EP1007221A1

EP1007221A1 - A device for discharging media

Info

Publication number: EP1007221A1
Application number: EP98946433A
Authority: EP
Inventors: Joachim Körner
Original assignee: Erich Pfeiffer GmbH; Ing Erich Pfeiffer GmbH
Current assignee: Aptar Radolfzell GmbH
Priority date: 1997-08-26
Filing date: 1998-08-26
Publication date: 2000-06-14
Also published as: JP2001513441A; WO1999010106A1; DE19736999A1; AU9347298A

Abstract

The invention relates to a device for discharging media with at least one discharging outlet for the media. Said device contains at least one plastic component (24) which is irradiated, whereby β and/or η irradiation can be used. The plastic component functions primarily as a seal or valve which is pre-stressed when mounted. The invention is particularly suitable for use in discharging devices which are provided with corresponding irradiated seals or sealing sleeves of pumps, or thrust piston pumps. Thermo-plastic material, mainly medium or low density polyethylene, is used.

Description

description

Removal device for media

The invention relates to a discharge device for media with at least one discharge opening for the medium.

Such discharge devices are known for a variety of designs for various applications. To the

Dosing, conveying or dispensing can be carried out gaseous, liquid, creamy, gel-like, powdery and / or solid media. Possibly. atomization can also be carried out. Well-known applications of such discharge devices are, for example, in the cosmetic or pharmaceutical field, but are also widespread in other fields of technology.

Previously known discharge devices of the type mentioned can often not meet the requirements with regard to mechanical, chemical and thermal resistance. On the one hand, this is due to the nature of the plastics used to manufacture them, but on the other hand, it is also due to the special use of these materials in such discharge devices. For example, certain

Components of the discharge device, which usually perform a sealing and / or valve function, are installed under pre-tension so that they can perform the desired function. In such cases, the desired restoring force caused by the preload must occur over the entire service life of the

Discharge device is retained. A lack of resistance of the plastic material to mechanical, chemical and in particular to temperature influences leads to undesirable relaxation effects, ie the necessary pretension is reduced over time. A negative influence on the commonly used plastic material Here, the temperature rises over a longer period of time, such as storing the discharge device at temperatures above 30 ° C to 50 ° C for several weeks.

The object of the invention is therefore to provide a discharge device of the type mentioned at the outset in which the disadvantages described are avoided. In this case, increased resistance, in particular increased temperature resistance, of important components of the discharge device and thus of the discharge device as a whole is to be achieved with comparatively simple means. The need to replace proven plastic materials for such components with new materials should be avoided if possible.

This object is achieved by a discharge device with the features of claim 1. Preferred embodiments of the discharge device are shown in subclaims 2 to 16. The wording of all claims is incorporated by reference into the content of this description.

The discharge device according to the invention is characterized in that it has at least one component made of plastic which is treated by irradiation. The

Radiation treatment usually takes place after the production of the component. The procedure is such that the corresponding component is manufactured and subjected to the radiation treatment in large numbers. The components treated in this way are then assembled together with the other components to form the discharge device according to the invention. Irradiation of the fully assembled discharge device with installation of a component that has not been irradiated before, however, should not be excluded according to the invention. In the invention, the radiation is preferably carried out with the aid of β-rays and / or y-rays, with radiation using β-rays being preferred. As is known, β-rays are electron beams (cathode rays) which emerge as accelerated particles from corresponding high-voltage cathodes. They are also emitted by natural and artificial radioactive emitters. Energy, power and radiation field can be varied in a manner known per se. Y-rays are high-energy electromagnetic radiation with a small wavelength, which is generated either by X-ray tubes or by suitable radionuclides. Here too, reference can be made to the known apparatuses of the prior art.

The use of ^ rays in the invention includes advantageous because usually larger quantities of product, in this case the corresponding components of the discharge device, can be irradiated than with β-rays. The - - rays have a greater range and thus a greater penetration depth than ß rays. In contrast, ß-rays can be metered better and, even with smaller product quantities, shorter radiation times can be achieved. Furthermore, the material degradation of the plastic component can be minimized when using β-rays. According to the invention, however, it is not only possible to use β or "V ^ rays, but also a combination of β and Y rays.

The (energy) dose of the radiation in the usual Gray unit (1 Gy = 1 J / kg) is usually up to 300 kGy and is preferably above 125 kGy. Preferred doses are between 150 kGy and 250 kGy, again a range between 150 kGy and 200 kGy is preferred. Usually, doses below 125 kGy do not or not permanently produce the effects sought here and doses above 300 kGy no longer significantly increase the desired effects.

The irradiation times can be varied in a manner known to the person skilled in the art. When using y-rays, it is preferred according to the invention if a radiation duration of 10 hours is selected per dose of 25 kGy. This results, for example, in the preferred doses of 150 kGy to 200 kGy radiation times of 60 to 80 hours. Corresponding doses can be achieved with the use of β-rays within much shorter periods, in particular within a few minutes to a few seconds. However, it must be taken into account here that due to the greater range and depth of penetration of γ-rays, significantly larger amounts of product can be treated at the same time than with ß-rays.

In further preferred embodiments of the invention, the irradiation is carried out under vacuum or under a protective gas atmosphere. This measure is particularly important for

Use of y ^ rays shown. The use of a vacuum or protective gas prevents interfering substances, which can also be associated with unpleasant smells, from being released. Such substances, which are associated with the degradation reactions occurring during the irradiation, in particular in the presence of oxygen, could possibly come into contact with the medium to be discharged via the irradiated component and the discharge device produced therefrom. In the described embodiments, nitrogen or noble gases such as argon can in particular be used as

Shielding gases can be used. However, it is particularly expedient to keep the components of the discharge device to be irradiated in an evacuated container during the irradiation. In the invention, the irradiation is preferably carried out in such a way that the components to be irradiated are packaged in suitable cartons or bags. Since the components are comparatively small, a large number of such components with a high packing density can be introduced into such a container. As described, it is advantageous if the container is evacuated and then sealed in an airtight manner, for example when plastic is used. Possibly. a protective gas can be introduced after the evacuation. The corresponding containers are then irradiated in a suitable manner, with the use of entire pallets can be treated with radiation at the same time. When using ß-rays are preferably individual containers, such as bags or the like. irradiated. Because of the relationships described above, the use of β-radiation is preferred in the invention.

The component made of plastic in the discharge device, which is treated by radiation, is preferably one which is in the installed state under a pretension, ie compressive or tensile stress. In this way, this component shows a certain restoring force that can be largely adjusted by the construction, which is characteristic of its function in the discharge device. In particular, such components have a sealing and / or a valve function within the discharge device. Such a component is preferably a seal which can be designed in particular as a lip seal and / or in the manner of a sleeve. Such a sealing sleeve can fulfill such a sealing function in several respects in the case of the discharge device having a push piston pump, as will be described in the following. It not only limits the actual metering chamber, but also seals it with respect to the discharge opening or with respect to one to the discharge opening leading channel. Furthermore, it can optionally seal against a further channel provided for pressure equalization, through which air can flow in for pressure equalization after the discharge process, for example. In the case of such components, a reliable sealing function over the entire life of the discharge device is of crucial importance, so that the advantages according to the invention are fully realized here.

In a further development, a conventional component of the discharge device has dimensions that are not more than 10 mm in at least one dimension, for example the thickness. In particular, the thickness of such a component, such as a sealing sleeve, is less than 5 mm, preferably less than 1 mm. In this way, adequate irradiation can be achieved with both y'-radiation and with β-radiation.

The component treated by radiation in the discharge device can in principle be made of a thermoset. However, it is preferably made of a thermoplastic

Plastic that is processed in a comparatively simple way, i.e. for example extruded, or injection molded. Known thermoplastics are, for example, polyethylene, polypropylene, the polyester and polyvinyl chloride. Possibly. Corresponding copolymers can also be selected for the production of the components. If it is not possible to increase the temperature resistance of the plastic by irradiation, this can be achieved, if necessary, by adding suitable additives to the plastic before the component is manufactured. Here, for example, it is possible and conceivable to use polyfunctional unsaturated compounds or else inorganic, metallic or organometallic compounds.

Preferred plastics in the invention are the poly ethylene and ethylene copolymers, in particular low and medium density polyethylene being preferred. "

The discharge devices according to the invention can be used for all media mentioned at the outset, for example for liquid media also in the form of solutions, for suspensions, gels and powders. They are also suitable for the discharge of so-called lotions, which are a special form of preparation for cosmetics and dermatics, among other things. Such lotions are generally aqueous or aqueous-alcoholic solutions or emulsions. However, as already mentioned, basically all possible, including technical, areas of application for the discharge devices are conceivable, although the area of cosmetics and pharmaceuticals should be particularly emphasized.

Accordingly, the dispensing devices claimed can be any metering, conveying and dispensing devices of the kind usually used for dispensing cosmetic and pharmaceutical products.

The discharge device according to the invention preferably comprises a pump for discharging the medium, in particular a lifting or. Thrust piston pump. The use of such pumps for the discharge devices affected by the invention is known. Accordingly, the radiation-treated plastic component can be one with a sealing and / or valve function within a pump, in particular a seal or sealing sleeve, which seals the pump chamber of the piston pump from the discharge opening, for example. This is described below with reference to the drawing using a special embodiment, which is not to be understood as restrictive.

In a further development, the discharge device according to the invention has a discharge head, in particular a so-called dosing head, on which the discharge opening is arranged. In which The discharge head can also be a so-called spray head, for example, which atomizes the medium to be discharged more or less finely during discharge.

It is also advantageous if two discharge units are provided in the discharge device according to the invention. These two units can, for example, be connected to one another via a plug-in and / or snap-in connection and form the essential functional part of the discharge device. The two units can be moved manually against one another, in particular with mutual axial displacement. In such two unit embodiments, preferably a first unit is from the discharge head, i.e. for example spray head or head for discharging a pasty mass, and a second unit is formed by the pump. The pump is then usually assigned to a media store or arranged on such a media store.

The described two-unit embodiments are, for example, hand-operated dispensers or dispensers, such as those used in the field of cosmetics as dispensers for perfume, shaving cream, soap, toothpaste etc. and in the field of pharmaceuticals as medicament spray, e.g. Nasal spray, are known.

Typical components of a pump, in particular the mentioned reciprocating or thrust piston pump, are, for example, in addition to the piston itself, including any intermediate piston, piston cylinder, sealing sleeve and sealing housing. The sealing sleeve is usually treated (after-) by irradiation after being made from plastic. An existing spray head, for example for a nasal spray, is usually constructed from a nozzle, adapter and, if appropriate, a protective cap that has been retrofitted. In the discharge device according to the invention, a so-called media guide is preferably provided, which ensures that the medium is forwarded or guided from the store via the pump which may be present to the discharge opening. This media guide comprises at least one discharge channel opening into the discharge opening. In a corresponding manner, a so-called fluid guide can also be provided, which serves to equalize the pressure through a fluid after the medium has been discharged. Accordingly, the fluid guide comprises at least one channel for pressure equalization. In principle, parts of the two existing channels can be used simultaneously to guide the medium and to guide the fluid.

Due to the fact that at least one prefabricated plastic component is subjected to radiation treatment, the discharge device according to the invention has an increased resistance to thermal influences, in particular to increased temperature, and possibly also to mechanical and chemical influences. This effect can be explained by an improvement in the structure of the plastic, with crosslinking of the plastic material playing a role. However, it must be taken into account here that when using components that are pretensioned, a high resilience (resilience) is sought. However, this basically requires the use of low-density plastics. On the other hand, good relaxation behavior is expected for plastics with a high density obtained after irradiation. Accordingly, the invention actually seems to run in opposite directions with an optimization

Related effects.

An explanation for the advantages obtained with the invention could be that three partially opposing effects are taken into account or optimized. So it turned out that the physical and chemical properties the plastic materials (raw materials) from which the components of the discharge device are made vary from batch to batch. For example, the temperatures up to which the thermoplastics used, for example the low-density polyethylenes, have certain desired values for the resilience, vary considerably, for example between 40 ° C. and 45 ° C. This means that the radiation treatment must provide a sufficiently high radiation dose in order to achieve a sufficient improvement in the relaxation capacity at higher temperatures, for example 50 ° C., for all possible batches of the plastic raw material. The second effect to be taken into account is the crosslinking that takes place during the irradiation, which is at least partially contrary to the third effect to be taken into account, namely the degradation of the plastic material Embodiments presented a way to achieve the necessary improvement in the properties of the plastic material.

As a further advantage it should be mentioned that in the invention the dimensions of the component are not influenced by the radiation treatment, so that the subsequent installation of this component can be carried out without any problems and no adaptation of the other components to the irradiated component has to be carried out.

Furthermore, the invention comprises a plastic component for a discharge device for media, which is radiation-treated after its manufacture. This component is shown in claim 17. Preferred embodiments result from claim 18 with a corresponding reference back to claims 2 to 11. Finally, the invention also comprises a method for producing a discharge device for media with at least one discharge opening, in which, according to claim 19, a prefabricated plastic component by irradiation is treated. Preferred embodiments of the method result from claim 20. The wording of claims 17 to 20 is hereby made to the content of this description, including the back-references.

The described features and further features of the invention result from the following description of preferred embodiments in conjunction with the claims and the drawings. The individual features can be implemented individually or in combination with one another.

The drawings show:

1 is a sectional view of a discharge device according to the invention with a pump and discharge head,

Fig. 2 is a partial sectional view of the pump of the discharge device shown in Fig. 1 with irradiated plastic component in the form of a sealing sleeve and

Fig. 3 experimental results on the radiation treatment of a sealing sleeve.

The discharge device 1 according to FIG. 1 is basically known with regard to construction and function. Using a specific example, their illustration is intended to show how the invention can be used analogously in a large number of different discharge devices. Accordingly, the in

1 and the pump shown in FIG. 2 are to be understood only as examples.

The discharge device 1 according to FIG. 1 has two units 2, 3 which can be moved manually relative to one another in the axial direction. The first unit 2 consists essentially of Chen from a discharge head 4 and the second unit 3 essentially from a pump 5, or the like by means of a housing 6, a corresponding housing part, a socket. is inserted into a memory 7, not shown in FIG. 1, for the medium. In this case, the pump 5, which is designed as a push piston pump in the present case, can suck in the medium via a riser pipe 8 and discharge it via the discharge head 4 when actuated. Between the pump 5 and the upper edge of the accumulator 7, an annular seal 9 serving for sealing is also shown in FIG. 1.

In the case of FIG. 1, the discharge head 4 is designed as a spray head and, as an essential component, has an adapter part 10 carrying a nozzle or an integrated nozzle piston part for the desired application, in the present case for a nasal spray. The adapter 10 also contains the lines or channels serving to guide the medium, of which essentially only the discharge channel 12 opening into a discharge opening 11 is shown in FIG. 1. At the end of the discharge channel 12, additional swirl channels can be provided to ensure discharge in the form of a cone. The discharge opening 11 is closed before or after the actuation by suitable sealing or closing means, which are preferably assigned to the discharge channel, possibly in the usual manner.

Furthermore, the discharge head 4 according to FIG. 1 comprises a protective cap 13, which is put over the adapter 10 when not in use or at least before first use and is held there in position, for example with the aid of suitable support or clamping elements 14, 15.

The discharge device 1 is conventionally made of plastic, different plastic materials being used or being able to be used for individual components. For example, there are accumulator 7 and riser pipe 8 made of PE, PP or PE-PP copolymers. Polypropylene is also used as the material for the housing 6. In this connection, reference can be made to the known prior art.

2 shows the pump 5 shown in FIG. 1 in an enlarged partial sectional view. The construction and function of such a thrust piston pump are also known in principle, so that a detailed description is unnecessary.

A (sealing) housing 21 with an internal piston 22 and intermediate piston 23 is shown as essential components of the pump 5 in FIG. 2. Next is a spring 26 which designates the ball 27 associated with the lower end of the pump 5 and the substantially cylindrical lower piece 25 of the pump 5.

Particularly noteworthy in FIG. 2 is the (sealing) sleeve 24 shown there, which is treated as a plastic component and thus gives the discharge device 1 according to FIG. 1 the advantageous properties described. This sealing sleeve 24 is preferably made from LDPE, ie low-density polyethylene, for example from Lupolen® from BASF. After its production, this sealing sleeve 24 is subjected to radiation treatment in the manner described and then assembled with the other components to form the discharge device 1. The sleeve 24 not only delimits the pump chamber and seals it from the discharge opening, but also closes the usual gaps provided in the pump 5, with the aid of which the required pressure equalization takes place after the discharge by the inflow of air. In the case shown, the sealing collar 24 has a thickness of approximately 5/10 mm in its upper (neck) region and approximately 5/10 mm to 8/10 mm in the lower region. When using a radiation-treated sealing cuff 24, preferably made of LDPE, show the advantages to be achieved according to the invention in a special way.

When the discharge device 1 shown in FIG. 1 is actuated by manual movement of the units 2, 3 against one another, the medium present in the pump chamber, which is not described in any more detail, is pressed into the discharge channel 12 with the aid of intermediate pistons 23, sleeve 24 and pistons 22 and, if necessary, after opening Existing locking or closing means are discharged through the discharge opening, possibly with atomization. The cuff 24, which is under elastic prestress, is widened to the outside in a known manner and thus suddenly clears the way for the medium from the pump chamber. When the actuation pressure is released, for example by the fingers placed on the corresponding contact surfaces, the first unit 2 returns to its starting position, for which the spring 26, which is designed as a compression spring, is responsible in the pump 5. As a result, medium 27 is sucked out of the reservoir 7 into the pumping chamber via the riser pipe 8 while lifting the ball. The resulting negative pressure is caused by the

Air sucked in from the outside balanced, for example via gaps between or within the components 21 and 25, which can be closed by the sleeve 24.

FIG. 3 shows the results of investigations on radiation treatment of sealing sleeves, such as the sealing sleeve 24 according to FIG. 2. The sleeves are made of LDPE, namely the product Lupolen 1810H from BASF. The properties of this material are known.

The relaxation behavior of the restoring force, i.e. the possible reduction of the preload in such sealing sleeves was investigated. For this purpose, the sealing sleeves were installed in a conventional manner in a pump 5 shown in FIG. 2 and in a discharge device 1 in accordance with FIG. 1. The

Sealing sleeve before installing either no radiation treatment or radiation treatment with different doses and then tested the dosing volume of appropriate discharge devices. When the cuff pre-tension is reduced, the effect occurs that the cuff collapses during the suction process, ie it lifts off the cylinder. As a result, the dosing or pump chamber is not completely filled with medium, which leads to undesirable fluctuations in the dosing volume.

In order to determine the influence of the radiation treatment on the relaxation behavior in relation to elevated temperatures, both the non-radiation-treated sleeves and the sleeves treated with different doses were stored for several weeks both at room temperature and at 50 ° C. and then the metered volume was tested.

As can be seen from FIG. 3, a total of fifteen tests were carried out, three tests each belonging to one radiation dose. Irradiations were carried out using y * radiation in a conventional y'-irradiation apparatus.

The individual tests have the following parameters:

Test No. DDoossis (in kGy) Storage period Storage temperature y ^ s

1 -

2 - 4 weeks room temperature

3 - 4 weeks at 50 ° C

4 50

5 50 4 weeks room temperature

6 50 4 weeks 50 ° C

7 125

8 125 4 weeks room temperature

99 112255 4 weeks at 50 ° C

10 175

11 175 4 weeks room temperature

12 175 4 weeks at 50 ° C

13 300

1144 330000 4 weeks room temperature

15 300 4 weeks at 50 ° C The test results according to FIG. 3 show that the dosing volume of the discharge device decreases very strongly with an unirradiated cuff as the storage temperature rises and the scattering of the dosing volume increases significantly. 3 also shows the positive influence of the post-treatment of the cuff by irradiation. With increasing radiation dose, the dosing volume remains largely constant even after four weeks of storage at elevated temperature and the dispersion of the dosing volume still decreases. Fig. 3 also gives one

Indicative of the ranges for the radiation dose claimed in the invention. It can be seen that radiation doses> 125 kGy, better> 150 kGy are suitable to ensure a clear and permanent stabilization of the dosing properties. The fluctuations are (still) greater than 125 kGy. Radiation doses above 300 kGy no longer have any noteworthy effect, especially considering economic reasons.

3 shows that the aftertreatment of a plastic component in the form of a sealing sleeve by irradiation is a very good, simple means of increasing the temperature resistance of the discharge device or of the pump present in the discharge device. The plastic material is only changed in its properties, but not in its geometric dimensions, so that a conventional construction of the discharge device can be used without further changes.

The test can be carried out in the same way with β-rays, with virtually no degradation of the plastic material taking place within the short irradiation times (a few minutes). This leads to an even better stabilization of the dosing properties (in particular even more constant, temperature-independent dosing).

Claims

Discharge device for media

1. discharge device for media with at least one discharge opening for the medium, characterized in that the discharge device (1) has at least one component made of plastic (24) which is treated by radiation.

2. Discharge device according to claim 1, characterized in that an irradiation with β-rays and / or y-rays, preferably an irradiation with β-rays, is provided.

3. Discharge device according to claim 1 or claim 2, characterized in that the radiation is provided with a dose up to 300 kGy, preferably with a dose greater than 125 kGy.

4. Discharge device according to claim 3, characterized in that the dose is between 150 kGy and 250 kGy, preferably between 150 kGy and 200 kGy.

5. Discharge device according to one of the preceding claims, characterized in that the irradiation is carried out under vacuum or a protective gas atmosphere.

6. Discharge device according to one of the preceding claims, characterized in that the component (24) is under tension or pretension in the state installed in the discharge device (1).

7. Discharge device according to one of the preceding claims, characterized in that the component (24) in the Discharge device (1) has a sealing and / or valve function.

8. Discharge device according to claim 7, characterized in that the component is a conventional one in

Discharge devices used seal, this seal is preferably designed in the manner of a sealing sleeve (24).

9. Discharge device according to one of the preceding claims, characterized in that at least one dimension of the component, in particular its thickness <10 mm, preferably <5 mm, preferably <1 mm.

10. Discharge device according to one of the preceding claims, characterized in that the component is made of a thermoplastic.

11. Discharge device according to claim 10, characterized in that the component made of polyethylene or a

Ethylene copolymer, preferably made of a medium or low density polyethylene.

12. Discharge device according to one of the preceding claims, characterized in that the discharge device has a pump (5), in particular a thrust or reciprocating piston pump.

13. Discharge device according to one of the preceding claims, characterized in that the discharge device has a discharge head (4) having the discharge opening (11), in particular a so-called dosing head.

14. Discharge device according to one of the preceding claims, characterized in that the discharge device has two units (2, 3) which can be moved relative to one another, wherein in particular a first unit (2) is formed by a discharge head (4) and a second unit (3) is formed by a pump (5) associated with a media store (7) and preferably arranged thereon.

15. Discharge device according to one of the preceding claims, characterized in that the discharge device has a so-called media guide with at least one discharge channel (12) opening into the discharge opening (11).

16. Discharge device according to one of the preceding claims, characterized in that the discharge device has a fluid guide serving for pressure equalization through a fluid with at least one fluid channel.

17. Plastic component for a discharge device for media, characterized in that it is treated by radiation after its manufacture.

18. Component according to claim 17, characterized by at least one feature of a characterizing part of at least one of claims 2 to 11.

19. A method for producing a discharge device for media with at least one discharge opening for the medium, characterized in that at least one component made of plastic of this discharge device is treated by radiation after its production.

20. The method according to claim 19, characterized by radiation or a component with at least one feature of the characterizing part according to at least one of claims 2 to 5 or 6 to 11.