EP3118128B1 - Shrinking device - Google Patents

Description

The present invention relates to a shrinking device according to the features of the preamble of claim 1.

The present invention relates to a shrinking device, for example a shrink tunnel, for shrinking packaging material around articles or article assemblies, for example for shrink-wrapping shrink-film packaging. The packaging material is generally wrapped as a foil blank by means of a wrapping system around the article or article assembly. Within the shrinking device, shrinkage medium, in particular hot air or the like, is generally applied via lateral shaft walls. on the wrapped with packaging material articles or article compositions. As a result, the packaging material is shrunk onto the article or the article composition, enclosing it closely and thus fixing the articles of an article compilation in this way.

The articles or article assemblies are moved through the shrinking device via an endless conveyor comprising an upper run and a lower run, for example a mat chain conveyor or the like. It is preferably provided that also shrinking medium acts from below through the upper run of the endless conveyor on the underside of the article or article compositions.

In order to support the movement of the endless conveyor within the shrinking device, support strips are usually arranged below the conveying surface, on which the upper strand of the endless conveyor rests and moves in the transport direction. In order to disturb the movement of the endless conveyor as little as possible, these sliding strips have little friction to the endless conveyor. Conventionally, pressed strips of pressed graphite are used. Pressed graphite, on the one hand, is very heat-resistant, so that it is well suited for use inside the shrinking device, in which generally high temperatures prevail. Furthermore, pressed graphite has good sliding properties, in particular, there is a low friction between the graphite strips and the resting area of the endless conveyor.

The problem here is that in the field of graphite strips no shrink medium can act from below on the article or article compilations. For this reason, the supporting wear strips are designed to be very narrow in order to shield as little as possible from the bottom of the article or article compositions shrinking medium, in particular the sliding strips are designed so narrow that they are arranged between two parallel rows of nozzles arranged below the upper strand distribution device for shrinking medium can be.

For example, in a shrink tunnel fifteen graphite strips are arranged in three parallel rows, which are each inserted into a C-profile. Here it is problematic that graphite is very brittle. This greatly limits the possibilities of designing the graphite strips.

An arrangement of support or slide strips below a mat chain conveyor is shown for example in FIG. 16 of the published patent application US 20040231301 A1 shown. In particular, in this case, an air chamber is arranged below the upper strand of the mat chain conveyor, having on its upper side nozzle rows, is passed through the hot air up to the mat chain conveyor. The support or slide strips are each designed so narrow that they can be arranged between two parallel rows of nozzles. Depending on the arrangement of the nozzles, a large number of support strips are necessary to form a sufficiently stable support for the mat chain conveyor.

The object of the invention is to eliminate the above-mentioned disadvantages of the prior art and in particular to increase the contact surface for the endless conveyor.

The above object is achieved by a shrinking device comprising the features in claim 1. Further advantageous embodiments are described by the subclaims.

The invention relates to a shrinking device for the processing of articles or articles packaged with packaging material, in particular shrink film. These are referred to below as pre-products. By treating the pre-products with shrinking medium, a product is produced, in which the packaging material adapts to the outer shape of the articles or article compositions and connects them together.

The shrinking device comprises a housing and has a plurality of distributing devices for shrinking medium. By way of example, the distribution devices are shaft walls delimiting a transport path laterally, via which the products are supplied with a shrinkage medium for forming the products. For example, the shaft walls have nozzle openings, via which the shrinking medium, for example hot air, passes in the direction of the pre-products into the interior of the shrinking device. For transporting the products encased in packaging material and products formed within the shrinking device through the shrinking device, an endless conveyor comprising an upper strand and a lower strand is used. The endless conveyor is permeable to shrink medium at least in the area of the upper strand.

The upper run is guided on at least one slide rail to form a stable transport surface for the pre-products and products.

According to one embodiment of the invention, the upper run is guided on a plurality of slide rails arranged in at least two parallel rows in order to form a stable transport surface for the pre-products and products.

Below the at least one slide strip a distribution device for shrinking medium between the upper run and the lower run of the endless conveyor is arranged. For example, the distribution device is a shaft which extends parallel to the upper strand along the transport path or conveying surface. At least the upper side of the distribution device has nozzle openings for shrinkage medium, which passes through the upper run in the interior of the shrinking device and in particular on the underside of the pre-products and products.

The supply of shrinkage medium from below can be uniform over the entire conveying surface of the upper run. However, it is also possible by the targeted adjustment and regulation of individual nozzle openings or for example by means of laterally displaceable and / or parallel to the conveying direction movable diaphragm elements o.ä. to limit the supply of shrinking agent to certain areas of the upper run. In particular, a special setting depending on be done by the respective product to limit the energy supply to the essential areas and thus to minimize energy consumption.

In order to achieve a better, in particular more uniform, support of the transport path or conveying surface and thus to achieve a particularly uniform conveying surface, it may be advantageous to design the at least one slide strip relatively wide. In order nevertheless to achieve a sufficient flow of the upper strand with shrink medium from below, the at least one slide strip, which forms a support for the upper run, through openings through which the shrinking medium can pass. As a result, in each case in the region of the support of the upper strand, shrinkage medium can reach the underside of the front products and products onto the at least one slide strip, as a result of which an improvement in product quality can be achieved.

Preferably, the passage openings are oriented orthogonally to the bearing surface of the at least one slide strip for the endless conveyor or orthogonal to the conveying surface formed by the upper run. However, according to an alternative embodiment, the passage openings may also be arranged at an angle deviating from 90 ° to the support surface of the at least one slide strip for the endless conveyor.

According to a preferred embodiment, the nozzle openings are arranged in a regular pattern. In particular, the passage openings are arranged regularly along the entire length and over the entire width of the at least one slide strip, so that over the entire transport path in the region of the at least one slide strip a uniform flow of the upper run is achieved with shrinkage medium.

According to one embodiment, it is provided that the pattern in which the passage openings of the at least one slide strip are arranged corresponds to the pattern of the nozzle openings of the distribution device arranged below the at least one slide strip. Preferably, the at least one slide strip is arranged such that passage openings of the at least one slide strip are respectively arranged in alignment with nozzle openings of the distributor device.

Preferably, the at least one slide strip made of graphite or a heat-resistant plastic. For example, polyetheretherketone (PEEK), Polyaryletherketone (PAEK), or polyimide (PI), as these plastics are heat-resistant and also have good sliding properties.

The passage openings preferably have a circular or a slot-shaped cross-section. Circular cross sections are created by drilling through the at least one slide strip at corresponding positions.

The formation of the passage openings depends inter alia on the material used for the at least one slide strip. When using graphite, the use of round holes is difficult due to the thermal expansion and brittleness of the material. Therefore, elongated holes are preferably used in graphite strips. The elongated holes are introduced, for example, by milling into the at least one graphite sliding strip. In the case of wear strips made of one of the abovementioned plastics, the through-openings, on the other hand, can easily have a circular diameter and can be produced by simply drilling (round) holes.

According to a preferred embodiment, the passage openings, in particular the round holes or oblong holes, on the upper side adjacent to the upper strand and / or of the distribution device adjacent lower side each contain chamfers to achieve better pre-distribution of the shrinking medium in the region of at least one slide strip.

The nozzle openings of the distributor are preferably arranged in parallel rows of nozzles. In particular, the rows of nozzles are aligned parallel to the transport direction of the pre-products or products on the upper strand of the endless conveyor. Between adjacent, parallel rows of nozzles, a first distance is formed in each case. The at least one slide strip is arranged parallel to the rows of nozzles and may have a width that is greater than the first distance between adjacent nozzle rows. This means in particular that the at least one slide strip can not be arranged between adjacent nozzle rows. However, since the at least one slide strip has the through-openings already described, shrinkage medium still passes at least largely without hindrance through the upper run of the endless conveyor to the underside of the pre-products or products. In particular, when the passage openings are preferably arranged in alignment with the nozzle openings, the shrinkage medium reaches the underside of the products or products better and more uniformly.

The at least one slide strip must be replaced if necessary, for example, in case of wear. Preferably, the at least one slide strip is arranged and fastened to at least one C-profile element, which extend below the upper run of the endless conveyor parallel to the nozzle rows of the distributor. So that the at least one C profile element does not disturb the flow of the shrinkage medium through the wear strips and through the upper strand of the endless conveyor to the underside of the pre-products or products, the at least one C profile element has, according to a preferred embodiment, formed air channels which extend extend orthogonal to a conveying plane of the upper run. Preferably, the air duct / air channels of the C-profile element and at least a portion of the passage openings of the sliding strips are arranged such that they are at least partially aligned after mounting the slide strip on the C-profile element. In particular, it is provided that the air channels of the C-profile elements are arranged in alignment with nozzle openings of the distributor and to passages of the slide strips.

According to one embodiment of the invention, a single sliding strip is provided which has substantially the same width as the upper strand and extends over the entire length of the upper run. In this case, for example, an attachment of the slide strip can be provided within the shrinking device on the lateral edges of the slide strip parallel to the conveying direction of the upper run, especially in a region in which no products are promoted, as these usually in the central region of the upper run and not in the lateral edge areas are positioned.

Due to the optimized guidance of the shrinking medium through the endless conveyor to the underside of the articles or article compilations, an optimum shrinkage result can be achieved in the lower region of the articles or article compilations, which in turn leads to an increased stability of the end product.

Since the at least one slide strip can be made wider, in particular since the at least one slide strip can extend in width over several nozzle rows of the distributor, the support surface for the upper run of the endless conveyor increases, which in turn leads to an improved, in particular more stable, conveying plane for the Pre-products or products leads. Due to the possibility of wider design of at least one slide bar is also the execution and Arrangement of the passage openings compared to narrower slide strips simpler and more cost-effective possible.

• Figur 1 zeigt eine schematische Ansicht einer erfindungsgemäßen Schrumpfvorrichtung von oben.
• Figur 2 zeigt eine schematische seitliche Ansicht einer erfindungsgemäßen Schrumpfvorrichtung.
• Figuren 3 und 4 zeigen unterschiedliche Ausführungsformen von Gleitleisten von oben.
• Figur 5 zeigt eine Schnittdarstellung durch eine Gleitleiste in seitlicher Darstellung.
• Figur 6 zeigt eine Befestigung einer Gleitleiste.

In the following, embodiments of the invention and their advantages with reference to the accompanying figures will be explained in more detail. The proportions of the individual elements to one another in the figures do not always correspond to the actual size ratios, since some shapes are simplified and other shapes are shown enlarged in relation to other elements for better illustration.

• FIG. 1 shows a schematic view of a shrinking device according to the invention from above.
• FIG. 2 shows a schematic side view of a shrinking device according to the invention.
• FIGS. 3 and 4 show different embodiments of wear strips from above.
• FIG. 5 shows a sectional view through a sliding strip in a lateral view.
• FIG. 6 shows an attachment of a slide strip.

For identical or equivalent elements of the invention, identical reference numerals are used. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures, which are required for the description of the respective figure. The illustrated embodiments are merely examples of how the device or method of the invention may be configured and are not an exhaustive limitation.

FIG. 1 shows a schematic view of a shrinking device 1 according to the invention from above and FIG. 2 shows a schematic side view of the shrinking device 1. This is used in particular for shrinking of flat packaging material 12 on Article 10 or article compositions. The wrapped with the packaging material 12 Article 10 or article compilations are referred to below as the pre-product 14.

The shrinking device 1 usually comprises a largely closed housing 100 with an inlet opening 101 for the pre-products 14 and an outlet opening 102 for the finished products 15. The pre-products 14 are in a Transport direction TR supplied on a first transport means 105 of the shrinking device 1 and enter via the inlet opening 101 in the enclosed by the housing 100 interior 103 of the shrinking device 1 a. In the inner space 103 of the shrinking device 1, the pre-products 14 are moved via a further endless conveyor 2 in the transport direction TR to the outlet opening 102 and thereby all-embracing acted upon by a shrinkage medium S. For example, hot air or the like. from the sides and / or from above and / or from below to the pre-products. As a result, the packaging material 12 is shrunk tightly around the articles 10 or article assemblies and the desired product 15 is formed. This is removed via the outlet opening 102 from the shrinking device 1 and then fed via a second transport means 106 further processing devices (not shown).

The endless conveyor 2 has an upper run 3 and a lower run 4. Preferably, the pre-products 14 are also applied from below with shrinking medium Su. For this reason, the endless conveyor 2 is permeable at least in the region of the upper strand 3 for shrinkage medium S, Su. The shrinking medium S, Su, for example, by a blower or similar. generated and passed over an arranged between the upper run 3 and the lower run 4 distribution device 6 to the underside of VorProdukte 14. The distributor 6 has nozzle openings 7, for example, on its upper side adjacent to the upper strand 3, via which the shrinkage medium Su, in particular hot air or the like, is provided. from below onto the underside of the pre-products 14 is aufgegedüst.

The upper strand 3 forms the conveying plane FE for the pre-products 14 and for the finished products 15. In order to stabilize the conveying plane FE, the upper strand 3 is preferably guided on arranged in at least two parallel rows slide strips 50. The distribution device 6 for the shrinkage medium S is arranged below the slide strips 50. So that the slide strips 50 do not interfere with the supply of shrinkage medium Su to the underside of the pre-products 14, they must conventionally be made very narrow and in each case between rows 9 of nozzle openings 7 (cf. FIG. 6 ) of the distribution device 6 are arranged. According to the invention, the sliding strips 50 have through openings 52 for the shrinkage medium Su.

FIGS. 3 and 4 show different embodiments of slide strips 50 from above, in particular, the figures show different embodiments of passages 52nd

In the FIG. 2 shown distribution device 6 for shrinking medium Su has on the upper strand 3 facing top nozzle openings 7, through which the shrinking medium Su is passed largely vertically through the upper strand 3 on the underside of the pre-products 14 and / or products 15. The nozzle openings 7 are preferably in a regular pattern, in particular in rows of nozzles or the like. arranged. The passage openings 52 of the slide strips 50 are preferably formed in a corresponding regular pattern. According to a preferred embodiment, the sliding strips 50 below the upper run 4 (see FIG. 2 ) are arranged and aligned such that the passage openings 52 of the slide strips 50 are each aligned with nozzle openings 7 of the distributor 6.

The wear strips 50 are made of a heat-resistant and lubricious material, such as graphite or a heat-resistant plastic. The passage openings 52a can according to the embodiment, a slide bar 50a in FIG. 3 a circular cross section or according to the embodiment, a slide bar 50b in FIG. 4 have a cross section in the form of a slot. Among other things, this depends on the type of material used. For slide strips 50 made of graphite, the use of passage openings 52b in the form of a slot is to be preferred due to the brittleness of the material.

Due to the embodiment with through openings 52, the slide strips 50 can now be made wider and are no longer in their width B ₅₀ on the distance A between rows of nozzles 9 of the distribution device 6 (see also FIG. 6 ). In particular, the slide strips 50 can now have a width B ₅₀ which extends over a plurality of adjacent nozzle rows 9 of the distributor 6.

FIG. 5 shows a sectional view through a slide bar 50 in a lateral view, in particular sectional view AA by a slide bar 50a according to FIG. 3 , The passage opening 52a has a chamfer 54 on the upper side of the slide strip 50a adjacent to the upper strand 3 (see also FIG FIG. 2 ). This causes an improved distribution of the shrinkage medium Su in the direction of the underside of the pre-products 14 or products 15.

FIG. 6 shows an attachment of a slide bar 50 to a C-profile element 60. The C-profile elements 60 extend below the upper run 3 parallel to the arranged in nozzle rows 9 nozzle openings 7 of the distributor 6. Preferably, the C-profile elements 60 air channels 62 formed. These extend in particular orthogonal to a conveying plane FE formed by the upper strand 3 and cause shrinkage medium Su to pass through the sliding strips 50 and thus in particular through the upper strand 3, even in the region of attachment of the sliding strips 50.

In this case, the air channels 62 of the C profile elements 60 are particularly preferably in alignment with the nozzle openings 7 of the distribution device 6 and are aligned with passage openings 52 of the slide strips 50.

FIG. 6 shows particularly clearly that due to the passage openings 52 of the slide strips 50 now also slide strips 50 can be used, which have a width B ₅₀ , which is a multiple of the distance A between the nozzle rows 9 of the distributor 6. The illustrated slide strip 50 has, for example, a width B ₅₀ which extends over three adjacent nozzle rows 9 of the distributor device 6.

The invention has been described with reference to a preferred embodiment. However, it will be apparent to those skilled in the art that modifications or changes may be made to the invention without departing from the scope of the following claims.

LIST OF REFERENCE NUMBERS

1

shrinker

2

The endless conveyor

3

obertrum

4

strand

6

distributor

7

nozzle opening

9

Düsenrehe / deer

10

items

12

packing material

14

Pre product

15

product

50

Slide Strip

52

Through opening

54

chamfer

60

C profile element

62

air duct

100

casing

101

inlet opening

102

outlet opening

103

inner space

105

first means of transport

106

second means of transport

A

distance

B ₅₀

Width of the sliding strip

FE

conveying plane

S / Su

shrink medium

TR

transport direction

Claims (10)

1. A shrinking apparatus (1) for heat shrinking planar packaging material (12) onto articles (10) or sets of articles,
   with an endless conveying means (2) that is permeable to shrink medium (S), the endless conveying means (2) comprising an upper strand (3) and a bottom strand (4);
   wherein the upper strand (3) is guided on at least one sliding rail (50);
   wherein a distribution device (6) for shrink medium (S) is disposed between the upper strand (3) and the bottom strand (4) below the at least one sliding rail (50); wherein at least the top side of the distribution device (6) has nozzle openings (7) for the shrink medium (S);
   wherein the at least one sliding rail (50) has passage openings (52) for the shrink medium (S).
2. The shrinking apparatus (1) as recited in claim 1, wherein the upper strand (3) is guided on sliding rails (50) that are disposed in at least two parallel rows.
3. The shrinking apparatus (1) as recited in claim 1 or 2, wherein the nozzle openings (7) are disposed in a regular pattern, in particular in nozzle rows (9); and wherein the passage openings (52) of the at least one sliding rail (50) are disposed in a corresponding regular pattern.
4. The shrinking apparatus (1) as recited in claim 3, wherein the passage openings (52) of the at least one sliding rail (50) are in each case disposed aligned with nozzle openings (7) of the distribution device (6).
5. The shrinking apparatus (1) as recited in one of the previous claims, wherein the at least one sliding rail (50) consists of graphite or of a heat-resistant plastic material.
6. The shrinking apparatus (1) as recited in one of the previous claims, wherein the passage openings (52) have a circular or a slot-formed cross section.
7. The shrinking apparatus (1) as recited in one of the previous claims, wherein the passage openings (52) have a chamfer (54) at the bottom side of the at least one sliding rail (50) adjacent to the distribution device (6) and/or at the top side of the at least one sliding rail (50) adjacent to the upper strand (3).
8. The shrinking apparatus (1) as recited in one of the previous claims, wherein the nozzle openings (7) of the distribution device (6) are disposed in parallel nozzle rows (9); wherein the nozzle rows (9) are aligned parallel to the transport direction (TR) of the articles (10) or, as the case may be, of the sets of articles on the upper strand (3) of the endless conveying means (2), said articles (10) or sets of articles being wrapped in packaging material (12); and wherein a first space (A) is formed in each case between adjacent, parallel nozzle rows (9); wherein the at least one sliding rail (50) is disposed parallel to the nozzle rows (9); and wherein the at least one sliding rail (50) in each case has a width (B₅₀) that is greater than the first space (A) between adjacent nozzle rows (9).
9. The shrinking apparatus (1) as recited in one of the previous claims, wherein the at least one sliding rail (50) is disposed at at least one C profile element (60); wherein the at least one C profile element (60) extends below the upper strand (3) parallel to the nozzle openings (7) of the distribution device (6), the nozzle openings being disposed in nozzle rows (9); wherein the at least one C profile elements (60) has air ducts (62) formed that extend orthogonally to a conveying surface (FE) formed by the upper strand (3).
10. The shrinking apparatus (1) as recited in claim 9, wherein the air ducts (62) of the C profile elements (60) are disposed aligned with nozzle openings (7) of the distribution device (6) and with passage openings (52) of the at least one sliding rail (50).

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