DE20100107U1 - Device for the controlled application of adhesives and / or sealants - Google Patents

Abstract

The invention relates to a device for the regulated application of adhesives and sealants to support materials (11), containing essentially the following components: a) a supply container for at least one adhesive and/or sealant (1), b) a delivery pump (2), c) an applicator head (3) comprising at least one applicator nozzle (4), d) a volume flow sensor (5) and e) a control unit (6) with an associated data processing programme. The supply container (1), the delivery pump (2) and the applicator head (3) with the at least one applicator nozzle (4) are interconnected by a distribution system (7) which conducts the adhesive and/or sealant (7). The volume flow sensor (5) and the control unit (6) with the associated data processing programme are interconnected by an impulse transmission line (8) and the control unit (6) with the associated data processing programme, the delivery pump (2) and the applicator head (3) are interconnected by control lines (9). The invention also relates to the use of this device and to a method using the device for the regulated application of adhesives and/or sealants to support materials. The invention is especially characterised in that the precise and constant application and metering of adhesives and/or sealants is made possible on a manufacturing scale.

Description

Henkel Limited Partnership on Shares and
Production technology Industrial service Borst
Dr. Bialas/HC/Ge
06.12.2000

Utility model application

H5128
"Device for the controlled application of adhesives and/or sealants"

The invention relates to a device for the controlled application of adhesives and/or sealants to carrier materials.

In many cases, for example, continuous adhesive and/or sealant tapes must be applied to a carrier material which is guided past a device, which basically consists of an application head with an application nozzle, in continuous form (e.g. material webs) or in the form of immediately successive material sections or material cuts. In other cases, there is a need to provide several application points on the same carrier material with the same adhesive and/or sealant, whereby, depending on the case, either continuous adhesive and/or sealant tapes, adhesive and/or sealant dots, adhesive and/or sealant beads of limited length or adhesive and/or sealant areas must be produced. For example, when producing packages, material webs or cuts must be provided with adhesive in the form of so-called glue dots, glue beads or glue areas to fix them in the positions that form the packages.

For dosing the adhesives and/or sealants, the application heads usually have valves that regulate the supply of the adhesives and/or sealants to the application nozzle via electronic control units.

For the majority of applications, it is often desirable to achieve a uniform application pattern and a defined application quantity or dosage of the adhesive and/or sealant to be applied and, in particular, to control the achievement of the desired application quantity.

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It is necessary to check the application of the adhesive and/or sealant, as it is not always possible to rule out with certainty, for example, a blockage in the pipe system, the application head, the application nozzle, in any filters present or a leak at any point in the device.
Differences between the desired and the practically achieved application quantity can occur, for example, due to production-related fluctuations in the feed pump pressure or due to viscosity changes, for example caused by temperature changes. Such fluctuations can in particular lead to the amount of adhesive and/or sealant applied being too small for the required bonding and/or sealing of the carrier material. Such effects are therefore often attempted to be counteracted by taking into account a safety reserve of the adhesive and/or sealant to be applied in addition to the theoretically required application quantity.

Safety reserves are taken into account in particular in processes in which the carrier materials have surfaces that are difficult to bond or seal; for example, these surfaces are painted, printed or surface-laminated. A safety reserve must also be taken into account if the bond is subject to high tensile stress. This is the case, for example, when carrier materials are bonded together under forced shaping and these carrier materials show an effort to return to their original shape. This happens, for example, when carrier materials are bonded along edges, e.g. when gluing wood edges. The safety reserve is also taken into account in processes in which a high heat resistance of the sealant or adhesive is required, for example when filling bonded or sealed carrier materials with hot filling material. Heat resistance is generally defined here as the ability of an adhesive layer to withstand temperature stress over a long period of time without deformation.

The control of whether the desired application of the adhesive and/or sealant is present on the carrier material is usually carried out randomly or continuously, for example by visual inspections and/or additionally

a) Moisture measurements if the applied adhesive contains water or

is solvent-based,

b) infrared sensors to determine the dosage of the adhesive and/or sealant applied to the substrate via the radiated heat,

c) gravimetrically, by weighing appropriately marked substrates before and after application of the adhesive and/or sealant.

d) Microwave or ultrasonic wave technology for measuring adhesive and/or sealant traces or adhesive and/or sealant layers.

The accuracy of the control options listed is not very high due to the measuring methods and additional external factors (e.g. air humidity). This is another reason for the commonly practiced additional dosing of the adhesive and/or sealant to be applied as a safety reserve.

If the adhesive and/or sealant is not applied to the substrate at all or only insufficiently, this generally results in the substrate being rejected. If one also takes into account that many processes in which adhesives and/or sealants are applied to substrates are carried out at high speeds, the economic loss due to rejection and the associated machine downtime caused by cleaning and repair work is not insignificant.
In order to be able to react more quickly to disruptions in the application of adhesives and/or sealants to carrier materials, devices are advantageous in which the application of the adhesive and/or sealant is monitored along the path between the storage container for the adhesive and/or sealant and the application nozzle and not only on the carrier material.

Such devices are known.

EP 0887 721 A1 discloses a monitoring system in which a monitor periodically collects input signals from a sensor and compares these collected signals with stored alarm limit values. The sensor detects a characteristic of a liquid flow through a distributor,

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for example, the liquid nozzle pressure. A pressure sensor integrated in the application head measures the static pressure of the liquid when the nozzle is closed and the dynamic pressure of the liquid when the nozzle is open. When the nozzle is open, the pressure drops depending on the flow rate. The measured pressures are compared with previously defined reference pressures and thus monitored. This function allows conclusions to be drawn about the correct pump pressure and the flow rate in the application head. However, the lower the flow of the liquid stream in the nozzle, the lower the measured differential pressure between the dynamic pressure and the reference pressure. It is therefore obvious that when small amounts of liquid flow through, for example less than 100 mg of liquid, sufficient differential pressure cannot be measured.

In the utility model no. 296 20 763.2, a device for applying adhesive is described, consisting of an adhesive storage container, a feed pump and an application head with at least one application nozzle, wherein the adhesive storage container, the feed pump and the application head are connected by a line carrying the adhesive, and which contains at least one adhesive volume flow sensor arranged between the feed pump and the at least one application nozzle. This

The adhesive volume flow sensor is used to measure the adhesive volume flow actually delivered by the feed pump to at least one application nozzle. If the sensor detects during a work cycle that no or insufficient adhesive is being delivered, a corresponding monitoring circuit causes an immediate interruption of the production process that is easily recognizable to the operating personnel.

The devices described control the application of adhesives and trigger an alarm if the application is interrupted, but are not used to control the precise dosing of adhesives. Furthermore, these devices cannot be used to determine the quantity or density of the liquid.

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The object of the present invention was therefore to avoid the disadvantages of the prior art and to improve and simplify existing devices for applying adhesives and sealants. This includes in particular the task of enabling improved control of the application, measurement of the amount applied and regulation of the amount of adhesives and sealants applied.

The inventive solution to the problem can be taken from the claims.

It essentially consists of a device for the controlled application of adhesives and sealants to carrier materials (11), which essentially contains the following components:

a) storage container for at least one adhesive and/or sealant (1),

b) feed pump (2),

c) application head (3) with at least one application nozzle (4),

d) volume flow sensor (5),

e) control unit (6) with associated data processing program,

wherein the storage container (1), the feed pump (2) and the application head (3) with at least one application nozzle (4) are connected to one another by a line system (7) carrying the adhesive and/or sealant, the volume flow sensor (5) and the control unit (6) with the associated data processing program are connected to one another by a pulse transmission line (8), the control unit (6) with the associated data processing program, the feed pump (2) and the application head (3) are connected to one another via control lines (9).

The adhesives or sealants are conveyed from a storage container (1) by the feed pump (2) via a line system (7) which has rigid and/or flexible lines and can be cooled or heated, to an application head (3) and there applied by means of the at least one application nozzle (4) to a carrier material (11) which is located on a continuously or

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discontinuously running transport device (12), for example a conveyor belt.

To generate pressure in the line system (7), intermittently operating feed pumps (2), such as piston pumps, or continuously operating feed pumps (2), such as gear pumps, can be used. The feed pump (2) can be operated both pneumatically and electronically.

The volume flow of the adhesive and/or sealant being conveyed is measured by means of a volume flow sensor (5), which is expediently arranged between the feed pump (2) and the at least one application nozzle (4).

In a particular embodiment, the volume flow sensor (5) is part of the application head (3) and, viewed in the flow direction of the conveyed adhesive and/or sealant, is arranged immediately in front of the at least one application nozzle (4).

This means that measurement delays and the influence of pressure fluctuations on the measuring system can be largely eliminated.

According to the principle of a rotary valve, the quantity of adhesive and/or sealant flowing through the volume flow sensor (5) is recorded and sent to the control unit (6) in the form of electrical pulses.

The volume flow sensor (5) can be seen as a component of a control circuit that controls the actual volume flow of the adhesive and/or sealant(s) delivered and draws attention to changes, for example a lack of adhesive and/or sealant.

A volume flow sensor (5) designed in the form of a reverse-operating gear pump is preferred, since this type of volume flow measurement can differentiate particularly small mass transports up to a lower limit of 10 mg, based on a density of 1 g/ml.

The volume flow sensor (5) measures partial quantities of the adhesive and/or sealant specified by the teeth. For each partial quantity that is conveyed by the rotational movement of the meshing teeth caused by the volume flow, an electrical pulse is sent via the magneto-electric sensor.

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As a rule, the magneto-electric sensor is a differential field plate sensor which is located above the gear rim of one of the two measuring gears and which emits an electrical impulse for each tooth passing under it. The mechanical part of such a sensor is known, for example, from DE 40 40 409 C1, while with regard to the associated, actual measuring sensor, reference is made to DE 40 42 397 C2.
To achieve greater measuring accuracy, several, preferably two, differential field plate sensors can be used above one or both measuring gear wheels, if necessary with a separate preamplifier. The precise installation position of the differential field plate sensor on the volume flow sensor for inductive detection of the measuring cell wheels is conveniently achieved by a high-temperature-resistant plastic holder, e.g. Teflon.
The volume flow sensor (5) is suitable for use in a temperature range between 20 ⁰ C and 300 ⁰ C, preferably 80 ⁰ C to 250 ⁰ C and particularly preferably between 160 ⁰ C and 210 ⁰ C.

Depending on the distance between the measuring gears, the resolution is between 0.001 ml and 2 ml, preferably between 0.003 ml and 1.5 ml and particularly preferably between 0.005 ml and 1 ml. The choice of the volume flow sensor (5) to be used depends on the viscosity and the amount of sealant and/or adhesive to be applied.

The electrical impulses emitted by the magneto-electric sensor are transmitted via a corresponding impulse transmission line (8) to the control unit (6) with the associated data processing program.

The control unit (6) with associated data processing program is understood below as a measuring and control unit which controls the application quantity of the adhesive and/or sealant onto the carrier material (11) via a continuous in-line setpoint adjustment and, if necessary, adjusts it to the setpoint.

The data processing program belonging to the control unit (6) is based on standard software according to the IEC 1131-3 standard, which contains language elements and programming rules for the programming languages used worldwide for

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programmable logic controllers. Specifically, for example, the STEP 7 programming software from the SIMATIC product family from Siemens meets this standard. The software is adapted to the needs of the device according to the invention and processes the data required for the continuous target value adjustment, whereby freely selectable upper and lower limits for the application quantity of the adhesive and/or sealant are selected as limit values within which an adjustment to the target value should take place.
If, for example, the amount of adhesive and/or sealant delivered slowly decreases due to an incipient blockage of the line system (7), the feed pump (2) is activated and the application of the adhesive and/or sealant is regulated by outputting an analogue signal and adjusted to the setpoint.

If the feed pump (2) is a pneumatically operated feed pump, a corresponding commercially available electropneumatic controller is required. The electropneumatic controller is preferably connected directly to the compressed air inlet of the pneumatically operated feed pump. If the feed pump (2) is an electronically operated feed pump, a corresponding controller card is required to regulate the pump frequency.

In a preferred embodiment, the device according to the invention for controlling the feed pump (2) additionally contains an encoder (13), in particular when a speed-dependent application of the adhesive and/or sealant is desired.

Encoders (13) or rotary encoders are used to detect the angle of rotation or the length and direction of a rotary or linear movement of moving bodies. For this purpose, the moving bodies have a location with magnetic, optical or other coding and are guided past a fixed sensor element, whereby an absolute value with regard to the angular position and direction (e.g. speed) can be determined in each position of the coded location in relation to the sensor.

The main components of optical encoders, for example, are the emitting system, a raster plate, usually a raster disk or a raster signal, and the detector system. The emitting system usually consists of

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from a light-emitting diode or laser diode. The light beam emitted by the laser diode is modulated by the grid plate. This is connected to the moving body and has a periodic opening pattern. The detector system records the transmitter signal of the laser diode modulated by the grid plate and provides the information about the counting pulse and direction of the movement at the output.

In principle, all encoders commonly available on the market can be used, but encoders that operate with an operating voltage of 10 volts to 30 volts are preferred. Other characteristic data of the encoder, such as pulse number, number of revolutions, gear ratio, etc. are already set when programming the control unit (6) with the associated

data processing program taken into account.

With the help of the encoder (13) it is possible to record the path and the time required for this of carrier materials (11) which are guided past the at least one application nozzle (4).

Encoder (13) and control unit (6) with associated data processing program are connected to each other via a corresponding transmission line (14).

The information provided by the encoder (13) is recorded by the control unit (6) with the associated data processing program, processed electronically ™ and enables speed-dependent control of the

Application quantity and application length of the adhesive and/or sealant.
The speed-dependent control refers to the speed of the carrier material (11) at which it is transported past the application nozzle (4).

Since the information supplied by the encoder (13) is continuously recorded and processed by the control unit (6) with the associated data processing program, in addition to the speed-dependent control, a permanent control of the dosing quantity of the adhesive and/or sealant as well as the dosing time is possible.

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The device according to the invention is used for the controlled application of adhesives and/or sealants to carrier materials (11), whereby

a) the volume flow of the adhesive and/or sealant conveyed is measured by means of a volume flow sensor (5),

b) the electrical impulses detected by the volume flow sensor (5) are transmitted to a control unit (6) with associated data processing program,

c) the control unit (6) with associated data processing program adjusts the application quantity of the adhesive and/or sealant onto the carrier material (11) to the target value via a continuous in-line SolMst adjustment by controlling the feed pump (2) and increasing or decreasing the output accordingly.

Exceeding or falling below the selected limit values is registered by the control unit (6) with the associated data processing program as a so-called fault, processed and expediently signaled as a fault message via electronic and/or acoustic functions.
For this purpose, the control unit (6) with the associated data processing program expediently has an output (10) for the external processing of fault messages.

For example, a computer monitor can be connected here and in the event of a fault, this will be shown on the display. Additionally or alternatively, acoustic (e.g. siren) or optical (e.g. warning light) functions can be connected via the output (10).
If necessary, the control unit (6) with the associated data processing program can also completely interrupt the delivery of the adhesive and/or sealant if, for example, an adjustment to the target value is no longer possible and in order to carry out necessary cleaning measures caused by the malfunction.

The device according to the invention is particularly suitable for applying glues, pastes, dispersion adhesives, solvent adhesives, contact adhesives, reaction adhesives, pressure-sensitive adhesives, pressure-sensitive hot melt adhesives and

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Hot melt adhesives. Reaction adhesives, pressure-sensitive adhesives, pressure-sensitive hot melt adhesives and hot melt adhesives are particularly suitable.

Hot melt adhesives are generally water- and solvent-free adhesives that are applied from the melt to the parts to be bonded and, after joining, physically harden and solidify as they cool.
Hot melt adhesives are widely used in industry, for example for bonding and laminating in the furniture, shoe, electrical, packaging and paper industries. In the packaging and paper industry, they are used, for example, for sealing or closing boxes, for laminating multi-layered papers or for binding books.

To manufacture medical items (e.g. plasters, bandages) or hygiene items (e.g. diapers, sanitary napkins), a wide variety of carrier materials are bonded together using hot melt adhesives. Materials such as polyolefin films, for example polyethylene films or polypropylene films, polyolefin fleeces, for example polyethylene fleeces or polypropylene fleeces, polyurethane films, polyurethane foams, films or molded bodies made of cellulose derivatives, for example from cellulose (tissues), films or molded bodies made of polyacrylates or polymethacrylates, films or molded bodies made of polyester can be bonded together. A bond can be made between the same materials or between different materials.
As labeling adhesives, hot melt adhesives are widely used in the food and beverage industry. In the cigarette industry, hot melt adhesives are used, for example, to bond cigarette filters.

A wide variety of polymers/copolymers are available as basic materials for hot melt adhesives, for example

- Polycondensates such as polyamide resins, copolyamides, polyamide/EVA copolymers, polyamide/siloxane copolymers, polyetheramides,

Polyesteramideimides, polyetheresteramides, polyesteramides and copolyesters, saturated polyesters,

* ♦

- Polyadducts such as reactive and non-reactive linear or slightly branched

thermoplastic polyurethanes and

- Polymers such as ethylene copolymers, copolymers of ethylene with unsaturated carboxylic acids, ethylene-vinyl acetate copolymers, ethylene terpolymers, e.g. ethylene-acrylate terpolymers, propylene/hexene, SIS and SBS copolymers as well as other thermoplastic elastomers and amorphous polyolefins, e.g. polyethylene, polyolefins produced via metallocene catalysis, in particular PP, and finally polybutene.

Preferred polymers are homo- and/or copolymers of olefinic monomers, in particular of alpha-olefins. These homo- and/or copolymers are prepared by polymerizing olefinic monomers with a chain length of C ₂ to C ₂ o. In particular, those homo- and/or copolymers of olefinic monomers are preferred which have been prepared using metallocene catalysts. Particularly preferred are homo- and/or copolymers of olefinic monomers which do not have any functional groups.

The polymers listed essentially determine the actual adhesive layer properties in terms of adhesion, strength and temperature behavior. To achieve other special properties (e.g. cohesion, viscosity, etc.), additives such as tackifying resins, waxes, plasticizers, e.g. oils, stabilizers, antioxidants and/or fillers are used.

Specific products for bonding and/or sealing are available from companies such as Henkel KGaA, Doms or Teroson. For flexible packaging or for paper finishing, adhesives such as Liofol, Lio-Clean or Liotron are used. Adhesives such as Euromelt, Dorus-PS, Adhesin J, Sichello J or Liotron are used to produce coatings, self-adhesive labels or adhesive tapes. Adhesives such as Euromelt, Pekal, Optal or Smeltan are used for plastic labeling, for example. Lioseal or Liotex are used for heat-sealing coatings or text laminations, for example.

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Products such as Technomelt, Adhesin or Curo are used in the field of carton packaging (outer carton closure, folding box closure, carton erection), deep-freeze packaging or pallet securing.

Sanicare adhesives are used in the hygiene sector (e.g. baby diapers, feminine hygiene or incontinence) or the medical sector (e.g. surgical drapes, bandages, plasters). Tobacoll adhesives are used in cigarette production (side seam closure, packaging, filter production, etc.).

Terostat, Macromelt or Macroplast are used in areas such as insulating glass bonding, cable filling compounds, wood processing or shoe manufacturing.

The device according to the invention is suitable for the controlled application of adhesives and/or sealants which, at the corresponding processing temperatures, have a viscosity of 20 mPas to 100,000 mPas, preferably 20 mPas to 40,000 mPas and particularly preferably between 20 mPas and 20,000 mPas, measured according to ASTM D 3236.

Corresponding processing temperatures are understood to mean temperatures between 20 ⁰ C and 300 ⁰ C, preferably 40 ⁰ C to 250 ⁰ C and particularly preferably between 40 ⁰ C and 200 ⁰ C.

These adhesives and/or sealants preferably do not show any stringing when they exit the application nozzle (3), particularly when small amounts in the order of 10 to 100 mg are applied. In the area of this very small quantity application, adhesives and/or sealants with a viscosity between 20 mPas and 20,000 mPas, measured according to ASTM D 3236, are particularly suitable, optionally in combination with an application head (3) with at least one application nozzle (4), wherein the at least one application nozzle (4) is designed in the form of a spiral spray nozzle. Ideally, the adhesives and/or sealants to be applied when applying very small quantities do not contain any solid components. If solid components are present, their particle size is no more than 5 micrometers.

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The device according to the invention is particularly preferably suitable for adhesives and/or sealants which have a constant viscosity at the corresponding processing temperature with a fluctuation of +/- 50% within the usual processing period. Under the usual

Processing periods range from 15 minutes to 72 hours.

For example, it is known that hot melt adhesives can undergo material changes when exposed to temperature, depending on their composition. Depending on the level and duration of the exposure to temperature, this can result in the evaporation of more volatile recipe components and/or at least partial thermal degradation. Thermal degradation can produce volatile decomposition products and/or so-called cracking or coking products, with cross-linking of unsaturated compounds that are already present or that are created by the exposure to temperature usually occurring as a precursor to cracking or coking. These material changes caused by exposure to temperature manifest themselves, for example, in a change in viscosity, but also in the beginning or induced inhomogeneity of a previously homogeneous composition, in partial or complete insolubility in mostly organic solvents in which the composition was completely soluble before exposure to temperature and/or in the form of a change in color and state of aggregation from, for example, pale yellowish liquids to black, varnish-like products.

The device according to the invention is particularly suitable for the controlled application and dosing of adhesives and/or sealants on a production scale:

Quantities of up to 300 l/min can be applied in a controlled manner, depending on the viscosity of the adhesive and/or sealant. The maximum speed at which the carrier material (11) can be moved past the application nozzle (4) and a controlled application is still possible is

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corresponds to the speed of the high-performance machines used in production.

The device according to the invention for the controlled application of adhesives and/or sealants to carrier materials (11) can be used both in intermittently and continuously carried out processes.

Depending on requirements, the volume flow sensor (5) is integrated into commercially available application heads (3), which are used to create dots, beads or to coat surfaces with adhesives and/or sealants:

- For example, the dot-like application of adhesives and/or sealants from a quantity of 10 mg, based on a density of 1 g/ml, can be controlled and regulated up to 2000 dots per minute.

- The information supplied by the encoder (13) to the control unit (6) with the associated data processing program and its continuous recording and processing allow the application of adhesives and/or sealants

♦ as a caterpillar, its length and application quantity are controlled and regulated,

♦ in the surface coating, for example with nozzle contact or in the spraying process, its quantity, based on the application area, can be monitored and regulated and kept constant at variable speeds of the carrier material (11) or applied at a speed adapted to the speed.

The device according to the invention can be used to determine the density and measure the applied quantity of adhesives and/or sealants. The accuracy of the measurement increases with increasing application quantity.
In a preferred embodiment, the device according to the invention is used to determine the density of adhesives and/or sealants which have a viscosity of 20 mPas to 100,000 mPas at the corresponding processing temperatures, measured according to ASTM D 3236. For this purpose, a freely selectable amount of the adhesive and/or sealant is applied to the application head (3)

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collected and the weight of the collected adhesive and/or sealant is determined.

The volume flow sensor (5), which is connected to the control unit (6) with the associated data processing program via a pulse transmission line (8), delivers a number of pulses corresponding to the amount of adhesive and/or sealant removed. Since a defined volume of adhesive and/or sealant is delivered per pulse, the control unit can be used to
(6) The density can be calculated using a data processing program and displayed, for example, on a computer display.
Manufacturing-related tolerances of the measuring gears and resulting deviations from the theoretically measured partial volume are taken into account and included in the evaluation as a tolerance factor.

In a further preferred embodiment, the device according to the invention is used to determine the applied quantity of adhesives and/or sealants which have a viscosity of 20 mPas to 100,000 mPas at the corresponding processing temperature, measured according to ASTM D 3236. If the density of the adhesive and/or sealant to be applied is known or has been determined, for example, by the method described above, the weight of the adhesive and/or sealant being delivered can be calculated together with the number of pulses delivered by the volume flow sensor (5) to the control unit (6) via the pulse transmission line (8) using a data processing program belonging to the control unit (6) and displayed, for example, on a computer display. Manufacturing-related tolerances of the measuring mechanism gears and resulting deviations from the theoretically recorded partial volume are taken into account and included in the evaluation as a tolerance factor.

Ideally, after calibration, the density of the adhesive and/or sealant remains constant.

This enables, in particular, the measurement and dosing of very small quantities of the adhesive and/or sealant applied or to be applied.
As already explained elsewhere, micro-quantities are understood to mean quantities of 10 mg to 100 mg, based on a density of 1 g/ml.

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In particular, when coating the surface of carrier materials (11) with adhesives and/or sealants, for example when coating nonwovens with adhesives, there is the advantage that with the device according to the invention the weight of the applied adhesive and/or sealant is recorded directly in the in-line process and does not have to be determined offline by randomly determining the surface weight of carrier materials (11).
For additional control of whether, in addition to the exact application quantity, a uniform distribution of the adhesive and/or sealant on the carrier material has taken place, a corresponding and known measuring device with infrared sensors can, if necessary, be combined with the device according to the invention via corresponding devices known to the person skilled in the art.

With the device according to the invention for applying adhesives and/or sealants, an absolute measuring accuracy of +/- 0.5% of the application quantity is achieved:

To control the application quantity, the weight of up to 100 carrier materials (11) was previously determined before and after the adhesive and/or sealant was applied, statistically evaluated and the application device calibrated based on the evaluation. The weight of the applied adhesive and/or sealant is often low relative to the weight of the carrier material (11), which results in a higher measurement inaccuracy in the weight determination. Other factors, such as moisture release from the carrier material or the adhesive and/or sealant after application to the carrier material (11) and before the weight is determined, increase the spread of the measurement.

The accuracy with which adhesives and/or sealants are applied and dosed consistently for the first time on a production scale and with which the application quantity can be determined enables the device according to the invention to be used not only as a permanently installed device in existing systems for applying adhesives and/or sealants, but also as a temporarily installed device in existing systems,

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for example as a measuring and control device for testing new adhesives and/or sealants.

The device according to the invention contributes greatly to improving quality. By continuously measuring and regulating the amount of adhesive and/or sealant fed, less waste is produced.

The usual 10-30% by weight additional reserve to the theoretically required adhesive and/or sealant application quantity is eliminated or can at least be drastically reduced. The disadvantages associated with overdosing of adhesive and/or sealant, such as the coated carrier materials (11) sticking to the transport devices (12) or the contamination of systems by adhesive and/or sealant residues, are thus eliminated.

also.

The device according to the invention is particularly suitable for applying adhesives, preferably hot melt adhesives, to carrier materials (11) for medical articles and hygiene articles.

It is conceivable that the device according to the invention can also be used for applying low and high viscosity liquids of all kinds, in particular liquids whose viscosity at corresponding processing temperatures is 20 mPas to 100,000 mPas, measured according to

ASTM D3236.

Liquids that meet such a requirement are processed in the food, cosmetics or chemical industries and are, for example, pastes or paints.

The device according to the invention for the controlled application of adhesives and/or sealants to carrier materials is explained in more detail below with reference to the drawing of an embodiment.

Fig. 1 shows:

In perspective, the new device with a volume flow sensor arranged directly in front of the application nozzles and the control unit as a measuring and control unit.

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Fig. 2 shows:

In section, a concrete embodiment of the housing for accommodating the volume flow sensor and

Fig. 3 shows:

In perspective, a volume flow sensor of a known type.

The device shown in Fig. 1 for the controlled application of adhesives and/or sealants to substrates consists of

a) storage container for an adhesive and/or sealant (1),

b) feed pump (2),

c) application head (3) with at least one application nozzle (4),

d) volume flow sensor (5),

e) control unit (6) with associated data processing program,

wherein the storage container (1), the feed pump (2) and the application head (3) with at least one application nozzle (4) are connected to one another by a line system (7) carrying the adhesive and/or sealant, the volume flow sensor (5) and the control unit (6) with the associated data processing program are connected to one another by a pulse transmission line (8), the control unit (6) with the associated data processing program, the feed pump (2) and the application head (3) are connected to one another via control lines (9) and the control unit (6) with the associated data processing program has an output (10) for the external processing of fault messages.

The volume flow sensor (5) is arranged between the feed pump (2) and the two application nozzles (4) in this example.

The volume flow sensor (5) serves, as mentioned above, to control the volume flow of the liquid supplied by the feed pump (2) from the storage tank (1) to the application nozzles.

(4) conveyed sealant and/or adhesive.

The volume flow sensor (5) is part of the application head (3) and, viewed in the flow direction of the adhesive and/or sealant being conveyed, is located immediately in front of

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the two application nozzles (4). This arrangement minimizes pressure fluctuations between the application nozzles (4) and the volume flow sensor (5) and thus improves the measurement accuracy. The volume flow of the adhesive and/or sealant flowing through the volume flow sensor (5) is recorded in the form of electrical pulses and sent to the control unit (6).

It is now essential for the device that the control unit (6) transmits the electrical impulses with a corresponding

Data processing program processes and, via a continuous SolMst adjustment in-line, adjusts the application quantity of the adhesive and/or sealant onto the carrier material (11) to the target value by controlling the feed pump (2) and increasing or decreasing the power accordingly. In the preferred embodiment shown, the control unit (6) is connected to an encoder (13) via a corresponding transmission line (14). With the help of the encoder (13), it is possible to record the path and the time required for carrier materials (11) to be guided past the application nozzles (4). The information supplied by the encoder (13) is recorded by the control unit (6) with the associated data processing program, processed electronically and enables speed-dependent control of the application quantity and the application length of the adhesive and/or sealant.

For better understanding, Fig. 1 also shows a continuously or discontinuously running transport device (12), for example a conveyor belt, and a carrier material (11) located thereon, for example a packaging blank to be glued.

For the sake of completeness, a commercially available volume flow sensor (5) is shown in Fig. 3, which does not require any further explanation.

In a specific and preferred embodiment of the device, the application head (3) is designed in the form of a cuboid-shaped housing (3') and is provided with a recess (15) corresponding to the housing shape of the volume flow sensor (5), in which the volume flow sensor (5) is inserted, which

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on the downstream side, via a channel (16) in the housing (3') it is connected to the valve housing (17) attached to the outside of the housing (3') and to the at least one application nozzle (4).

The valve housing (17) indicated in Fig. 2 also requires no further explanation, since nothing changes in such valve housings (17) with their application nozzles (4).

22 List of reference symbols:

(1) Storage container for an adhesive and/or sealant,

(2) Feed pump,

(3) Application head with at least one

(4) Application nozzle,

(5) Volume flow sensor,

(6) Control unit with associated data processing program,

(7) Pipe system connecting the storage container (1), the feed pump (2) and the application head (3) with at least one application nozzle (4),

(8) Pulse transmission line, connects volume flow sensor (5) and the control unit (6),

(9) Control lines (9), connect control unit (6), feed pump (2) and application head (3),

(10) Output for external processing of fault messages (to control unit (6)),

(11) Carrier material,

(12) Transport device,

(13) Encoder or rotary encoder,

(14) Transmission line, connects encoder (13) and control unit (6)

(15) Recess in the special shape (3') of the application head (3)

(16) Channel

(17) Valve housing

Claims (10)

1. Device for the controlled application of adhesives and sealants to carrier materials ( 11 ), which essentially contains the following components: a) storage container for at least one adhesive and/or sealant ( 1 ), b) feed pump ( 2 ), c) application head ( 3 ) with at least one application nozzle ( 4 ), d) volume flow sensor ( 5 ), e) control unit ( 6 ) with associated data processing program, wherein the storage container ( 1 ), the feed pump ( 2 ) and the application head ( 3 ) with at least one application nozzle ( 4 ) are connected to one another by a line system ( 7 ) carrying the adhesive and/or sealant,
the volume flow sensor ( 5 ) and the control unit ( 6 ) with associated data processing program are connected to each other by a pulse transmission line ( 8 ) and
the control unit ( 6 ) with associated data processing program,
the feed pump ( 2 ) and the application head ( 3 ) are connected to each other via control lines ( 9 ). 2. Device according to claim 1, characterized in that the volume flow sensor ( 5 ) is arranged between the feed pump ( 2 ) and the at least one application nozzle ( 4 ). 3. Device according to claim 1 or 2, characterized in that the volume flow sensor ( 5 ) is designed in the form of a reverse-operating gear pump. 4. Device according to at least one of claims 1 to 3, characterized in that the volume flow sensor ( 5 ) is a component of the application head ( 3 ) and, viewed in the flow direction of the conveyed adhesive and/or sealant, is arranged immediately in front of the at least one application nozzle ( 4 ). 5. Device according to at least one of claims 1 to 4, characterized in that the application head ( 3 ) is designed in the form of a cuboid-shaped housing ( 3 ') and is provided with a recess ( 15 ) corresponding to the housing shape of the volume flow sensor ( 5 ), in which the volume flow sensor ( 5 ) is inserted, which is connected on the downstream side via a channel ( 16 ) in the housing ( 3 ') to the valve housing ( 17 ) of the at least one application nozzle ( 4 ) attached to the outside of the housing ( 3 '). 6. Device according to at least one of claims 1 to 5, characterized in that the volume flow sensor ( 5 ) is integrated in commercially available application heads ( 3 ) which are used for producing dots, beads or for surface coating with adhesives and/or sealants. 7. Device according to claim 1, characterized in that the control unit ( 6 ) with associated data processing program is connected to an encoder ( 13 ) via a corresponding transmission line ( 14 ). 8. Device according to claim 1, characterized in that the control unit ( 6 ) with associated data processing program has an output ( 10 ) for external processing of fault messages. 9. Device according to at least one of claims 1 to 8, characterized in that it is installed permanently or for a limited period of time in already existing processing plants for applying adhesives and/or sealants. 10. Device according to at least one of claims 1 to 9, characterized in that the information supplied by an encoder ( 13 ) can be recorded and electronically processed by the control unit ( 6 ) with the associated data processing program and the application quantity and the application length of the adhesive and/or sealant can be regulated as a function of the speed.