing polyurethane adhesives. For epoxy adhesives (which have long curing cycles and viscosity that is sensitive to temperature changes), centrifugal force can easily cause the adhesive to separate. Furthermore, large modules are difficult to adapt to the load-bearing and speed requirements of centrifuges, severely limiting application scenarios.

[0003] 2. High Risk of Residual Air Bubbles and Sealing Failure: Air bubbles are the core hidden danger affecting the sealing performance of the adhesive. Current processes cannot balance the triangular relationship of "vacuum control - air bubble escape - adhesive stability". If the vacuum is insufficient (e.g., below -0.06MPa), the air trapped in the adhesive during the injection process is difficult to expel. The air bubbles formed after curing will cause gaps between the hollow fibers and the adhesive, leading to media leakage. If the vacuum is too high (e.g., below -0.12MPa), it will destroy the adhesive's colloidal structure, causing the continuous precipitation of tiny air bubbles inside the adhesive, forming a "foamy colloid". This not only reduces the strength of the colloid but also blocks the interfiber channels of the hollow fibers, affecting the flux of the membrane module. In addition, differences in the operating rhythm during manual adhesive injection (e.g., inconsistent injection speed) can also lead to air entrapment, further exacerbating the air bubble problem.

[0004] 3. Temperature imbalance leading to abnormal curing: Mainstream potting adhesives such as epoxy and polyurethane are highly sensitive to temperature. Existing processes lack a "whole-process temperature coordinated control" mechanism, resulting in large fluctuations in curing quality. During the potting stage, if the ambient temperature is too low (e.g., below 15℃), the adhesive viscosity will increase significantly (e.g., the viscosity of epoxy adhesive can exceed 4000 mPa·s), reducing fluidity and making it difficult to penetrate into the gaps of high-density fiber bundles, forming "local blank areas." If the temperature is blindly increased to reduce viscosity (e.g., exceeding 60℃), the pre-curing reaction of the adhesive will be accelerated, causing the adhesive to clump before the potting is completed, resulting in "insufficient adhesive" or "white core" (a white, loose area where the adhesive has not been fully cured). During the curing stage, the adhesive releases a large amount of heat during curing (e.g., the peak heat release during epoxy adhesive curing can reach over 70°C). If the temperature is not controlled in time, local high temperatures can cause the adhesive to become brittle. In the secondary curing stage, if the temperature is not properly controlled (e.g., the heating rate exceeds 5°C / min), it will cause thermal stress differences between the adhesive and hollow fibers and tubes, leading to cracking or debonding of the adhesive, which seriously affects the long-term stability of the components.

[0005] 4. Poor coordination of process parameters and low operational error tolerance: Existing processes require simultaneous control of multiple parameters such as vacuum level, vibration frequency, dispensing speed, and temperature, and these parameters have complex coupling relationships, making precise matching difficult. For example, to prevent the adhesive from "climbing" along the gaps between the fibers (a siphon height exceeding 10mm will cause fiber embrittlement), the adhesive viscosity needs to be increased. However, high-viscosity adhesive is prone to "not being able to be drawn out" during vacuum dispensing, requiring vibration-assisted homogenization. Furthermore, excessively high vibration frequencies (e.g., exceeding 25Hz) can cause adhesive splashing, while excessively low frequencies (e.g., below 5Hz) cannot break air bubbles, creating a "parameter contradiction." In addition, existing processes lack a real-time feedback mechanism; for example, the dispensing pressure cannot be dynamically adjusted based on changes in adhesive weight, relying solely on operator experience. This results in yield differences exceeding 15% between different batches, making it difficult to meet the stability requirements of large-scale industrial production.

[0006] 5. Lack of compatibility with large and special structural components: With the increasing demand for high-flow-rate membrane modules in fields such as industrial water treatment and blood purification, large hollow fiber membrane columns with diameters exceeding 150mm and lengths exceeding 1m are becoming increasingly common. However, existing processes cannot solve the problem of glue injection. On the one hand, the tubing of large membrane columns is mostly thin-walled (such as PP material tubing with a wall thickness of less than 3mm). When using traditional vacuum injection, excessive pressure difference between the inside and outside of the tubing can cause deformation of the tubing (such as sidewall dents), damaging the module structure. On the other hand, the fiber bundle loading of large membrane columns can reach tens of thousands of strands, with extremely small gaps between the strands (such as less than 0.1mm). Existing injection methods cannot fully penetrate the glue to the depth of the end (usually requiring a penetration depth of more than 40mm), resulting in incomplete end sealing and easy media leakage during high-pressure operation.

[0007] Therefore, based on this, the technical solution of the present invention is proposed. Summary of the Invention

[0008] To address the problems existing in the prior art, the present invention provides a glue-filling system for hollow fiber ends, the glue-filling system comprising: The glue dispensing unit is filled with glue for dispensing. A glue-to-be-filled unit; the glue-to-be-filled unit is connected to the glue-injection unit; the glue-to-be-filled unit contains hollow fibers, and the glue in the glue-injection unit is injected into the glue-to-be-filled unit through a pipeline for filling the ends of the hollow fibers with glue; Vacuum pumping unit; the vacuum pumping unit is connected to the unit to be glued and is used to create a negative pressure in the glue dispensing system; Pressure regulating unit: The pressure regulating unit is connected to the dispensing unit and is used to provide pressure to the dispensing unit; Heating unit: The heating unit is connected to the glue-to-be-applied unit and is used to heat the glue at the end of the glue-to-be-applied unit.

[0009] Preferably, the dispensing system further includes a weight monitoring unit and a vibration unit; wherein: The weight monitoring unit is connected to the glue dispensing unit and is used to monitor the weight of the glue during the dispensing process; The oscillation unit is connected to the heating unit and is used to oscillate the glue to be heated.

[0010] Based on the same technical concept, the present invention further provides a dispensing process, wherein the dispensing process requires the aforementioned dispensing system and includes the following steps: (I) Assemble the dispensing system: The glue is poured into the glue injection unit, and the units are connected through pipelines; (II) Preheating dispensing system: (II-1) Set the temperature of the heating unit to preheat the ends of the hollow fiber to remove moisture and reduce the viscosity of the glue injected later. (II-2) Open the valves of the vacuum unit and the pressure regulating unit; (II-3) Set the oscillation frequency of the oscillation unit to enter the oscillation state; (III) Start the dispensing process: (III-1) Turn on the vacuum unit, adjust the vacuum level and pump the glue into the unit to be glued; (III-2) Open the pressure regulating unit according to the vacuum suction speed to form a positive pressure auxiliary pressure on the glue inside the glue dispensing unit, and push the glue into the glue dispensing unit for dispensing. (III-3) The weight monitoring unit monitors the glue changes in real time and adjusts the vacuum unit and / or pressure regulating unit according to the glue injection speed until the set glue injection weight is reached; (III-4) After the glue has been poured, turn off the vacuum unit, pressure regulating unit, vibration unit and heating unit, and release the air pressure of the glue pouring system to the standard atmospheric pressure so that the glue can be statically cured. (IV) In-situ secondary curing: After static curing and stabilization, the heating unit is turned on to raise the temperature for in-situ secondary curing, and the potting process is completed.

[0011] Preferably, in step (I), the adhesive is an epoxy-based two-component adhesive, wherein: The epoxy two-component adhesive includes component A and component B, and the weight ratio of components A to B is 50-100:46-50. The viscosity of the mixture of components A and B is 900-3300 mPa·s.

[0012] Preferably, in step (II-1), the preheating temperature is 20-50°C.

[0013] Preferably, in step (II-3), the oscillation frequency is 0-20Hz.

[0014] Preferably, in step (III-1), the vacuum degree is adjusted to -0.15~0.15MPa.

[0015] Preferably, in step (III-2), the positive pressure assist pressure is 0.01-0.15 MPa.

[0016] Preferably, in step (III-4), the static curing time is 6-48 hours.

[0017] Preferably, in step (IV), the in-situ secondary curing temperature is 50-120℃ and the time is 0.5-24h.

[0018] The beneficial effects of this invention are as follows: This invention, by constructing a "multi-unit collaborative control dispensing system" and a "precise control process for all parameters," fundamentally solves the core problems of existing hollow fiber end dispensing processes, such as poor adaptability, abnormal curing, and complex operation. It achieves a comprehensive improvement in dispensing quality, efficiency, and industrial adaptability. Specific beneficial effects are as follows: (I) Core Advantages: Overcoming technological limitations and achieving full-scenario adaptation This invention breaks through the limitations of existing processes by employing a "vacuum-positive pressure coordinated injection" and a "modular unit design," making it adaptable to the full range of hollow fiber injection needs, from small laboratory components to large industrial membrane columns. On one hand, the coordinated control of the vacuum unit and pressure regulating unit can both break up air bubbles in the adhesive and promote adhesive penetration through negative pressure, and balance the pressure difference between the inside and outside of the tubes through positive pressure (0.01-0.05MPa), preventing deformation of thin-walled tubes (such as PP tubes with a wall thickness of 2-3mm) during vacuum injection, successfully achieving stable injection of large membrane columns with a diameter of over 200mm. On the other hand, the real-time linkage between the injection unit and the weight monitoring unit can dynamically adjust the injection pressure and speed according to the adhesive viscosity (900-3300mPa・s), achieving uniform injection for both high-viscosity epoxy adhesives and low-viscosity polyurethane adhesives, solving the adaptation problem of existing processes where "high-viscosity adhesives are difficult to vacuum, while low-viscosity adhesives are easy to climb."

[0019] (ii) Quality Assurance: Eliminate curing abnormalities and improve sealing and structural stability. 1. Precise temperature control eliminates bubbles and curing defects: The heating unit's "segmented temperature control mechanism" (preheating at 20-50℃ during the glue injection stage and heating at 50-120℃ during the secondary curing stage) solves the problems of residual moisture and viscosity during the glue injection stage (preheating can reduce glue viscosity by 30%-50% and remove moisture from the fiber surface to prevent bubble formation). Furthermore, in-situ secondary curing releases stress between the glue, fiber, and tubing. Experimental data shows that using this invention's process results in a low bubble rate, no "white core" or "insufficient glue" phenomena, a stable glue hardness of 75-90HD, and a 0% debonding rate, significantly superior to existing processes (bubble rate 5%-10%, debonding rate 3%-8%).

[0020] 2. Vacuum-Positive Pressure Synergistic Enhancement of Penetration Depth: By optimizing the matching relationship between vacuum degree (-0.08~-0.1MPa) and positive pressure auxiliary pressure, the adhesive can fully penetrate into the gaps between high-density filament bundles, with a penetration depth exceeding 40mm. Even in scenarios with the maximum density of filament bundle loading (such as more than 50 filament bundles per square centimeter), it can still achieve full-area sealing at the end, avoiding the local leakage problem caused by insufficient penetration in existing processes.

[0021] (III) Efficiency and cost optimization: Achieve automated control and reduce the operational threshold. 1. Automated parameter coordination improves yield and efficiency: The weight monitoring unit provides real-time feedback on glue weight changes and dynamically adjusts the parameters of the vacuum unit and pressure regulating unit. It can achieve coordinated control of glue dispensing speed, pressure and temperature without manual intervention, significantly improving the operational error tolerance and stabilizing the product yield at over 98% (compared to 75%-85% for existing processes). At the same time, the total dispensing time can be controlled between 15-120 minutes, adapting to the curing characteristics of different glues and avoiding efficiency fluctuations caused by differences in the rhythm of manual operation.

[0022] 2. Modular design reduces equipment costs: The dispensing unit, heating unit, and vibration unit of the dispensing system are all modularly designed and can be flexibly combined according to production needs (e.g., the vibration unit can be discarded for low-viscosity glue). There is no need to purchase equipment separately for different specifications of components, reducing equipment investment costs by 40%-60%, and maintenance is convenient, making it suitable for large-scale production of small and medium-sized enterprises.

[0023] (iv) Structural innovation: adapting to specific needs and expanding application boundaries This invention optimizes the end-sealing adhesive tray structure of the adhesive-filling unit (e.g., by adding multiple sets of adhesive inlet holes and designing guide grooves), making it adaptable to the preparation of hollow fiber membrane columns of any size. It has been successfully applied to large industrial membrane columns with a diameter of 200 mm and a length of 1.2 m, as well as micro hollow fiber components (5-10 mm in diameter) in the field of blood purification. At the same time, the annular heating module of the heating unit is closely fitted with the bottom adhesive-filling component, realizing precise local heating at the end and avoiding energy waste caused by overall heating. Energy consumption is reduced by 25%-30% compared with existing processes. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the glue dispensing system.

[0026] Figure 2 This is a schematic diagram of the heating unit.

[0027] Figure 3 These are actual photos of the sample before (left) and after (right) the glue-pouring process.

[0028] The attached figures are labeled as follows: 1-Glue dispensing unit; 2-Glue-to-be-dispensed unit; 3-Vacuum pumping unit; 4-Pressure regulating unit; 5-Oscillation unit; 6-Heating unit; 61-Bottom glue dispensing assembly; 62-Annular heating module; 7-Weight monitoring unit. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] Example 1 refer to Figure 1 This embodiment provides a glue-filling system for hollow fiber ends, the glue-filling system comprising: Glue injection unit 1; the glue injection unit 1 is filled with glue for use in glue dispensing; Glue-to-be-filled unit 2; the glue-to-be-filled unit 2 is connected to the glue-injection unit 1; the glue-to-be-filled unit 2 contains hollow fibers, and the glue in the glue-injection unit 1 is injected into the glue-to-be-filled unit 2 through a pipeline for filling the ends of the hollow fibers with glue; Vacuum unit 3; the vacuum unit 3 is connected to the glue-to-be-applied unit 2 and is used to create a negative pressure in the glue-applied system; Pressure regulating unit 4: The pressure regulating unit 4 is connected to the glue injection unit 1 and is used to provide pressure to the glue injection unit 1; Vibration unit 5 and heating unit 6: The vibration unit 5 and the heating unit 6 are connected to the glue-to-be-applied unit 2 and are used to vibrate and heat the glue at the end of the glue-to-be-applied unit 2.

[0031] As an optional implementation, the dispensing system further includes a weight monitoring unit 7; wherein: The weight monitoring unit 7 is connected to the glue dispensing unit 1 and is used to monitor the weight of the glue during the dispensing process.

[0032] More specifically, the glue dispensing unit 1 can be a glue dispensing bucket for storing glue; the glue-to-be-dispensed unit can also be a cylindrical component for placing hollow fibers; the vacuum unit 3 can be a vacuum pump for providing vacuum suction power, and the vacuum level can be adjusted as needed; the pressure regulating unit 4 can be a pressure regulating valve for providing compressed air at a certain pressure; and the vibration unit 5 can be a conventional vibration table with adjustable vibration frequency.

[0033] Heating unit 7 consists of two parts, such as Figure 2 As shown, these are the bottom glue injection assembly 61 and the annular heating module 62, respectively; wherein: The bottom injection assembly 61 is an assembly with a flow channel, a sealing chuck (or sealing surface), and one or more bottom injection holes. It is typically made of silicone or plastics such as PTFE, PP, PE, or PC, or even metal. Its function is to provide a bowl-shaped adapter that allows glue to be injected from the bottom and creates a seal with the hollow fiber end.

[0034] The ring heating module 62 is a heating component with temperature control function. It can typically be a ceramic heating ring, a silicone heating ring (or strip), a high-temperature resistant asbestos heating ring (or strip), or other functional materials that have heating and temperature control capabilities and can form a relatively tight fit with the bottom adhesive injection component (the ring heating module is sleeved on the outside of the bottom adhesive injection component).

[0035] Example 2

[0036] This embodiment provides a potting process, which requires the use of the aforementioned potting system. The potting process includes the following steps: (I) Assemble the dispensing system: The glue is poured into the glue injection unit, and the compressed air pipeline is connected to each unit for assembly; wherein, the glue brand used in this embodiment is Henkel E20-HP; the weight ratio of component A to component B is 100:50, and the viscosity of the glue after mixing is 3300 mPa·s. (II) Preheating dispensing system: (II-1) Set the temperature of the heating unit according to the characteristics of the adhesive and the process requirements, and heat the temperature to 30°C to preheat the ends of the hollow fiber to remove moisture and reduce the viscosity of the subsequent injected adhesive. The preheating process continues until the glue pouring is finished. (II-2) Open the valve on the vacuum unit connection pipeline; open the valve on the pressure regulating unit injection pipeline; (II-3) Set the oscillation frequency of the oscillation unit to 10Hz to enter the oscillation state; (III) Start the dispensing process: (III-1) Turn on the vacuum unit, adjust the vacuum level to -0.07MPa, and slowly pump the glue into the unit to be glued; (III-2) Open the pressure regulating unit according to the vacuum suction speed, set the positive pressure auxiliary pressure to 0.02MPa, and assist in pushing the glue in the dispensing unit into the dispensing unit; (III-3) Monitor the weight change trend and adjust the vacuum level (or positive pressure in the glue tank) according to the glue injection speed to ensure that the glue injection speed reaches the relevant indicators (generally, the reasonable total injection time is 15min-120min, depending on the glue and the properties of the filaments; in this embodiment, the total injection time is 60min). When the weight monitoring reaches the set injection weight, the system vacuum pump is turned off, the positive pressure regulating valve is turned off, the vibrator is turned off, and the end insulation module is turned off. The air pressure in the glue tank and the membrane column is released to the standard atmospheric pressure, and the glue injection fixture enters the locked state, entering the static curing stage of the glue. For example, the first stage of stable curing time required for epoxy glue is generally >12h (the static curing time in this embodiment is 14h). During this stage, a large amount of heat is released in the partial epoxy curing process. A fan can be placed on the outside of the end sealing assembly to blow away the heat and avoid the glue thermal explosion reaction. (IV) In-situ secondary curing: After the first stage of curing and stabilization, the heating unit is restarted to heat the end to 80°C for a secondary curing reaction (this varies depending on the type of adhesive and the goal of the secondary curing). Generally, secondary curing at lower temperatures allows the adhesive to maintain good elasticity but results in lower hardness; higher secondary curing temperatures typically allow the adhesive to reach extremely high hardness, but this is accompanied by embrittlement and decreased elasticity). Heating is stopped after 8 hours, when the required time for the secondary curing reaction has been reached.

[0037] The actual photos of the obtained samples are as follows Figure 3 As shown.

[0038] Examples 3-6 The processes of Examples 3-6 are basically the same as those of Example 2, with only some parameters being adjusted, as shown in Table 1.

[0039] Table 1 glue brands A and B mixing ratio Viscosity after mixing (mPa·s) potting process Glue application effect Example 2 (Henkel E20-HP) 100:50 3300 Continue preheating until dispensing is complete; Vacuum: -0.07 MPa; Positive pressure: 0.02 MPa; Vibration: 10 Hz; Secondary curing: 80℃ / 4h Injection volume: 500g; Glue height: >45mm; Glue hardness: >85HD Example 3 (Henkel E30-CL) 100:46 2000 Continue preheating until dispensing is complete; Vacuum: -0.05 MPa; Positive pressure: 0.017 MPa; Vibration: 10 Hz; Secondary curing: 80℃ / 2h Injection volume: 500g; Glue height: >40mm; Glue hardness: >90HD Example 4 (Goodtop Bond 280) 50:50 1500 Preheat for 30 minutes; Vacuum: -0.05 MPa; Positive pressure: 0.01 MPa; Vibration: 20 Hz; Secondary curing: 80℃ / 2 hours Injection volume: 500g; Glue height: >40mm; Glue hardness: >80HD Example 5 (Juli JL-528) 50:50 1250 No preheating; Vacuum: -0.07 MPa; Positive pressure: 0.01 MPa; Vibration: Stop; Secondary curing: 80℃ / 2h Injection volume: 550g; Glue height: >40mm; Glue hardness: >80HD Example 6 (Alic H150) 50:50 900 No preheating; Vacuum: -0.07 MPa; Positive pressure: 0.01 MPa; Vibration: Stop; Secondary curing: 65℃ / 2h Injection volume: 600g; Glue height: >45mm; Glue hardness: >75HD Furthermore, the present invention uses the adhesive of Example 2 with more refined process parameters, as shown in Table 2.

[0040] Table 2

[0041] Note: RT stands for Room Temperature.

[0042] Table 2 outlines experiments based on parameters such as "dispensing base model, heating temperature, vibration frequency, vacuum degree, positive pressure, dispensing time, glue level, and maximum siphon height." Table 2 shows that: (1) Combining heating, oscillation, positive pressure and vacuum can significantly increase the glue injection speed.

[0043] (2) Combining heating, oscillation, positive pressure and vacuum can control the injection time of glue.

[0044] (3) The oscillation frequency has no significant effect on the glue climbing height.

[0045] (4) The present invention can fully control the liquid level of the glue.

[0046] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A dispensing system for hollow fiber ends, characterized in that, The dispensing system includes: The glue dispensing unit is filled with glue for dispensing. A glue-to-be-filled unit; the glue-to-be-filled unit is connected to the glue-injection unit; the glue-to-be-filled unit contains hollow fibers, and the glue in the glue-injection unit is injected into the glue-to-be-filled unit through a pipeline for filling the ends of the hollow fibers with glue; Vacuum pumping unit; the vacuum pumping unit is connected to the unit to be glued and is used to create a negative pressure in the glue dispensing system; Pressure regulating unit: The pressure regulating unit is connected to the dispensing unit and is used to provide pressure to the dispensing unit; Heating unit: The heating unit is connected to the glue-to-be-applied unit and is used to heat the glue at the end of the glue-to-be-applied unit.

2. The glue-filling system for hollow fiber ends according to claim 1, characterized in that, The dispensing system also includes a weight monitoring unit and a vibration unit; wherein: The weight monitoring unit is connected to the glue dispensing unit and is used to monitor the weight of the glue during the dispensing process; The oscillation unit is connected to the heating unit and is used to oscillate the glue to be heated.

3. A potting process, characterized in that, The dispensing process employs the dispensing system described in claim 1 or 2, and the dispensing process includes the following steps: (I) Assemble the dispensing system: The glue is poured into the glue injection unit, and the units are connected through pipelines; (II) Preheating dispensing system: (II-1) Set the temperature of the heating unit to preheat the ends of the hollow fiber to remove moisture and reduce the viscosity of the glue injected later. (II-2) Open the valves of the vacuum unit and the pressure regulating unit; (II-3) Set the oscillation frequency of the oscillation unit to enter the oscillation state; (III) Start the dispensing process: (III-1) Turn on the vacuum unit, adjust the vacuum level and pump the glue into the unit to be glued; (III-2) Open the pressure regulating unit according to the vacuum suction speed to form a positive pressure auxiliary pressure on the glue inside the glue dispensing unit, and push the glue into the glue dispensing unit for dispensing. (III-3) The weight monitoring unit monitors the glue changes in real time and adjusts the vacuum unit and / or pressure regulating unit according to the glue injection speed until the set glue injection weight is reached; (III-4) After the glue has been poured, turn off the vacuum unit, pressure regulating unit, vibration unit and heating unit, and release the air pressure of the glue pouring system to the standard atmospheric pressure so that the glue can be statically cured. (IV) In-situ secondary curing: After static curing and stabilization, the heating unit is turned on to raise the temperature for in-situ secondary curing, and the potting process is completed.

4. The potting process according to claim 3, characterized in that, In step (I), the adhesive is an epoxy-based two-component adhesive, wherein: The epoxy two-component adhesive includes component A and component B, and the weight ratio of components A to B is 50-100:46-50. The viscosity of the mixture of components A and B is 900-3300 mPa·s.

5. The potting process according to claim 3, characterized in that, In step (II-1), the preheating temperature is 20-50℃.

6. The potting process according to claim 3, characterized in that, In step (II-3), the oscillation frequency is 0-20Hz.

7. The potting process according to claim 3, characterized in that, In step (III-1), the vacuum degree is adjusted to -0.15~0.15MPa.

8. The potting process according to claim 3, characterized in that, In step (III-2), the positive pressure auxiliary pressure is 0.01-0.15 MPa.

9. The potting process according to claim 3, characterized in that, In step (III-4), the static curing time is 6-48 hours.

10. The potting process according to claim 3, characterized in that, In step (IV), the temperature for the in-situ secondary curing is 50-120℃ and the time is 0.5-24h.

Images