A syringe with self-lubricating function

Abstract

This invention discloses a self-lubricating syringe, belonging to the field of medical device technology. The syringe includes a syringe barrel and a piston. A coating is fixed to the outer surface of the piston and / or the inner surface of the syringe barrel. The coating is made of a homogeneous material with a coefficient of friction of less than or equal to 0.2. This solution utilizes a coating of homogeneous material with a coefficient of friction of less than or equal to 0.2 to treat the outer surface of the piston and / or the inner surface of the syringe barrel, enabling good sealing and lubrication of the piston and syringe without the need for lubricant. Because this product completely avoids the use of lubricant, it solves the problems of impurities and particles introduced by lubricants, as well as the compatibility issues between lubricants and drugs.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a syringe with self-lubricating function. Background Technology

[0002] During use, syringes require lubrication of the inner wall and piston to ensure the smooth injection of medications and other products into the human body. Dimethyl silicone oil is commonly used as a lubricant in the industry. However, some medications injected through syringes can react with the lubricant, altering some of the drug's properties, producing suspended lubricant particles, or generating unwanted microparticles. For example, some protein-based drugs can react with silicone oil, causing protein aggregation.

[0003] Currently, the following solutions are used in the market to address the interaction between lubricants and drugs:

[0004] 1) Reduce or eliminate the adverse effects of lubricant by decreasing the amount of lubricant used;

[0005] 2) A sealing and lubrication effect is achieved by adding non-lubricating substances between the syringe barrel and the piston;

[0006] 3) Some special processes are adopted. For example, for glass syringes, baking siliconization is used to reduce the adverse effects of lubricant. Baking siliconization refers to coating the inner circumference of the syringe with silicone in emulsion form, and then baking it at high temperature (200℃~330℃) to fix the silicone. By fixing the silicone to the inner circumference of the syringe, silicone is prevented from mixing into the medicine.

[0007] 4) Avoid using lubricant on the syringe by changing the structure or material of the syringe.

[0008] However, the existing solutions described above still have the following drawbacks:

[0009] 1) Some products cannot completely avoid the use of lubricants;

[0010] 2) Some solutions require changes to the product structure and can only be used with pre-filled syringes;

[0011] 3) Some solutions have complex product structures and low reliability;

[0012] 4) Some solutions use other types of lubricants or coatings, which raises concerns about product safety and drug compatibility;

[0013] 5) Special processes require investment in production equipment and additional procedures, increasing product costs.

[0014] Therefore, how to solve the compatibility problem between lubricant and drug while ensuring good lubrication between the piston and the inner wall of the syringe is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0015] In view of this, the purpose of the present invention is to provide a syringe with self-lubricating function, which can ensure the sealing and lubrication of the syringe product without the use of lubricant. The product completely avoids the use of lubricant, and solves the problems of impurities and particles introduced by lubricant and the compatibility between lubricant and drug.

[0016] To achieve the above objectives, the present invention provides the following technical solution:

[0017] A self-lubricating syringe includes a syringe barrel and a piston, wherein a coating is fixed on the outer surface of the piston and / or the inner surface of the syringe barrel, and the coating is a film with a coefficient of friction between surfaces of the same material less than or equal to 0.2.

[0018] Preferably, the outer surface of the piston that contacts the inner wall of the syringe is fixed with the coating.

[0019] Preferably, the thickness of the coating is 0.05 mm to 2 mm.

[0020] Preferably, the coating is a polytetrafluoroethylene film, or an ultra-high density polyethylene film, or a polyacetal film, or a polyoxymethylene film, or a polycarbonate film, or a polyamide film, or a polysulfone film, or a polyimide film, or a chlorinated polyether film, or a polyphenylene sulfide film, or a polyterephthalate film.

[0021] Preferably, the piston is surrounded by a raised sealing ring that mates with the inner wall of the syringe.

[0022] Preferably, a plurality of sealing rings are arranged axially around the outer periphery of the piston, and the sealing rings are interference-fitted with the inner wall of the syringe, wherein the interference fit between some of the sealing rings and the inner wall of the syringe is smaller than the interference fit between the remaining sealing rings and the inner wall of the syringe.

[0023] Preferably, the outer peripheral surface of the sealing ring that contacts the syringe has an annular groove.

[0024] Preferably, the sealing ring includes a sealing ring body surrounding the piston and a covering film fixed to the outer peripheral surface of the sealing ring body, wherein the covering film of the sealing ring has the annular groove.

[0025] Preferably, the piston includes a piston tail facing outward from the syringe and a piston head facing inward from the syringe, wherein the outer peripheral surface of the piston tail in contact with the inner wall of the syringe gradually moves away from the inner wall of the syringe in the direction from the piston head to the piston tail.

[0026] Preferably, the piston includes a piston tail facing outward from the syringe and a piston head facing inward from the syringe, and there is a gap between the piston tail and the inner wall of the syringe.

[0027] Preferably, the syringe further includes a plunger, the piston includes a piston tail facing outward from the syringe barrel, and the plunger includes a plunger head facing inward from the syringe barrel;

[0028] Wherein, the end face of the push rod head abuts against the end face of the piston tail; or, the piston tail is provided with a blind hole for the push rod head to be inserted into the piston, the blind hole being a straight hole or a threaded hole that is clearance-fitted with the push rod head, and the pulling force applied to the piston when the push rod head is pulled out of the blind hole is less than the static friction between the piston and the inner wall of the syringe.

[0029] The present invention provides a self-lubricating syringe, comprising a syringe barrel and a piston. A coating is fixed to the outer surface of the piston and / or the inner surface of the syringe barrel. This coating is made of a homogeneous material with a coefficient of friction of less than or equal to 0.2. This solution utilizes a coating of homogeneous material with a coefficient of friction of less than or equal to 0.2 to treat the outer surface of the piston and / or the inner surface of the syringe barrel, enabling good sealing and lubrication of the piston and syringe without the need for lubricant. Since this product completely avoids the use of lubricant, it solves the problems of impurities and particles introduced by lubricants, as well as the compatibility issues between lubricants and drugs.

[0030] The present invention has the following beneficial effects:

[0031] 1) The solution of this invention can realize the lubricant-free design of all types of syringes, and has strong adaptability;

[0032] 2) This solution does not change the overall layout of the product. For equipment that requires automated production (such as product filling), the product can be processed and produced without changing or purchasing new equipment, reducing equipment debugging and saving equipment and space costs.

[0033] 3) The product achieves the goal of being completely lubricant-free, avoiding the reaction between lubricant and product, and reducing the harm of suspended lubricant to the human body;

[0034] 4) The coating in this solution not only provides lubrication and sealing, but also isolates the drug from the piston, reducing the biological risks of the product. Attached Figure Description

[0035] 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.

[0036] Figure 1 This is a schematic diagram of the overall internal structure of the syringe in a specific embodiment of the present invention;

[0037] Figure 2 for Figure 1 A magnified view of part A in the middle;

[0038] Figure 3 This is a schematic diagram of the piston and sealing ring structure in a specific embodiment of the present invention;

[0039] Figure 4 for Figure 3 A magnified view of part B in the middle section;

[0040] Figure 5 This is a schematic diagram of a piston structure with annular grooves in a specific embodiment of the present invention;

[0041] Figure 6 for Figure 5 A magnified view of part C in the middle;

[0042] Figure 7 This is a schematic diagram of the grooved processing on the coating of the piston in a specific embodiment of the present invention;

[0043] Figure 8 This is a schematic diagram of the structure of the piston after slotting on the coating in a specific embodiment of the present invention;

[0044] Figure 9 for Figure 8 A magnified view of part D in the middle;

[0045] Figure 10 This is a schematic diagram of the piston and piston tail structure in a specific embodiment of the present invention;

[0046] Figure 11 for Figure 10 A magnified view of part E in the middle;

[0047] Figure 12 This is a schematic diagram of a piston being punched along the piston axis in the prior art;

[0048] Figure 13 This is a schematic diagram of a piston being machined radially along the piston in a specific embodiment of the present invention;

[0049] Figure 14 This is a schematic diagram of the push rod and piston contact structure in a specific embodiment of the present invention;

[0050] Figure 15 This is a schematic diagram showing the connection between the push rod and the piston through a straight hole in a specific embodiment of the present invention;

[0051] Figure 16 This is a schematic diagram showing the connection between the push rod and the piston through a threaded hole in a specific embodiment of the present invention.

[0052] Figures 1 to 16 middle:

[0053] 1-Syringe, 2-Piston, 3-Push rod, 4-Covering film, 5-Sealing ring, 6-Annular groove, 7-Piston tail, 8-Straight hole, 9-Threaded hole. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Please refer to Figures 1 to 16 This invention provides a self-lubricating syringe, comprising a syringe barrel 1 and a piston 2. A coating 4 is fixed to the outer surface of the piston 2 and / or the inner surface of the syringe barrel 1. The coating 4 is a film of the same material with a coefficient of friction of less than or equal to 0.2 between surfaces. This solution utilizes a film of the same material with a coefficient of friction of less than or equal to 0.2 to treat the outer surface of the piston 2 and / or the inner surface of the syringe barrel 1, enabling the piston 2 and the syringe barrel 1 to achieve good sealing and lubrication without the need for lubricant. Since this product completely avoids the use of lubricant, it solves the problems of impurities and particles introduced by lubricants, as well as the compatibility issues between lubricants and drugs.

[0056] The syringe products to which this invention applies have a generally consistent structure with common syringe products. The syringe barrel can be made of different materials, commonly medical-grade materials including glass, COP, COC, PP, and PC, but resin and metal can also be used. The products can have different specifications, generally ranging from 0.1ml to 200ml. The syringe products to which this invention applies come in various forms, such as disposable sterile syringes, pre-filled syringes, pre-filled syringes, and flush-sealed syringes, and can also be used for non-disposable syringes. The products can be equipped with accessories of different specifications and functions. During use, the syringe draws in or expels the medication through the injection needle or dispensing device.

[0057] The syringe provided by this invention includes a syringe barrel 1, a piston 2, and a plunger 3, and can also be equipped with functional accessories such as an injection needle, a protective cap, and a handle assist structure. In this solution, a self-lubricating film is coated or adhered to the outer periphery of the piston 2 and / or the inner surface of the syringe barrel 1. The film is made of solid or liquid materials with good lubrication properties, such as polytetrafluoroethylene (PTFE) or ultra-high density polyethylene. That is, this product uses a material with a low coefficient of friction (the coefficient of friction between surfaces of the same material is less than or equal to 0.2) to treat the product surface, and uses a low-friction material to coat the piston 2 and / or syringe barrel 1 to ensure that the sealing and sliding performance between the piston 2 and the syringe barrel 1 meets the requirements of relevant standards, allowing the piston 2 and syringe barrel 1 to slide relative to each other with relatively low resistance (resistance between 0N and 50N) after assembly. In this solution, the coefficient of friction between PTFE and PTFE is approximately 0.04. Of course, in addition to polytetrafluoroethylene (PTFE) or ultra-high-density polyethylene (UHDPE) films, other materials with similar properties can also be used for coating in this solution, such as certain engineering plastics: polyacetal films, polyoxymethylene (POM) films, polycarbonate films, polyamide films, polysulfone films, polyimide films, chlorinated polyether films, polyphenylene sulfide (PPS) films, and polyterephthalate (PTA) films, etc. These materials all have low coefficients of friction. Furthermore, when using liquid materials for coating, methods such as sputtering, electrophoretic deposition, plasma spraying, ion plating, electroplating, chemical generation, impregnation, and roller coating can be used to form the film, which will be in a solid state after coating.

[0058] This product solution has no lubricant on either the piston 2 or the syringe 1. The lubricant-free portions of the piston 2 and / or syringe 1 can be achieved by coating all or part of the piston 2 and / or syringe 1 with a film. Partial coating of the piston 2 and / or syringe 1 does not necessarily mean complete coating; the film 4 can have various shapes, such as annular, cylindrical, partial, or a combination of shapes. The film 4 in this solution can be attached to the outer surface of the piston 2 and / or the inner surface of the syringe 2 using any suitable process, such as liquid coating, hot pressing, or adhesive bonding.

[0059] Preferably, a film 4 is fixed to the entire outer surface or part of the outer surface of the piston 2 that contacts the inner wall of the syringe 1. The entire surface of the piston 2 that contacts the inner wall of the syringe 1 is cylindrical. In this design, the entire cylindrical surface of the piston 2 can be fixed with a film 4, or a film 4 can be fixed to a part of the surface of the cylindrical surface. For example, several annular films 4 can be arranged along the axial direction of the cylindrical surface.

[0060] In addition, the thickness of the coating 4 is preferably 0.05mm to 2mm to ensure that the coating 4 can provide effective lubrication and sealing contact between the piston 2 and the syringe 1, and also to reduce the processing difficulty of the coating 4.

[0061] like Figure 3As shown, preferably, a raised sealing ring 5 that mates with the inner wall of the syringe 1 is provided around the outer periphery of the piston 2. The sealing ring 5 can be an integral part of the piston 2, or it can be fixed to the piston 2 by axial stacking or peripheral adhesive bonding. In this design, the sealing ring 5 is preferably manufactured as an integral part of the piston 2.

[0062] In order to further reduce the friction between piston 2 and the inner wall of syringe 1 and ensure better sliding performance, the structure of the sealing part of piston 2 has been adjusted in this solution.

[0063] Please refer to Figure 3 and Figure 4 In a preferred embodiment, multiple sealing rings 5 ​​are arranged axially around the outer periphery of the piston 2. The sealing rings 5 ​​are interference-fitted with the inner wall of the syringe 1, with some sealing rings 5 ​​having a smaller interference fit than the remaining sealing rings 5. This embodiment reduces the radius of one or more sealing rings 5, such that the radius of the reduced sealing ring 5 is ΔR smaller than the radius of the unreduced sealing ring 5. Figure 4 As shown, this reduces the pressure and contact area of ​​the piston 2 on the inner wall of the syringe 1. This solution reduces the friction between the piston 2 and the syringe 1 by decreasing the interference fit between part of the sealing ring 5 and the inner wall of the syringe 1, thereby improving sliding performance.

[0064] Please refer to Figure 5 and Figure 6 In the second preferred embodiment, an annular groove 6 is formed on the outer peripheral surface of the sealing ring 5 that contacts the syringe 2. This embodiment further reduces the contact area between the piston 2 and the inner wall of the syringe 1 by forming a groove on the outer peripheral surface of the sealing ring 5, and also reduces the pressure between the piston 2 and the inner wall of the syringe 1 to a certain extent, thereby reducing the friction between the two. The annular groove 6 can be formed on a single sealing ring 5, or it can be added to several sealing rings 5 ​​simultaneously.

[0065] It should be noted that the aforementioned annular groove 6 can be manufactured using direct molding, tool cutting, or laser cutting. The annular groove 6 can be machined not only on the surface of the piston 2 but also on the coating material 4. Please refer to... Figures 7 to 9 Preferably, the sealing ring 5 includes a sealing ring body surrounding the piston 2 and a film 4 fixed to the outer circumferential surface of the sealing ring body. The film 4 of the sealing ring 5 has an annular groove 6. In this design, the annular groove 6 can be processed on the film 4 on the outer side of the sealing ring 5 using laser cutting. Figure 7 The triangle on the left represents the laser cutting position. The cut material accumulates on both sides of the cutting area and comes into contact with the inner wall of syringe 1 when used in conjunction with it. Due to the excellent self-lubricating properties of the coating material 4 and the small contact area after cutting, the sliding performance of the product is further improved.

[0066] Please refer to Figure 10 and Figure 11 In the third preferred embodiment, the piston 2 includes a piston tail 7 facing outwards from the syringe 1 and a piston head facing inwards from the syringe 1. The outer circumferential surface of the piston tail 7, which contacts the inner wall of the syringe 1, gradually moves away from the inner wall of the syringe 1 along the direction from the piston head to the piston tail 7. Specifically, this embodiment changes the cut edge position of the piston tail 7 from straight to oblique, so that the cut edge of the piston tail 7 forms an angle α with the inner wall of the syringe 1, reducing the contact area between the two and thus reducing friction. Due to the punching process, the piston tail of existing products is parallel or interference-fitted with the inner wall of the syringe. This embodiment changes the position of the cut edge of the piston tail 7 from parallel to the inner wall of the syringe 1 to an angle α with the inner wall of the syringe 1, thereby reducing the contact between the piston 2 and the inner wall of the syringe 1 and thus reducing friction.

[0067] Please refer to Figure 12 and Figure 13 In the fourth preferred embodiment, the piston 2 includes a piston tail 7 facing outwards from the syringe 1 and a piston head facing inwards from the syringe 1, with a gap between the piston tail 7 and the inner wall of the syringe 1. Specifically, this embodiment achieves the above objective by changing the cutting method of the piston tail 7. In the prior art, the piston 2 is obtained by punching material along the piston 2 axis during processing. Figure 12 The arrows in the diagram represent the axial cutting direction; this solution changes the cutting method to a radial cut along piston 2, as shown below. Figure 13 The radial tangent direction indicated by the middle arrow shows that the diameter of the piston tail 7 after tangent cutting is smaller than the inner diameter of the syringe 1, thus creating a gap to prevent the piston tail 7 from directly contacting the syringe 1 and thereby reducing friction.

[0068] Preferably, the syringe of this solution also includes a plunger 3, the piston 2 includes a piston tail 7 facing the outside of the syringe 1, and the plunger 3 includes a plunger head facing the inside of the syringe 1; during injection, medical personnel operate the plunger 3 and use the plunger head to drive the piston 2 to push into the inside of the syringe 1, thereby injecting the contents.

[0069] For products such as pre-filled syringes, to prevent reuse, this solution allows for optimized design of the push rod 3 and piston 2 structures. For example, the end face of the push rod head abuts against the end face of the piston tail 7 (e.g., Figure 14 (as shown); or, the piston tail 7 has a blind hole for the push rod head to be inserted into the piston 2, the blind hole being a straight hole 8 that is clearance-fitted with the push rod head (as shown). Figure 15 (as shown) or threaded hole 9 (as shown) Figure 16As shown in the diagram, the threaded portion of the threaded hole 9 uses a small undercut (generally 0-5mm), and the pulling force applied to the piston 2 when the plunger head is pulled out of the blind hole is less than the static friction between the piston 2 and the inner wall of the syringe 1. In this way, the plunger 3 and piston 2 can ensure normal injection. After injection, because the outward pulling force applied to the piston 2 by the plunger head is insufficient to overcome the static friction between the piston 2 and the inner wall of the syringe 1, the piston 2 cannot be pulled out by the plunger 3, thus achieving the self-destruction purpose of the syringe.

[0070] The present invention has the following beneficial effects:

[0071] 1) The solution of this invention can realize the lubricant-free design of all types of syringes, and has strong adaptability;

[0072] 2) This solution does not change the overall layout of the product. For equipment that requires automated production (such as product filling), the product can be processed and produced without changing or purchasing new equipment, reducing equipment debugging and saving equipment and space costs.

[0073] 3) The product achieves the goal of being completely lubricant-free, avoiding the reaction between lubricant and product, and reducing the harm of suspended lubricant to the human body;

[0074] 4) The coating in this solution not only provides lubrication and sealing, but also isolates the drug from the piston, reducing the biological risks of the product.

[0075] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A disposable syringe with self-lubricating function, comprising a syringe barrel (1) and a piston (2), characterized in that, A coating (4) is fixed on the outer surface of the piston (2) and / or the inner surface of the syringe (1), wherein the coating (4) is a film with a friction coefficient between surfaces of the same material less than or equal to 0.2; The thickness of the coating (4) is 0.05 mm to 2 mm; The coating (4) is a polytetrafluoroethylene film, or an ultra-high density polyethylene film, or a polyacetal film, or a polyoxymethylene film, or a polycarbonate film, or a polyamide film, or a polysulfone film, or a polyimide film, or a chlorinated polyether film, or a polyphenylene sulfide film, or a polyterephthalate film. The piston (2) is surrounded by a raised sealing ring (5) that fits with the inner wall of the syringe (1); The piston (2) has a plurality of sealing rings (5) arranged axially on its outer periphery. The sealing rings (5) are interference-fitted with the inner wall of the syringe (1). The interference of some of the sealing rings (5) with the inner wall of the syringe (1) is smaller than that of the remaining sealing rings (5) with the inner wall of the syringe (1). The sealing ring (5) includes a sealing ring body surrounding the piston (2) and a film (4) fixed to the outer circumferential surface of the sealing ring body. The film (4) of the sealing ring (5) has an annular groove (6). The annular groove (6) is processed on the film (4) on the outer side of the sealing ring (5) by laser cutting. The syringe also includes a plunger (3), the piston (2) includes a piston tail (7) facing outward from the syringe (1), and the plunger (3) includes a plunger head facing inward from the syringe (1); Wherein, the end face of the push rod head abuts against the end face of the piston tail (7); or, the piston tail (7) is provided with a blind hole for the push rod head to be inserted into the piston (2), the blind hole is a straight hole (8) or a threaded hole (9) that is clearance-fitted with the push rod head, the threaded part of the threaded hole (9) adopts a backing amount of 0 to 5 mm, and the pulling force applied to the piston (2) when the push rod head is pulled out of the blind hole is less than the static friction force between the piston (2) and the inner wall of the syringe (1).

2. The syringe according to claim 1, characterized in that, The piston (2) has the coating (4) fixed on its entire outer surface or part of its outer surface that contacts the inner wall of the syringe (1).

3. The syringe according to claim 1, characterized in that, The sealing ring (5) has an annular groove (6) on its outer peripheral surface that contacts the syringe (1).

4. The syringe according to claim 1, characterized in that, The piston (2) includes a piston tail (7) facing the outside of the syringe (1) and a piston head facing the inside of the syringe (1). The outer peripheral surface of the piston tail (7) that contacts the inner wall of the syringe (1) gradually moves away from the inner wall of the syringe (1) in the direction from the piston head to the piston tail (7).

5. The syringe according to claim 1, characterized in that, The piston (2) includes a piston tail (7) facing the outside of the syringe (1) and a piston head facing the inside of the syringe (1), and there is a gap between the piston tail (7) and the inner wall of the syringe (1).

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