Valve
A bi-injection moulded self-closing valve assembly is described. The assembly comprises a valve overmoulded on an insert. The overmoulded valve is injected using side gating of the mould.
1. A self-closing valve assembly comprising a valve overmoulded on an insert, in which the insert is formed by lateral injection, and in which the overmoulded valve is injected by: generally central injection; off-centre injection; or lateral injection to form a valve injection point, in which the valve includes a valve head in which one or more slit lines are to be formed, and in which the valve injection point is located away from the one or more slit lines.
2. An assembly as claimed in claim 1 , in which the insert includes a side wall and the valve injection point is located on one end of the side wall.
3. An assembly as claimed in claim 1 , in which the valve includes a side wall and the valve injection point is located on one end of the side wall.
4. An assembly as claimed in claim 1 , in which the valve includes a valve head and the valve injection point is located generally centrally on the valve head.
5. An assembly as claimed in claim 1 , in which the insert is a retaining ring.
6. An assembly as claimed in claim 1 , in which the valve is formed from a TPE material.
7. An assembly as claimed in claim 1 , in which the insert is formed from polypropylene.
8. An assembly as claimed in claim 1 , comprising a side gated polypropylene ring and a side gated TPE valve.
9. An assembly as claimed in claim 1 , comprising a side gated polypropylene ring and a centre gated TPE valve.
10. An assembly as claimed in claim 1 , comprising a side gated polypropylene ring and an off-centre gated TPE valve.
11. An assembly as claimed in claim 1 , in which the valve comprises an injection moulded body formed from a TPE material, the injection moulded body includes a peripheral sidewall and a central valve head, in which an injection gate for the body is formed away from a centre of the valve head.
12. An assembly as claimed in claim 11 , in which the injection gate is formed in the peripheral sidewall.
13. An assembly as claimed in claim 1 , comprising a valve sub-assembly, comprising a self-closing valve and an outer retaining ring, formed by a bi-injection moulding process, the ring is injected using a side gated injection process and the valve is injected using a side gated injection process.
14. A method of forming a valve sub-assembly according to claim 1 , comprising the steps of injection moulding the insert using a lateral gate and overmoulding the valve using a lateral gate, further comprising the step of slitting the valve to provide one or more slits, in which the one or more slits are formed so as not to coincide with an infection gate vestige thereon.
15. A self-closing valve comprising an injection moulded body formed from a TPE material, the injection moulded body includes a peripheral sidewall and a central valve head, in which an injection gate for the body is formed away from a centre of the valve head wherein the central valve head includes one or more slit lines, and in which the injection gate for the body is located away from the one or more slit lines.
16. A method of forming a self-closing valve according to claim 14 , comprising the step of injection moulding the valve with an off-centre injection gate.
17. A method as claimed in claim 16 , further comprising the step of slitting the valve, in which the slit/s are formed so as not to coincide with an injection gate vestige thereon.