Encapsulation process for multi-lumen tubes used for blood collection

Abstract

The present invention discloses a coating process for a multi-lumen tube for blood collection, which belongs to the technical field of medical tools. The technical scheme includes the following steps: 1) Pretreatment: Select a multi-lumen tube to be coated, place the multi-lumen tube in a constant temperature drying oven for constant temperature drying, place the multi-lumen tube in a dust-free environment after drying, and cool to room temperature; 2) Section cleaning: Use a dust-free cloth dipped in an organic solvent to clean and wipe the end face of the multi-lumen tube; 3) Plasma surface treatment: Place the wiped multi-lumen tube in a surface treatment machine for surface treatment; 4) Injection molding coating: Place the multi-lumen tube on a coating mold for injection molding coating. The present invention solves the problem that it is difficult to effectively weld and coat the multi-lumen tube and the multi-lumen tube joint by performing a plasma pretreatment process on the end face, selecting a highly soluble organic solvent, and adopting a suitable injection molding coating process, thereby reducing the unqualified rate in the production process and improving production efficiency and product quality.

Description

Technical Field

[0001] The invention belongs to the technical field of medical tools, and in particular relates to a multi-lumen tube encapsulation process for blood collection. Background Art

[0002] With the continuous advancement of medical technology, blood collection, as an important part of clinical diagnosis, has attracted wide attention for its accuracy and efficiency. As one of the key components of the blood component separator, the multi-lumen tube assembly realizes the diversified collection and processing of blood samples by setting multiple independent cavities in the same tube body, greatly improving the flexibility and efficiency of blood collection. The multi-lumen tube assembly is made of a multi-lumen tube and a multi-lumen tube joint bonded together, such as Figure 1 As shown, because it bears the high-speed rotation force of the separator during the blood separation process, it has high requirements for strength, toughness and the bonding firmness of each component. In addition, in order to ensure that blood does not leak during the blood separation process, its air tightness requirements are also relatively high. According to the blood component separator product registration and technical review guidelines and the industry standard "YY0613-2007 Disposable Centrifugal Bag Blood Component Separator", the air tightness requirements are: close one end of the multi-lumen pipeline, and connect a gas higher than the atmospheric pressure of 50kPa from the other end, and it should last for 15s without leakage; tensile strength requirements: hang the multi-lumen tube assembly vertically, hang a 15N weight at the bottom, and it should be able to maintain 15s without falling off at each bonding point.

[0003] At the same time, since the multi-lumen tube is a multi-hole pipeline, such as Figure 2 As shown, Figure 2 Taking the five-hole tube as an example, the interval surface between the pipelines is narrow, resulting in a small interface contact area, making it difficult to achieve effective contact without leakage with the multi-lumen tube connector; in addition, the multi-lumen tube is made of thermoplastic polyester elastomer, and different brands of materials are difficult to weld due to their different physical properties, resulting in difficulty in achieving effective leakage-free welding of the multi-lumen tube with the multi-lumen tube connector.

[0004] In order to solve the above problems, a variety of improvement schemes have emerged in the prior art, among which the encapsulation process is an important technical means. The encapsulation process forms an integrated product structure by wrapping hard plastic or elastomeric materials on the outside of the hose, thereby improving the structural strength, sealing performance and biocompatibility of the blood collection tube. However, the existing encapsulation process still has some shortcomings, such as insufficient bonding strength between the encapsulation material and the hose, difficulty in controlling the uniformity of the encapsulation layer, and low production efficiency. Summary of the invention

[0005] The present invention provides a coating process for a multi-lumen tube for blood collection, which solves the problem of difficult effective welding and coating of multi-lumen tubes and multi-lumen tube joints by performing a plasma pretreatment process on the end surface, selecting a highly soluble organic solvent, and adopting a suitable injection molding coating process.

[0006] The technical solution of the present invention is:

[0007] The encapsulation process of a multi-lumen tube for blood collection comprises the following steps:

[0008] 1) Pretreatment: Select the multi-lumen tube to be encapsulated, place the multi-lumen tube in a constant temperature drying oven for constant temperature drying, and after drying, place the multi-lumen tube in a dust-free environment and cool it to room temperature;

[0009] 2) Surface cleaning: Use a dust-free cloth dipped in an organic solvent to clean and wipe the end surface of the multi-lumen tube;

[0010] 3) Plasma surface treatment: Place the wiped multi-lumen tube in a surface treatment machine for surface treatment;

[0011] 4) Injection molding: Place the multi-cavity tube into the overmolding mold for injection molding.

[0012] Preferably, in step 1), the drying temperature is 78-82° C. and the drying time is 7.5-8.5 h.

[0013] Preferably, in step 2), the organic solvent is dichloromethane, and the wiping times is three times.

[0014] Preferably, in step 3), the power of the surface treatment machine is 200W, the treatment time is 2min, and the gas type is a mixed gas of oxygen, nitrogen and argon, wherein oxygen accounts for 20%-50%, nitrogen accounts for 10%-50%, and argon accounts for 10%-50%.

[0015] Preferably, in step 4), the injection temperature is set to 230-235° C., the injection pressure is set to 25-35 bar, the sol speed is set to 40-50 mm / s, and the holding time is set to 10-20 s.

[0016] Preferably, the rubber material used for the injection molding in step 4) is thermoplastic polyester elastomer (TPEE).

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention combines solvent cleaning and plasma surface treatment technology, which can significantly remove impurities such as oil, dust, oxides, etc. attached to the end surface of the multi-lumen tube. Plasma treatment not only further deeply cleans the surface, but also changes the microstructure of the material surface through the bombardment of high-energy particles, increases the surface roughness and energy, and thus significantly improves the surface activity; the enhancement of surface activity provides more binding points for subsequent adhesives, so that the adhesives can more effectively penetrate into the material surface, form stronger intermolecular interaction forces, and lay a solid foundation for bonding.

[0019] 2. During the plasma treatment process, the active particles (such as ions, electrons, free radicals, etc.) generated can react chemically or physically with the material surface of the multi-lumen tube end face to form a uniform and dense chemical bonding layer or cross-linking layer. This newly formed surface layer not only enhances the surface energy of the material, but also improves the wettability and adhesion of the material, allowing the adhesive to spread more evenly on the material surface to form a continuous and dense bonding interface. Therefore, plasma treatment significantly reduces the risk of poor bonding, such as debonding, delamination, etc.

[0020] 3. The injection molding coating process can ensure that the adhesive is evenly distributed between the multi-lumen tube and the joint, and achieve high-strength chemical and physical bonding through molecular chain diffusion and entanglement under high temperature and high pressure. According to batch inspection data statistics, the unqualified rate of multi-lumen tube coating has dropped from 15.7% of the conventional coating process in the industry to 0.

[0021] 4. The present invention reduces the unqualified rate in the production process to 0 through the synergistic effect between the pretreatment, cross-section cleaning treatment, plasma surface treatment and injection molding and encapsulation process steps, which are indispensable to each other, thereby improving production efficiency and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of a multi-lumen tube assembly in the prior art.

[0023] Figure 2 It is a schematic diagram of the cross section of a multi-lumen tube in the prior art, taking five holes as an example. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0025] The multi-lumen tube for blood collection in the following embodiments and comparative examples takes a five-lumen tube as an example.

[0026] Example 1

[0027] The encapsulation process of the multi-lumen tube for blood collection comprises the following steps:

[0028] 1) Pretreatment: Select the multi-lumen tube to be encapsulated, place it in a constant temperature drying oven for constant temperature drying, the drying temperature is 80°C, the drying time is 8 hours, and the temperature and humidity in the drying oven are maintained constant. After drying, place the multi-lumen tube in a dust-free environment and cool it to room temperature;

[0029] 2) Cleaning of the cross section: Dip a dust-free cloth in dichloromethane solvent and press gently to remove excess solvent to prevent the solution from dripping; wipe the end surface of the multi-lumen tube evenly and carefully, and replace a new dust-free cloth with solvent after each wipe, and wipe it three times in total; during the wiping process, ensure that there are no residual stains and solvents on the end surface to avoid affecting the subsequent bonding effect;

[0030] 3) Plasma surface treatment: Place the wiped multi-lumen tube in a surface treatment machine for surface treatment. The power of the surface treatment machine is 200W, the treatment time is 2 minutes, and the gas type is a mixed gas of oxygen, nitrogen and argon, in which oxygen accounts for 20%, nitrogen accounts for 50%, and argon accounts for 30%;

[0031] 4) Injection molding: Place the multi-lumen tube on the overmolding mold for injection molding. The material of the overmolding material is thermoplastic polyester elastomer, which is consistent with the material of the multi-lumen tube. The injection temperature is set to 232°C, the injection pressure is 30 bar, the sol speed is 45 mm / s, and the holding time is 15 s.

[0032] The air tightness and tensile strength of multiple groups of multi-lumen tubes for blood collection obtained by the above process were tested. The air tightness met the requirement of no leakage for 15 seconds, and the tensile strength test showed that the tubes could be maintained without falling off for 15 seconds, thus meeting the use requirements of the blood component separator.

[0033] Example 2

[0034] The encapsulation process of the multi-lumen tube for blood collection comprises the following steps:

[0035] 1) Pretreatment: Select the multi-lumen tube to be encapsulated, place the multi-lumen tube in a constant temperature drying oven for constant temperature drying, the drying temperature is 78°C, the drying time is 7.5h, and the temperature and humidity in the drying oven are maintained constant. After drying, place the multi-lumen tube in a dust-free environment and cool it to room temperature;

[0036] 2) Cleaning of the cross section: Dip a dust-free cloth in dichloromethane solvent and press gently to remove excess solvent to prevent the solution from dripping; wipe the end surface of the multi-lumen tube evenly and carefully, and replace a new dust-free cloth with solvent after each wipe, and wipe it three times in total; during the wiping process, ensure that there are no residual stains and solvents on the end surface to avoid affecting the subsequent bonding effect;

[0037] 3) Plasma surface treatment: Place the wiped multi-lumen tube in a surface treatment machine for surface treatment. The power of the surface treatment machine is 200W, the treatment time is 2 minutes, and the gas type is a mixed gas of oxygen, nitrogen and argon, in which oxygen accounts for 50%, nitrogen accounts for 40%, and argon accounts for 10%;

[0038] 4) Injection molding: Place the multi-lumen tube on the overmolding mold for injection molding. The material of the overmolding material is thermoplastic polyester elastomer, the injection temperature is set to 230°C, the injection pressure is 25 bar, the sol speed is 40 mm / s, and the holding time is 10 s.

[0039] The air tightness and tensile strength of multiple groups of multi-lumen tubes for blood collection obtained by the above process were tested. The air tightness met the requirement of no leakage for 15 seconds, and the tensile strength test showed that the tubes could be maintained without falling off for 15 seconds, thus meeting the use requirements of the blood component separator.

[0040] Example 3

[0041] The encapsulation process of the multi-lumen tube for blood collection comprises the following steps:

[0042] 1) Pretreatment: Select the multi-lumen tube to be encapsulated, place the multi-lumen tube in a constant temperature drying oven for constant temperature drying, the drying temperature is 82°C, the drying time is 8.5h, and the temperature and humidity in the drying oven are maintained constant. After drying, place the multi-lumen tube in a dust-free environment and cool it to room temperature;

[0043] 2) Cleaning of the cross section: Dip a dust-free cloth in dichloromethane solvent and press gently to remove excess solvent to prevent the solution from dripping; wipe the end surface of the multi-lumen tube evenly and carefully, and replace a new dust-free cloth with solvent after each wipe, and wipe it three times in total; during the wiping process, ensure that there are no residual stains and solvents on the end surface to avoid affecting the subsequent bonding effect;

[0044] 3) Plasma surface treatment: Place the wiped multi-lumen tube in a surface treatment machine for surface treatment. The power of the surface treatment machine is 200W, the treatment time is 2 minutes, and the gas type is a mixed gas of oxygen, nitrogen and argon, in which oxygen accounts for 40%, nitrogen accounts for 10%, and argon accounts for 50%;

[0045] 4) Injection molding: Place the multi-lumen tube on the overmolding mold for injection molding. The material of the overmolding material is thermoplastic polyester elastomer, the injection temperature is set to 235°C, the injection pressure is 35 bar, the sol speed is 50 mm / s, and the holding time is 20 s.

[0046] The air tightness and tensile strength of multiple groups of multi-lumen tubes for blood collection obtained by the above process were tested. The air tightness met the requirement of no leakage for 15 seconds, and the tensile strength test showed that the tubes could be maintained without falling off for 15 seconds, thus meeting the use requirements of the blood component separator.

[0047] Comparative Example 1

[0048] Different from Example 1, this comparative example does not include step 2) cross-section cleaning treatment, and the remaining steps and processes are the same as those in Example 1. The multiple groups of multi-lumen tubes for blood collection obtained by the above process were tested for air tightness and tensile strength. The air tightness of some products could not meet the requirement of no leakage for 15 seconds, and the tensile strength test could not maintain 15 seconds without falling off, which could not meet the use requirements of the blood component separator, and the unqualified rate was 7%.

[0049] Comparative Example 2

[0050] Different from Example 1, this comparative example does not include step 1) pretreatment, and the remaining steps and processes are the same as those in Example 1. The multiple groups of multi-lumen tubes for blood collection obtained by the above process are tested for air tightness and tensile strength. The air tightness of some products cannot meet the requirement of no leakage for 15 seconds, and the tensile strength test cannot maintain 15 seconds without falling off, which cannot meet the use requirements of the blood component separator, and the unqualified rate is 9.5%.

[0051] Comparative Example 3

[0052] Different from Example 1, in this comparative example, the pretreatment temperature in step 1) is 75°C (, and the remaining steps and processes are the same as those in Example 1. The multiple groups of multi-lumen tubes for blood collection obtained by the above process are subjected to air tightness and tensile strength tests. The air tightness of some products cannot meet the requirement of no leakage for 15 seconds, and the tensile strength test cannot maintain 15 seconds without falling off, which cannot meet the use requirements of the blood component separator, and the unqualified rate is 3.5%.

[0053] Comparative Example 4

[0054] In this comparative example, a conventional encapsulation process is adopted, which does not include step 1) to step 3 in Example 1. The multi-lumen tube is placed on the encapsulation mold for injection molding. The material of the injection molding encapsulation is thermoplastic polyester elastomer, the injection temperature is set to 232°C, the injection pressure is 30 bar, the sol speed is 45 mm / s, and the holding time is 15 s. The air tightness and tensile strength of multiple groups of multi-lumen tubes for blood collection obtained by the above process are measured. The air tightness of some products cannot meet the requirement of no leakage for 15 s, and the tensile strength test cannot maintain 15 s without falling off, which cannot meet the use requirements of the blood component separator, and the unqualified rate is 15.7%.

[0055] The air tightness and tensile strength of the multi-lumen tubes for blood collection after the process treatment of the above-mentioned Examples 1-3 and Comparative Examples 1-4 were measured in accordance with the blood component separator product registration and technical review guidelines and the industry standard "YY0613-2007 Disposable Centrifugal Bag Blood Component Separator".

Claims

1. A process for encapsulating a multi-lumen tube for blood collection, characterized in that: The following steps are involved: 1) Pretreatment: Select the multi-lumen tube to be encapsulated, place the multi-lumen tube in a constant temperature drying oven for constant temperature drying, and after drying, place the multi-lumen tube in a dust-free environment and cool it to room temperature; 2) Surface cleaning: Use a dust-free cloth dipped in an organic solvent to clean and wipe the end surface of the multi-lumen tube; 3) Plasma surface treatment: Place the wiped multi-lumen tube in a surface treatment machine for surface treatment; 4) Injection molding and encapsulation: Place the multi-cavity tube on the encapsulation mold for injection molding and encapsulation; In step 1), the drying temperature is 78-82°C and the drying time is 7.5-8.5h; In step 2), the organic solvent is dichloromethane and the number of wiping is three times; In step 3), the power of the surface treatment machine is 200W, the treatment time is 2 minutes, and the gas type is a mixed gas of oxygen, nitrogen and argon, of which oxygen accounts for 20%-50%, nitrogen accounts for 10%-50%, and argon accounts for 10%-50%; In step 4), the injection temperature is set to 230-235°C, the injection pressure is 25-35 bar, the sol speed is 40-50 mm / s, and the holding time is 10-20 s; The rubber material used for the injection molding in step 4) is a thermoplastic polyester elastomer.

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