EP2386362A2 - Adhesive application device - Google Patents

Abstract

The method involves providing a flowable adhesive for a dosing device (1) in a storage container. The flowable adhesive is subjected to a pressure. The flowable adhesive is dispensed at an outlet channel of the dosing device by opening and closing a closure device for the outlet channel. The flowable adhesive, dispensed from the outlet channel, is applied on a surface. An independent claim is also included for an adhesive application device with an additional kit.

Description

Description of the invention

The present invention relates to a metering system for glue or in general for adhesives and a method for metering adhesives.

Background of the invention

Glue or general adhesive application systems find their application among others in the packaging industry. Exemplary fields of application are folding carton production, sheet processing (for example, envelopes, mailers, etc.) and / or fold gluing, for example in the processing of corrugated cardboard.

Known glue application systems are based on metering valves, as used for example in the DE 41 13 445 C2 are described. The metering valves generally have a metering piston which is part of an electromagnet and through which the metering piston can be moved upwards. The downward movement is generally by a compression spring. In a non-activated state of the magnet, the dosing piston is due to the existing spring pressure on the valve body, in detail on the nozzle, on: The valve is closed. There is no adhesive applied. In a switched-on state of the magnet the spring force is overcome and the metering piston lifted from the valve body: The valve is open. The adhesive is applied.

The aim here is the most accurate possible bonding, in particular both in terms of the positioning of the adhesive as well as in terms of the applied amount of the adhesive. The viscosity of the adhesive is a very important parameter. Properties, such as course and / or layer thickness of the cured adhesive, are significantly influenced by the viscosity of the adhesive.

In the known systems, the viscosity is determined in a reservoir connected to the metering valve. In general, the principle of a rotational viscometer known from the prior art is used here. In this case, the torque is measured, which is transmitted from a cylinder rotating at a constant speed through the space located in the space, especially for non-Newtonian, liquid on a second, coaxial cylinder.

Occurring temperature and / or pressure changes, such as in the connection to the metering device and / or within the metering device, which lead to a change in viscosity, can not be detected here.

An insufficiently defined viscosity of the adhesive during application of the adhesive generally results in an insufficiently metered amount of adhesive at the nozzle opening, so that, for example, the adhesive seam is not sufficiently defined.

General description of the invention

Against the background of the invention, the object is to provide a dosage for flowable materials, which at least reduces the disadvantages of the prior art.

It should be possible in particular to be able to integrate the invention into existing dosing concepts or to be able to expand the known dosing concepts.

The objects are achieved by a dosing system for a flowable material and a method for dosing a flowable material according to the independent claims.

Advantageous embodiments are the subject of the respective subclaims.

The invention initially provides a method for dosing a flowable material, in particular for applying an adhesive, comprising the method steps,

• Beaufschlagen des fließfähigen Klebstoffes mit einem Druck,
• Dosieren des bereitgestellten fließfähigen Klebstoffes an einem Austrittskanal der Dosiervorrichtung durch ein Öffnen und Schließen einer Verschlusseinrichtung für den Austrittskanal, und
• Auftragen des dosierten, aus dem Austrittskanal austretenden fließfähigen Klebstoffes auf eine Fläche, wobei
• die Viskosität des fließfähigen Klebstoffes in der Dosiervorrichtung bestimmt wird, und die Dosierung des Klebstoffes anhand des Wertes der Viskosität erfolgt

Providing a flowable material, in particular an adhesive for a metering device in a storage container,

• Applying pressure to the flowable adhesive,
• Dosing of the provided flowable adhesive at an outlet channel of the metering device by opening and closing a closure device for the Exit channel, and
• Applying the metered, emerging from the outlet channel flowable adhesive on a surface, wherein
• the viscosity of the flowable adhesive is determined in the metering device, and the dosage of the adhesive is based on the value of the viscosity

• eine Kammer mit einem Austrittskanal zum Bereitstellen des fließfähigen Materials,
• eine Einrichtung zur Druckbeaufschlagung des fließfähigen Materials, und
• eine Verschlusseinrichtung für den Austrittskanal, so dass das bereitgestellte fließfähige Material dosierbar ist, sowie
• eine Einrichtung zum Erfassen der Viskosität des fließfähigen Materials, und
• eine Regeleinrichtung, welche die Verschlusseinrichtung ansteuert, wobei die Auftragsmenge unter Berücksichtigung des gemessenen Wertes der Viskosität geregelt wird.

In addition, within the scope of the invention is also a metering system for providing a flowable material, in particular for applying an adhesive, or an adhesive application device with at least one metering device. The adhesive application device with metering device comprises

• a chamber having an exit channel for providing the flowable material,
• a device for pressurizing the flowable material, and
• a closure device for the outlet channel, so that the provided flowable material is metered, as well as
• a device for detecting the viscosity of the flowable material, and
• a control device, which controls the closure device, wherein the order quantity is controlled taking into account the measured value of the viscosity.

The process according to the invention can be carried out in particular by means of the system according to the invention. The system according to the invention is in particular designed for carrying out the method according to the invention.

As is said, the flowable material is preferably an adhesive which is generally also referred to as a glue for many applications, in particular also in the gluing of cellulose-containing materials, such as cardboard, paper and wood. As such, the flowable material is flowable at the selected operating temperature or ambient temperature, or it may be made flowable, for example, by a temperature increase and / or diluent. The metering device preferably comprises a metering valve. The exit channel is preferably formed as a nozzle. The closure device is preferably an anchor or a metering piston.

One idea of the invention is based on being able to infer flowable material from the viscosity determined on the metered amount, ie the amount of the leaked and applied from the metering device at a given pressure. According to the invention, the measurement or determination of the viscosity takes place in or within the metering device. For example, the measurement takes place in the chamber of the metering device and / or in the outlet channel and / or in the region of the outlet channel. The device for detecting the viscosity is associated with the metering device. In a first embodiment according to the invention, the determined actual viscosity is compared with a desired viscosity of the flowable material. In the light of simple control or monitoring of the quality, it may be sufficient to determine only the viscosity without taking further action, if at all necessary.

However, if measures are to be taken, in a first embodiment, an adaptation of the determined viscosity or actual viscosity to the desired viscosity of the flowable material. These are means, or a device for viscosity adjustment is provided. These viscosity modifiers can be used for metering the adhesive based on the viscosity value.

The viscosity adjusting means are formed in a first embodiment as a means for temperature adjustment. To increase the viscosity, for example, the temperature, in particular locally, can be increased by means of a heating wire and / or microwave radiation. The same applies to a viscosity reduction, for example by means of a Peltier element.

As an alternative and / or supplement to the temperature adjustment, the means for viscosity adjustment are formed as a means for diluting the flowable material and thus for reducing the viscosity and / or as a means for reducing or thickening the flowable material and thus for increasing the viscosity. These are added to or mixed with the flowable material.

Conversely, instead of dilution with a suitable diluent, thickening may be accomplished by removing thinners, such as a solvent, from the adhesive. Removal of the thinner is possible in a simple manner in that the adhesive is heated by means of a lifting device and thinner is thereby evaporated.

To compare the actual viscosity with the desired viscosity and / or for adaptation, in particular for controlling and / or regulating the viscosity, the control device or a control system is provided. The control system may be provided, for example, as a preferably electronic circuit and / or by means of a computing device.

In an alternative or additional embodiment, by means of the control device, an adjustment of the pressure with which the flowable material is provided for and / or in the metering device takes place.

In a further alternative or supplementary variant, the regulating device is used to adapt times in which the closure device is in an open and / or in a closed position, for example by determining the position of a piston.

Another alternative or additional embodiment is characterized by adjusting a flow volume or opening formed between the closure device and the exit channel in an open position of the closure device. For example, the stroke of a closure device designed as a metering piston is adapted.

Preferably, the variables mentioned are individually and / or in combination adapted so that a disturbing deviation from a desired viscosity is compensated. The Compensation is in particular such that the metered or applied amount of flowable material again corresponds to a desired value.

In a first embodiment of the invention, determining the viscosity comprises measuring the temperature of the flowable material, for example by means of a preferably integrated temperature sensor arranged in the outlet channel or in the nozzle. The temperature can be measured directly in or on the flowable material. However, it can also be measured indirectly via the temperature of the wall which is in contact with the flowable material. The invention is characterized in that the means for detecting the viscosity comprises at least one temperature sensor. Preferably, the measured temperature is compared with a temperature-viscosity characteristic curve. In general, an individual temperature-viscosity characteristic exists for each flowable material, depending on its degree of dilution or, more generally, on its composition. By a simple comparison with a characteristic curve, in particular with knowledge of the composition and / or the degree of dilution of the flowable material, the viscosity can be determined on the basis of the associated characteristic curve, for example by means of a computing device.

The temperature measurement is based in a first variant on a temperature-dependent expansion or shrinkage of at least one material. The temperature measurement is based on a frequency measurement in a second supplementary or alternative embodiment. However, the temperature measurement is preferably based on a measurement of the electrical Resistance, electrical current and / or electrical voltage. An example of such a temperature sensor is a temperature-dependent electrical resistance.

In a specific embodiment, the temperature of an actuating device, or the drive for the closure device, preferably via a measurement of the electrical resistance of the actuator, measured. The actuator is provided, for example, using a coil or coil system that generates magnetic forces that are applied to another element.

In another embodiment of the invention, the viscosity is determined by measuring the local pressure of the flowable material. For this purpose, the device for detecting the viscosity comprises at least one pressure sensor. The prevailing in the metering pressure in the flowing adhesive is dependent on the pressurization. In this case, in a flowing state, in particular when the closure device is in an open position, there is a pressure difference between the pressure prevailing in the metering device and the applied pressure. The pressure difference is caused by the flowable material emerging from the outlet channel and the resulting pressure drop. The pressure drop or the pressure difference is dependent on the viscosity of the flowable material. In this embodiment of the invention, it is therefore expedient to measure the pressure there with a pressure sensor, where the flowable material flows during the application. Preferably Therefore, a pressure change or the pressure drop in the outlet channel is determined. According to one embodiment, when determining a pressure or a pressure difference, the invention is characterized by determining a deformation, which is caused by the action of the flowable material, of a membrane which is preferably arranged in the metering device and is connected to the outlet channel. The pressure sensor can thus be formed with a membrane. The bending of the membrane can be detected, for example, inductively, capacitively and / or piezoelectrically.

In another embodiment, the viscosity is determined via a movement of a test body in the flowable material and / or a penetration depth of the test body into the flowable material. For this purpose, the device for detecting the viscosity has a test body whose movement in the flowable material, for example via a torque, can be evaluated.

In one embodiment, no additional test body is used. Rather, the test body can also be provided, for example, by the closure device, and preferably its movement behavior can be evaluated. In this case, the viscosity is determined in particular via a movement of the closure device in the flowable material and / or a changed relative position or height of the closure device in the flowable material, in particular with respect to the outlet channel during opening. For example, at a same current pulse to open the valve or the closure device is the Height or stroke of the closure device depending on the viscosity of the flowable material.

A further determination of the viscosity according to the invention is based on an acoustic measurement and / or on a high-frequency measurement. For this purpose, the device or have the means for detecting the viscosity of a transmitter and a receiver for sound, preferably ultrasound, and / or for high frequency. Transmitter and receiver can be arranged arbitrarily in the metering device. In general, transmitter and receiver are arranged separately. Transmitter and receiver in one embodiment form a unit or are formed as a single component.

In a variant of the acoustic measurement, for example, the quality, for example the vibration curve, preferably the damping, of a vibration is evaluated. For example, the vibration of a quartz crystal is more strongly attenuated in a flowable material of higher viscosity than in a flowable material of lower viscosity. Thus, the viscosity of the flowable material may be determined by the decay of the transmitted waves, for example, ultrasonic waves, at a given and / or measured temperature and / or a particular and / or measured composition of the flowable material. The waves, for example ultrasonic waves, can also be pulsed.

In a further variant of the example acoustic measurement, the viscosity of the flowable material by a frequency and / or a phase shift of a Signals are determined. The wave, for example, ultrasonic wave, this can be modulated arbitrarily.

Another alternative or additional embodiment of the example acoustic measurement is characterized in that the viscosity is determined by detecting a frequency shift, in particular as a result of the Doppler effect. In this case, the viscosity of the flowable material is determined by the flow rate or by a change in the flow rate. Preferably, the transmitter and receiver assembly is aligned with the flow direction of the flowable material. For example, with at least transmitter, for example an ultrasound transmitter, and at least one receiver, for example ultrasound receivers, the flow can be determined at a given temperature. It is also possible to carry out a viscosity determination. From this measurement, additional information about the viscosity can be obtained. The accuracy of the measurement is increased. Preferably, the transmitter and receiver assembly is aligned with the flow direction of the flowable material. For example, the sensors, in particular with at least one transmitter and at least one receiver, may be arranged aligned such that their connection line lies in the direction, preferably parallel, to the flow direction of the flowable material.

The knowledge and / or the adjustment of the viscosity of the flowable material is also important insofar as the viscosity is also dependent on the carrier on which the flowable material is to be metered or applied.

For example, a carrier is a carton bottom for making a carton or a paper for making an envelope. The properties of the support or the support surface are considered to be important, for example with respect to the material, the roughness, the dimensions and / or the geometry. Therefore, in one embodiment, the invention is also characterized in that the viscosity of the flowable material to be metered or applied is adapted to the carrier.

For this purpose, it is provided in one embodiment of the invention that the carrier to which the flowable material is to be metered or applied, is detected prior to application of the flowable material. For detection, a, preferably optical, sensor for detecting the carrier, to which the flowable material is to be metered, is provided. This sensor is preferably arranged in front of the metering device. That the sensor for detecting the carrier is arranged in a sequence of steps at least one step before dosing by or before the metering device.

In order to be able to determine or determine and / or adapt the corresponding viscosities and / or carriers, the dosing system according to the invention has a control system. The control system preferably comprises a reservoir in which at least one temperature-viscosity curve and / or a pressure-viscosity curve and / or motion-viscosity curve and / or carrier-viscosity curve are or are stored. The control system may be provided by a, preferably electronic, circuit and / or a computing device.

The control system may be positioned on the metering device. In a further embodiment, however, the control system is positioned away from the metering device. The metering device can be wirelessly controlled and / or regulated. WLAN represents an example of a wireless transmission. As a result, the parameters for operation of the dosing device can be selectively and / or autonomously transmitted, for example, directly to a receiver and / or networked wireless devices. About this wireless connection, the metering device can also be parameterized and / or addressed.

Thus, the metering device can be controlled and / or regulated remotely and / or by means of parameters which are transmitted wirelessly, for example from the network. It should be mentioned for this purpose, if the sensor for detecting the carrier, which takes over the monitoring of the supplied material to be bonded, discovers that, for example, another type of cardboard to the metering device or nozzle. In this case, a signal is then wirelessly sent to the nozzle. The transmitted signal may contain the desired viscosity and / or be used in a computing device to calculate the viscosity and to change it, preferably locally and / or temporarily.

In a further development, the transmitted signals can be assigned to the means for temperature adaptation in such a way that the signals not only control and / or regulate the means for temperature adaptation but also couple them to this and in particular provide energy. In one embodiment According to the invention, the temperature can be locally heated by means of a kind of mini or micro heater, for example by means of a heating wire and / or a, preferably local, microwave radiation, such as an RF micro-antenna. In this case, the antenna or the receiver for the signals can also be the heater, which for example increases the viscosity for a variable period of time. The same applies to a reduction in viscosity, for example by means of a Peltier element. Accordingly, the invention is characterized in that the metering device is wirelessly controllable and the means for viscosity adjustment of the flowable material can be coupled to the wirelessly transmitted signals.

Further, the viscosities are changed as needed to at least reduce the incidence of spurious particles generated during application. The disturbing particles are caused in particular by the opening and closing of the closure device. They are, so to speak, remnants of the flowable material, which still lie in the gap between the closure device and outlet channel during opening and closing and spray away when closing.

Preferably, the viscosity is also measured in a storage container, which is connected to the metering device. This gives the basic value of the viscosity at the ambient temperature.

In the scope of the invention is also a supplementary kit or a kit for retrofitting for a metering system according to the invention, which is preferably already in operation. The kit includes a sensor for detection the temperature in the metering device and / or a sensor for determining the pressure in the metering device and / or a test body whose movement is evaluable, for moving in the metering device and / or a transmitter for ultrasound and / or a receiver for ultrasound and / or a high-frequency transmitter and / or a high-frequency receiver and / or means for adjusting the viscosity of a flowable material.

• Fig. 1 zeigt ein Dosierventil in einer perspektivischen Darstellung.
• Fig. 2.a bis 2.c zeigen das Dosierventil aus Fig. 1 in einer Seitenansicht (Fig. 2.a), in einer Frontansicht (Fig. 2.b) und in einer Unteransicht (Fig. 2.c).
• Fig. 3 zeigt die Bestandteile des Dosierventils aus Fig. 1 in einer Explosionsdarstellung.
• Fig. 4 zeigt das Dosierventil aus Fig. 1 in seinem Querschnitt.
• Fig. 5 zeigt eine schematische Detailansicht der Kammer, des Austrittskanals und der Verschlusseinrichtung des Dosierventils aus Fig. 4.
• Fig. 6.a bis 6.c zeigen anhand schematischer Detailansichten der Seitenwand (Abschnitts Z1) der Kammer drei Ausführungsformen von Mitteln, beziehungsweise Einrichtungen zum Erfassen der Viskosität des Klebstoffs über den Druck (Fig. 6.a), mittels eines Testkörpers (Fig. 6.b) und über das Schwingungsverhalten (Fig. 6.c).
• Fig. 7.a und 7.b zeigen eine schematische Detailansicht der Seitenwand (Abschnitts Z2) der Kammer mit eingebauten Mitteln zum Anpassen der Viskosität des Klebstoffs.

The present invention will be explained in detail with reference to the following embodiments. For this purpose, reference is made to the accompanying drawings. The same reference numerals in the various drawings refer to the same parts.

• Fig. 1 shows a metering valve in a perspective view.
• Fig. 2.a to 2.c show the metering valve Fig. 1 in a side view ( Fig. 2.a ), in a front view ( Fig. 2.b ) and in a subview ( Fig. 2.c ).
• Fig. 3 shows the components of the metering valve Fig. 1 in an exploded view.
• Fig. 4 shows the dosing valve Fig. 1 in its cross section.
• Fig. 5 shows a schematic detail view of the chamber, the outlet channel and the closure device of the metering valve Fig. 4 ,
• Fig. 6.a to 6.c show on the basis of schematic detail views of the side wall (section Z1) of the chamber three embodiments of means, or means for detecting the viscosity of the adhesive on the pressure ( Fig. 6.a ), by means of a test body ( Fig. 6.b ) and the vibration behavior ( Fig. 6.c ).
• Fig. 7.a and 7.b show a schematic detail view of the side wall (section Z2) of the chamber with built-in means for adjusting the viscosity of the adhesive.

Detailed description of the invention

Valves, pumps and pressure vessels form the essential components for an application system which is used for a flowable material, in particular for an adhesive or a glue.

The FIGS. 1 to 4 show a metering device 1, which is also referred to as a metering valve or valve or order valve, in various representations. Fig. 4 additionally shows other elements of an adhesive application device 9 with the metering device 1. The valve 1 shown is a valve for applying preferably low-viscosity adhesives, in particular having a viscosity of up to about 500 mPa.s (Brookfield). Examples of adhesives are, in particular, water-based dispersion adhesives, starch adhesives and / or dextrin adhesives. Since, depending on the application often simultaneously adhesive and sealing properties are required to be under an adhesive and a Sealant and / or a binder understood. The adhesive may be, for example, a wood adhesive, metal adhesive, paper adhesive, automobile adhesive, packaging adhesive, paving adhesive and / or tile adhesive.

The valve 1 shown is a fast-switching, electrically operated valve. Preferably, the working pressure is in a range of about 1 to 6 bar.

The adhesive exits through the exit channel 170. The diameter of the outlet channel 170, which is also referred to as a nozzle, according to one embodiment of the invention, a diameter in the range of 0.2 to 0.8 millimeters, for example, 0.4 mm. For the closure device 160, which is also referred to as anchor or piston or metering piston, switching frequencies of up to about 600 cycles / second can be achieved. The device enables contactless adhesive application. The distance between nozzle 170 and a product is generally 5 to 10 mm.

The operation of the valve 1 is based on FIG. 4 explained. The device is equipped with a magnetic coil 120, a spring-loaded armature, or a closure device 160, preferably with a ball needle 161, and a nozzle 170, preferably a stainless steel nozzle. The ball needle 161 closes the valve seat in the nozzle 170 in the unactuated state. The adhesive is under pressure at the valve seat. As already stated above, for example, the adhesive will be at a pressure in a range of about 1 to about 6 bar provided. For this purpose, the metering device 1 as a device for pressurizing the adhesive 15 to a compressed air connection 500, to which a pump 16 is connected to provide the pressure used.

The adhesive 15 is fed to the dosing device 1 via an inlet 18 connected to the bottom of a reservoir 17 to an adhesive connection 300. In order to supply the adhesive 15 under overpressure, alternatively or in addition to the compressed air connection 500, other means for pressurizing can also be seen. For example, a conveyor in the supply line 18, such as an eccentric screw pump for conveying viscous media is conceivable.

By a current pulse to the coil 120, the armature or the closure device 160 is pulled up against the spring 270 and releases the nozzle opening 170, so that the adhesive emerges. After the decay of the current pulse, the closure device 160 closes under the spring pressure, the adhesive flow is interrupted. The device allows a dot as well as a coating application of the adhesive. In machine standstill, the shutter 290 closes under spring pressure and covers the nozzle 170 airtight. For this purpose, an electropneumatic 2/2-way valve is preferably used. The closure 290 is automatically opened as soon as a product enters under the order valve 1. During work breaks the shutter 290 is closed automatically.

The amount of adhesive or dot size per stroke depends on the viscosity of the adhesive, the applied pressure, the open time and / or the armature stroke. The setting of the required amount of adhesive is carried out, for example, by adjusting the adhesive pressure, adjusting the armature stroke and / or adjusting the activation time of the valve 1 (for example by means of a control device, not shown). For example, an increase in adhesive pressure leads to larger dots. The pressure is adapted to the adhesive viscosity. The higher the viscosity the higher the pressure to choose. The point size can be adjusted, for example, by means of the valve lift. For this purpose, a stroke adjustment 140 is provided. This serves to achieve an adjusted adjustment of the working stroke. This adjusted setting can also be done automatically via a control loop. An upper and lower limit are set by adjusting the stroke. The lower limit is the so-called zero stroke adjustment: no adhesive is emitted. The upper limit is the working stroke setting: the desired dot size of the adhesive is achieved.

The knowledge of the viscosity of the adhesive plays a decisive role. In the known systems, the viscosity outside of in FIGS. 1 to 4 valve 1 shown determined. For example, the viscosity is determined in a reservoir connected to the metering valve 1. Temperature and / or pressure changes, such as in the connection to the metering device 1 and / or within the metering device 1, which lead to a change in viscosity, can not be detected.

Based on Fig. 4 It can be seen that the power supply of the solenoid coil 120 via the electrical connection 400 of the metering device 1 takes place. The power supply is effected via a control device 25 connected to the electrical connection 400. A device for detecting the viscosity of the adhesive in the form of a viscosity sensor 20 is also connected to the control device 25 via the electrical connection 400. The control device 25, which controls the closure device, regulates the application quantity taking into account the value of the viscosity measured by the viscosity sensor 20. A simple way of regulation consists in an adjustment of the ratio of the opening and closing times of the valve. In particular, the order quantity can be kept constant independently of the viscosity value by the regulation.

FIG. 5 shows a detailed view of the chamber 10, also referred to as the nozzle outlet channel 170 and also referred to as the anchor closure device 160 of the valve 1 from FIG. 4 , For reasons of improved clarity, the spring 270 is not shown.

In a first embodiment of the invention, a kind of calibration measurement is carried out to determine the viscosity before the actual operation of the device. For this purpose, a defined current pulse is applied to the coil 120. The armature 160 will experience a different acceleration as a function of the viscosity and / or achieve a different height H. By an acceleration characteristic and / or a height characteristic can be concluded that the viscosity of the adhesive. The Acceleration characteristic and / or the height characteristic can or can be determined experimentally or empirically and / or based on model calculations, in particular with a defined variation of the viscosity.

In a second variant, a measurement of the temperature is provided for determining the viscosity. The knowledge of the temperature-viscosity characteristic for the adhesive used allows an indirect determination of the viscosity. For this purpose, a temperature sensor is provided in the valve 1. This can preferably be arranged in the region of the nozzle 170, for example within the nozzle 170, in the wall 101 of the chamber 10 and / or as indicated in or on the armature 160.

Possible principles for determining the temperature are based, for example, on a mechanical detection of the temperature, an electrical quantity measurement and / or a frequency measurement. A concrete example of the former group are materials with different coefficients of thermal expansion. In particular, a bimetallic thermometer may be mentioned here. Concrete examples of the second group are thermocouples and / or the use of the temperature-dependent electrical resistance of conductors and semiconductors. Here, in particular, a Pt100 resistor may be mentioned. A concrete example of the latter group is the temperature-dependent difference frequency of differently cut quartz crystals. It should be noted that the list is only an example and not exhaustive.

An elegant principle for the dosing device 1 described above is based on the principle of resistance measurement. In detail, in this case, the resistance R in the coil 120, which depends on the temperature of the adhesive, could be measured. Such a system could also be provided in a simple manner as a kind of supplementary kit for metering devices 1 which are already in operation.

The Figures 6.a to 6.c show further possibilities for the determination of the viscosity. They show a schematic detail view of the side wall 101 of the chamber 10 with built-in means 20 for detecting the viscosity of the adhesive.

In Figure 6.a the measurement of the viscosity takes place via the pressure with which the adhesive rests against a membrane 21. A portion of the wall 101 of the chamber 10 is for this purpose as or formed with a membrane 21. The membrane is shown for a non-deformed state (with a solid line) and for two loaded and therefore deformed states (each with a dashed line). Depending on the prevailing or applied pressure in the chamber, the membrane 21 is deformed to different degrees. It has a different curvature radius KR. It can be an integrated, adapted to the design membrane, or even a wall-mounted commercial pressure sensor can be used. The pressure depends on the one hand on the working pressure with which the adhesive is provided in the dosing device 1. This is initially set initially. The final or actual pressure in the dosing device, However, in particular in the region of the nozzle 170 is additionally dependent on the temperature and / or viscosity of the adhesive. Detecting this membrane deformation can be done for example by capacitive sensors, piezoelectric sensors and / or as shown by inductive sensors. Preferably, the viscosity can be determined by means of a deformation-viscosity characteristic curve.

At the in Figure 6.b In the illustrated embodiment, the measurement of the viscosity takes place via a test body 22. The test body 22 is here arranged laterally in a recess of the chamber wall. This is shown by way of example cylindrical. The test body 22 is associated, for example, with a capacitive actuator, a piezoelectric actuator and / or an inductive actuator, as shown here, with which a force is exerted on the test body. In the case of the inductive actuator, a defined current pulse is applied to the coil. The test body 22 will experience a different acceleration depending on the viscosity of the adhesive and / or achieve a different penetration depth L into the chamber. The penetration depth L can be measured, for example, via a scale arranged on the test body 22. The acceleration can be determined, for example, with an acceleration sensor arranged on the test body 22. The viscosity of the adhesive can be deduced by means of a motion characteristic, such as an acceleration characteristic and / or a penetration characteristic.

A further embodiment of the invention is based on an acoustic measurement of the viscosity, preferably by means of Ultrasonic. The measurement of the time and / or the propagation speed of an acoustic pulse allows a conclusion on the viscosity of the adhesive. For this purpose, for example, in the recess of the wall 101 (see in Figure 6.b ) transmitter and armature 160 (see in FIG. 5 ) A receiver, in particular with arbitrary angles to each other, be arranged.

According to another embodiment of the invention, the viscosity is determined by the quality of a vibrating system. This measurement principle is based on the fact that in a viscous medium, the attenuation of a signal, such as the vibration of a resonant oscillating element increases. The quality factor of a vibration decreases accordingly. An embodiment is in Fig. 6.c shown. Through the wall 101 of the chamber 10 connecting lines are performed, which contact a vibrating electromechanical device. At the in Fig. 6.c As shown, a vibrating quartz 23 or other piezoelectric crystal is provided. If the crystal, for example, excited by an electrical pulse, the crystal oscillates with a correspondingly the quality of the system time-decaying, or damped oscillation, which can be tapped at the leads 24 as an electrical signal. The damping depends on the temperature-dependent viscosity of the surrounding medium. On the basis of the Abklingverhaltens the vibration, therefore, the viscosity can be determined.

Finally, the show Figures 7.a and 7.b Two possible variants for adjusting the viscosity. The means for viscosity adjustment 30 are each in the flow direction the or the viscosity sensors 20 arranged (see FIG. 5 ). The means for adjusting the viscosity 30 are each, in particular together with the viscosity sensor 20, coupled to the control system or even part of the control system.

In Figure 7.a First, the viscosity adjustment is illustrated by means of a temperature adjustment. There is a heating wire 31 inserted in the side wall. This can also be arranged only on the top of the side wall, inside or outside. A favorable position of the heater is in the region or within the outlet opening 170. The temperature is increased locally in the adhesive by means of the heating wire. In addition, the control of the piston movement based on the caused by the different temperatures at the outlet opening and the piston viscosity gradient can be done.

The heating wire can be heated directly conductive, preferably with a current flow in the heating wire. To achieve a fast, accurate adjustment, several heating devices can be provided. In the variant with the heating wires, a first heating wire can be provided further upwards along the flow direction for coarser control of the viscosity and a further, more quickly heated heating wire directly at the outlet opening 170.

In addition to conductive heating, inductive heating is also possible. In the variant shown, the heating wire 31 acts as an antenna for radiation, for example for microwave radiation. The heating wire 31 is thus heated by the incident radiation.

By irradiated electromagnetic radiation can continue to be locally selectively heated parts of the metering device. For example, an electromagnetic alternating field can be directed directly at the ball needle and the ball needle can be heated selectively.

In Figure 7.b the viscosity adjustment is illustrated by means for dilution 32 and / or by means for thickening 33 of the flowable material. It is to a valve 34 introduced in the side wall. On the outside of two containers with the means 32 and 33 are arranged. Depending on whether the viscosity of the adhesive is to be increased or decreased, one agent 32 or the other agent 33 is added to the adhesive.

It will be apparent to those skilled in the art that the described embodiments are to be understood as exemplary. The invention is not limited to these but can be varied in many ways without departing from the spirit of the invention. Features of individual embodiments and the features mentioned in the general part of the description can each be combined with each other and with each other.

LIST OF REFERENCE NUMBERS

1

Dosing device or metering valve or valve

10

chamber

101

Wall of 10

20

viscosity sensor

21

Pressure sensor or membrane

22

test body

25

control device

30

Means for adjusting the viscosity

31

Means for heating the flowable material or heating wire

32

Means for diluting the flowable material

33

Means for thickening the flowable material

34

Valve

100

Valve without hood

110

Bracket (complete)

111

Leimanschlussnippel

112

O-ring

120

solenoid

130

armature housing

140

Lift regulation compl.

141

O-ring

160

Locking device or anchor (complete)

161

ball needle

170

Nozzle or outlet channel or outlet opening

200

Hood with nozzle closure

210

closure cap

220

screw

230

Air connection nipple

240

O-ring

250

Stand Off

260

air piston

270

feather

280

Screw

290

Closure or slider (complete)

291

slide rubber

292

Senkschraube

300

adhesive connection

400

Electrical connection

500

Compressed air connection

Claims (15)

Method for dosing and applying an adhesive, comprising the method steps Providing a flowable adhesive for a metering device in a storage container, Applying a pressure to the flowable adhesive, Dosing the provided flowable adhesive at an outlet channel of the dosing device by opening and closing a closure device for the outlet channel, and - Applying the metered, emerging from the outlet channel flowable adhesive on a surface, wherein - The viscosity of the flowable adhesive is determined in the metering device, and the dosage of the adhesive is based on the value of the viscosity. Method according to the preceding claim, characterized by comparing the determined viscosity with a desired viscosity of the flowable material. Method according to one of the preceding claims, characterized by adjusting the viscosity to the desired viscosity of the flowable material. Method according to one of the preceding claims, characterized
in that for reducing the viscosity, means for heating and / or for increasing viscosity are provided for cooling the flowable material and / or
in that for reducing the viscosity, means for diluting and / or increasing viscosity are provided for thickening the flowable material. Method according to one of the preceding claims, characterized by
adjusting a pressure with which the flowable material for the metering device is provided and / or
by adjusting times when the closure device is in an open or closed position and / or
by adjusting a flow volume formed between the closure device and the outlet channel in an open position of the closure device. Method according to one of the preceding claims, characterized in that the determination of the viscosity comprises measuring the temperature of the flowable material and in particular a comparison of the measured temperature with a temperature-viscosity curve. Method according to one of the preceding claims, characterized
that the temperature measurement is based on a temperature-dependent expansion or contraction of at least one material and / or
that the temperature measurement is based on a frequency measurement, and / or
that the temperature measurement on a measurement of the electrical resistance, the electric current and / or the voltage is based and / or
that the viscosity is determined by measuring the pressure of the flowable material and / or
that the viscosity is determined by means of a movement of a test body in the flowable material and / or a penetration depth of the test body into the flowable material, and / or
that the viscosity of a movement of the closure means in the flowable material and / or a relative change in position of the closure device in the flowable material 'is determined and / or
that the viscosity is determined via an acoustic measurement and / or via a high-frequency measurement. Method according to one of the preceding claims, characterized in that a carrier, on which the flowable material is to be metered, is detected prior to applying the flowable material. Method according to one of the preceding claims, characterized in that the viscosity of the flowable material to be metered is adapted to the carrier. Adhesive application device with at least one metering device, further comprising a chamber with an outlet channel for providing the flowable material, - A device for pressurizing the flowable material, and - A closure device for the outlet channel, so that the provided flowable material dosed is as well a means for detecting the viscosity of the flowable material, and - A control device which controls the closure device, wherein the order quantity is controlled taking into account the measured value of the viscosity. Adhesive application device according to the preceding claim, characterized
in that the means for detecting the viscosity comprise at least one temperature sensor and / or
in that the means for detecting the viscosity comprise at least one pressure sensor and / or
in that the means for detecting the viscosity comprise a test body whose movement in the flowable material can be evaluated and / or
that the means for detecting the viscosity include a transmitter and preferably a receiver for ultrasound and / or for high frequency. Adhesive application device according to one of the preceding claims, characterized by a control system for adjusting the viscosity of the flowable material,
preferably comprising viscosity adjustment means and / or a reservoir in which at least one temperature-viscosity curve and / or a pressure-viscosity curve and / or a motion-viscosity curve and / or a carrier-viscosity curve are stored. An adhesive application apparatus according to any one of the preceding claims in
by a sensor for detecting the carrier on which the flowable material is to be metered, wherein the sensor for detecting the carrier is arranged in front of the metering device and / or
by a sensor for detecting the carrier on which the flowable material is to be metered, wherein the sensor for detecting the carrier is located in the metering device and performs a preliminary measurement of this metering measuring device. Adhesive application device according to one of the preceding claims, characterized in that the metering device is wirelessly controllable and / or the means for adjusting the viscosity of the flowable material to wirelessly transmitted signals can be coupled. Supplementary kit for an adhesive application device according to one of the preceding claims comprising a sensor for determining the temperature in the metering device and / or a sensor for detecting the pressure in the metering device and / or a test body, the movement of which can be evaluated, for moving in the metering device and / or a transmitter for ultrasound and / or a receiver for ultrasound and / or a transmitter for high frequencies and / or a receiver for high frequencies and / or means for adjusting the viscosity of a flowable material.

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