Method of making a seal having slit formed therein
View Patent ↗A valve for selectively permitting a fluid flow between first and second medical implements is disclosed. The valve has a housing with an interface suitable for receiving a connector portion of a first medical device such as a catheter, and a seal made of a flexible material. The seal has a first end in fluid communication with the interface, a second end suitable for receiving the second medical device, and at least one slit in fluid communication with the first end and the second end. The slit defines a restricted fluid flow path and a relatively small interior volume when in an undisturbed state, defines an expanded fluid flow path and a larger interior volume upon the introduction of the second medical instrument into the slit, and retracts to define a restricted flow path and a small interior volume upon the withdrawal of the second medical device from the seal.
1. A method of making a medical valve seal element having a body made of a flexible material and a slit formed within the body between adjacent first and second slit walls, the method comprising:
molding first and second preforms, each comprising one of said first and second slit walls and a perimeter edge portion;
pressing said first and second preforms together so that said first and second slit walls face each other;
positioning an overmold plate around said first and second preforms to create a cavity around at least a portion of said first and second preforms; and
molding an additional amount of a flexible material to at least part of said perimeter edge portions of said first and second preforms so that said first and second preforms and said additional material form a unitary mass with said slit formed therein.
2. The method of claim 1 , wherein the step of molding an additional amount of flexible material to at least part of the perimeter edge portions of the first and second preforms comprises injecting a thermoset material into the cavity formed by the first and second preforms and the overmold plate.
3. The method of claim 1 , wherein the overmold plate comprises a generally planar body defining an overmold opening, the overmold opening having an inner perimeter that conforms to an outer edge of the medical valve seal element.
4. The method of claim 3 , wherein the overmold plate comprises a mandrel projecting from a lower inner portion of the overmold plate, the mandrel configured to form a lead lumen in the medical valve seal element.
5. The method of claim 4 , wherein the step of positioning an overmold plate around the first and second preforms to create a cavity around at least a portion of the first and second preforms comprises positioning the first and second preforms between an upper surface of the mandrel and an inner surface of an upper portion of the overmold plate.
6. The method of claim 1 , wherein the overmold plate has a thickness substantially similar to a thickness of the combination of the first and second preforms after the first and second preforms have been pressed together.
7. The method of claim 1 , wherein the overmold plate has a thickness greater than a thickness of the combination of the first and second preforms after the first and second preforms have been pressed together.
8. The method of claim 7 , wherein the step of molding an additional amount of a flexible material to at least part of the perimeter edge portions of the first and second preforms comprises molding an additional amount of flexible material to outer surfaces of the first and second preforms opposite the slit walls.
9. The method of claim 1 , wherein the step of molding an additional amount of flexible material to at least part of the perimeter edge portions of the first and second preforms further comprises applying pressure to the first and second preforms such that the additional amount of flexible material does not migrate between the facing slit wall portions of the first and second preforms.
10. The method of claim 1 , wherein the step of molding the first and second preforms comprises the steps of:
injecting a first quantity of a thermoset material into a first cavity formed between a first mold pair;
injecting a second quantity of the thermoset material into a second cavity formed between a second mold pair; and
heating the first mold pair and the second mold pair to a set temperature of the thermoset material.
11. The method of claim 10 , wherein the step of molding the first and second preforms further comprises the step of applying pressure to at least one of the first mold pair and the second mold pair to prevent the thermoset material from leaking.
12. The method of claim 10 , wherein the step of molding an additional amount of a flexible material to at least part of the perimeter edge portions of the first and second preforms is conducted before the first and second preforms have cooled substantially from the set temperature.
13. The method of claim 1 , wherein the first and second preforms each comprise a substantially planar body and the first and second slit walls each comprise a substantially planar inner surface.
14. The method of claim 1 , wherein the slit is configured to resist being separated.