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US 2006/0157502 A1Published application
Tube with head made of multilayer materials and manufacturing process
AssigneeCebal
InventorsJean-Paul Meausoone, Michel Bosshardt, Roger La-Palus
Life of this patent
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Abstract
A method for manufacturing a tube head including the steps of using a co-injection head having an annular outlet and which can be supplied simultaneously with a thermoplastic structure material A and a thermoplastic barrier material B is disclosed.
Claims15
Plastic tube head (2), designed to be assembled with a skirt (3) to form a tube (1), comprising a typically threaded orifice (20) and a shoulder (21) comprising an annular connection part (22) to the said skirt, characterized in that,
- a) the said head (2) is formed by co-injection and comprises a thermoplastic multilayer material comprising an internal layer (24) and an external layer (23) in structure material A, and at least one inner layer (25) in barrier material B,
- b) the said inner layer (25) is encased by the said internal layer (24) and external layer (23), including at the ends of the said head where the said internal and external layers are joined together in one layer, the distances “e” and “e′” between each of the ends (250, 251) of the said inner layer and the corresponding end of the said head being between 0.02 mm and 5 mm, such that the said inner layer made of a barrier material (25) extends over the greatest possible height, while its ends remain encased or encapsulated by the junction of the said internal layer (24) and external layer (23).
2-16. (canceled)
Process for manufacturing a tube head comprising followings steps:
- a) using a co-injection head which has an annular outlet and which can be supplied simultaneously with a thermoplastic structure material A and a thermoplastic barrier material B,
- b) in the time elapsing from 0 to τ, placing a mold having an annular cavity near the co-injection head such as said annular outlet is in communication with said cavity;
- c) co-injecting said materials in said cavity during a time elapsing from τ to T0, by carrying out said following steps:
- c1) injecting the structure material A from T to (τ+t),
- c2) co-injecting structure material A and barrier material B between (τ+t) and (T0−t′)
- c3) injecting the structure material A from (T0−t′) to T0, until the cavity is filled;
- d) maintaining the injection pressure on the structure material A for an additional time T′, which is equal to at least T0, in order to stabilize the quantity of injected structure material;
- e) opening the mold thus filled and extracting the molded piece that comprises an inner layer of said barrier material B, the ends of the said inner barrier being entirely encapsulated by said structure material A;
- f) eliminating the injection gate.
6 more elements
Dependencies are inferred from the claim text.