DE102017114733A1 - Apparatus and method for heating blanks and / or packs and / or packages of composite material by orientation polarization - Google Patents

Abstract

Shown and described is an apparatus for heating blanks (1) and / or packaging shells (10) and / or packages of composite material by orientation polarization, comprising: at least one transport device (17) for transporting the blanks (1) and / or the packaging shells ( 10) and / or the packages along a transport direction (T), at least one unit (19) for generating electromagnetic waves, and at least one conductor means (20A, 20B, 20C) connected to the unit (19) for generating the electromagnetic waves, wherein the conductor means (20A, 20B, 20C) forms a gap (S). In order to enable a specific heating of limited - in particular narrow, linear - areas of the blanks (1) or packing shells (10) or packaging during continuous transport of the blanks (1) or packing shells (10) or packaging, it is proposed that the longitudinal direction (Xs) of the gap (S) corresponds to the transport direction (T) of the blanks (1) and / or the packing shells (10) and / or the packages. Also shown and described is a method of heating blanks (1) and / or pack coats (10) and / or packages of composite material by orientation polarization.

Description

The invention relates to a device for heating blanks and / or packaging coats and / or packages of composite material by orientation polarization, comprising: at least one transport device for transporting the blanks and / or the packaging coats and / or the packages along a transport direction, at least one unit for production of electromagnetic waves, and at least one conductor means connected to the electromagnetic wave generating unit, the conductor means forming a gap.

The invention also relates to a method of heating blanks and / or packaging coats and / or packages of composite material by orientation polarization.

Packaging can be made in different ways and from a variety of materials. A widespread possibility of their production is to produce a blank from the packaging material, from which by folding, sealing and further steps first a packing jacket and finally a packaging is formed. This production method has the advantage, among other things, that the blanks are very flat and can thus be stacked to save space. In this way, the blanks or packing coats can be made at a different location than the forming and filling of the packaging coats done. As a material composites are often used, for example, a composite of several thin layers of paper, cardboard, plastic or metal, especially aluminum. Such packaging is widely used, especially in the food industry.

Numerous devices and methods are known in the field of packaging technology, with which flat folded packaging coats can be unfolded, closed on one side, filled with contents and then completely closed.

A special challenge is the closing of the packaging coats, because the closure requires a reliable sealing of the packaging coats, which also has to withstand subsequent transport and other stresses. Closure often takes place in two steps: First, the packing jacket is heated ("activated") in the area to be closed. Subsequently, the opposite sides of the packing jacket are pressed together ("pressed") in the area to be closed. The cohesion between the compressed areas is achieved, for example, by providing an inner plastic layer which becomes viscous when heated and thus forms a bond during the subsequent pressing. This process is also referred to as "sealing".

The activation - ie heating - of the packaging coats can be done for example by hot air. This has the advantage that packing coats can be heated from all materials. In addition, a hot air blower is very robust. However, a disadvantage is the very high energy requirement, through which the production costs increase considerably. The high energy requirement is due, for example, to the fact that the heating energy has to be transported via the air to the surfaces to be heated, whereby the air itself heats up.

Alternatively, the activation or heating of the packaging coats can be carried out by electromagnetic induction. Inductive heating refers to a process in which electrically conductive bodies are heated by eddy current losses that occur in the conductive bodies. A prerequisite for the application of this method is therefore that the packing shells have electrically conductive areas. In any case, many packing sheaths have a layer of metal, in particular of aluminum, since in this way a particularly good shielding of the contents of the package against light and oxygen can be achieved. In such a package coats there is therefore the possibility of heating the packing jacket by induction. Likewise, a layer of an electrically conductive plastic could be heated inductively. Although the induction initially only causes heating of the electrically conductive layer; by thermal conduction and a corresponding arrangement of the layers, however, an indirect heating of the internal plastic layer responsible for the bonding can also be achieved. An advantage of inductive heating is that the heat is generated directly in the electrically conductive area and - unlike when heated by hot air - does not have to be transferred by heat conduction. This results in a high degree of efficiency, so that the energy demand and the costs can be kept low. In addition, the amount of heat input is very precisely controlled. However, a significant disadvantage of inductive activation is that this method is limited to packaging shells with a conductive layer. Therefore, this disadvantage weighs particularly difficult because on most bottling plants different packing coats are to be processed, so that a possible universally applicable activation process is sought.

Another alternative is heating by microwaves. When microwaves act it is electromagnetic waves. Microwaves can be used for heating because they can penetrate most materials and thereby stimulate their molecules to move, which heats up the materials. The excitation of dipole molecules, such as water molecules, works particularly effectively since microwaves are alternating electric fields in which the electrically unbalanced dipole molecules are turned back and forth and thus change their orientation ("orientation polarization"). The friction of the dipole molecules at their neighbors creates heat.

A microwave heating device for ceramic parts is for example from the EP 2 100 479 B1 known. The microwave oven shown there is designed as a continuous furnace, which has the advantage that a continuous heating or drying is possible. The disadvantage, however, is that the microwave oven described therein provides a uniform distribution of the microwave field. This makes it impossible to heat only certain selected areas of the items conveyed by the oven without thereby also heating the remaining areas of the items. The microwave oven shown there is therefore not suitable for the activation of blanks or packaging coats of food packaging, since there is usually only a local - usually linear - heating in the area of seams is required.

A system for applying microwave energy to web-shaped materials is known from EP 0 667 732 A1 known. In the device shown there, the microwaves are conducted from a source through two cables across a housing. The housing has slots through which the sheet material can enter the housing and exit the housing. An advantage lies in the possibility of a continuous movement of the web-like material. The disadvantage, however, is that the two cables extend transversely through the entire housing. This has the consequence that always the entire width of the web-like material is detected by the microwaves and thus heated. Therefore, this solution does not make it possible to heat only a portion of web-like materials. The solution is therefore also unsuitable for the activation of blanks or packaging coats of food packaging, since there is usually only a local - usually linear - heating in the area of seams is required.

Against this background, the invention has the object, the above-described and previously explained device and the corresponding method in such a way and further that a specific heating limited - especially narrow, linear - areas of the blanks or packaging coats or packaging preferably continuous Transport the blanks or packaging coats or packaging is made possible.

This object is achieved in a device according to the preamble of claim 1, characterized in that the longitudinal direction of the gap corresponds to the transport direction of the blanks and / or the packaging coats and / or the packaging.

A device according to the invention serves the purpose of heating blanks and / or packing shells and / or packages made of composite material or partial areas thereof by orientation polarization. Orientation polarization is the polarization which is determined by the orientation (orientation) of permanent electrical dipoles, eg. As water, is effected in an electric field. The articles to be heated may in particular be individualized blanks and / or pack coats and / or packages, ie already separate from one another. The composite material may comprise a layer of an electrically conductive material such as aluminum. Alternatively, the composite material may also be free of electrically conductive layers. The device is initially distinguished by at least one transport device for transporting the blanks and / or the packaging shells and / or the packages along a transport direction. In the transport submission is an advantageous, although not mandatory equipment. On a transport device could be dispensed, for example, in a manual transport of the objects to be heated, although this seems reasonable only for very small numbers. The device is further characterized by at least one unit for generating electromagnetic waves. An electromagnetic wave is a wave of coupled electric and magnetic fields, for example radio waves or microwaves, but also the visible part of the light. This unit may for example have a magnetron or an LC resonant circuit. The power of the unit for generating the electromagnetic waves is preferably in the range between 1 kW and 3 kW, but it may also be more than 3 kW, for example at least 5 kW. In order to increase the power, it is possible to feed each individual conductor device through two (or more) units for generating electromagnetic waves. The device also comprises at least one conductor device connected to the unit for generating the electromagnetic waves. A conductor device is understood to be an electrically conductive component whose extent in the longitudinal direction is substantially greater than the extent in the transverse direction and / or in the vertical direction. Suitable materials for the conductor device have proven to be copper, silver, gold, tungsten and aluminum. The at least one conductor device should be connected directly or indirectly (ie via further components) to the unit for generating the electromagnetic waves. This serves the purpose of influencing the propagation of the electromagnetic waves through the conductor device. With the connection is meant in particular an electrically conductive connection. The conductor device should also be shaped such that it forms a gap. A shallow gap enables particularly effective heating with efficient use of energy. Although the area of application of the device is limited to very flat, thin materials due to the narrow gap; However, this is not a disadvantage in the field of packaging technology, since very thin materials are regularly processed there.

According to the invention, it is proposed that the longitudinal direction of the gap corresponds to the transport direction of the blanks and / or the packaging shells and / or the packaging. By this arrangement it is achieved that the material to be heated blanks or packing coats or packaging can be performed along the conductor device sufficiently long time even at high transport speed, whereby a reliable heating is ensured. A particular advantage of this arrangement of the conductor device is that the heating of narrow portions - for example, narrow strips - the blanks or packaging coats or packaging is possible without this, the other areas are heated. This is because the conductor device usually has a narrow, elongated shape, so that an arrangement of the conductor device in the transport direction - in contrast to an arrangement transverse to the transport direction - heated only a narrow range of blanks or packaging coats or packages. This has several advantages. A first advantage is that in the sealing of seams of packaging, only heating in the area of the seam is desired, since heating in other areas could at most result in damage to the packaging material. Another advantage of concentrated, spatially limited heating is a reduced energy requirement.

According to one embodiment of the device, it is provided that the unit for generating electromagnetic waves is a unit for generating microwaves. Microwaves are usually understood as electromagnetic waves in the frequency range between 300 MHz and 300 GHz. The microwaves can be generated for example by a magnetron or by an LC resonant circuit. When generated by a magnetron are preferably electromagnetic waves having a frequency in the range between 430 MHz and 10 GHz, in particular between 915 MHz and 6 GHz (eg about 5.8 GHz), in particular between 915 MHz and 3 GHz, in particular between 2 GHz and 3 GHz (eg, about 2.45 GHz). A higher efficiency would be achieved with a - at least approximately - tuned to the resonance frequency of water frequency, which is about 22.23 GHz. Ideally, therefore, the nearest free frequency is chosen. At such frequencies, the electromagnetic waves after the s.g. Skin effect, although only a minimal penetration depth. However, this would be completely sufficient for the very special case of activating only a few tenths of a millimeter thick layers of a carton-based composite packaging.

According to an alternative embodiment of the device, however, it is provided that the unit for generating electromagnetic waves is a unit for generating radio waves. Under radio waves are usually understood electromagnetic waves in the frequency range between 80 KHz and 300 MHz. The radio waves can be generated for example by an LC resonant circuit.

A further embodiment of the device provides that the conductor device is formed by a band conductor. Strip conductors are - preferably solid - conductors, whose extension in the longitudinal direction is substantially greater than the extension in the transverse direction and / or in the vertical direction. The cross section of the strip conductor can be, for example, rectangular or T-shaped. To form a gap, the strip conductor may comprise two mutually parallel sections ("conductors") between which the gap is located. The two sections of the strip conductor may be interconnected or separated. With separate sections, it can be provided that each section of the strip conductor is connected to a separate device for generating electromagnetic waves, so that different frequencies can be set in the sections.

For this embodiment, it is further provided that the strip conductor, viewed in the longitudinal direction of the gap, has a varying cross-sectional area. In particular, it may be provided that one or all of the conductors of the strip conductor have a varying cross-sectional area as seen in the longitudinal direction of the gap. By changing along the length of the cross-sectional area a more uniform heating can be achieved because forming standing waves are forced on the conductor device on stationary local sections of the conductor device and a Mittragen the standing waves through the material to be machined (ie the blank, the packing jacket or the packaging) effectively avoided or at least minimized. The cross-sectional area can, for example, be alternately larger and smaller again. The change in the cross-sectional area can take place in the transverse direction and / or in the vertical direction of the strip conductor. The change may be a periodic change, a local change, or a non-periodic ("chaotic") change in cross-sectional area. A variation of the cross-sectional area may relate to a change in the shape and / or the size of the area. The variation of the cross-sectional area can result in a change in the gap width; however, the gap width can also remain constant in the longitudinal direction.

According to a further embodiment of the device is provided that the conductor device is formed by a waveguide. Waveguides are conductors with a hollow interior whose extent in the longitudinal direction is substantially greater than the extent in the transverse direction and / or in the vertical direction. The cross section of the waveguide may be rectangular, oval or round, for example. Waveguides have - except for a gap for introducing the composite material to be heated - a circumferential cross section. The gap therefore represents the only opening of the waveguide. In order to facilitate transport through the gap, that is to avoid a complex lifting and lowering of the blanks, packing shells or packaging, the inlet and outlet sides preferably have an alignment with the gap in the form of a recess on, which is formed at a reasonable height. Waveguides have the advantage of a particularly low-loss transmission of electromagnetic waves. In addition, waveguides have the advantage that the electromagnetic field due to reflections on the walls almost exclusively in the interior of the waveguide propagates, so that little or no shielding is required.

A further embodiment of the device is characterized by at least two conductor devices connected to the unit for generating electromagnetic waves. The use of two or more conductor devices has the advantage, in particular in the case of a strip conductor, that the materials to be heated can be irradiated on both sides with electromagnetic waves. On the one hand, this ensures reliable heating and, on the other hand, allows efficient use of energy. Bilateral exposure to electromagnetic waves also has the advantage that composite materials can also be heated which, in addition to absorbing layers (e.g., paper, paperboard, plastic) also contain reflective layers (e.g., aluminum). It is also conceivable that at least two conductor devices connected to the unit for generating electromagnetic waves are connected in series one behind the other. This makes it particularly easy to implement at a given transport speed a long activation width with effective design of the individual conductor devices.

With regard to the gap, a further embodiment of the device provides that the gap width of the gap is adjustable. An adjustability of the gap is required, for example, in order to be able to optimally adapt the gap to the number and the thickness of the layers or layers of the composite material. The adjustability of the gap can be achieved for example by a movable mounting of the conductor device. This also allows an oscillating change in the gap width.

With regard to the gap width, it is further proposed that the gap has a gap width in the range between 0.35 mm and 12.0 mm, in particular between 0.8 mm and 3.0 mm, in particular between 1.0 mm and 1.8 mm. A gap with the specified gap width has proved to be a good compromise between universal use (the largest possible gap width) and effective heating (minimum gap width). When using strip conductors rather narrow gap widths are preferred (up to about 3.0 mm) while in waveguides also much larger gap widths are possible (up to about 12.0 mm). Overall, it can be stated that the gap should be as small as possible. On the other hand, contact with the conductor elements must be avoided at all costs, as otherwise energy-related flashovers may occur.

A further embodiment of the device is characterized by at least one matching network. A matching network is preferably used in multi-section tape conductors ("ladders"). When using a waveguide, however, no matching network is needed. The sections of the stripline may be interconnected, for example, by the matching network. Through a matching network, a symmetrical excitation of the different sections of the strip conductor can be achieved. In addition, it can be achieved that the ground potential lies on a plane in the middle between the two strip conductors. The matching network may comprise a balancing member (so-called "balun"), which allows a transition between a balanced line system and a single-ended line system. If a plurality of band conductors are provided, an adaptation network is preferably provided at each junction of the band conductors. Preferably, the matching network is arranged at the end of the band conductor.

A further embodiment of the device is characterized by a terminating resistor, in particular a water load, which is connected to the at least one conductor device. Standing waves on the conductor device can be minimized by means of a defined terminating resistor. Standing waves are stationary stress peaks that lead to an inhomogeneous heating of the blanks or packing shells. The terminating resistor is preferably arranged at the end of the conductor device. The design of the terminating resistor as a water load has the advantage that even large outputs can be converted into heat and simply dissipated ("dull").

In a further embodiment of the device, it is provided that the at least one conductor device has a coating, in particular a ceramic, Teflon, PEEK or anodized coating. Due to the elasticity of the blanks or packaging coats or packaging, contact between the conductor device and the blanks or packaging coats or packaging can not be ruled out. A coating - in particular a lubricious coating - has the advantage that the friction is reduced in the case of contact between the blanks or packaging coats or packages and the conductor device. This has the advantage that the blanks or packaging coats or packages are not damaged and are not pinched or displaced even when in contact with the conductor device. In this way, uninterrupted operation is ensured even at high transport speeds.

Slide coatings made of Teflon (polytetrafluoroethylene) have a particularly low friction and are also very heat resistant. Coatings made of PEEK (polyetheretherketone) are characterized by their high temperature resistance and abrasion resistance. Suitable coatings can also reduce the risk of flashovers, with coating thicknesses of about 30 microns to about 200 microns being preferred.

A further embodiment of the device provides that the at least one conductor device has an effective range whose length is in the range between 0.2 m and 4.5 m, in particular between 0.25 m and 2.5 m, in particular between 0.4 m and 2.0 m. The effective range is understood to be that section of the conductor device on which the blanks or packing shells or packagings are passed. The effective areas are preferably approximately linearly shaped and arranged very close to the blanks or pack coats or packages passed by. A length in the specified range represents a good compromise between the longest possible exposure time (the longest possible length) and an efficient use of energy (the shortest possible length). In waveguides higher energy densities are achievable compared to strip conductors, so that shorter reaction times (shorter activation time) necessary are, whereby a shorter length is possible. But since the losses within the waveguide are smaller compared to strip conductors, larger lengths are possible, which allows the use of weaker energy sources.

According to a further embodiment of the device, it is provided that the at least one conductor device is connected in series in the transport direction of the blanks and / or packing shells and / or packaging with at least one further conductor device. Through several rows of conductor devices several blanks or packing coats or packages can be heated simultaneously. This allows a particularly high production capacity. Preferably, the conductor means are arranged in parallel rows.

In a further embodiment of the invention, it is provided that the transport device is designed as a conveyor belt with cells for receiving the blanks and / or the packaging coats and / or the packaging. By a conveyor belt or a transport belt high tensile forces can be transmitted, which allow to transport a plurality of blanks or packaging coats or packages at constant distances from each other. The cells serve to receive the blanks and / or packaging coats and / or packaging. The blanks or packaging coats or packaging can be held in the cells both by a positive connection and by a frictional connection. It can be provided that the conveyor belt is set up for a continuous transport of the blanks or packing shells. This has the advantage of an uninterrupted and smooth movement. Alternatively, the conveyor belt may be arranged for a discontinuous transport of the blanks or packing shells. This has the advantage that some processing steps can be carried out more easily with stationary blanks or pack coats.

According to a further embodiment of the device, it is provided that the transport device has at least two cells, which can be moved individually at least in sections, for receiving the blanks and / or the packaging shells and / or the packages. Individually movable cells are understood in particular to be cells whose transport speed is set individually can be. This allows - in contrast to a conveyor belt or a conveyor belt - the individual acceleration of the cells, ie the individual increase and / or decrease in the speed of the cells. In this way, the speed of the cells can be adapted particularly well to the requirements of the respective processing station (eg heating by orientation polarization) and deviate locally from the average line speed in terms of amount upwards or downwards. Deviations of more than 20%, preferably even more than 30% or even more than 40% and up to about 50% or even up to about 75% of the speed amount can be reasonably realized. Preferably, at least two cells are independently movable.

In addition, the individual adjustability of at least two movable cells has the consequence that the distances between the cells can also change. As a result, it is possible, for example, to transport the cells at a very small distance from one another through a single processing station (for example heating by orientation polarization). In this way, a particularly high efficiency of a device for heating web material, blanks and / or packaging coats and / or packages of composite material can be achieved by polarization orientation, since the energy offered by her in operation at a high density of customers (web goods, blanks and / or packaging coats and / or packaging made of composite material) is particularly well usable and the amount of residual energy available for unwanted leakage effects is automatically reduced in this way.

Individual mobility of the cells can be achieved, for example, by an electromechanical linear drive.

• - eine Transporteinrichtung mit wenigstens einer Transportschiene, und
• - wenigstens zwei entlang der Transportschiene bewegliche, an der Transportschiene angeordnete Transportschlitten,
• - wobei die Transportschlitten zum Transport wenigstens eines Zuschnitts und/oder eines Packungsmantels und/oder einer Verpackung eingerichtet sind und vorzugsweise wenigstens abschnittsweise getaktet entlang eines Produktivbereichs der Transportschiene bewegt werden, und
• - wobei die Transportschiene und die Transportschlitten derart elektromotorisch miteinander in Wirkverbindung sind, dass die Transportschlitten entlang eines Produktivbereichs mit zwei voneinander verschiedenen Indizes bewegt sind.

In other words, a device for heating web material, blanks and / or packaging coats and / or packages of composite material by orientation polarization, comprising:

• - A transport device with at least one transport rail, and
• at least two transport carriages movable along the transport rail and arranged on the transport rail,
• - Wherein the transport carriage for the transport of at least one blank and / or a packing jacket and / or a package are set up and preferably at least partially cycled along a productive range of the transport rail are moved, and
• - Wherein the transport rail and the transport carriages are in such an electromotive manner in operative connection with each other, that the transport carriages are moved along a productive area with two different indexes.

In contrast to the widely used rotating machines, a linear motor does not put the objects it drives into a rotating movement (rotational movement), but moves them along a straight or even curved path (translational movement). The blanks or packaging coats or packaging can be held in the cells both by a positive connection and by a frictional connection.

In a further embodiment of the device, it is provided that the transport device has at least one rotating transport means for transporting web material, the blanks and / or the packaging coats. Preferably, the transport device has at least two rotating transport means. The means of transport may be, for example, rollers or rollers, with which a non-positive transport of the web, the blanks and / or the packaging coats takes place. For example, two rollers or rollers may be arranged such that a gap is formed between them, through which the web, the blanks and / or the packaging coats are pulled or pushed non-positively. Belts or belts may be looped around the rollers or rollers, allowing longer gaps and thus longer transport distances. Alternatively or additionally, the transport device may have at least one gripper. By web material is meant a web-shaped material; for example, a sheet-like condition exists before the material is divided into blanks, from which packing coats and later packages are formed. The web material may in particular be formed by a composite material.

The device can finally be supplemented by a shielding device for enclosing the electromagnetic waves generated during operation. By a shielding the health and safety regulations can be met even with high-power electromagnetic waves. Preferably, the shielding device is designed such that the radiation at a distance of 10 cm has a power density of 5 mW / cm ² or less.

The object described at the outset is also achieved by a method for heating blanks and / or pack coats and / or packages made of composite material Orientation polarization. The method comprises the following steps: a) provision of an apparatus for heating blanks and / or packaging coats and / or packages by orientation polarization with at least one unit for generating electromagnetic waves and with at least one conductor device connected to the unit for generating electromagnetic waves; b) providing at least one blank and / or a packaging casing and / or a packaging; and c) heating the blank and / or the package jacket and / or the package by orientation polarization within a gap formed by the conductor means. The method is characterized in that the transport direction of the blanks and / or the packing shells and / or the packages corresponds to the longitudinal direction of the gap.

As has already been described in connection with the device, the method is based on the idea that the blanks or packaging coats or packages should not be completely heated, but only in certain areas. This can be achieved by the conductor device not spanning the blanks or packing sheaths or packages transversely, but arranged such that their longitudinal direction corresponds to the transport direction of the blanks or packing shells or packagings.

An embodiment of the method provides that in step a) a device according to one of claims 1 to 17 is provided. The device described above is suitable in all the embodiments shown in a special way for carrying out the method, since the described arrangement of the conductor device is a structurally simple way to heat only portions of the blanks or packaging coats or packaging.

In a further embodiment of the method it is proposed that in step c) microwaves having a frequency in the range between 300 MHz and 300 GHz, in particular between 915 MHz and 6 GHz or in the range of 22 GHz, or radio waves with a frequency between 15 MHz and 300 MHz are generated. In the specified frequency ranges, a particularly effective heating was achieved. If microwaves are generated, microwaves in the range between 915 MHz and 6 GHz (for example, about 5.8 GHz), in particular between 915 MHz and 3 GHz, in particular between 2 GHz and 3 GHz (for example about 2.45 GHz), are preferred.

According to a further embodiment of the method, it is provided that in step c) microwaves or radio waves with different frequencies are generated. High-frequency waves with different wavelengths ensure particularly uniform heating (avoidance of "hot spots"). If a plurality of conductor devices or a conductor device with several sections are provided, for example, each conductor device or each section can be acted upon by high-frequency waves having a different frequency. It is preferred that overlap two different frequencies in the gap. It is therefore conceivable in the embodiment of a conductor device, for example, a strip conductor or waveguide, that in the direction of transport a first and opposite to the transport direction from the first different, second frequency is fed into the conductor means, wherein superimpose the two frequencies fed in the gap S. , In order to be able to respond to material changes, it is also conceivable that the unit for generating electromagnetic waves, such as a magnetron or an LC resonant circuit with adjustable frequencies applies.

According to a further embodiment of the method, blanks and / or packing shells and / or packages having a moisture content in the range between 3% and 12%, in particular between 5.5% and 9% are provided in step b). The adjustment of the moisture content has a great influence on the result of the heating, since electromagnetic waves primarily excite dipoles such as water molecules. In particular, the moisture must be absorbed by the layers of paper, paperboard or cardboard since the remaining layers can absorb little or no moisture (e.g., layers of plastic or aluminum).

A further embodiment of the method provides that in step b) blanks and / or packing shells and / or packages are provided with at least one electrically conductive layer, in particular with an aluminum layer. The heating of composite materials with metal layers is particularly demanding because metals reflect electromagnetic waves and thus can not heat either the metal layer or the layers behind the metal layer. The method described also succeeds in heating materials with reflective layers by arranging the conductor device on the side of the metal layer to be heated or by arranging on both sides.

According to a further embodiment of the method, it is provided that the blank and / or the packing jacket and / or the packaging is moved at least in sections at a constant speed, in particular in step c) is moved at a constant speed. Alternatively, it may be provided that the blank and / or the packaging casing and / or the packaging at least is moved in sections with changing speed, in particular in step c) is moved with changing speed. For this purpose, a transport device with cells for receiving the blanks and / or the packing shells and / or the packaging may be provided. In this case, the cells should be moved at a corresponding speed (ie at a constant speed or with a changing speed). A movement of the cells (or the blanks / packs of coats / packages therein) at a constant speed has the advantage of simple process control and constant distances between successive cells. The constant speed in step c) (ie during heating) may be lower, equal to or higher than the other transport speed, ie the transport speed before and / or after the heating. A movement of the cells (or the blanks / packaging coats / packages) with changing speed has the advantage that the residence time in the device (and thus the duration of the heating) can be adjusted individually. In addition, by changing the speed, the distance between the blanks / wrappers / packages to be heated can be adjusted - at least if the change in speed does not occur simultaneously and identically for all cells. For example, can be reduced by a reduction in the transport speed, the distance between the blanks / packaging coats / packages to be heated before heating (if necessary, to zero) and increased after heating by increasing the transport speed of the distance again. This can be a more efficient heating of the blanks / packaging coats / packaging done. Also during step c) - ie during heating - a change in speed can take place. This serves for example to reduce the negative influence of standing waves on the heating. It can be provided that the same - identical - distance is set between successive blanks / pack coats / packages; but it can also be provided that different - for example alternating - distances are set between successive blanks / packaging coats / packaging.

• 1A: einen aus dem Stand der Technik bekannten Zuschnitt zum Falten eines Packungsmantels,
• 1B: einen aus dem Stand der Technik bekannten Packungsmantel, der aus dem in 1A gezeigten Zuschnitt gebildet ist, im flach gefalteten Zustand,
• 1C: den Packungsmantel aus 1B im aufgefalteten Zustand,
• 1D: den Packungsmantel aus 1C mit vorgefalteten Boden- und Giebelflächen,
• 1E: den Packungsmantel aus 1C nach dem Verschweißen,
• 1F: den Packungsmantel aus 1E in einer Draufsicht,
• 2A: eine erste Ausgestaltung einer erfindungsgemäßen Vorrichtung in einer Vorderansicht,
• 2B: die Vorrichtung aus 2A in einer Seitenansicht entlang der Schnittebene IIB-IIB aus 2A,
• 3A: eine zweite Ausgestaltung einer erfindungsgemäßen Vorrichtung in einer Draufsicht,
• 3B: die Vorrichtung aus 3A in einer Seitenansicht entlang der Schnittebene IIIB-IIIB aus 3A,
• 4A: eine dritte Ausgestaltung einer erfindungsgemäßen Vorrichtung in einer Vorderansicht,
• 4B: die Vorrichtung aus 4A in einer Seitenansicht entlang der Schnittebene IVB-IVB aus 4A,
• 5A: eine vierte Ausgestaltung einer erfindungsgemäßen Vorrichtung in einer Draufsicht, und
• 5B: die Vorrichtung aus 5A in einer Seitenansicht entlang der Schnittebene VB-VB aus 5A.

The invention will be explained in more detail with reference to a drawing showing only a preferred embodiment. In the drawing show:

• 1A a blank known from the prior art for folding a packing jacket,
• 1B : A known from the prior art packing jacket, consisting of the in 1A formed blank, in the flat folded state,
• 1C : the packing jacket off 1B in the unfolded state,
• 1D : the packing jacket off 1C with prefolded floor and gable surfaces,
• 1E : the packing jacket off 1C after welding,
• 1F : the packing jacket off 1E in a plan view,
• 2A FIG. 1 shows a first embodiment of a device according to the invention in a front view, FIG.
• 2 B : the device off 2A in a side view along the cutting plane IIB - IIB out 2A .
• 3A FIG. 2: a second embodiment of a device according to the invention in a top view, FIG.
• 3B : the device off 3A in a side view along the cutting plane IIIB - IIIB out 3A .
• 4A FIG. 3: a third embodiment of a device according to the invention in a front view, FIG.
• 4B : the device off 4A in a side view along the cutting plane IVB - IVB out 4A .
• 5A a fourth embodiment of a device according to the invention in a plan view, and
• 5B : the device off 5A in a side view along the cutting plane VB-VB 5A ,

In 1A is a blank known in the art 1 represented, from which a packing jacket can be formed. The cut 1 may comprise several layers of different materials, for example paper, cardboard, plastic or metal, in particular aluminum. The cut 1 has several fold lines 2 on that folding the blank 1 should facilitate and the cutting 1 split into several areas. The cut 1 can be in a first side surface 3 , a second side surface 4 , a front surface 5 , a back surface 6 , a sealed area 7 , Floor surfaces 8th and gable surfaces 9 be divided. From the cut 1 a packing jacket can be formed by cutting the blank 1 folded so that the sealing surface 7 with the front surface 5 connected, in particular welded 5 can be.

1B shows a known from the prior art packing jacket 10 in the flat folded Status. Already related to 1A described areas of the packing jacket are in 1B provided with corresponding reference numerals. The packing jacket 10 is from the in 1A shown blank 1 educated. For this purpose, the blank was 1 folded so that the sealing surface 7 and the front surface 5 are arranged overlapping, so that the two surfaces can be welded together flat. The result is a longitudinal seam 11 , In 1B is the packing coat 10 shown in a flat folded state. In this state, there is a side surface 4 (in 1B hidden) under the front surface 5 while the other side surface 3 on the rear surface 6 (in 1B covered). In the flat folded state, several pack coats 10 be stacked particularly space-saving. Therefore, the packing coats 10 often stacked at the place of manufacture and transported in batches to the place of filling. Only there, the packaging coats 10 are stacked and unfolded to be filled with content, such as food.

In 1C is the packing coat 10 out 1B shown in the unfolded state. Again, those are already related 1A or 1B described areas of the packing jacket 10 provided with corresponding reference numerals. The unfolded state is understood to mean a configuration in which an angle of approximately 90 ° is formed between the two respectively adjacent surfaces 3, 4, 5, 6, so that the packing jacket 10 - Depending on the shape of these surfaces - has a square or rectangular cross-section. Accordingly, the opposite side surfaces 3, 4 are arranged parallel to each other. The same applies to the front surface 5 and the back surface 6 ,

1D shows the packing jacket 10 out 1C in the pre-folded state, ie in a state in which the fold lines 2 both in the area of the bottom surfaces 8 and in the area of the gable surfaces 9 have been prefolded. Those areas of the floor surfaces 8th and the gable surfaces 9 attached to the front surface 5 and to the back surface 6 abut, are also called rectangular areas 12 designated. The rectangular areas 12 are folded inwards during the pre-folding and later form the bottom or the gable of the packaging. Those areas of the floor surfaces 8th and the gable surfaces 9 attached to the side surfaces 3 . 4 adjacent, however, are called triangular surfaces 13 designated. The triangular surfaces 13 are folded outwards at the prefolding and form protruding areas of excess material, which are also called "ears" 14 be designated and applied to the packaging in a later manufacturing step - such as by sealing or adhesive method.

In 1E is the packing coat 10 out 1D after welding, so shown in the filled and closed state. In this state is already spoken of a "packaging". In the area of floor surfaces 8th and in the area of the gable surfaces 9 arises after closing a fin seam 15 , In 1E stand the ears 14 and the fin seam 15 from. Both the ears 14 as well as the fin seam 15 are applied in a later manufacturing step, such as by sealing or gluing process.

1F shows the packing jacket 10 out 1E in a top view. 1F also contains an enlarged view of the area of the longitudinal seam 11 , In the perspective shown, it can be seen that the fin seam 15 of the wrapper 10 in the region of the longitudinal seam 11 a thickness D ₂ which is greater than the thickness D ₁ in the remaining area of the fin seam 15 , This is because the end area 5 ' the front surface 5 and the end area 7 ' the sealing surface 7 in the region of the longitudinal seam 11 form an overlap. In the area of the longitudinal seam 11 indicates the fin seam 15 So at least a three-layer instead of a two-layer construction. The fat D ₁ the fin seam 15 is for example in the range between 0.8 mm and 1.0 mm, while the increased thickness D ₂ the fin seam 15 for example, in the range between 1.2 mm and 1.5 mm. The transition between the different thicknesses is also referred to as "layer jump". In addition to the overlap, one or both end regions 5 ' . 7 ' be folded over. A refolding of the inner end region (in 1F : End area 7 ' ) has the advantage that only the innermost layer of the material of the blank 1 can come into contact with the contents of the packaging. As a result, other layers of the material 5 of the blank 1 , For example, a middle layer of cardboard, are separated from the contents of the package. In this way, both the tightness of the packaging and hygienic requirements are ensured. A complete refolding of the inside end area 7 ' However, this would lead to a further increase in the thickness of the fin seam 15 to lead. It can therefore be provided that only a few layers of the end region 7 ' , in particular the innermost layer of the end region 7 ' be folded over. For this purpose, the remaining layers are separated or peeled off before refolding.

In 2A is a first embodiment of a device according to the invention 16 for heating pack coats 10 made of composite material by orientation polarization in a front view. As part of the device 16 is first a conveyor belt 17 with cells 18 shown in which the packing shells 10 are transported before, during and after heating. The transport direction T the packing coats 10 runs therefore parallel to conveyor belt 17 , The device 16 includes a unit 19 for the generation of microwaves (alternatively: radio waves) and two conductors 20A (in 2A hidden) and 20B a strip conductor associated with the microwave generating unit 19 are connected. The two leaders 20A . 20B of the strip conductor have a rectangular cross-sectional area and are mounted such that their longitudinal direction of the transport direction T the packing coats 10 equivalent. The ladder 20A . 20B the strip conductor are also mounted such that there is a gap between them S arises, whose longitudinal direction xs the transport direction T the packing coats 10 equivalent. The gap S also has a vertical direction Ys and a transverse direction Zs on, perpendicular to each other and perpendicular to the longitudinal direction xs of the gap S run (see coordinate system in 2A) , Shown are also two adaptation networks 21A . 21B , each two conductors 20A . 20B merge the band conductor and connect together. Both adaptation networks 21A . 21B are connected to terminating resistors 22A, 22B, which may be designed, for example, as a water load.

At the in 2A illustrated device 16 become the packing coats 10 with their protruding fin seam 15 in the transport direction T through the gap S led by the ladders 20A . 20B of the strip conductor microwaves emitted to be welded areas of the packing shells 10 (here: the fin seam 15 ) heat.

2 B shows the device 16 out 2A in a side view along the cutting plane IIB - IIB out 2A , For those areas of the device 16 already related to 2A are described in 2 B corresponding reference numerals used. In the side view is the implementation of the fin seam 15 through the gap S clearly. The gap S arises between the opposing (side by side) arranged ladders 20A . 20B the strip conductor and has a gap width B _s in the range between 0.8 mm and 3.0 mm, in particular between 1.0 mm and 1.8 mm. In 2 B is also the connection network behind the cutting plane 21B and the associated microwave generating unit 19 and the associated termination resistance 22B recognizable.

In 3A is a second embodiment of a device according to the invention 16 ' for heating blanks 1 made of composite material by orientation polarization in a plan view. For those areas of the device 16 ' already related to 2A or 2 B are described in 3A corresponding reference numerals used. An essential difference between the first embodiment of the device 16 ( 2A . 2 B) and the second embodiment of the device 16 ' is that with the second embodiment of the device 16 ' not the fin seams 15 of packing coats 10 but the sealing surfaces 7 of blanks 1 to be heated. From the sealing surfaces 7 later the longitudinal seams arise 11 of the packing coats 10. In the in 3A condition shown therefore are still blanks 1 , from which later packing coats 10 should arise.

The structure of the second embodiment of the device 16 ' is comparable to the structure of the first embodiment 16 : Also the device 16 ' has a conveyor belt 17 with cells 18 on where the blanks 1 lying horizontally first to the device 16 ' be guided and after heating the sealing surfaces 7 be transported further. The transport direction T the blanks 1 therefore runs parallel to the conveyor belt 17 , Also the device 16 ' includes a unit 19 for the generation of microwaves (alternatively: radio waves) and two conductors 20A (in 3A hidden) and 20B a strip conductor associated with the microwave generating unit 19 are connected. The two leaders 20A . 20B of the band leader have one T -shaped cross-sectional area and are mounted such that their longitudinal direction of the transport direction T the blanks 1 equivalent. The ladder 20A . 20B the strip conductor are also mounted such that there is a gap between them S arises, whose longitudinal direction X _S the transport direction T the blanks 1 equivalent. The device 16 ' also includes two customization networks 21A . 21B , each two conductors 20A . 20B merge the band conductor and connect together. Both adaptation networks 21A . 21B are with terminators 22A . 22B connected, which may for example be designed as a water load.

3B shows the device 16 ' out 3A in a side view along the cutting plane IIIB - IIIB out 3A , For those areas of the device 16 ' already related to 2A to 3A are also described in 3B corresponding reference numerals used. In the side view is the implementation of the sealing surfaces 7 through the gap S clearly. The gap S arises within the strip conductor between the two opposite (superimposed) arranged conductors 20A . 20B the strip conductor and has a gap width bs in the range between 0.8 mm and 3.0 mm, in particular between 1.0 mm and 1.8 mm. In 3B is also the connection network behind the cutting plane 21B and the associated microwave generating unit 19 and the likewise associated terminating resistor 22B recognizable.

In 4A is a third embodiment of a device according to the invention 16 " to the Heating of pack coats 10 of composite material shown by orientation polarization in a front view. For those areas of the device 16 " already related to 2A to 3B are also described in 4A corresponding reference numerals used. The third embodiment of the device 16 " largely corresponds to the first embodiment of the device 16 ( 2A . 2 B) , where the band conductor with its two conductors 20A . 20B through a waveguide 20C was replaced.

4B shows the device 16 " out 4A in a side view along the cutting plane IVB - IVB out 4A , For those areas of the device 16 " already related to 2A to 4A are also described in 4B corresponding reference numerals used. In the side view is the implementation of the fin seam 15 through the gap S clearly. The gap S arises between the opposite edges of the waveguide 20C and he has a gap width B _s in the range between 0.35 mm and 12.0 mm, in particular between 0.8 mm and 3.0 mm, in particular between 1.0 mm and 1.8 mm. In 4B is also the connection network behind the cutting plane 21B and the associated microwave generating unit 19 and the associated termination resistance 22B recognizable.

In 5A is a fourth embodiment of a device according to the invention 16 '' for heating blanks 1 made of composite material by orientation polarization in a plan view. For those areas of the device 16 "' already related to 2A to 4B are described in 5A corresponding reference numerals used. The fourth embodiment of the device 16 '' largely corresponds to the second embodiment of the device 16 ' ( 3A . 3B) , where the band conductor with its two conductors 20A . 20B through a waveguide 20C have been replaced.

5B finally shows the device 16 '' out 5A in a side view along the cutting plane VB-VB 5A , For those areas of the device 16 "' already related to 2A to 5A are described in 5B corresponding reference numerals used. In the side view, the implementation of the sealing surfaces 7 through the gap S clearly. The gap S arises between the opposite (stacked) edges of the waveguide 20C and has a gap width B _s in the range between 0.35 mm and 12.0 mm, in particular between 0.8 mm and 3.0 mm, in particular between 1.0 mm and 1.8 mm. In 5B is also the connection network behind the cutting plane 21B and the associated microwave generating unit 19 and the associated termination resistance 22B recognizable.

LIST OF REFERENCE NUMBERS

1:

cut

2:

fold line

3, 4:

faces

5:

front surface

5 ':

End portion (the front surface 5)

6:

rear surface

7:

sealing surface

7 ':

End area (the sealing area 7)

8th:

floor area

9:

gable area

10:

pack casing

11:

longitudinal seam

12:

rectangular area

13:

triangular face

14:

ear

15:

fin seal

16, 16 ', 16 ", 16"':

Apparatus for heating blanks / packs / packages

17:

conveyor belt

18:

cell

19:

Unit for generating microwaves / radio waves

20A, 20B:

Conductor (a band leader)

20C:

waveguide

21A, 21B:

Matching network

22A, 22B:

terminator

bs:

Width (of the gap S)

D ₁ :

Thickness (the fin seam 15)

D ₂ :

increased thickness (the fin seam 15)

S:

gap

T:

Transport direction (blanks 1 / packing coats 10)

X _S :

Longitudinal direction (of the gap S)

Y _S :

Vertical direction (of the gap S)

Z _S:

Transverse direction (of the gap S)

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2100479 B1 [0009]
• EP 0667732A1 [0010]

Claims (25)

Device for heating blanks (1) and / or packaging sheaths (10) and / or packages of composite material by orientation polarization, comprising: - at least one transport device (17) for transporting the blanks (1) and / or the packaging sheaths (10) and / or the packages along a transport direction (T), - at least one unit (19) for generating electromagnetic waves, and - at least one conductor device (20A, 20B, 20C) connected to the unit (19) for generating the electromagnetic waves, - the conductor device (20A, 20B, 20C) forms a gap (S), characterized in that the longitudinal direction (Xs) of the gap (S) of the transport direction (T) of the blanks (1) and / or the packing shells (10) and / or the packaging corresponds. Device after Claim 1 , characterized in that the unit (19) for generating electromagnetic waves is a unit for generating microwaves. Device after Claim 1 , characterized in that the unit (19) for generating electromagnetic waves is a unit for generating radio waves. Device according to one of Claims 1 to 3 , characterized in that the conductor means is formed by a ribbon conductor (20A, 20B). Device after Claim 4 , characterized in that the strip conductor (20A, 20B) has a varying cross-sectional area when viewed in the longitudinal direction (Xs) of the gap (S). Device according to one of Claims 1 to 3 , characterized in that the conductor device is formed by a waveguide (20C). Device according to one of Claims 1 to 6 characterized by at least two conductor means (20A, 20B, 20C) connected to said electromagnetic wave generating unit (19). Device according to one of Claims 1 to 7 , characterized in that the gap width (Bs) of the gap (S) is adjustable. Device according to one of Claims 1 to 8th , characterized in that the gap (S) has a gap width (Bs) in the range between 0.35 mm and 12.0 mm, in particular between 0.8 mm and 3.0 mm, in particular between 1.0 mm and 1.8 mm. Device according to one of Claims 1 to 9 characterized by at least one matching network (21A, 21B). Device according to one of Claims 1 to 10 , characterized in that the at least one conductor device (20A, 20B, 20C) has a coating, in particular a ceramic, Teflon or PEEK coating. Device according to one of Claims 1 to 11 , characterized in that the at least one conductor device (20A, 20B, 20C) has an effective region whose length is in the range between 0.2 m and 4.5 m, in particular between 0.25 m and 2.5 m, in particular between 0 , 4 m and 2.0 m. Device according to one of Claims 1 to 12 , characterized in that the at least one conductor device (20A, 20B, 20C) in the transport direction (T) of the blanks (1) and / or packing shells (10) and / or packaging with at least one further conductor device (20A, 20B, 20C) in Row is switched. Device according to one of Claims 1 to 13 , characterized in that the transport device is designed as a conveyor belt (17) with cells (18) for receiving the blanks (1) and / or the packing shells (10) and / or the packaging. Device according to one of Claims 1 to 13 , characterized in that the transport device has at least two at least partially individually movable cells (18) for receiving the blanks (1) and / or the packing shells (10) and / or the packaging. Device according to one of Claims 1 to 13 , characterized in that the transport device has at least one rotating transport means for transporting web goods, the blanks (1) and / or the packing shells (10). Device according to one of Claims 1 to 16 characterized by a shielding device for housing the electromagnetic waves generated during operation. Method of heating blanks (1) and / or packaging sheaths (10) and / or packages of composite material by orientation polarization, comprising the following steps: a) providing a device for heating blanks (1) and / or pack shells (10) and / or packaging by orientation polarization with at least one unit (19) for generating electromagnetic waves and at least one with the unit (19) for generating electromagnetic wave connected conductor means (20A, 20B, 20C); b) providing at least one blank (1) and / or a packing jacket (10) and / or a packaging; and c) heating the blank (1) and / or the packaging jacket (10) and / or the packaging by orientation polarization within a gap (S) formed by the conductor device (20A, 20B, 20C), characterized in that the transport direction (T ) of the blanks (1) and / or the packing shells (10) and / or the packaging of the longitudinal direction (Xs) of the gap (S) corresponds. Method according to Claim 18 , characterized in that in step a) a device (16, 16 ', 16 ", 16''') according to one of Claims 1 to 17 provided. Method according to Claim 18 or Claim 19 , characterized in that in step c) microwaves with a frequency in the range between 300 MHz and 300 GHz, in particular between 915 MHz and 6 GHz or radio waves with a frequency between 15 MHz and 300 MHz are generated. Method according to one of Claims 18 to 20 , characterized in that in step c) microwaves or radio waves are generated with different frequencies. Method according to one of Claims 18 to 21 , characterized in that in step b) blanks (1) and / or packing shells (10) and / or packages are provided with a moisture content in the range between 3% and 12%, in particular between 5.5% and 9%. Method according to one of Claims 18 to 22 , characterized in that in step b) blanks (1) and / or packing shells (10) and / or packages are provided with at least one electrically conductive layer, in particular with an aluminum layer. Method according to one of Claims 18 to 23 , characterized in that the blank (1) and / or the packing jacket (10) and / or the packaging is at least partially moved at a constant speed. Method according to one of Claims 18 to 24 , characterized in that the blank (1) and / or the packing jacket (10) and / or the packaging is at least partially moved with changing speed.

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