Patent Application
20230294906
The present disclosure relates to emptying highly viscous substances, i.e., paste-like material, out of supplied transport containers, especially cartridges, in a bubble-free manner.
When processing highly viscous substances, e.g., in adhesive technology or the cosmetics industry, these substances or their individual components are delivered in transport containers such as cylindrical cartridges, which are generally made of plastic, with a capacity of one or more liters. The viscose material contained in the transport containers must be supplied from there to the consumer free of bubbles, i.e., without air pockets, using a doser or a mixer.
General references to cartridges in the present description are intended to encompass all transport containers that are open at both ends, but are closable, and that include a pusher that is moved inside the container tightly along the inner circumference of the cylindrical cartridge. The pusher is introduced from a rear end of the cartridge, while the opposite front end generally has a much smaller removal opening that is closed during transportation and can be opened for removal of the material.
The removal from the cartridge and the transport via a supply line (the discharge line) to the remote consumer is to be carried out as required and automatically without any time-consuming manual reworking. The emptying of the usually quite expensive materials is to be possible with as little remaining residue as possible. In addition, no air should be able to reach the material during emptying, or even air still contained in the material should be able to escape.
So far, this is attempted by inserting a degassing nozzle between the discharge line, usually a hose line, to be connected to the removal opening, and the removal opening, to which negative pressure can be applied. However, by this method, only gas bubbles can be removed that appear after opening of the removal opening and connection to the discharge line, but not gas bubbles that are, for example, finely distributed inside the material.
In general, it is known to degas fluid materials in a thin-layer process:
In this process, the material is guided over a surface in the form of a layer as thin as possible, thereby massively increasing the surface area of the flowing material, so that the probability of a contained gas bubble coming into contact with the surface of the layer and thus outgassing from the material is largely increased.
Furthermore, when removing barrels with viscous material, which are delivered as transport containers, it is known to empty such a barrel by way of a barrel follower plate placed on the material, but, already prior to inserting the barrel follower plate into the barrel and placing it onto the material, to apply negative pressure, in particular a vacuum, to the space around it and for this purpose, arrange a pressure-tight housing around it that includes a negative pressure connection.
However, due to the lack of a second opening, the material is conveyed out of a single opening at the top of the barrel, namely through the hollow piston rod attached to the barrel follower plate and pressing it downwards.
For this purpose, the barrel follower plate must be pressed against the material with high pressure, for which the stability of the barrel itself in a radial direction quite often is insufficient, but the barrel must be held together radially in a corresponding support device.
In the case of cartridges, the material is to be pressed out by means of the pusher located therein, which can be moved along a mostly round inner cross-section that is constant in a main extension direction of the cartridge, through the discharge opening provided in the opposite end face of the cartridge.
It is therefore an object of the present invention to provide a method for emptying cartridges in a bubble-free manner, by way of which also gas bubbles can be removed that exist inside the material prior to delivery to a consumer. Moreover, it is an object to provide an emptying device suited for this.
To empty a cartridge in a bubble-free manner, a viscous material is pressed out of a removal opening of the cartridge into a large-surface distributing head that has a plurality of small outlet openings on its lower side such that a plurality of thin strands of the viscous material are produced. The strands have a very large surface area in comparison to their volume. So that gas that is outgassed in the process can be removed, a vacuum is applied about the strands. The strands fall into a collecting container disposed underneath. After the cartridge is completely emptied, the viscous material is transported from the collecting container via an outlet opening disposed in the bottom of the collecting container and into a discharge line that is connected to a consumer of the viscous material. The discharge line can be connected to a doser. The viscous material can be forced out of the outlet opening by pressing the distributing head downward into the open side of the collecting container.
An emptying device for emptying a viscous material in a bubble-free manner out of a removal opening of a cartridge involves extruding a plurality of thin strands of the material. The emptying device includes a collecting container mounted to a base frame and a cartridge carrier that is guided in a pressing direction towards the base frame. The cartridge carrier is adapted to hold the cartridge. A cartridge plunger is adapted to push a pusher of the cartridge in the pressing direction. A discharge drive drives the cartridge plunger. A distributing head divides the viscous material exiting the removal opening into the plurality of thin strands that travel downwards in straight lines from the distributing head. The distributing head is fastened to the removal opening and is adapted to move axially in the collecting container in the pressing direction. A first vacuum housing connects in an air-tight manner to the collecting container and to an outer circumference of the cartridge even while the cartridge moves relative to the first vacuum housing. A second vacuum housing is disposed inside the cartridge carrier and connects in an air-tight manner to the outer circumference of the cartridge. The cartridge plunger passes through the second vacuum housing in an air tight manner.
A method for emptying viscous material in a bubble-free manner out of a cartridge involves extruding a plurality of thin strands of the viscous material. A pusher connected to a cartridge plunger is axially pushed through the cartridge in a pressing direction towards a removal opening of the cartridge. The pusher fits tightly in the cartridge. The viscous material is pressed out of the removal opening and through a distributing head such that the viscous material is divided into the plurality of thin strands. The plurality of thin strands are collected in a collecting container to which a discharge line is connected. A negative pressure is maintained in the collecting container while the plurality of thin strands are being collected in the collecting container. The negative pressure is a vacuum with a residual pressure inside the collecting container of at most 50 mbar. A negative pressure is also maintained in the cartridge behind the pusher while the viscous material is being pressed out of the removal opening. After the plurality of thin strands have been collected in the collecting container, the viscous material is pressed out of the collecting container through the discharge line by pushing the distributing head as a discharge piston axially down into the collecting container.
Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims.
The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention.
Reference will now be made in detail to some embodiments of the invention, an example of which is illustrated in the accompanying drawing.
With regard to the novel method, the object is solved in that in pressing out the material from the removal opening by means of axial displacement of a pusher, the material is divided into a plurality of thin strands. As a result of the large increase in surface area, the probability that a gas bubble in the material coming into contact with the surface of such a thin strand is much higher, and, of course, the higher the thinner the strands are. The strands are dropped into a collecting container open to the top and mix with the fluid material provided therein, which is delivered from the collecting container to a consumer by way of a main feed pipe connected to the lower part of the container.
In order to prevent new gas pockets from forming when the thin strands are combined with the material in the collecting container, at least the area where the material is divided into a large number of thin strands, i.e., approximately from the removal opening to the upper open end of the collecting container, is held under negative pressure during the emptying process of the cartridge, and preferably also during discharge of the material from the collecting container to a consumer.
The gas contained in an opening gas bubble in the material is then discharged from this area and, if there is nearly a vacuum in the area, no new gas pockets can form. Negative pressure within the context of the present description is understood to mean that this is in particular approximately a vacuum with a residual pressure of 50 mbar at most, preferably 10 mbar at most, further preferably 1 mbar at most.
For transportation to the consumer, the material is pressurized in the direction of the mouth of the discharge line at the collecting container, at the latest after the cartridge is completely emptied, which is preferably done by moving forward a discharge piston guided tightly within the collecting container from an open side in the direction of the mouth of the discharge line, preferably in the direction of the bottom of the mostly pot-shaped collecting container where the mouth is in the bottom.
As the collecting container is filled with material in a vacuum environment and as such a discharge piston is inserted under vacuum into the open upper side of the collecting container, no more gas pockets are formed, even if, after insertion of the discharge piston into the open upper side of the collection container, there still was a clearance between the discharge piston and the upper side of the filling of material, since it no longer contains any air.
Splitting of the material coming out of the removal opening as one thick strand into a plurality of thin strands is carried out by means of a distributing head, which in particular has a plurality of outlet openings for each thin strand. The viscous material is extruded out of the distributing head in the form of the plurality of thin strands. Advantageously, this distribution head, which during emptying of the cartridge is preferably arranged at a distance above the open top of the collecting container, is subsequently used as a discharge piston, especially after completely emptying the cartridge, and is inserted into the collecting container and is tightly guided downwards, for which the distribution head must have suitable dimensioning.
On the one hand, no separate discharge piston is required for this purpose, and on the other hand, it is prevented thereby that a separately existing discharge piston is placed below the distributing head and above the opening of the collecting container and is lowered into it only then, which would be much more time-consuming. Preferably, the distributing head alone is not pushed axially into the collecting container, but rather together with the cartridge, to the front end of the removal opening to which it is attached so that the cartridge thus acts as a plunger that moves the distributing head axially.
Preferably, the cartridge is moved axially by being fixed with its rear end in both axial directions, i.e., both upwards and downwards, in a cartridge carrier and this cartridge carrier can be moved back and forth in a pressing direction by way of a conveying drive.
For pressing the material out of the cartridge, a cartridge plunger of a cartridge drive is fixed to the rear side of the pusher facing away from the material and presses the pusher further forwards in the direction of the removal opening.
To ensure a tight fit of the pusher on the inner circumference of the cartridge, the cartridge can also be supported radially on its outer circumference.
Preferably, the area on the outside, i.e., the back side, of the pusher up to the exit point of the cartridge plunger from the cartridge drive, is kept under negative pressure during the emptying process, so that no air is present on the back side of the pusher that could penetrate the material in case of a possible leak between the pusher and the inner circumference of the cartridge.
Preferably, instead or in addition, only the area on the back side of the cartridge plunger can be evacuated, but not up to its exit point from the cartridge drive, but merely to a front part of the cartridge plunger.
In order to be able to perform emptying, the cartridge with the distributing head already attached to its removal opening is inserted under the retracted cartridge plunger in a direction transverse to the pressing direction and fixed in the cartridge carrier in alignment with the cartridge plunger, the cartridge carrier being displaced, particularly upwards, from the collecting container to such an extent that, in inserting the cartridge into the cartridge carrier, the distributing head is still above the collecting container.
With regard to the novel method, the object is solved in that in pressing out the material from the removal opening by means of axial displacement of a pusher, the material is divided into a plurality of thin strands. As a result of the large increase in surface area achieved by the plurality of thin strands, the probability that a gas bubble in the material coming into contact with the surface of such a thin strand is much higher, and, of course, the thinner the strands are the higher the probability.
The strands are dropped into a collecting container open to the top and mix with the fluid material provided therein, which is delivered from the collecting container to a consumer by way of a main feed pipe connected to the lower part of the container.
In order to prevent new gas pockets from forming when the thin strands are combined with the material in the collecting container, at least the area where the material is divided into a large number of thin strands, i.e., approximately from the removal opening to the upper open end of the collecting container, is held under negative pressure during the emptying process of the cartridge, and preferably also during discharge of the material from the collecting container to a consumer.
The gas contained in an opening gas bubble in the material then is discharged from this area and, if there is nearly a vacuum in the area, no new gas pockets can form.
Negative pressure within the context of the present description is understood to mean that this is in particular approximately a vacuum with a residual pressure of 50 mbar at most, preferably 10 mbar at most, further preferably 1 mbar at most.
For transportation to the consumer the material is pressurized in the direction of the mouth of the discharge line at the collecting container, at the latest after the cartridge is completely emptied, which is preferably done by moving forward a discharge piston guided tightly within the collecting container from an open side in the direction of the mouth of the discharge line, preferably in the direction of the bottom of the mostly pot-shaped collecting container where the mouth is in the bottom.
As the collecting container is filled with material in a vacuum environment and as such a discharge piston is inserted under vacuum into the open upper side of the collecting container, no more gas pockets are formed, even if, after insertion of the discharge piston into the open upper side of the collection container, there still was a clearance between the discharge piston and the upper side of the filling of material, since it no longer contains any air.
Splitting of the material coming out of the removal opening in one thick strand into a plurality of thin strands is carried out by means of a distributing head, which in particular has a plurality of outlet openings for each thin strand.
Advantageously, this distributing head, which during emptying of the cartridge is preferably arranged at a distance above the open top of the collecting container, is subsequently used as a discharge piston, especially after completely emptying the cartridge, and is inserted into the collecting container and is tightly guided downwards, for which the distribution head must have suitable dimensioning.
On the one hand, no separate discharge piston is required for this purpose. On the other hand, it is prevented thereby that a separately existing discharge piston is placed below the distributing head and above the opening of the collecting container and is lowered into it only then, which would be much more time-consuming. Preferably, the distributing head alone is not pushed axially into the collecting container, but rather together with the cartridge, to the front end of the removal opening to which it is attached so that the cartridge thus acts as a plunger that moves the distributing head axially.
Preferably, the cartridge is moved axially by being fixed with its rear end in both axial directions, i.e., both upwards and downwards, in a cartridge carrier and this cartridge carrier can be moved back and forth in a pressing direction by way of a conveying drive.
For pressing the material out of the cartridge, a cartridge plunger of a cartridge drive is fixed to the rear side of the pusher facing away from the material and presses the pusher further forwards in the direction of the removal opening.
To ensure a tight fit of the pusher on the inner circumference of the cartridge, the cartridge can also be supported radially on its outer circumference.
Preferably, the area on the outside, i.e., the back side, of the pusher up to the exit point of the cartridge plunger from the cartridge drive, is kept under negative pressure during the emptying process, so that no air is present on the back side of the pusher that could penetrate the material in case of a possible leak between the pusher and the inner circumference of the cartridge.
Preferably, instead or in addition, only the area on the back side of the cartridge plunger can be evacuated, but not up to its exit point from the cartridge drive, but merely to a front part of the cartridge plunger.
In order to be able to perform emptying, the cartridge with the distributing head already attached to its removal opening is inserted under the retracted cartridge plunger in a direction transverse to the pressing direction and fixed in the cartridge carrier in alignment with the cartridge plunger, the cartridge carrier being displaced, particularly upwards, from the collecting container to such an extent that, in inserting the cartridge into the cartridge carrier, the distributing head is still above the collecting container.
As can be discerned from
The upper free ends of these two piston rods 13a, 14a, which can be moved synchronously, are connected to each other by a yoke 23, on which the cartridge drive 4 in the form of preferably only one cartridge working cylinder 15 projects centrally, this time with the bottom of cylinder 15b pointing upwards, so that the piston rod 15a as a cartridge plunger 15a extends downwards therefrom and protrudes through an opening in the yoke 23, which is formed in the cartridge receptacle 16 of cartridge carrier 3, into a cartridge 100 suspended therein and aligns therewith.
In this case, the cartridge carrier 3 consists of a rectangular profile open in the second transverse direction 12 on at least one side, preferably continuously, which is preferably attached to the underside of the yoke 23, which is narrow enough in the first transverse direction 11 to dip between the two discharge working cylinders 13, 14.
Thereby, in the lower horizontal plate of the rectangular profile, there is a recess in the second transverse direction 12 (see
The cartridge insertion process will be described later by way of
In this suspended state, the cartridge 100 extends through the cartridge receptacle 16 and points downward with its generally smaller removal opening 100a at the opposite end.
As depicted in
For emptying, in accordance with the invention, the closing element 102 is removed and instead a distributing head 7 is screwed to the removal opening 100a, preferably with its own thread, in particular an external thread, as a fastening device 7a to the thread, in particular internal thread 100a1, which will be explained later.
In
On the base frame 1, in particular on the base plate 1, a collecting container 2 is mounted between the two discharge working cylinders 13, 14 and in alignment with the cartridge working cylinder 15, which likewise is operated pneumatically, and the cartridge 100 firmly held in the cartridge receptacle 16.
The distributing head 7 fits tightly into the pot-shaped collecting container 2 open at the top.
The yoke 23 can be raised sufficiently so that the distributing head 7 is above the collecting container 2, and lowered enough so that the distributing head 7 rests on the bottom of the collecting container 2.
The piston rod, i.e., the cartridge plunger 15a, of the cartridge working cylinder 15 carries a pressing head at its lower free end, the downwardly facing end face of which is adapted to the concave curvature of the upper side of the pusher 101 and fits into the latter.
The cartridge working cylinder 15 is dimensioned in such a way that, when the piston rod 15a is fully retracted into its cylinder 15b, i.e., raised, the pressing head 24 is located at a height fully above the suspended cartridge 100 and, in the fully extended state, is close to the bottom of the cartridge 100 at its removal opening 100a, with only the pot-shaped pusher 101 in between.
In the lower region of the emptying device 200, preferably in the bottom of the collecting container 2, an outlet opening 29 is provided, which is connected to a discharge line 20 leading to a remote consumer for the material M.
For feeding material M from the cartridge 100 to the discharge line 20 and thus to the consumer, a cartridge 100 must first be installed in the emptying device as shown in
For this purpose (see
Subsequently, the annular cover 21b of a first vacuum housing 21 is pushed from the emptying end onto the outer circumference of the cartridge 100 or—if provided—of the support sleeve 103 to such an extent that the distributing head 7 can then be attached to the lower removal opening 100a, in particular can be screwed into the internal thread 100a1 thereof. This sequence is necessary because the outer circumference of the distribution head 7 is larger than the outer circumference of the cartridge 100 and also the inner circumference of the annular cover 21b.
Then the cartridge 100, if necessary along with surrounding support sleeve 103 as well as cover 21b and distributing head 7, is pushed into the cartridge receptacle 16 in the second transverse direction 12 and, by means of the fixing device 3a, the edge 100b1 and possibly the edge of the supporting sleeve 103 located beneath, are pressed firmly onto the upper side of the cartridge receptacle 16, these parts preferably being sealed off from one another by means of concentric circumferential O-rings 27.
Subsequently, in
By this, the cartridge 100 is fixed in all horizontal directions, so that this represents a first part of the fixing device 3a, and at the latest when the pressing head 24 dips into the cartridge 100, the pressing piston is released from the bottom of the second, pot-shaped vacuum housing 22, so that the latter with its lower annular edge representing the second part of the fixing device 3a is pressed downwards onto the laterally projecting edge 100b1 by way of a coil spring 28, which is concentrically arranged around the piston rod 15a between the second vacuum housing 22 and the yoke 23, more precisely, at the upper side of the cartridge carrier 3, which is rectangular in the side view.
When the pressing head 24 is then moved further downward as shown in
As soon as the pusher 101 has reached the lower end of the cartridge 100 on the removal side and the cartridge 100 is empty, the piston rods 13a, 14a of the two working cylinders 13, 14 are synchronously retracted downwards into the cylinders 13b, 14b, as shown in
By moving even further down, the distributing head 7, acting as a discharge piston 5, pushes the material down out of the collection container 2 into the discharge line 20 and thus to the remote consumer.
According to the invention, the material M is thereby degassed as follows. As depicted in perspective in
So that the strands S1, S2, S3 exit from those outlet openings 17 downwards in a straight line, a sharp tear-off edge 18 is formed around each outlet opening 17, which is achieved, for example, by arranging an annular groove 19 around each outlet opening 18 in the generally flat lower side of the distributing head 7, which, together with the inner circumference of the outlet opening 17, forms the circumferential, sharp, i.e., acute-angled, tear-off edge 18.
As a result, the strands S1, S2 fall downwards into the collecting container 2 in parallel instead of being deflected laterally, as is possible with one-sided adhesion and very quickly combining again with neighboring strands S2, S3, for this large surface area, which is maintained as long as possible on the thin strands S1, S2, S3, is required in order to open gas pockets existing in the strand and allow the gas to escape.
In this case, the distributing head 7 is located above the collecting container 2, which is why it is necessary for the strands S1, S2, S3 to fall downwards in straight lines.
In order to prevent air from the environment from entering the material M again when the material is pressed out and collected in the collecting container 2, a first vacuum is formed around it.
For this purpose, the first vacuum housing 21 is provided that is equipped with a negative pressure connection 8 and whose upper, annular cover 21b with its upper through-opening abuts the outer circumference of the cartridge 100 and whose sleeve-shaped lower part 21a with its lower through-opening abuts the outer circumference of the collecting container 2, sealed in each case, for example, via O-rings 27.
To prevent air from being forced past the seal of the pusher 101 into the material M in the cartridge when the press head 24 is inserted into the cartridge 100 when the pressing head 24 is retracted, the bell-shaped second vacuum housing 22, which has its opening facing downwards, is seated on the upper edge 100b1 of the suspended cartridge 100 with its circumferential walls on this edge 100b1.
The cartridge plunger 15a of the cartridge working cylinder 15 can be pushed tightly through an opening in the upwardly facing bottom of the pot-shaped second vacuum housing 22, O-rings 27 preferably being used again for sealing.
Via the negative pressure connection 9 also provided on the vacuum housing 22, air contained therein is extracted as soon as it is seated on the cartridge and even before the pressing head 24 enters the cartridge, for which purpose the second vacuum housing 22 is preferably dimensioned in such a way that the pressing head 24 does not abut tightly on the inner circumference of the pot-shaped second vacuum housing 22.
In order to ensure that any residual air that may still be present between the distributing head 7 and the surface of the material is not pressed into the material M when the distributing head 7 is moved into the collecting container 2, despite there being the first vacuum, a venting valve can be provided in the back side facing away from the material, i.e., the bottom of the collecting container 2, hence the upper side of the distributing head 7, through which air entering the hollow interior of the distributing head 7 via the lower outlet openings 17 would be released upwards into the first vacuum. The venting valve can be a simple diaphragm that is permeable to air but not to the material M to be conveyed. In this way, any air pockets that may still exist in the material M in the cartridge 100 can be removed before the material M reaches the consumer via the discharge line 20.
Although the present invention has been described in connection with certain specific embodiments for instructional purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102020131081.1 | Nov 2020 | DE | national |
| PCT/EP2021/081528 | Nov 2021 | WO | international |
This application is filed under 35 U.S.C. § 111(a) and is based on and hereby claims priority under 35 U.S.C. § 120 and § 365(c) from International Application No. PCT/EP2021/081528, filed on Nov. 12, 2021, and published as WO 2022/112022 A1 on Jun. 2, 2022, which in turn claims priority from German Application No. 102020131081.1, filed in Germany on Nov. 24, 2020. This application is a continuation-in-part of International Application No. PCT/EP2021/081528, which is a continuation-in-part of German Application No. 102020131081.1. International Application No. PCT/EP2021/081528 is pending as of the filing date of this application, and the United States is an elected state in International Application No. PCT/EP2021/081528. This application claims the benefit under 35 U.S.C. § 119 from German Application No. 102020131081.1. The disclosure of each of the foregoing documents is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2021/081528 | Nov 2021 | US |
| Child | 18200485 | US |
