WO2012110235A1

WO2012110235A1 - Method for producing a container for a bulk product

Info

Publication number: WO2012110235A1
Application number: PCT/EP2012/000668
Authority: WO
Inventors: Peter Kertels
Original assignee: Noatec Gmbh
Priority date: 2011-02-16
Filing date: 2012-02-15
Publication date: 2012-08-23
Also published as: CN103476683A; EP2675726A1; KR20140027112A; US20140061244A1; DE102011011352B4; DE102011011352A1; BR112013020830A2; CA2830345A1; JP2014506859A; RU2013140862A

Abstract

The invention relates to a container (10) for a bulk product, comprising a housing (12) and a rubber-elastic force-generating body (24) protruding into the housing and having a filling space for receiving the bulk product. The force-generating body has a closed first longitudinal end and is suspended relative to the housing in the area of an opposite second longitudinal end. When being filled, the force-generating body expands radially and axially in the housing in such a manner that when a partially filled state is reached said body makes contact with a first wall part (16) of the housing (12) radially bounding the expansion, and when filling is continued the first longitudinal end approaches a second wall part (18) of the housing axially bounding the expansion as the axial enlargement of the area of contact between the force-generating body and the first wall part increases. Before the force-generating body is filled, at least one part the first wall part on the inside of the housing and/or at least one part of the outer face of the force-generating body is subjected to a friction-reducing surface treatment.

Description

Method for producing a container for a product

The invention relates to a method for producing a container for a filling material, wherein the container comprises a housing and a protruding into the housing rubber elastic force generating body having a longitudinal axis and with a filling space for receiving the medium, wherein the force generating body has a closed first longitudinal end and in the area an opposite second longitudinal end is suspended relative to the housing, wherein the force-generating body when it is filled in the housing - with respect to the longitudinal axis - radially and axially expands.

The elastic extensibility of the force-generating body can be used in such a container to produce a force acting on the filling material, resulting from the tensile stress of the force-generating body application force, which can drive out the contents of the force generating body. The contents may be, for example, a liquid, pasty, creamy or gel-like substance, which is to be dispensed in a dosed manner by means of the container. For metering the amount applied, the container can be equipped with a user-operable valve system.

In preferred embodiments of the container, the total application force acting on the contents alone results from the expansion stress of the force-generating body, i. Additional force generating means in the form of a propellant gas or separate spring elements are dispensable. Of course, it goes without saying that such additional force-generating means can be provided as supportive if desired, wherein advantageously at least the predominant part of the total available application force results from the expansion stress of the force-generating body.

With regard to the state of the art to containers with an elastically extensible force generating body for receiving a metered ausbringfähigen filling material is exemplified in WO 2007/009651 A2, DE 103 10 079 AI,

US 3,672,543, DE 43 33 627 C2, DE 201 20 143 Ul, DE 201 20 142 Ul,

DE 10 2004 005 881 AI and EP 0 361 091 AI referenced. Furthermore, reference is made to CH 591 901 A5 and EP 0 276 097 A2. Both documents disclose an expandable inflation bladder arranged in a cylinder-bottle-like outer housing which, when filled, expands both radially and axially with respect to a housing axis. In the CH document, the bladder is to be received in the final filling state without significant obstruction - neither through the housing bottom nor through the cylinder jacket. According to the EP document, the filling bladder in the final filling state should completely fill the space available inside the housing and press it intimately against the housing wall.

In contrast thereto, the invention is based on such a configuration of the housing and the force-generating body that the force-generating body expands radially and axially when filled in such a way in the housing relative to the longitudinal axis that it reaches a partial filling state in particular at a distance from the second longitudinal end to a radial extension limiting the first wall portion of the housing applies and with continued filling, the first longitudinal end of an expansion axially delimiting second wall portion of the housing under increasing axial enlargement of the area of the system of the power generating body to the first wall portion approaches ,

If the friction between the force-generating body and the housing is comparatively high in such an expansion behavior of the force-generating body, it may happen that the force-generating body rolls essentially exclusively in the course of its expansion on the first housing wall part, without a significant slipping movement of the force-generating body taking place on this wall part. It has been found that this rolling or the absence of slippage can lead to considerable axial forces exerted by the force-generating body on the connection means provided for its suspension in the housing and thus ultimately on the housing. Under certain circumstances, these axial forces can be so great that a connection solution can occur in the path between the force-generating body and the housing.

An object of the invention is, therefore, to show a way in which the risk of detachment of the same when filling the force-generating body can be reduced by the occurrence of excessive axial forces. To solve this problem, the invention provides a method for producing a container for a filling according to claim 1. The container comprises a housing and an elastomeric force generating body projecting into the housing with a longitudinal axis and with a filling space for receiving the contents, wherein the force generating body has a closed first longitudinal end and is suspended in the region of an opposite second longitudinal end relative to the housing. The force generating body expands during its filling in such a manner in the housing - with respect to the longitudinal axis - radially and axially, that it applies to achieve a partial filling state, in particular at a distance from the second longitudinal end to a radially limiting the first wall portion of the housing and in the case of continued filling, the first longitudinal end approaches a second wall part of the housing axially delimiting the extension with increasing axial enlargement of the area of the system of the force-generating body on the first wall part. According to the invention, the method is characterized in that at least part of the first wall part inside the housing and / or at least part of the force generating body is subjected to a friction-reducing surface treatment on the outside before filling the force-generating body. The surface treatment may include applying a friction-reducing substance to the first wall part or / and the force-generating body. Alternatively or additionally, the surface treatment may comprise a fluorination of the first wall part or / and of the force-generating body.

If a friction-reducing substance is applied, it is preferable to provide at least the first wall part of the housing with such a friction-reducing substance. However, it should not be ruled out, at least in addition, to apply a friction-reducing substance to the outer surface of the force-generating body. However, since the layer thickness of the applied substance decreases with increasing expansion of the force-generating body (the same amount of the substance must spread to a steadily increasing surface), exclusive wetting of the force-generating body with the friction-reducing substance (without simultaneous application of such a substance to the Housing) as not preferred, although not excluded in principle. The reduced friction between the force generating body and the housing due to the surface treatment allows a better slippage of the force generating body on the first housing wall part, thereby facilitating the axial expansion of the force generating body, minimizing axial force peaks of the force generating body on other components of the container and equalizing the stresses in the material of the force generating body. It has been found that in this way even a shorter axial dimensioning of the force generating body is possible and thus the material usage per manufactured power generating body can be reduced, which nevertheless can lead to a total of relevant cost savings in the context of a mass production despite the additional expense for the surface treatment.

As a friction-reducing substance, for example, a lubricant based on water can be used, in the simplest case even pure water. In addition to water, such a water-based lubricant may include, for example, glycerin as another ingredient. The friction-reducing substance may in such embodiments with time partially or even substantially completely volatilize, the then increased friction between the force generating body and housing for the emptying of the force generating body will usually have no adverse effect, especially in view of the slowness, with which emptying is usually done in comparison to the filling.

The order of the friction-reducing substance can be done for example by spraying, dipping, spinning or brushing. In particular, when the friction partners (ie, the housing and the force generating body) both have a low surface energy, it may be advantageous to achieve a fine atomization by spraying the friction reducing substance so as to provide the desired surface areas of the housing or / and the force generating body with the To dampen friction-reducing substance over a large area, because a low surface energy makes the wettability difficult; It can be said that fluids tend to bead off a surface of low surface energy. If the surface energies of the friction partners make this possible, instead of atomizing the friction-reducing substance, the application can be carried out, for example, with a roller or a brush or in a dipping process. The surface treatment can be limited to those wall parts of the housing to which an expansion-related, in particular axial slippage of the force-generating body can occur at all. For example, it may be possible to leave the second housing wall part, which limits the axial extent of the force-generating body, which can be arranged in a bottom area of the housing free from the friction-reducing substance, if at all - even in the lubricated case - at most negligible sliding movements would occur there.

With regard to the choice of material, a silicone rubber, preferably an addition-crosslinking silicone rubber (in particular a liquid silicone rubber), is recommended for the force-generating body, although other elastomers (such as polyurethane) should not be excluded. Especially in the case of a power generating body based on silicone should be used as a friction-reducing substance, a silicone-free and mineral oil-free lubricant.

The friction-reducing substance may be a wipeable, non-adherent lubricant, although it is not excluded in the invention, at least on the inside of the housing to apply a firmly adhering lubricant.

The implementation of a friction-reducing surface treatment is particularly useful for material pairings with relatively strong mutual friction. For example, in a case made of polyethylene or polypropylene, a relatively high friction is found with the power generating body, especially when made of a silicone rubber. Other plastics can also show a comparatively strong friction with respect to the surface of a silicone rubber body. In that regard, the invention is by no means limited to housings made of PE (polyethylene) or PP (polypropylene). For example, it is basically conceivable to use a housing made of PMMA (polymethylmethacrylate) or PET (polyethylene terephthalate), in which case, however, the surface treatment should preferably produce a permanent friction-reducing layer on the first wall part or on the force-generating body. Such a durable friction reducing layer may be formed, for example, by a non-evaporating lubricant, which then forms a permanent barrier between the PMMA or PET material of the housing and the material of the power tool. can form body. The background is that many fabrics may tend to "stick dry" with self-adhering silicone (materials from a liquid silicone rubber, for example, show such a self-adhesive property.) This "dry bonding" results from the formation of hydrogen bonds between the rubbing partners, resulting in a permanent bond can. For PMMA and PET, such a "dry bonding" is to be feared, which is why the surface treatment in these

Plastic materials should form a permanent barrier to the material of the force generating body. Polyethylene and polypropylene, on the other hand, have no oxygen atoms in the molecular structure, which avoids the formation of hydrogen bonds to silicone. As far as a material without oxygen atoms in the molecular structure is used for the housing, it is therefore not absolutely necessary to provide a permanent friction-reducing barrier between the housing and the force-generating body. Instead, a fleeting lubrication can suffice there.

The housing shape may be, for example, bottle or can-like; In this case, it may, for example, be approximately cylindrical or have regions of different diameters, for example in the manner of a conical shape or with a more complex diameter profile. In any case, the housing is longer than wide, wherein the force-generating body is arranged with its longitudinal axis along the longitudinal extent of the housing in this. In such a housing shape, which thus deviates significantly from a spherical shape in the direction of an elongated shape, an expansion behavior of the force-generating body has been found to be advantageous, in which he applies radially before reaching a certain desired Endbefüllungszustands radially first time to a shell portion of the housing and thereafter in this area undergoes no significant further radial expansion. Nevertheless, there is still sufficient space for a further expansion of the force-generating body in the axial direction in this state. This allows in particular an expansion behavior in which the force-generating body initially begins to expand radially in an approximately central region of its axial length and the radial expansion continues comparatively uniformly axially towards the closed end of the force-generating body - with simultaneous axial expansion thereof. Such an expansion behavior has proven to be advantageous in order to obtain stable and reproducible filling and expansion conditions in a mass production. In a preferred embodiment, the first wall part of the housing may have at least one channel-like indentation, for example, on its housing-side wall surface in the region of the system of the force-generating body. Such a recess can be used for the defined prevention of the sliding movement of the force generating body on the first wall part. The indentation represents a local increase in diameter at which the force-generating body can expand more radially. The expansion of the force-generating body into the indentation can locally stop or at least reduce the slipping motion of the force-generating body, even if the friction-reducing surface treatment approaches the area of the friction-reducing surface treatment By targeted positioning of one or more indentations on the first wall part of the housing, therefore, stable, reproducible conditions with low dispersion can be created in series production, as far as the expansion behavior of the force-generating body is concerned.

Preferably, the expansion behavior of the force generating body is such that it does not apply axially before reaching a filling volume to the second wall portion of the housing, which is at least 1.5 times, more preferably at least 2.0 times, more preferably at least 2.5 -fold, preferably at least 2.8 times a Einfüllvolumens is from which the

Force generating body radially applies to the first wall portion of the housing.

The expansion behavior of the force-generating body may be such that it rests radially against the first wall portion of the housing before reaching a filling level of 50%, better 45%, even better 40%, preferably 35% of a specified nominal filling volume of the container. The nominal filling volume may correspond, for example, to a filling indication attached to the outside of the container and directed to the buyer or user. This can for example be printed or embossed or otherwise formed.

Relative to an empty volume of the housing, ie the internal volume present in the empty housing (without the force generating body), the expansion behavior of the force generating body may be such that it is preferred before reaching a filling level of 45%, better still 40%, even better 35% 30% of the void volume of the housing radially to the first wall part of the housing applies.

With regard to the axial extent, the expansion behavior of the force generating body can be such that it does not reach the filling level of 75%, better 80%, even better 85%, preferably 90% of a specified nominal filling volume of the container axially to the second wall part of the housing applies.

Alternatively or additionally, the expansion behavior of the force-generating body can be such that it does not engage axially against the second wall portion of the housing upon filling before reaching a filling level of 60%, better 65%, even better 70%, preferably 75% of the empty volume of the housing.

In the housing, the force-generating body is preferably provided with a filling-related axial elongation of at least 1.6 times, more preferably at least 1.7 times, even better at least 1.8 times, its axial length in the unfilled state. without the force-generating body axially abutting the housing with its closed end. This allows an expansion behavior of the force generating body, in which he filled axially with a nominal filling volume specified for the container axially at least 1.6 times, more preferably at least 1.7 times, more preferably at least 1.8 times its axial Length in the unfilled state expands.

In a preferred embodiment, the force-generating body has an opening in the region of its second longitudinal end and is connected in this area to a relatively stiffer, annular connecting body, which in turn is connected to at least one further container component, in particular at least one component of the housing, as part of the container assembly , The force generating body can be produced by injection molding and molded onto the connecting body.

According to a further aspect, the invention provides a container for a filling material, wherein the container comprises a housing and a protrude ^¬ in the housing ^¬ the rubber-elastic force generating body having a longitudinal axis and with a filling space for receiving the medium, wherein the Krafterzeu- tion body has a closed first longitudinal end and is suspended in the region of an opposite second longitudinal end relative to the housing, wherein the force generating body in its filling in such a manner in the housing - with respect to the longitudinal axis - radially and axially expands, that it reaches a Partial filling state, in particular at a distance from the second longitudinal end to a radial extension limiting first wall portion of the housing applies and continued filling the first longitudinal end of an expansion axially delimiting second wall portion of the housing under increasing axial enlargement of the area of the system of the force generating body to the first wall portion approaches. In the course of the expansion of the force generating body of this at least partially performs a sliding movement on the first wall part, wherein for defined influencing and possibly suppressing this sliding movement of the first wall portion on its housing-side wall surface in the region of the system of the force generating body has one or more, for example groove-like indentations. For example, the first wall part can be designed with at least one groove-like indentation, which is located in

Circumferential direction of the housing over the entire circumference or only a part of the housing circumference extends.

The invention will be explained below with reference to the accompanying drawings. They show:

1 is a Axiallängsschnitt through a designed as a fire extinguisher container according to an embodiment,

2 is a spray head of the container of FIG. 1 in an enlarged view,

3a to 3e axial longitudinal sections of the container of FIG. 1 (omitting a valve assembly) in different phases of the filling of a force-generating body,

Fig. 4 is an exemplary diagram for illustrating a filling process of the container of Fig. 1 and Fig. 5 shows schematically a phase of the manufacturing process of the container of Fig. 1, wherein in this phase, a housing of the container inside with a

Lubricant is sprayed.

Reference is first made to FIGS. 1 and 2. The container shown there, designated 10, is exemplified as a hand-held fire extinguisher, although other forms of use, such as dispensers for cosmetics, food or technical substances such. Lubricants are equally possible. Generally, the container 10 serves for storage and metered dispensing of a filling material, whereby the external configuration of the container may be, for example, bottle-like or can-like (with for example cylindrical or barrel-shaped basic shape) or follow any other shapes.

The container 10 has, in the example shown, a housing 12 made of polyethylene or polypropylene, for example, with a housing axis 14, a generally cylindrical shell portion 16 surrounding the shaft 14, and a bottom portion 18 closing the shell 12 axially adjacent the shell portion 16. In the region of the axially upper end of the casing part 16 of the housing 12 extends radially inwardly and forms a housing neck 20 with a housing opening 22nd

In the housing 12, specifically in the region of the housing neck 20, a rubber-elastic force generating body 24 is suspended, which projects into the designated interior 26 of the housing 12. The force generating body 24 is designed to be elongated in the unfilled, relaxed state in the manner of a condom and has a longitudinal axis 28. In its interior, it forms a filling chamber 30, which serves to receive a sprayable, such as foaming filling material. In the example case considered here, the filling material is an extinguishing agent, for example in the form of a quenching gel or an extinguishing liquid. The force-generating body 24 is produced in an injection molding process with a ball-like rounded closed end 32 and an opening 34 formed at the opposite longitudinal end, preferably made of a silicone material, in particular liquid silicone rubber. It is understood that other elastomeric materials are equally usable, such as a polyurethane-based plastic. The force generating body 24 is formed in one piece in the example shown, but it may optionally inside or / and outside be coated comparatively thin with a permanent layer of another material.

The force-generating body 24 is suspended in the housing 12 in such a way that in the unfilled state its longitudinal axis 28 extends substantially parallel to the housing axis 14, in particular coincident with it approximately. In the region of its open longitudinal end, it is connected to a connecting ring 36, which is made of a comparatively stiff material which is as inelastic as possible and which in turn is fastened to the housing 12. In the example shown, the connecting ring 36 has an axially extending portion 38, with which it is inserted into the housing opening 22. This axially extending portion 38 extends from an approximately annular disc-shaped portion 40, which projects beyond the axially extending portion 38 both radially inwardly and radially outwardly. With its radially outer part of the annular disc portion 40 covers the housing neck 20, while at its radially inner edge has an axially projecting upstanding extension 42, which serves for mounting a, for example, aluminum or tinplate cover part 44. Overall, the connecting ring 36 can be considered in cross-section in a rough approximation as T-shaped, wherein the axial portion 38 forms the main leg of the T and the annular disc portion 40 forms the transverse leg of the T. The T-shape of the connecting ring 36 is slightly modified in the example shown, due to the presence of the projecting axially upward projection 42.

For attachment of the connecting ring 36 to the housing 12, for example, an adhesive connection between the portion 38 and / or the radially outer portion of the portion 40 and the housing 12 may be provided. It is also conceivable to fix the connecting ring 36 to the housing 12 by means of a snap or clamping connection or by means of a thread or a bayonet closure.

The connection between the connecting ring 36 and the force generating body 24 is cohesively. Specifically, the force generating body 24 is molded onto the connecting ring 36, for which purpose the Ver ^¬ binding ring 36 can be inserted as a prefabricated component in the intended for the force generating body 24 injection mold in the context of the injection process. It can be seen that the force-generating body 24 only on the radially inner side of the connecting ring 36 is molded onto these. The radially outer regions of the connecting ring 36 are free of the material of the force-generating body 24. This is advantageous for the pressure conditions in the filled state; Tensile stresses in the connecting region between force-generating body 24 and connecting ring 36 can be better avoided.

For good adhesion of the connecting ring 36 to the force-generating body 24, the connecting ring 36 is preferably made of a polyamide or of polybutylene terephthalate (PBT) or polyethylene terephthalate (PET).

The cover part 44 is connected in its radially outer region by a crimp connection with the axial extension 42 of the connecting ring 36. In the crimping area, a sealing ring 46, which in the example shown is cross-sectioned in cross-section, is inserted between the cover part 44 and the extension 42 in order to prevent undesired discharge of filling material from the filling space 30 at the connection point between cover part 44 and connecting ring 36.

The cover member 44 serves as a support of a valve assembly, generally designated 48, which may be clamped, glued, or otherwise attached to the cover member 44, for example. It intersperses with a valve main body 50 a unspecified, central opening of the cover member 44 and has a niederzudrückendes by the user in the axial direction actuator 52, which also forms an outlet channel 54 for the extinguishing agent to be sprayed. Depending on the configuration, in particular viscosity of the extinguishing agent, the geometry of the outlet channel 54 may be different.

The force-generating body 24 is formed in the example shown on a majority of its axially below (ie, beyond) the connecting ring 36 lying length in the manner of a hose having both inner peripheral side and outer peripheral side circular cross-section. In the tubular area, there are no strong fluctuations in the wall thickness, especially no changing increases and decreases of the wall thickness. This tubular portion begins approximately at a dashed line in Fig. 1 at 56 shown axial position and extends axially to where the wall of the force generating body 24 begins to converge in the region of the closed end 32. This position is schematically indicated in FIG. 1 at 58. At least in the axial tube area between the positions 56, 58, either (i) the wall thickness of the force generating body 24 increases evenly toward the closed end 32, or (ii) the wall thickness remains constant, but the diameter becomes toward the closed end 32 evenly smaller (because of the constant wall thickness, the diameter decrease applies equally to the inner diameter as well as the outer diameter). Both a linear increase in thickness and a linear decrease in diameter (with constant wall thickness) of the wall of the force-generating body 24 in the tubular region promote an expansion behavior, as shown in Figs. 3a to 3e and will be explained later. In the case of a thickness increase, this can continue beyond the lower axial end of the hose region of the force-generating body 24 into the region of the closed end 32.

For example, the force-generating body 24 in the tubular region may have an inner peripheral surface 60 that tapers conically with respect to the closed end 32, relative to the longitudinal axis 28, and an outer circumferential surface 62 that extends in a circular-cylindrical manner relative to the axis 28. The included between the conically tapered inner peripheral surface and the cylindrical outer peripheral surface angle (widening angle of the wall thickness) is for example about 0.2 to 0.3 degrees. Over an axial distance of example ^¬ example, about 10 cm corresponds to the wall thickness increase then a few tenths of a millimeter (eg, about 0.4 - 0.5 mm).

Alternatively, both the outer peripheral surface and the inner peripheral surface of the force generating body 24 may be tapered, both tapering toward the closed end 32 of the force generating body. However, the taper of the inner peripheral surface may be stronger than that of the outer peripheral surface, so that an overall increase in the wall thickness as it progresses towards the closed end 32 of the force generating body results. The expansion angle of the wall thickness may in turn have a value in the order of tenths of degrees or it may be slightly smaller than before, because due to the taper of the outer peripheral surface of the wall thickness increase an effective diameter reduction of Krafter ^¬ generating body is superimposed. As a further alternative, the diameter of the force-generating body 24 alone can be reduced in the tubular region with a constant wall thickness. The inner peripheral surface and the outer peripheral surface are preferably both tapered in this case and both taper at the same taper angle toward the closed end 32. The diameter reduction angle may have a similar value (in the order of tenths of degrees) as previously the wall thickness expansion angle.

Overall, the range of continuous increase of the wall thickness of the force generating body 24 or / and continuous reduction of the diameter extends over a majority of the axial total length of the force generating body 24, for example at least 70% or even at least 75%.

Axially above the beginning of the tubular region given by the position 56, the force-generating body 24 may have a more complex wall geometry. However, the axial length of this region is short compared to the total length of the force generating body 24. In the example shown, the force-generating body 24 in the region of the axially lower end of the connecting ring 36 has a point of increased wall thickness, at which a radially inwardly projecting, circumferential wall thickening 63 is located. The wall thickening 63 helps to keep the stresses in the material of the force-generating body 24 in the region of the axially lower end of the connecting ring 36 low. At the same time, it can serve as a demoulding aid for the mold core of the injection mold used to produce the force-generating body 24.

Reference is now made to Figs. 3a to 3e. FIG. 3 a shows the unfilled state of the force-generating body 24. It can be seen that the force-generating body 24 has an axial distance from the bottom part 18 of the housing 12. He also has round radial distance from the skirt portion 16, and this is true at least for ^¬ that region in which the force-generating body 24 is radially extensible and is not prevented as far as possible through the connecting ring 36 at a radial expansion.

When filling the force-generating body 24 with extinguishing agent (or in general: contents), the force-generating body 24 begins to expand. FIGS. 3 b, 3 c, 3 d, and 3 e indicate expansion states of the force-generating body 24 different degrees of filling up to a final filling state (Figure 3e). The filled volume in the final filling state is dependent on a nominal filling quantity prescribed for the container 10 and in any case is greater than this.

The dead volume of the force generating body 24 (inner volume in the unfilled state) can be kept small by providing a volume displacer (not shown in detail).

The expansion of the force generating body 24 takes place both in the radial direction and in the axial direction. It will be appreciated that the radial extent is first approximately greatest in an axial center region of the force generating body 24 (centered on its respective axial length). With a sufficient degree of filling, the force-generating body 24 finally abuts the casing part 16 all around (FIG. 3c). As a result, two subspaces 64, 66 between the housing 12 and the force generating body 24 are separated axially above and below the contact area, in which the force generating body 24 abuts the shell portion 16, whose volumes increasingly decrease upon further filling of the force generating body 24. The abutment region, in which the force-generating body 24 bears against the jacket part 16, expands in both axial directions, i. axially downwards and axially upwards, further out (although more towards axially lower). The casing part 16 forms a radial expansion limiting first wall part in the context of the invention.

In the final filling state, the force-generating body 24 has expanded axially to at least close to the bottom part 18 of the housing 12 and preferably rests flat in an approximately spherical base recess 68 (see FIG. 3d). In this state, the force generating body 24 abuts on a large part of the axial length of the shell part 16 at this. The Ansto ^¬ Shen of the force generating body 24 on the bottom part 18 is preferably carried out shortly before reaching the nominal filling, for example, only after filling of at least 80%, better at least 85% and more preferably at least 90% of the nominal filling quantity of the container 10. An invagination of the force generating body 24 in In the case of such an expansion behavior of the force-generating body 24, the area of the bottom part 18 can be avoided, at least as long as the filled medium does not freeze and does not thereby increase its volume. ßert. The bottom part 18 forms a second wall part bounding the axial extension in the sense of the invention.

The stored in the force generating body 24 Dehnspannung causes a force acting on the filled product force through which the filling material is expelled from the container 10 upon actuation of the valve assembly 48. Other force generating means are not present in the container 10 shown. The application force is completely applied by the force generating body 24.

The filling amount (filling volume) to be filled up to the final filling state may be, for example, between 105% and 115% of the nominal filling amount assigned to the container 10. Preferably, as part of the filling of the container 10 so much filling material is filled that the total amount filled corresponds to the nominal filling quantity plus the initial volume of air in the filling space 30 in the unfilled state of the force generating body 24 plus an additional volume. This additional volume serves to compensate for losses that may result from a decreasing recovery capability of the stretched body generating body 24 and from depletion of contents of the fill through the wall of the force generating body 24. For example, the additional volume may once again be at least as great as the initial volume of air in the filling space 30 of the unstretched force-generating body 24.

FIG. 4 shows, by way of example, qualitative developments for axial elongation (characteristic curve 1) and diameter expansion (characteristic curve 2) when the container 10 is filled. Up to a filling volume Vi, the force-generating body 24 can expand both axially and radially without restriction through the housing 12. When the filling volume Vi is reached, the force-generating body 24 first comes into contact with the casing part 16 of the housing 12. This corresponds to the state shown in FIG. 3c. The term force element used in FIG. 4 refers to the force-generating body 24; Wall means the part of the housing wall formed by the shell part 16.

After exceeding the filling volume Vi, the contact area, in which the force generating body 24 bears against the shell part 16, expands in the axial direction, but there is no further diameter expansion of the force Therefore, in the diagram of FIG. 4, the characteristic curve 2 changes from the filling volume Vi into a horizontal straight line. At the same time, the tip of the force generating body 24 (ie, its closed end 32) shifts axially toward the bottom part 18. This is indicated in the diagram of Figure 4 by a continued increase in the characteristic curve 1 beyond the filling volume Vi.

Upon reaching a filling volume V ₂ , the axially lower end 32 of the force generating body 24 abuts the bottom part 18 of the housing 12. At the latest then the filling process is completed. There is no further, at least no significant, further filling beyond this point of impact of the force generating body 24 at the bottom portion 18. Optionally, the filling process can be completed before the force generating body 24 abuts the bottom part 18. In any case, the filling volume V ₂ , at which the filling process is completed, is above the nominal filling volume of the container 10. To give a numerical example, with a specified nominal filling volume of 800 cm ^{3 of} the container 10, the total filled filling volume V _{2 could be} about 900 cm ³ ,

The graph of Figure 4 illustrates that the first-time radial contact of the force generating body 24 takes place on the shell part 12 comparatively early, before the final filling state (filling volume V ₂ ) is reached. The filling volume Vi can be, for example, between 20% and 50%, preferably between 25% and 40%, of the filling volume V ₂ . In other words, the filling volume V _{2 is} at least 2.0 times, for example approximately 3.0 times or even an even greater multiple of the filling volume i. Based on the nominal filling volume indicated for the container 10, the filling volume Vi can be, for example, about 30% to 35% of the nominal filling volume. As an alternative to the nominal filling volume, a referencing to the void volume of the housing 12 is conceivable. Among the volume of Gehäu ^¬ seinnenraums 26 is meant in the absence of power generating body 24th Based on such a void volume of the housing 12, the filling volume Vi can be for example between about 20% and 30%.

Overall, the diameter expansion of the force generating body 24 to the abutment on the shell part 16, for example, be between 200% and 300%, the axial elongation upon reaching the filling volume V ₂ can example ^{¬ be} between 80% and 150%. The free space in the unfilled state axially below the force generating body 24 to the bottom portion 18 of the housing 12 is dimensioned so that the force generating body 24 applies only after filling a nominal filling volume of the container 10 more than sufficient filling amount to the bottom part 18, ie after more than 100 % of the nominal filling volume. For example, it may be that an installation of the force-generating body 24 at the bottom part 18 takes place only after filling at least 110% or even at least 120% of the nominal filling volume of the container 10. With reference to the void volume of the housing 12, by contrast, the axial free space below the force-generating body 24 can be dimensioned such that a bearing of the force-generating body 24 does not take place on the bottom part 18 before at least 85%, preferably at least 90% of the housing vial volume is filled into the force-generating body 24.

The friction between the inner surface of the housing 12, particularly the inner surface of the skirt portion 16, and the outer surface of the force generating body 24 may be considerable. This is especially true in the case of manufacturing the force generating body 24 from a silicone rubber. Silicone materials often have a surface that makes anything but smooth sliding possible. If the housing 12 is also made of a plastic, in particular polyethylene or polypropylene, a material pairing between the housing 12 and the force generating body 24 can easily result, which prevents almost any slipping (sliding).

However, it has been shown that in the expansion phase of the force generating body 24, when it already rests radially on the shell portion 16 of the housing 12, slipping of the force generating body 24 along the shell portion 16 in the axial direction is advantageous to excessively high axial forces on the connecting ring 36 avoid, which may even lead to a detachment of the connecting ring 36 from the housing 12 under certain circumstances. In the sequence of FIGS. 3a to 3e, therefore, in the situations of FIGS. 3c and 3d, the force-generating body 24 should be able to slide axially against the jacket part 16 of the housing 12 in order to avoid such force peaks and for a balanced distribution of the stresses in the material of the force distribution body 24 to care. For this purpose, in the manufacture of the container 10, specifically before the installation of the force-generating body 24 into the housing 12, the inner surface surface of the housing 12, at least in the region of the jacket part 16, is sprayed with a friction-reducing substance, as shown schematically in FIG. 5. The friction-reducing substance is preferably a water-based lubricant (eg with glycerine as a further main constituent), which may at least partially volatilize over time. On the other hand, a silicone-based or mineral oil-based lubricant should not be used if a silicone rubber force generating body is used because the lubricant might attack the material of the force generating body.

The lubricant is sprayed as shown in FIG. 5, for example by means of a spray bar 70, which can dive through the housing neck 20 into the housing 12. By means of the spray bar 70, the jacket part 16 can be sprayed on the inside with the lubricant at least over part of its axial length and, if desired, also the bottom part 18 of the housing 12. A schematically indicated spray control unit 72 controls the spraying process.

After the inside lubrication of the housing 12 and the extraction of the spray bar 70 from the housing 12 is then in the assembly of Be ^¬ container 10 of the previously separately manufactured force generating body 24 (together with the adhesive thereon connecting ring 36) inserted into the housing 12 and with this connected. This is indicated schematically in FIG. 5 by an arrow 74. Then the finished container can be filled with the desired contents, after the valve assembly 48 (or other suitable valve means) was previously added.

Alternatively or additionally to the application of a lubricant, a friction reduction between the housing 12 and the force-generating body 24 can be achieved by fluorination of at least one of the two surfaces forming the friction pairing. By fluorination, the surface properties can be changed and thus reduce the friction. Both silicone materials and other plastics can usually be fluorinated well. The fluorinated compounds on the surface of the body thus treated are generally comparatively stable, so that fluorination is not only possible, but especially if the materials of the housing 12 and of the force-generating body 24 are at risk of dry adhesion By forming hydrogen bonds, fluorination can then create a permanent separation layer. the one which prevents the formation of such hydrogen bonds or at least reduces in number.

FIGS. 1 and 3a to 3e clearly show a plurality of radial indentations 76 formed in the casing part 16 of the housing 12, the notion of indentation being understood here from the perspective of a viewer looking at the casing part 16 on the inside of the casing. The indentations 76 are groove-like in the example shown and extend in the circumferential direction of the shell part 16. You can z. B. over the entire housing circumference. Alternatively, a plurality of indentations 76 may be arranged in an axial plane in the circumferential direction one behind the other at a distance. In the example shown, moreover, such indentations 76 are provided in several axial planes one above the other. At least a portion of the indentations 76 is located in a region of the shell part 16, in which the force-generating body 24 rests against the shell part 16 in the course of its expansion over the respective indentation 76, the force-generating body 24 expanding slightly more in the region of the indentation 76 can, ie into the indentation 76 can expand into. This causes, so to speak, a "locking" of the force-generating body 24 in the indent 76, so that locally a slipping movement of the force-generating body relative to the jacket part 16 can be restricted or even prevented 76 'identified indentations take place such a "locking" of the force generating body relative to the housing 12, because it is these indentations 76', which completely covers the force generating body 24 until reaching the Endbefüllungszustands.

Claims

claims

1. A method for producing a container (10) for a filling material, wherein the container comprises a housing (12) and a projecting into the housing rubber-elastic force generating body (24) having a longitudinal axis (28) and with a filling space (30) for receiving the medium includes,

wherein the force generating body has a closed first longitudinal end (32) and is suspended in the region of an opposite second longitudinal end relative to the housing,

wherein the force generating body when it is filled in such a manner in the housing - with respect to the longitudinal axis - radially and axially expands, that it reaches a partial filling state, in particular at a distance from the second longitudinal end to a radially limiting the first wall part (16) of the Housing (12) applies and with continued filling, the first longitudinal end (32) an expansion axially delimiting the second wall portion (18) of the housing (12) with increasing axial enlargement of the area of the system of the power generating body to the first wall portion approaches, wherein the Manufacturing method before filling the force generating body at least a part of the first wall part (16) inside the housing o / / and at least a part of the force generating body (24) is externally subjected to a friction-reducing surface treatment.

2. The method of claim 1, wherein the surface treatment comprises applying a friction-reducing substance to the first wall part (16) or / and the force-generating body (24).

3. The method of claim 2, wherein the friction-reducing substance is applied in a spray, dip, spin or brush method.

4. The method according to claim 2 or 3, wherein the friction-reducing substance is a water-based lubricant is used.

5. The method according to any one of claims 2 to 4, wherein as a friction-reducing substance, a lubricant is used which is free of components based on Sili ^¬ kon or mineral oil.

6. The method according to any one of claims 2 to 5, wherein a non-adhesive lubricant is used as the friction-reducing substance.

7. The method according to any one of the preceding claims, wherein the surface treatment comprises a fluorination of the first wall part (16) and / or the force generating body (24).

8. The method according to any one of the preceding claims, wherein the housing (12) made of polyethylene or polypropylene is made.

9. A method according to any one of claims 1 to 7, wherein the housing is made of polymethyl methacrylate or polyethylene terephthalate and the surface treatment is a durable friction reducing layer on the first

Wall part (16) and / or produced on the force generating body (24).

10. The method according to any one of the preceding claims, wherein the force generating body (24) is made of a silicone rubber.

11. The method according to any one of the preceding claims, wherein the first wall portion (16) on its housing-side wall surface in the region of the system of the force-generating body has at least one, for example groove-like indentation.

12. Container, produced according to one of the preceding claims.

13. container (10) for a filling material, wherein the container comprises a housing (12) and a projecting into the housing rubber-elastic force generating body (24) having a longitudinal axis (28) and with a filling space (30) for receiving the filling material,

wherein the force generating body when it is filled in such a manner in the housing - with respect to the longitudinal axis - radially and axially expands, that it reaches a partial filling state, in particular at a distance from the second longitudinal end to a radially limiting the first wall part (16) of the Housing (12) applies and with continued filling the first longitudinal end (32) approximates an expansion axially delimiting second wall part (18) of the housing (12) with increasing axial enlargement of the area of the system of the force generating body on the first wall part, whereby in the course of the expansion of the force generating body (24) at least in parts, a sliding movement on the first wall portion (16) performs, wherein the first wall portion (16) on its housing-side wall surface in the region of the system of the force generating body has one or more, for example groove-like indentations.