Method for making a container for a fluid substance dispensing device and dispensing device for the said fluid substance
A method for making a fluid substance container starting from a preform, the container coupled by a ring nut to a hermetic pump to form a fluid substance dispensing device, including heating and blow-moulding the preform to obtain the container; the preform formed of an external body and an internal body mutually assembled before being blow-moulded, the external body being cup-shaped with a first free end, the internal body being cup-shaped with a second free end having a flange whereby, when the internal body and external body are assembled, the flange abuts the first free end and protrudes a distance along an external perimeter of the external body near the free end, the external body being configured to form—once blow-moulded—the external recipient of the container while the internal body is configured to form a deformable bag housed inside the container, the ring nut having a undercut which engages the flange so that when the ring nut is removed the now empty deformable bag comes with it, in addition to the pump.
1. A method of making a container ( 1 ) of a fluid substance starting from a preform ( 2 ), the container ( 1 ) being associated by a ring nut ( 9 ) to a hermetic pump (P) to form a dispensing device of a fluid substance ( 30 ), comprising the steps of heating the preform and blowing it to obtain the container ( 1 ), the preform ( 2 ) being formed by an external body ( 3 ) and an internal body ( 4 ) mutually assembled via a coupling step before being blown, the external body ( 3 ) being cup-shaped and equipped with a first free end ( 5 ), the internal body ( 4 ) being cup-shaped and having a second free end ( 6 ) which has a flange ( 7 ) configured so that, when the internal body ( 4 ) is assembled to the external body ( 3 ), the flange ( 7 ) abuts against the first free end ( 5 ) and perimetrically protrudes (S) with respect to an external perimeter of the external body ( 3 ) in proximity of said free end ( 5 ), the external body ( 3 ) being configured to form, once blown, an outer vessel ( 3 A) of the container ( 1 ) while the internal body ( 4 ) being configured to form a deformable bag ( 4 A) housed inside the container ( 1 ), the ring nut ( 9 ) having an undercut ( 9 A) which engages the flange ( 7 ) so that, when the ring nut ( 9 ) is removed from the container ( 1 ), after that it has been assembled on the container ( 1 ) to hold the pump (P), brings with it the empty deformable bag ( 4 A) together with the pump (P), wherein the ring nut ( 9 ) and the pump (P) are associated with the container ( 1 ) already formed, characterized in that the inner body ( 4 ) and the outer body ( 2 ) are heated together and blown in a single step to form the container ( 1 ), and during blowing, the wall of the deformable bag ( 4 A) only partially adheres to the outer vessel ( 3 A) due to the presence of an air gap present in the preform ( 2 ), wherein suitable air passages ( 11 A, 11 B) allow air to be discharged during the coupling step between the outer body ( 3 ) and the inner body ( 4 ) to form the preform ( 2 ), wherein the same air passages ( 11 A, 11 B), during the blowing phase of the tube ( 2 ), are closed to ensure the maintenance of an air gap during the bottle forming.
2. The method according to claim 1 , in which the external body ( 2 ), near the first free end ( 5 ), has a thread ( 8 ) for coupling with a counter-thread ( 9 B) of the ring nut ( 9 ).
3. The method according to claim 2 , wherein the undercut ( 9 A) is defined at the top of the counter-thread ( 9 B) of the ring nut ( 9 ).
4. The method according to claim 1 , in which air passages ( 11 A, 11 B) are provided between the internal body ( 4 ) and the external body ( 3 ) which put the exterior of the internal body ( 4 ) in communication with the outside of the container ( 1 ).
5. The method according to claim 4 , wherein the air passages ( 11 A) open on an upper surface ( 12 ) of the flange ( 7 ) or on a lower surface ( 13 ) of the flange ( 7 ) in abutment against said first free end ( 5 ) of the external body ( 3 ).
6. The method according to claim 1 , in which channels ( 12 ) are provided between the internal body ( 4 ) and the external body ( 3 ), located in correspondence with an area that will form a neck ( 13 ) of the container ( 1 ), the channels communicating with said passages ( 11 A, 11 B).
7. The method according to claim 1 , wherein between the pump (P) and the deformable bag ( 4 A) there is provided a sealing gasket ( 14 ) equipped with a first sealing lip ( 14 A) on the pump body (P) and a second sealing lip ( 14 B) on an internal surface of the deformable bag ( 4 A), or in which the sealing gasket ( 14 ) is equipped with its own flange ( 14 C) housed in a seat ( 15 ) provided on the flange ( 7 ) of the internal body ( 3 ).
8. The method according to claim 1 in which the inner body ( 3 ) is formed by two external layers ( 20 ) and a further layer ( 21 ) sandwiched between the external layers ( 20 ).
9. The method according to claim 1 , wherein the outer body ( 3 ) or the inner body ( 4 ) are made by injection molding.