The present invention relates to a valve joint and the process of its manufacture.
Many fluid product dispensing devices comprise valves, particularly measuring valves, to dispense the product contained in the device, by means of an aerosol propellant. For ecological reasons, conventional aerosol propellants of the CFC type used in the past have been steadily replaced by aerosol propellants, which are less harmful to the environment, such as particularly the gases HFC 134a or HFC-227. The use of these aerosol propellants however brings with it a certain number of problems. On the one hand they place increased stress on the joints, which can bring about more significant swelling, liable to lead to a problem of blocking of the valve which slides within: the joints, a problem generally denoted by the expression xe2x80x9cstickingxe2x80x9d. On the other hand the joint may be led to release compounds known by the term extractables. These extractables are compounds, extracted from the joints by the propellant, which contaminate or pollute the fluid product to be dispensed.
The purpose of the present invention is to provide a joint and a manufacturing process of said joint which does not have the above-mentioned drawbacks.
Another purpose of the present invention is to provide a joint and a process for its manufacture which is simple and inexpensive to carry out.
The purpose of the present invention is to provide a joint, which can be used with HFC-134a or HFC-227 gases, in respect of which the release of extractables is reduced.
Another purpose of the present invention is to provide a joint, which can be used with HFC-134a or HFC-227 gases, which reduce valve blocking problems.
The object of the present invention is therefore a process for manufacturing a valve joint of a dispensing valve of a fluid product dispensing device, said joint being intended to come into contact with a fluid product comprising an aerosol propellant of the HFC-134a or HFC-227 type, with or without alcohol, characterised in that said process includes a joint surface treatment, said surface treatment reducing the friction coefficient of the joint so as to reduce the risks of the valve blocking and/or said surface treatment creating a barrier on the joint surface so as to reduce the level of extractables from said joint.
To advantage, said joint includes one or more of the following materials: nitrile, neoprene, butyl, halobutyl, EPDM (ethylene propylene diene), SBR (styrene butadiene), HNBR (hydrogenated nitrile).
According to a first embodiment of the invention, said surface treatment is of the chemical type.
To advantage, said surface treatment includes grafting halogens on the joint surface.
To advantage, the halogens include chlorine and/or fluorine.
To advantage, said surface treatment includes oxidising the joint surface in a chlorinated medium.
To advantage, said surface treatment includes immersing the joint in a solution containing water, hydrochloric acid and bleach.
According to a second embodiment of the invention, said surface treatment is of the physical type.
To advantage, said surface treatment includes modifying the joint surface by means of electron beams.
To advantage, said surface treatment includes subjecting the joint to an irradiation treatment, the power of which may vary from about 150 KeV to about 10 MeV.
Another object of the present invention is a valve joint of a dispensing valve of a fluid product dispensing device, said joint being intended to come into contact with a fluid product comprising an aerosol propellant of the HFC-134a or HFC-227 type, with or without alcohol, characterised in that said joint comprises a surface subjected to a surface treatment, said surface treatment being adapted to lower the friction coefficient of the joint so as to reduce the risks of the valve blocking and/or to create a barrier on the joint surface so as to reduce the level of extractables from said joint.
To advantage, said joint includes one or more of the following materials: nitrile, neoprene, butyl, halobutyl, EPDM, SBR, HNBR.
According to a first embodiment variant, the joint surface is modified by grafting atoms of chlorine and/or fluorine.
According to a second embodiment variant, the joint surface is irradiated by electron beams, the power of which may vary from about 150 KeV to about 10 MeV.