Specialized tooling for overmolding and method for manufacturing flexible substrate components - Patents.com

Abstract

A method for overmolding a tubular structure, comprising inserting a core pin into the tubular structure such that at least a portion of a body of the core pin extends at least partially from the tubular structure, the method further comprising clamping the tubular structure in a Z-direction to a mold cavity structure using a retaining structure, the retaining structure including an angled portion and a flexible portion extending from the mold cavity structure, the method also comprising injecting a thermoplastic material into a mold cavity of the mold cavity structure to overmold at least a portion of the tubular structure, the injecting of the thermoplastic material comprising contacting the portion of the core pin extending from the tubular structure with the thermoplastic material.

Description

[Technical field]

[0001] The present disclosure relates to a method for forming an overmolded flexible substrate component on a tubular structure, and the overmolded tubular structure. More specifically, the present disclosure relates to a method for injection molding an overmolded component using a specialized overmolding tool, and an injection molded tubular structure having an overmolded component. The overmolded component can be a sheath for a catheter or a stent or a connector that is part of a connection assembly for transferring fluids from a chemical and / or biological process, etc., through several different tubes, fittings, and / or reservoirs. [Background technology]

[0002] Methods and apparatus for injection molding objects are well known: for example, a mold cavity having the shape of the desired object is formed from at least two parts, a liquefied material is injected into the mold cavity, the liquefied material is allowed to solidify, and the final molded object is removed from the mold.

[0003] In some cases, the molded object is a tubular structure that requires a hollow section to form, for example, a tube, a pipe, a connector for a tube and a pipe, or other similar tubular structure, and conventional tooling methods use a core pin with a support mechanism to keep the core pin in place during the injection molding process. In such cases, the solid core pin usually requires some type of locking mechanism that abuts the rear end of the core pin to provide resistance to maintain the placement of the core pin against the high pressure provided during the injection of the liquefied material. Retaining the core pin helps reduce / eliminate flash, for example, preventing the liquefied material from entering or forming inside the hollow section of the molded object at the intersection of the core pin. Reducing or eliminating flash can avoid defects in the molded components that can lead to interruption of the flow path of the tubular structure and / or failure, for example, leakage, breakage, or rupture. In other prior art injection molding processes, a threaded core pin is used, but the core pin is not retained, which can result in flashing between the tubular structure and the core pin.

[0004] Furthermore, some conventional injection molding methods use a solid mandrel with a long length, e.g., a core pin that is a solid metal section, e.g., a mandrel that can be as long as 36 inches, so that the core pin extends from the mold die such that injection molding of the tubular structure requires a large press size. Furthermore, due to the length of the solid mandrel core pin, the core pin is difficult to manage, resulting in a complicated process for replacement of the core pin for overmolding tubular structures of different lengths. Furthermore, considering the long length of the core pin, the core pin is difficult to remove from the tubular structure, and therefore, any attempt to remove the core pin may cause damage to the tubular structure.

[0005] That is, conventional injection molding processes have problems with forming tubular structures with overmolded components; conventional molding equipment / molds do not adequately reduce or prevent flashing of liquefied material, and further, require the use of overmolding tooling that is difficult to manage because the overmolding tooling has a large footprint size and uses long core pins of solid core material that are difficult to manage, remove, and / or eject. Summary of the Invention

[0006] In one embodiment, a method for overmolding a tubular structure is provided that includes overmolding a polymer connector onto two or more polymeric tubular structures, each having an inner core pin, by applying a preload force to the two or more tubular structures to secure the inner core pin against movement within a first mold cavity during mating of a second mold cavity and injection molding of the connector.

[0007] In another embodiment, a method for overmolding a tubular structure includes inserting a core pin into the tubular structure to cause at least a portion of a body of the core pin to extend at least partially from the tubular structure, the core pin comprising a body and a flexible portion connected to the body, the flexible portion extending from the tubular structure. The method further includes clamping the tubular structure in a Z-direction and / or a retraction direction to a mold cavity structure using a retaining structure, the retaining structure including an angled portion, the flexible portion extending from the mold cavity structure. The method also includes injecting a thermoplastic material into a mold cavity of the mold cavity structure to overmold at least a portion of the tubular structure, the injecting of the thermoplastic material including contacting the portion of the core pin extending from the tubular structure with the thermoplastic material.

[0008] The details of one or more embodiments of the disclosure are set forth in the accompanying drawings and description, and in the claims.

[0009] Reference is made to the accompanying drawings which form a part of this disclosure and which illustrate embodiments in which the systems and methods described herein may be practiced. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a special forming tool according to one embodiment. [Diagram 2] 2 is a cross-sectional view of the special forming tool of FIG. 1 prior to connection of the upper and lower halves of the forming apparatus. [Diagram 3] 3 is a cross-sectional view of the retention structure of the special forming tool of FIG. 2 taken along line 3-3. [Figure 4] 2 is a cross-sectional view of the special forming tool of FIG. 1 when the upper and lower halves of the forming apparatus are connected. [Diagram 5] 2 is a cross-sectional view of a perspective view of the special forming tool of FIG. 1 with the upper and lower halves of the forming apparatus connected; FIG. [Figure 6] 2 is an enlarged cross-sectional view of the special forming tool of FIG. 1 with the upper and lower halves of the forming apparatus connected; FIG. [Figure 7] FIG. 2 is a perspective view of one embodiment of a retaining structure for the special forming tool of FIG. [Figure 8] 8 is an end view of an embodiment of a retention structure of the special forming tool of FIG. 7. [Figure 9] 2 is a cross-sectional view of another embodiment of a retention structure of the special forming tool of FIG. 1. FIG. [Figure 10] 2 is a perspective view of another embodiment of a core pin retention system for the special forming tool of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Like numbers refer to like features.

[0012] This application is related to U.S. patent application Ser. No. 62 / 274,357, entitled OVERMOLDED TUBUING CONNECTORS, the entirety of which is incorporated herein by reference.

[0013] The present disclosure relates to a method for forming an overmolded flexible substrate component on a tubular structure, and the overmolded tubular structure. More specifically, the present disclosure relates to a method for injection molding an overmolded component using a specialized overmolding tool, and an injection molded tubular structure having an overmolded component. The overmolded component can be a connector that is part of a connection assembly for transferring fluids from a chemical and / or biological process, etc., through several different tubes, fittings, and / or reservoirs. A specific injection molding method for forming a tubular structure in which the overmolded component is a connector is described below for a fluid connection assembly, but it is understood that such description is not intended to limit the scope of the present disclosure, but is provided as an embodiment thereof. For example, in one embodiment, the injection molding method can also be used to form connections for catheters, stents, tubes for other fluid assemblies, or other tubular structures having a hollow core portion with an overmolded component for transferring fluids.

[0014] 1 and 2 show an exemplary embodiment of a special tooling apparatus for overmolding to provide a tubular structure with an overmolded component having a hollow portion, for example, to form tubes, pipes, connectors for tubes and pipes, catheters, stents, or other similar tubular structures that may be used to transport fluids. In one embodiment, the injection molding process includes injecting a liquefied polymeric material to overmold at least one tubular structure, preferably to form an overmolded connector for two or more tubular structures. The injection molding process includes using a special tooling molding apparatus 10 including a lower half 20 and an upper half 30, which have complementary structures for injection molding. It will be appreciated that when the lower half 20 and the upper half 30 are connected or engaged, a sealed mold cavity is formed to receive the injected liquefied polymeric material to form an overmolded component or portion on the tubular structure.

[0015] The bottom half 20 of the molding apparatus 10 includes a bottom half mold cavity 22 for receiving at least one tubular structure 40 and a core pin 50. The bottom half mold cavity 22 includes one half of a predetermined shape for forming an overmolded component or part over the tubular structure 40 and the core pin 50. The bottom half 20 further includes at least one retaining structure 24 for clamping and / or holding the position of the tubular structure 40 to prevent movement of the tubular structure 40 during the injection molding process. Although FIGS. 1 and 2 show the use of two retaining structures 24, it is understood that the number of retaining structures 24 can vary depending on the number of tubular structures and / or whether a preload force is required for overmolding the tubular structures, as discussed further below. The bottom half 20 of the molding apparatus 10 can also include additional structures, such as guide sleeves, cooling systems, guide pins / plates, the disclosure of which is not necessary for an understanding of the present overmolding method.

[0016] The top half 30 of the molding apparatus 10 includes a top half mold cavity 32 having complementary halves of a predetermined shape for forming an overmolded component or portion over the tubular structure 40 and the core pin 50, an abutment structure 34 having a complementary shape, e.g., oppositely sloped surfaces, for engaging the holding structure 24, and a clamping portion 36 for clamping or holding the tubular structure, e.g., configured to hold or hold the tubular structure 40 in at least the Z direction and / or the retracted orientation during the injection molding process. The top half 30 of the molding apparatus 10 may also include additional structures, such as a die spring, a cooling system, guide pins or pillars, ejector pins / plates, positioning rings, thermoplastic inlet ports, etc.

[0017] The predetermined shape of the mold cavity can be any shape for forming an overmolded component or part over a tubular structure and a core pin, which is either prefabricated in the molding die or provided as an insert that is inserted into molding apparatus 10. For example, the shape can be for producing overmolded components for catheters, dilators, fasteners, needles, connectors, luers, hubs, cannulae, etc. In one embodiment, the overmolded part can have a shape for forming a sheath or balloon over a tube to form a catheter, or for forming a sheath over a cannula for a stent.

[0018] In one embodiment, the predetermined shape is a connector for a fluid connection system, the connector having at least two connector portions. The at least two connector portions extend from a center of the connector and have a first end connected to the center of the connector and a second end connected to a second open end of one of the plurality of tubes, and each of the at least two connector portions is formed with a conical taper, and an outer diameter of the first end at the center of the connector is larger than an outer diameter of the second end of the connector portion such that the connector portion is flexible. The connector portion is formed continuously with the tubular structure such that an internal flow passage is formed continuously between the connector portion and the tubular structure. Because the overmolded component is overmolded onto the tubular structure, the internal flow passage of the connector portion is complementary in configuration to an outer surface of the tubular structure such that the tubular structure can be at least partially disposed within the connector portion. Thus, the connector portions of the connector are fluidly connected to each other and to the plurality of tubular structures through the center of the connector. In this embodiment, the connector has an internal flow passage having an inner diameter equal to or similar to the inner diameter of the tubular structure, although it is understood that the connector can also have an internal flow passage having an inner diameter larger or smaller than the inner diameter of the tube depending on the requirements for transporting medical or biological fluids. That is, the size of at least the inner diameter of the connector and / or tubular structure is volume dependent, e.g., the connector can be sized to be used as a reducer, an expander, or a combination thereof.

[0019] The connectors may include strain relief portions to make the connectors more flexible. For example, each connector portion may include a plurality of rib sections disposed along an outer surface of the conically tapered connector portion. The plurality of rib sections may be disposed side-by-side along the length of the connector portion, with the outer diameter of the rib section disposed closest to or adjacent the center of the connector portion being greater than the outer diameter of the rib section disposed at the second end of the connector portion. Such a configuration allows the connector portions of the connector to further articulate, e.g., move, such that when the tubular structure is moved or adjusted, the connector portions articulate and / or bend, and the tubular structure is not stressed and restrictions in the flow path are prevented. That is, there is no kinking of the tubular structure and / or pinching or buckling of the tubular structure, thereby maintaining the transition of flow between the connector and the tubular structure, e.g., maintaining smooth flow bends along the flow path.

[0020] It is understood that the connectors can have different configurations, for example, the connectors can have four connector portions provided as a four-arm cross design, or the connectors can include multiple connector portions arranged as any combination of a four-arm cross mold design, a six-arm cross mold design (or star mold design), a T-shaped design, a Y-shaped design, an elbow mold design, or combinations thereof. The connector design configuration can be selected based on the number of bag assemblies that need to be filled, the layout of the bag assembly or processing equipment, or other design considerations. For example, the connectors can be configured as reducers, expanders, or combinations thereof when different sizes of tubing or components need to be connected.

[0021] The retaining structure 24 can be any device that provides a clamping or holding force at least in the Z direction and / or retraction direction, e.g., vertically and / or horizontally relative to the molding apparatus 10, to clamp and / or hold the position of the tubular structure 40 during the injection molding process. The retaining structure 24 can also be configured to hold the position of the core pin 50 or provide a preload force to the core pin 50 during the injection molding process. For example, in one embodiment, the retaining structure 24 can include an upper half and a lower half, with at least the lower half being connected to or otherwise disposed in the lower half 20 of the molding apparatus 10, e.g., in a cavity or opening that can be secured to the lower half 20 using an insert, screw, pin, or the like. The upper and lower halves of the retaining structure 24 can be joined together using screws, bolts, latches, or other fastening devices to engage them. Thus, when the upper and lower halves of the retaining structure 24 are fastened or attached to one another, the inner surface of the retaining structure 24 clamps and / or holds the tubular structure 40 to provide a force in the Z direction and / or retraction direction to maintain alignment of the tubular structure 40. The retaining structure 24 may also include an angled portion 25 on the upper half for engaging with the abutment structure 34 of the upper half 30 of the molding apparatus 10, and a spring 220 on the lower half of the retaining structure 24 that abuts the lower half 20 of the molding structure 10. It is understood that the angled portion 25 of the retaining structure has a surface that is inclined between 5 and 80 degrees, preferably 10 and 40 degrees, relative to a plane perpendicular to the retaining structure. The angle of inclination of the angled portion 25 of the retaining structure 24 may depend on the predetermined amount of force applied to the core pin required to maintain alignment of the core pin during the injection molding process and to counteract the molding pressure exerted by the pressurized liquefied polymeric material.

[0022] In one embodiment, a core pin 50 having a body or mandrel 211 and a flexible portion 212 connected to the body 211 can be used with the molding apparatus 10. The body 211 of the core pin 50 can have a tapered configuration, for example, one end of the body 211 has a diameter larger than the diameter of the remainder of the body 211. The body 211 having a tapered configuration can include indicia or boundaries to aid in positioning the body 211 within the tubular structure 40 such that a majority of the body 211 is inserted into the tubular structure 40 and a portion of the body 211 extends at least partially out of the tubular structure 40. The indicia or boundaries can correspond to a portion of the body 211 having a larger diameter than the remainder of the body to form a fluid-tight seal between the body 211 of the core pin 50 and the hollow portion of the tubular structure 40. In one embodiment, the flexible portion 212 also extends out of the tubular structure 40 such that a majority of the body 211 is positioned or oriented within the tubular structure 40.

[0023] In one embodiment, the taper of the body 211 is provided such that the portion of the body 211 having a smaller diameter is at least partially disposed within an undercut region of the retention structure 24, which is understood to have an inner surface having a different shape than the remainder of the retention structure 24 such that the tubular structure 40 is at least partially deformed within the undercut region. For example, as seen in FIG. 3, the tubular structure 40 has an outer surface having an initial shape A that is substantially circular. However, when the undercut region of the retention structure 24 is closed, the tubular structure 40 is at least partially deformed to have a different outer surface shape B, e.g., flattened, that is different from the shape of the outer surface of the tubular structure not disposed within the retention structure 24, which increases the frictional engagement between the retention structure 24, the tubular structure 40, and the body 211 of the core pin 50. Thus, not only does the undercut area of ​​the retaining structure 24 hold the tubular structure against backflow from the mold pressure during the injection molding process by providing an interference fit, but the retention and deformation of the tubular structure 40 provides a sealing effect that prevents liquefied material from the injected thermoplastic material from entering the retaining structure 24. In one embodiment, a taper of the body 211 of the core pin 50 can also be provided such that a portion of the body 211 having a larger diameter is located in the area between the retaining structure 24 and the mold cavity to further provide a sealing effect that prevents liquefied material from entering the retaining structure 24.

[0024] To further facilitate sealing of the retention structure 24 from the liquefied material, the shape of the inner surface of the retention structure 24 at one end of the tubular structure 40 may be different than the shape of the molding surface of the mold cavity 22 adjacent to the retention structure 24, e.g., the transition between the retention structure 24 and the mold cavity 22 / 32 for forming the overmolded component. For example, the inner surface of the retention structure 24 may be more oval, while the molding surface is more circular. Thus, when the top half 30 is joined with the bottom half 20 of the molding apparatus, the tubular structure 40 has a different outer surface shape between the mold cavity 22 and the retention structure 24 to further seal the liquefied material within the mold cavity of the molding apparatus 10.

[0025] Body 211 may be made from stainless steel, copper, titanium, nickel, aluminum, tungsten carbide, steel nitride, flexible nitinol, alloys thereof, and combinations thereof. It is understood that body 211 may include coatings, surface texturing, etc. to aid in positioning and guiding body 211 within tubular structure 40.

[0026] The flexible portion 212 can be a wire, flexible tube, or cable made from hard plastic, steel, stainless steel, aluminum, alloys thereof, multiple steel cords or wires, and the like. The flexible portion 212 can include a bulleted end for insertion into a tubular structure and / or to aid in removing or ejecting the core pin 50 from the tubular structure 40. It is understood that because the core pin 50 includes at least the flexible portion 212, the size and / or footprint occupied by the injection mold / device can be reduced, the length of the core pin can be adjusted to allow overmolding of tubular structures of various lengths, and the length of the core pin can be managed, providing an improvement over the conventional design of the injection mold / device. That is, in the conventional design of the injection mold / device, various steel core pins or mandrels having various lengths, e.g., 6 inches, 1 foot, and up to 3 feet, were provided for overmolding of tubular structures of various lengths. A core pin or mandrel made from a solid metal section was inserted into the tubular structure and braced to prevent the core pin or mandrel from being displaced from the tubular structure during the injection molding process, so that one end of the core pin or mandrel extended from the tubular structure and the injection molding apparatus. The length of the solid metal core pin or mandrel not only increased the size of the footprint of the molding apparatus, but also resulted in a complicated process for managing the use of the core pin or mandrel with the tubular structure.

[0027] On the other hand, in one embodiment, because the core pin 50 of the present disclosure includes a flexible portion 212, the core pin can be used with a tubular structure of potentially infinite length, depending on, for example, the length of the flexible portion, since only the body of the core pin 50 is clamped and positioned in or near the mold cavity and subjected to molding pressure during the injection molding process. Furthermore, because the flexible portion 212 is used for insertion into the tubular structure and positioning of the body 211 of the core pin 50, the core pin 50 is easier to install and manage than a traditional solid steel mandrel. Furthermore, the flexible portion 212 can be wrapped or otherwise positioned using a retention system, for example wrapped around a spool or clamped or clipped to the side of a molding apparatus, such that the flexible portion 212 does not interfere with the molding die / device during the injection molding process, providing a more compact molding apparatus, for example a smaller molding apparatus, in which the footprint of the press size may be minimized.

[0028] With reference to Figures 1-4, one embodiment of a method for overmolding a tubular structure using a special tool molding apparatus 10 is described below. Although the figures show a completed tubular structure and overmolded components forming a fluid connector to more easily understand the present disclosure, the following description is directed to a general method for forming the overmolded components. Furthermore, since the left and right sides of the molding apparatus 10 are similar in structure and function, a description of one side is provided herein. The injection molding process can also be used to overmold tubular structures for various products without departing from the scope of the present disclosure.

[0029] First, the tubular structure 40 is prepared by inserting a core pin 50 into the tubular structure 40. For example, the flexible portion 212 can be inserted into the tubular structure 40 and pulled through the tubular structure 40 such that the body 211 of the core pin 50 engages within the hollow portion of the tubular structure 40. Thus, as the flexible portion 212 of the core pin 50 is pulled through the tubular structure 40, the tubular structure 40 engages the body 211 until one end of the tubular structure 40 is located or aligned, for example, near a marking or boundary on the body 211.

[0030] After the core pin 50 is inserted into the tubular structure 40, the combined tubular structure 40 and core pin 50 are positioned within the lower half mold cavity 22. The retaining structure 24 is then closed to clamp at least a portion of the body 211 of the core pin 50 and the tubular structure 40 by providing a force in at least the Z direction and / or retraction direction to clamp and / or hold the tubular structure 40 within the lower half 20 of the molding apparatus 10. For example, the closure of the retaining structure 24 provides an interference fit to maintain the alignment of the tubular structure as described above, e.g., the tubular structure is deformed to increase the frictional engagement between the retaining structure 24, the tubular structure 40, and the core pin 50.

[0031] In a further step, the top half 30 is joined with the bottom half 20 of the molding apparatus 10 as shown in FIG. 4 to form a sealed mold cavity for overmolding the tubular structure 40 and the core pin 50 in a predetermined shape. For example, in one embodiment, the thermoplastic material is fed and injected such that the thermoplastic material contacts at least a portion of the core pin extending from the tubular structure and the outer surface of the tubular structure in the sealed mold cavity, such that the overmolded component includes a hollow portion in fluid communication with the tubular structure. The thermoplastic material is fed from a hopper and can be melted and fed at a molding pressure between 5,000-50,000 PSIG, preferably around 10,000 PSIG. The thermoplastic material can be selected from a variety of thermoplastic polymers and / or thermosetting elastomers such that the tubular structure and the overmolded portion are flexible. For example, the tubular structure and overmolded portion can be formed from a thermoplastic polymer selected from the group consisting of fluoropolymers, polyurethanes, vulcanizates, flexible polyvinyl chloride (PVC), thermoplastic elastomers (TPE), high density polyethylene (HDPE), ethylene-vinyl acetate (EVA), copolymers / polyolefins, high impact polystyrene (HIPS), polypropylene (PP), acrylonitrile butadiene styrene (ABS), polytetrafluoroethylene (PTFE, or ETFE), or blends thereof, or thermoset elastomers such as liquid silicone rubber (LSR) or blends thereof. Thus, the tubular structure and overmolded components can be made from materials that remain flexible even at cryogenic temperatures, e.g., −196° C. The tubular structure and the connector can be made from the same or different materials, but are generally made from materials that are physically compatible, e.g., the tubular structure and the overmolded component have similar or identical thermal expansion / contraction coefficients, similar melting temperatures and flow characteristics, the same chemical resistance or compatibility, and / or other properties necessary for the application of the fluid connection assembly, such as UV protection.The tubular structure and overmolded components can also be made from materials that are relatively inert, eg, do not leach or significantly absorb pharmaceuticals or biological fluids, and / or are non-reactive.

[0032] After the overmolded component or portion 430 is formed contiguously with the tubular structure 40 and solidifies, the top half 30 of the molding apparatus 10 can be separated from the bottom half 20, and the tubular structure 40 and the overmolded portion 430 can be removed from the holding structure 24 and the mold cavity. The core pin 50 can then be removed and / or ejected from the tubular structure 40 by engaging the flexible portion 212 of the core pin 50 and providing a force in the X direction away from the overmolded portion 430. The tubular structure 40 with the overmolded portion can be engaged, for example, using a holding device that clamps around the overmolded portion 430 and provides a force in the opposite direction to that provided to the flexible portion 212. In one embodiment, a device or tool having slits and / or openings can be used to engage the rounded end of the flexible portion 212 for that engagement to aid in the removal of the core pin 50 from the tubular structure 40.

[0033] In another embodiment, an additional step of generating a preload force on the tubular structures and the core pin is provided. For example, the molding apparatus of Figures 1-4 can be used to manufacture a fluid connection assembly having a plurality of tubes or tubular structures and an overmolded connector connecting the plurality of tubes or tubular structures. For example, the method includes overmolding a polymer connector onto two or more polymeric tubular structures, each having an inner core pin, by applying a preload force to the two or more tubular structures to secure the inner core pin from moving in the first mold cavity during mating and injection molding of the second mold cavity to form an overmolded connector.

[0034] For example, similar to the method described above, a first tubular structure 40 is prepared by first inserting a first core pin 50 having a first body or mandrel 211 and a first flexible portion 212 into the first tubular structure 40. The first flexible portion 212 is inserted into and pulled through the first tubular structure 40 such that the first body 211 of the first core pin 50 is engaged within the hollow portion of the first tubular structure 40. As the first flexible portion 212 of the first core pin 50 is pulled through the first tubular structure 40, the first tubular structure 40 engages with the first body 211 until one end of the first tubular structure 40 is positioned at or near a marking or boundary on the first body 211. The first flexible portion 212 also extends from the first tubular structure 40 , with the majority of the first body 211 disposed or oriented within the first tubular structure 40 .

[0035] Similarly, the second tubular structure 40 is prepared by inserting a second core pin 60 having a second body and a second flexible portion into the second tubular structure 40 such that at least a portion of the second body of the second core pin 60 extends at least partially from the second tubular structure 40. The second body having a tapered configuration may also include indicia or boundaries to aid in positioning the second body within the second tubular structure 40 such that a majority of the second body is inserted into the second tubular structure 40 and a portion of the second body extends at least partially from the second tubular structure 40. In one embodiment, the second flexible portion also extends from the second tubular structure 40 and a majority of the second body is positioned or oriented within the second tubular structure 40. It will also be appreciated that in one embodiment, the second core pin may connect two tubular structures 40 by extending the second body to connect both tubular structures 40.

[0036] The combined first core pin 50 and first tubular structure 40, and the combined second core pin 60 and second tubular structure 40, can then be positioned within the lower mold cavity 22 such that one end of the first core pin 50 in the first tubular structure 40 abuts the second core pin 60 in the second tubular structure 40 to form an intersection or abutment between the core pins in a central portion of the mold cavity. For example, in one embodiment, one end of the first core pin 50 has a shape that corresponds to the outer surface shape of the second core pin 60, e.g., a crescent shaped end that can engage and align the first core pin 50 with the circular tubular outer surface of the second core pin 60. That is, the second core pin 60 may include a body that traverses the entirety of the mold cavity and connects the two tubular structures 40 to provide a junction, such as an exterior surface of the body of the core pin, forming a junction or intersection where one end of the first core pin 50 is joined with the second core pin 60. It is understood that the end of the first core pin may have other geometries or shapes, such as butt or block ends, C-shapes, pins, star shapes, etc., that engage with corresponding geometries or shapes on the second core pin 60 to align the first core pin 50 and second core pin 60.

[0037] 2, the first tubular structure 40 and first core pin 50 may then be clamped to the lower half 20 of the molding apparatus 10 by closing the retaining structure 24. It will be appreciated that clamping the first tubular structure to the first core pin also increases the engagement between the first core pin and the first tubular structure by applying a force in at least the Z direction and / or retraction direction to clamp and / or retain the first tubular structure 40 within the lower half 20 of the molding apparatus 10, e.g., providing an interference fit to at least maintain alignment of the first tubular structure with the first core pin.

[0038] In one embodiment, the first body 211 can be tapered such that the portion of the first body 211 having a smaller diameter is at least partially disposed within an undercut region of the retaining structure 24, and the undercut region can have an inner surface having a different shape than the remainder of the retaining structure such that the first tubular structure 40 is at least partially deformed within the undercut region. Thus, not only does the undercut region of the retaining structure 24 hold the first tubular structure 40 to prevent backflow of the first tubular structure 40 against molding pressure during the injection molding process by providing an interference fit, but the holding and deformation of the first tubular structure 40 provides a sealing effect to prevent liquefied material from entering the retaining structure 24 during the injection molding process. In one embodiment, the taper of the first body 211 of the first core pin 50 can also be provided such that the first body 211 having a larger diameter is disposed in the region between the retaining structure 24 and the mold cavity to further provide a sealing effect to prevent liquefied material from entering the retaining structure 24.

[0039] To further facilitate sealing of the retention structure 24 from the liquefied material, the shape of the inner surface of the retention structure 24 at one end of the first tubular structure 40 may be different from the shape of the molding surface of the mold cavity 22 adjacent to the retention structure 24, such as the transition between the retention structure 24 and the mold cavity 22 / 32 to form an overmolded component. Thus, when the top half 30 is joined with the bottom half 20 of the molding apparatus, the first tubular structure 40 has a different outer surface shape between the mold cavity 22 and the retention structure 24 to further seal the liquefied material within the mold cavity of the molding apparatus 10.

[0040] In a further step, the top half 30 is joined with the bottom half 20 of the molding apparatus 10 to form a sealed mold cavity for overmolding the first and second tubular structures in a predetermined shape, e.g., with connectors, as shown in FIG. 4. In one embodiment, the top half 30 includes a clamping portion 36 for clamping and holding the second tubular structure 40 in at least the Z direction and / or the retraction direction within the molding apparatus. The clamping portion 36 can have the same or similar features as the holding structure 24, e.g., undercut areas or deformed portions, for example, to have an inner surface shape different from the mold cavity and / or another portion of the clamping portion 36 to clamp and / or hold the second tubular structure and to prevent liquefied material from the injected thermoplastic material from entering the clamping portion 36.

[0041] When the top half 30 is joined with the bottom half 20 of the molding apparatus 10, the abutment structure 34 of the top half 30 engages the inclined surface 25 of the retaining structure 24 of the bottom half 20, and a preload force is generated on the first core pin 50 in the X direction toward the second core pin 60. For example, as seen in FIG. 2, a gap "g" is provided between the retaining structure 24 and the mold cavity 22 of the molding apparatus 10, and as seen in FIGS. 5 and 6, the retaining structure includes a bolt 220 provided in a cavity of the lower half of the retaining structure that abuts the bottom half 20 of the mold cavity 22. When the spring 220 is in a relaxed state, the spring 220 maintains the clearance or distance of the gap "g". When the top half 30 is joined to the bottom half 20 of the molding apparatus 10, the abutment structure 34 engages the inclined portion 25 of the holding structure 24, and the holding structure 24 moves or slides in the X direction, compressing the spring 240, as seen in Figures 4, 5 and 6. The predetermined total preload force is provided when the spring is fully compressed, e.g., when the gap "g" is near or reduced to zero, e.g., when the separation between the molding apparatus and the holding structure is closed or almost nonexistent. The initial gap distance "g" is provided at a distance of 0.001 inches to 0.10 inches, preferably about 0.03 inches, so that the holding structure 24 can be moved or slid toward the mold cavity to generate the required amount of preload force. Thus, the holding structure 24 clamps or holds the first tubular structure 40 together with the first core pin 50, so that the first core pin 50 in the first tubular structure is subjected to a preload force. Thus, the first core pin 50 is maintained and / or abutted against the second core pin 60 at their intersection in the mold cavity even under molding pressure during the injection molding process. The gap "g" can also be provided to create timing of advancement of the retaining structure 24 during mating of the top half 30 and bottom half 20 of the molding apparatus 10, for example, a gradual increase in preload force between the first core pin 50 and second core pin 60 is provided as the top half 30 is mated with the bottom half 20 until a full preload force is provided. It is understood that in one embodiment, the top half 30 of the molding apparatus 10 can include a spring and compression device to prevent vertical movement of the retaining structure 24 during mating of the top half 30 and bottom half 20 of the molding apparatus 10.It will also be appreciated that the gap "g" and the angle of inclination of the angled portion 25 of the retaining structure 24 can be adjusted together to provide the predetermined amount of force (or incremental amounts of force) applied to the core pin needed to maintain alignment of the core pin during injection molding and counter the molding pressure applied by the pressurized liquefied polymeric material. That is, the retaining structure 24 can be designed and configured with the appropriate angle of inclination of the angled portion and gap "g" depending on the amount of predetermined force needed to counter the molding pressure, the material of the tubular structure, the material of the polymeric material being injected, etc.

[0042] A thermoplastic material is then fed and injected into the mold cavity formed from the lower mold cavity 22 and the upper mold cavity 32 such that the thermoplastic material contacts at least a portion of the first core pin extending from the first tubular structure and the second core pin extending from the second tubular structure to overmold the core pins and the tubular structures and form a connector fluidly connecting the first tubular structure and the second tubular structure. The thermoplastic material is fed from a hopper and can be melted and fed at a pressure between 5,000-50,000 PSIG, preferably around 10,000 PSIG. The thermoplastic material can be selected from a variety of thermoplastic polymers and / or thermosetting elastomers such that the tubular structures and the overmolded portion are flexible. For example, the tubular structure and overmolded portion can be formed from a thermoplastic polymer selected from the group consisting of fluoropolymers, polyurethanes, vulcanizates, flexible polyvinyl chloride (PVC), thermoplastic elastomers (TPE), high density polyethylene (HDPE), ethylene-vinyl acetate (EVA), copolymers / polyolefins, high impact polystyrene (HIPS), polypropylene (PP), acrylonitrile butadiene styrene (ABS), polytetrafluoroethylene (PTFE, or ETFE), or blends thereof, or thermosetting elastomers such as liquid silicone rubber (LSR) or blends thereof. Thus, the tubular structure and overmolded portion can be made from a material that remains flexible even at cryogenic temperatures, e.g., −196° C. The tubular structure and connectors can be made from the same or different materials, but are generally made from materials that are physically compatible, e.g., the tubular structure and overmolded portion have similar or the same thermal expansion / contraction coefficients, similar melting temperatures and flow properties, the same chemical resistance or compatibility, and / or other properties required for the application of the fluid connection assembly, such as UV blocking properties. The tubular structure and overmolded portion can also be made from materials that are relatively inert, eg, do not leach or significantly absorb pharmaceuticals or biological fluids, and are non-reactive.

[0043] After the overmolded portion 430 is formed continuously with the tubular structure 40 and solidified, the upper half 30 of the molding apparatus 10 can be separated from the lower half 20, and the tubular structure 40 and the overmolded portion 430 can be removed from the holding structure 24 and the molding apparatus 10. Once the upper half 30 is separated from the lower half, the spring 220 can return the holding structure 24 to a neutral or initial position to provide a subsequent preload force to a subsequent core pin for a subsequent overmolding operation. The first core pin 50 can then be removed and / or ejected from the first tubular structure 40 by engaging the flexible portion 212 of the first core pin 50 and providing a force in the X direction away from the overmolded portion 430. The second core pin 60 can then be removed and / or ejected from the second tubular structure 40 by engaging the flexible portion 212 of the second core pin 60 as described in the above embodiment.

[0044] The overmolding tooling can then be used to form subsequent overmolding operations, such as spine assemblies for fluid connection assemblies. Specifically, the tooling and overmolding method allow for the formation of connectors on tubular structures in a one-step molding operation, such that after at least one tubular structure has been overmolded with a connector, additional tubular structures can be placed and then overmolded by the steps described above. With such features, repeatable structures can be formed without inclusions, blockages or obstructions, thereby providing a continuous flow path within the tubular structures and overmolded connectors without the deficiencies of prior art injection molding processes.

[0045] Thus, a special tooling apparatus and method for overmolding tubular structures is provided that has several advantages over conventional injection molding processes. For example, in one embodiment, a specific slide carrier method is provided that can generate a preload force on the core pins and / or maintain the alignment of the tubular structure, avoiding substantial deformation of the tubular structure. That is, the core pins at the intersections / junctions between the core pins are preloaded with a force in the X direction, so that the core pins are held and positioned during the injection molding process to reduce and / or prevent flashing, e.g., intrusion of thermoplastic material into the tubular structure, by preventing separation of the core pins. Thus, inclusions, blockages, or obstructions of the flow paths of the connector and tubular structure are mitigated or eliminated, thereby providing a continuous flow path inside the tubular structure and overmolded connector.

[0046] In other words, the methods described herein for forming an overmolded component on a tubular structure using the methods and / or molding apparatus described herein have the advantage of at least forming an overmolded component having flow paths that are free of blockages, inclusions, and / or obstructions between the overmolded component and the tubular structure, e.g., little or no defects in the molded component that may lead to failure, e.g., leakage, breakage, or rupture. Thus, the method of forming an overmolded component on a tubular structure avoids the creation of pockets that may accumulate fluids and result in contamination and cell failure, e.g., the internal flow paths are smooth, or avoid failure, while maintaining sufficient pulling force. Furthermore, it has been surprisingly found that in some embodiments, because the connector and the tubular structure are formed sequentially, if the connector and the tubular structure are made from the same or similar materials, e.g., have the same or similar thermal properties, the fluid connection assembly formed therefrom can be used in cryogenic processes while maintaining the structural integrity of the system, e.g., leakage and / or contamination is prevented. For example, the connector can withstand impact testing at -196°C, freeze drop testing at -195°C, and can be used in freeze-thaw applications.

[0047] Although the above has been described with respect to the retaining structure 24 for clamping a first tubular structure, it will be appreciated that various variations of the retaining structure can be used in which the retaining structure 24 can be provided to clamp a portion of a tubular structure and / or a core pin that requires movement of the retaining structure 24 to provide a pressure force, for example a core pin that engages with the outer surface or end of another core pin.

[0048] 7, in one embodiment, the retaining structure 24 may include a clam shape or hinge design. The retaining structure 24 includes a hinge 710 and a pivot hole 715 connected to the hinge 710, allowing the top half 740A of the retaining structure 24 to open to insert the tubular structure 40 and close with the bottom half 740B to clamp or hold the tubular structure 40. The top half 740A may be coupled to the bottom half 740B using a mechanical locking system, such as a lever latch, pin, screw, or similar mechanical locking device that allows for locking and releasing of the top half 740A from the bottom half 740B.

[0049] In one embodiment, as shown in FIG. 8, the hinge 810 includes a slot 820 that allows the upper half 840A to be raised and lowered relative to the lower half 840B. For example, the pivot pin 815 can be raised and lowered within the slot 820, thereby raising the upper half 840A to accommodate the tubular structure 40 between the upper half 840A and the lower half 840B. The upper half 840A and the pivot pin 815 can then be lowered to clamp and / or retain the tubular structure 40 within the retaining structure 24. It is understood that the receiving space between the upper half 840A and the lower half 840B can have an inner surface with a different shape for clamping and / or retaining the tubular structure 40. For example, in one embodiment, the containment space has a non-circular profile, e.g., a circularity of 0.9 to 0.99 and / or a circularity of 0.95 to 1.1, such that the tubular structure at least partially deforms when the top half 840A is in a clamped position with the bottom half 840B, so that the tubular structure has an outer surface shape, e.g., a flattened shape, that is different from the initial outer surface shape of the tubular structure to seal the clamped portion of the tubular structure from the injected thermoplastic material. In a preferred embodiment, the containment space has a rounded shape at the top half 840A and the bottom half 840B of the holding structure 24. However, the containment space can have other surface shapes that allow deformation of the tubular structure 40 to clamp the tubular structure 40 to the molding apparatus 10 without damaging the outer surface of the tubular structure 40. It is understood that in any of the embodiments, the shape of the inner surface of the holding structure 24 can depend on many factors, such as the malleability of the tubular structure, the pressure of the injection molding device, and the amount of predetermined force required for the core pin.

[0050] In another embodiment, as seen in FIG. 9, the retaining structure 24 includes a collet 924 that is provided around the tubular structure 40 after the core pin 50 is installed. The collet 924 is a compressible collar made of hard plastic or steel. The collet 924 can be provided against the outer end of the retaining structure 24 or within the internal cavity of the retaining structure 24. Thus, when the retaining structure 24 is moved or slid in the X direction, the collet 24 is compressed and engages the tubular structure 40 and the core pin 50. Thus, when the retaining structure 24 is engaged by the abutment structure of the upper half of the molding apparatus 10, the retaining structure 24 is slid or moved toward the molding apparatus to compress the spring 240, and the collet 924 is compressed and slid to provide a preload force to the core pin 50, so that one end of the core pin 50 maintains engagement with the second core pin at the intersection in the mold cavity during the injection molding process.

[0051] In one embodiment, the retaining structure 24 can include additional structures or components to increase frictional contact between the retaining structure and the tubular structure. For example, a film such as silicone or rubber can be applied to the clamping portion of the retaining structure 24, or a rigid plastic material can be provided between the clamping portion and the tubular structure.

[0052] Furthermore, as described above, since the core pin includes a flexible portion, it is understood that the core pin can be used to accommodate various lengths for overmolding tubular structures, since the body is the only part of the core pin that is clamped and held by the molding device during injection molding. Since the flexible portion is flexible, e.g., a wire, flexible tube, cable, etc., the flexible portion can be moved or wrapped using a holding system to reduce the footprint size of the molding device. Thus, the flexible portion does not interfere with the molding die / device during the injection molding process, e.g., the flexible portion can be wrapped around a spool or clamped or clipped on the side of the molding device to provide a more compact molding device, e.g., a smaller molding device, in which the footprint of the press size can be minimized.

[0053] For example, in one embodiment, as seen in FIG. 10, the tubular structure 40 having the core pin 50 is positioned within the retaining structure 24 and the lower half mold cavity 22 such that the flexible portion 212 of the core pin 50 extends from the molding apparatus 10. The flexible portion 212 can then be guided or otherwise held within a spool 1060 provided on the outer portion of the clamping apparatus 10. Thus, the flexible portion 212 of the core pin 50 can be positioned or moved to be stored out of the way to provide a more compact molding apparatus. It will be appreciated that in other embodiments of the invention, the flexible portion 212 can also be guided or otherwise held by a clamp or retaining ring or the like provided on the outer portion of the clamping apparatus 10.

[0054] Aspects: Any of the embodiments 1 to 12 can be combined with any of the embodiments 13 to 17, or vice versa.

[0055] Aspect 1. A method for overmolding a tubular structure, comprising: inserting a core pin into the tubular structure to cause at least a portion of a body of the core pin to extend at least partially from the tubular structure, the core pin comprising a body and a flexible portion connected to the body, the flexible portion extending from the tubular structure; clamping the tubular structure to a mold cavity structure in a Z direction and / or a retraction direction using a retaining structure, the retaining structure comprising an inclined portion, the flexible portion extending from the mold cavity structure; and injecting a thermoplastic material into a mold cavity of the mold cavity structure to overmold at least a portion of the tubular structure, the injecting comprising contacting the thermoplastic material with a portion of the core pin extending from the tubular structure.

[0056] Embodiment 2. The method of embodiment 1, wherein the flexible portion of the core pin is a wire, a flexible tube, or a cable.

[0057] Embodiment 3. A method according to any of embodiments 1-2, wherein the body of the core pin has a tapered structure and indicia on the body of the core pin, and inserting the core pin includes inserting a flexible portion of the core pin into the tubular structure and aligning one end of the tubular structure with the indicia on the body of the core pin, and / or the body includes a portion having a diameter smaller than a diameter of the body of the core pin, the portion having the smaller diameter corresponding to a portion of the tubular structure in the retaining structure.

[0058] Embodiment 4. The method of any of embodiments 1-3, further comprising removing the core pin from the tubular structure by engaging a flexible end of the core pin.

[0059] Embodiment 5. The method of any of embodiments 1-4, wherein clamping the tubular structure to the mold cavity structure includes at least partially deforming the tubular structure such that the tubular structure has an outer surface shape that is different from an initial outer surface shape of the tubular structure, thereby sealing the clamped portion of the tubular structure from the injected thermoplastic material.

[0060] Embodiment 6. The method of any one of embodiments 1-5, wherein the inner surface shape of the portion of the retaining structure that contacts the outer surface of the tubular structure is different from the shape of the molding surface of the mold cavity adjacent to the retaining structure.

[0061] Aspect 7. The method of any of aspects 1-6, further comprising: inserting a second core pin into the second tubular structure to abut the core pin in the tubular structure against the second core pin in the second tubular structure to form an intersection; and during joining of the halves of the mold cavity structure, preloading the clamped tubular structure by engagement of the retaining structure to provide a preload force in the X direction toward the mold cavity structure to the clamped tubular structure, preloading the core pin in the tubular structure against the second core pin, and maintaining the core pin abutting the second core pin during injection of the thermoplastic material, wherein the engagement of the retaining structure includes mating an abutment structure with the retaining structure, the abutment structure including a structure complementary to the angled portion of the retaining structure during joining of the halves of the mold cavity structure; and wherein the injection of the thermoplastic material into the mold cavity further comprises overmolding the tubular structure and the second tubular structure to form a connector fluidly connecting the tubular structure and the second tubular structure.

[0062] Embodiment 8. The method of embodiment 7, wherein precompressing the clamped tubular structure comprises sliding the retaining structure in the X direction toward the mold cavity structure.

[0063] Embodiment 9. The method of embodiment 8, wherein the sliding of the retaining structure includes compressing a spring in the retaining structure against the mold cavity structure, such that when the mold cavity halves are separated, the spring returns the retaining structure to a neutral position.

[0064] Aspect 10. The method of any of aspects 7-9, wherein the connector comprises at least two connector portions, each of the at least two connector portions extending from a center of the connector and having a first end connected to the center of the connector and a second end connected to a second open end of one of the plurality of tubes, and each of the at least two connector portions is formed with a conical taper, and an outer diameter of the first end at the center of the connector is greater than an outer diameter of the second end of the connector portion such that the connector portions are flexible.

[0065] Embodiment 11. The method of any of embodiments 7-10, wherein the core pin of the tubular structure has a shape corresponding to the shape of the outer surface of the second tubular structure.

[0066] Embodiment 12. The method of any of embodiments 7-11, wherein preloading the core pin in the tubular structure against the second core pin comprises sliding the retaining structure in the X direction toward the mold cavity structure by 0.001 inches to 0.10 inches, preferably about 0.03 inches.

[0067] Aspect 13: A method comprising overmolding a polymer connector onto two or more polymeric tubular structures, each having an internal core pin, by applying a preload force to the two or more tubular structures to secure the internal core pin from moving within a first mold cavity during mating of a second mold cavity and injection molding of the connector.

[0068] Aspect 14. The method of claim 13, wherein the diameter of the inner core pin subjected to the preload force is smaller than the diameter of the body of the core pin such that the inner core pin is not displaced from the other inner core pin during injection molding, and the preload force is provided such that one of the two or more polymeric tubular structures can slide in the X direction toward the other inner core pin.

[0069] Embodiment 15. The method of any of embodiments 13-14, wherein the force preloading includes clamping the tubular structure to the mold cavity structure in the Z direction and / or the retraction direction using a retaining structure, and the retaining structure includes a slope.

[0070] Aspect 16. The method of aspect 15, wherein the force preloading includes preloading the clamped tubular structure by engaging a retaining structure during joining of the first mold cavity and the second mold cavity to provide a preload force in the X direction on the clamped tubular structure toward the mold cavity structure.

[0071] Embodiment 17. The method of embodiment 16, wherein precompressing the clamped tubular structure comprises sliding the retaining structure in the X direction toward the first mold cavity and the second mold cavity.

[0072] The examples disclosed in this application should be considered in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the appended claims, rather than the foregoing description, and all modifications that come within the meaning and scope of the claims are intended to be embraced therein.

Claims

1. 1. A method for overmolding a tubular structure, comprising: inserting a core pin into the tubular structure such that at least a portion of a body of the core pin at least partially extends from the tubular structure, the core pin comprising the body and a flexible portion connected to the body, the flexible portion extending from the tubular structure; clamping the tubular structure to a mold cavity structure in a Z direction and / or a retraction direction using a retaining structure, the retaining structure including an inclined portion and the flexible portion extending from the mold cavity structure; injecting a thermoplastic material into a mold cavity of the mold cavity structure to overmold at least a portion of the tubular structure, the injecting including contacting the thermoplastic material with the portion of the core pin extending from the tubular structure; A method comprising:

2. The method of claim 1 , wherein the flexible portion of the core pin is a wire, a flexible tube, or a cable.

3. the body of the core pin has a tapered configuration and indicia on the body of the core pin, and the inserting of the core pin includes inserting the flexible portion of the core pin into the tubular structure and aligning one end of the tubular structure with the indicia on the body of the core pin; and / or The method of claim 1 , wherein the body includes a portion having a diameter smaller than a diameter of the body of the core pin, the portion having the smaller diameter corresponding to a portion of the tubular structure in the retaining structure.

4. The method of claim 1 , further comprising removing the core pin from the tubular structure by engaging the flexible end of the core pin.

5. 2. The method of claim 1 , wherein the clamping of the tubular structure to the mold cavity structure includes at least partially deforming the tubular structure such that the tubular structure has an outer surface shape that is different from an initial outer surface shape of the tubular structure to seal the clamped portion of the tubular structure from the injected thermoplastic material.

6. The method of claim 1 , wherein an inner surface shape of the portion of the retaining structure that contacts the outer surface of the tubular structure is different from a molding surface shape of the mold cavity adjacent the retaining structure.

7. inserting a second core pin into a second tubular structure such that the core pin in the tubular structure abuts the second core pin in the second tubular structure to form an intersection; preloading the clamped tubular structure by engagement of the retaining structure during joining of the halves of the mold cavity structure to provide a preload force in an X direction towards the clamped tubular structure, preloading the core pin in the tubular structure against the second core pin, and maintaining the core pin in abutment against the second core pin during the injection of the thermoplastic material, wherein the engagement of the retaining structure includes engaging an abutment structure with the retaining structure during the joining of the halves of the mold cavity structure, the abutment structure including a structure complementary to the angled portion of the retaining structure. Further comprising: and wherein the injecting of the thermoplastic material into the mold cavity further comprises overmolding the tubular structure and the second tubular structure to form a connector fluidly connecting the tubular structure and the second tubular structure. The method of claim 1.

8. The method of claim 7 , wherein the pre-compressing the clamped tubular structure comprises sliding the retaining structure in the X direction toward the mold cavity structure.

9. 9. The method of claim 8, wherein the sliding of the retaining structure includes compressing a spring within the retaining structure against the mold cavity structure, the spring returning the retaining structure to a neutral position when the halves of the mold cavity are separated.

10. 8. The method of claim 7, wherein the connector comprises at least two connector portions, each of the at least two connector portions extending from a center of the connector and having a first end connected to the center of the connector and a second end connected to the second open end of one of the plurality of tubes, and each of the at least two connector portions is formed with a conical taper, and an outer diameter of the first end at the center of the connector is greater than an outer diameter of the second end of the connector portion such that the connector portions are flexible.

11. The method of claim 7 , wherein the core pin of the tubular structure has a shape that corresponds to a shape of an outer surface of the second tubular structure.

12. 8. The method of claim 7, wherein the preloading of the core pin within the tubular structure against the second core pin comprises sliding the retaining structure toward the mold cavity structure in an X direction between 0.001 inches and 0.10 inches, preferably about 0.03 inches.

13. overmolding a polymer connector onto two or more polymer tubular structures, each having an internal core pin, by applying a preload force to the two or more tubular structures to secure the internal core pin against movement within the first mold cavity during mating of a second mold cavity and injection molding of the connector. A method comprising:

14. 14. The method of claim 13, wherein a diameter of the inner core pin subjected to the preload force is smaller than a diameter of the body of the core pin such that the inner core pin is not displaced from the other inner core pin during the injection molding, and the preload force is provided such that one of the two or more polymeric tubular structures can slide in an X direction toward the other inner core pin.

15. The method of claim 13 , wherein the preloading of the force comprises clamping the tubular structure to a mold cavity structure in a Z direction and / or a retraction direction using a holding structure, the holding structure comprising a ramp.

16. 16. The method of claim 15, wherein the preloading of the force comprises preloading the clamped tubular structure by engaging the retaining structure during the joining of the first mold cavity and the second mold cavity to provide a preload force on the clamped tubular structure in an X direction toward the mold cavity structure.

17. 17. The method of claim 16, wherein the pre-compressing the clamped tubular structure comprises sliding the retaining structure in the X direction toward the first mold cavity and the second mold cavity.

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