DE102004004827B4 - Labeling device and labeling method - Google Patents

Abstract

labeling, having a pressure stamp (1) with integrated inductor (3) for heating an electrical leading item to be labeled (7).

Description

The The present invention relates to a labeling apparatus as well a labeling method, in particular for labeling metallic Items.

at the labeling of objects Using self-adhesive labels is often intended as one as possible permanent connection between label and article to be labeled to achieve. This is to ensure that the text and / or image information with which the label is provided even with continued use of the article available directly on the item is. This is for example with nameplates or labels with Warnings the case.

Around a good bond between label and substrate too achieve, become common Labeling used in which each to be attached Label by means of a pressure stamp with high force is pressed against the respective object to be labeled.

Some Pressure-sensitive adhesives develop their best only after exposure to higher temperatures Adhesive force to the ground, because because of the softening above a certain temperature range, a better adaptation of the pressure-sensitive adhesive to the surface structure and thus an increased adhesion is reached. After cooling to room temperature is then a high resistance achieved against external influences, which manifests itself, for example, in a high achievable steam jet resistance.

The described increase the resistance a pressure-sensitive adhesive bond by heating makes you in the Take advantage of practice in two ways. Either the one to be labeled becomes Substrate heated before applying the label, or there is a heat storage of the article after the actual labeling process. Both approaches own the disadvantage that it about time-consuming processes act, and that the Facilities for heating additional Claim space.

Special Relevance possesses the addressed problem area with the labeling metallic objects, because in many technical fields straight components, which difficult environmental influences are made of metals or alloys. In particular, the labeling of metallic objects, such as in parts labeling in mechanical engineering, thus often requires special activities to improve the adhesion between label and substrate.

in view of the problem described, it is an object of the present invention to provide a labeling device which increases the Adhesion between label and substrate without space consuming or downstream heaters allowed. Furthermore, lies the Invention the task is based, in particular with this device executable To provide a labeling method, which increases the Adhesion between label and substrate without time-consuming or downstream heaters allowed. That's it Pay attention to the labeling of metallic objects.

According to one Aspect of the present invention achieves this object by a Labeling device according to claim 1 solved. Under an electric conductive object is understood according to the invention an object at least at the point to be labeled, near the surface at room temperature a specific electrical resistance smaller 100 μΩ · m. These include primarily metallic objects.

advantageous embodiments the labeling device according to the invention can designed according to claims 2-10 be.

According to one Another aspect of the present invention is achieved by the task a method according to claim 11 solved, for which preferably a device according to the invention is used.

through of the in the stamp integrated inductor, the object to be labeled during the pressing of a label locally heated inductively. Inductive heating allows one opposite usual Heating methods by orders of magnitude higher power transmission per area. Thus, the maximum inductive maximum per unit area is transferable Performance about two orders of magnitude higher than the area-related Heating power of an infrared spotlight. Opposite the Heating by means of a conventional Electric radiant heater is the difference about one more power of ten. Corresponding through inductive heating very short heating times possible, so that too at high cycle times of the labeling and accordingly short contact times the latter for one sufficient surface heating of the to be labeled objects suffice. Labeling and heating of the substrate can take place at the same time. Long preheating or warm storage times of the labeled or freshly labeled objects omitted.

Likewise, no space-consuming additional heating unit or warm storage unit is more required. In the form of one or more conductor loop (s), conductor coil (s) or meandering or spiral executable, preferably mainly consisting of copper inductor requires in its integration into the pressure pad very little space.

inducers can advantageously water-cooled be, for example in the form of internally cooled copper tubes.

The for the Operation of the inductor required AC voltage may vary Frequency range advantageously by means of a static frequency converter, Thyristor converter, transistor inverter or high-frequency converter (e.g., tube generator) be generated. Other components of a suitable induction heater are a grid feed, which are generally directly connected to the AC or three-phase network can be connected, a transmission path, if necessary, a compensation capacitor, as well as a control unit.

The Heat arises by induction of eddy currents in the object to be labeled itself. Therefore, heating power losses low and the efficiency correspondingly high. Also, none arise heat loss on a conveyor, as with a preheating of the object to be labeled when feeding from the heating unit to the label application unit the case is.

Farther is advantageous that the Penetration depth of the induced currents is low - at room temperature and an AC frequency of 500 Hz about 1.4 mm for steel and 4 mm for Aluminum, at higher Frequencies much lower, such as less than 1 mm for both mentioned materials at 10 kHz. The largest current density is at the Surface reached and falls towards the interior of the object to be labeled exponentially from. The heat is thus generated where it is for the treatment of the label adhesive is needed, namely near the surface.

One Another advantage is the high accuracy with which the heat and thus the heating temperature of the object to be labeled is adjustable. In connection with the heating from the ground can be at appropriate regulation sometimes even thermally sensitive label films be used, as in. Area of the label film the temperature is lower than at the transition between substrate and label adhesive. By a suitable choice of cycle time and energy input, the gluing parameters are very high good adjustable and maintainable, so that an adaptation to others substrates or otherwise changed Framework conditions easily possible is.

The inventive method, as well as the device according to the invention, Also suitable when using labels with thermal activatable adhesive (for example, conventional hotmelt) instead a pressure-sensitive adhesive. This results in the same advantages as with the application for Pressure-sensitive adhesive coated labels, namely no additional Heating or reheating times and the elimination of space-consuming separate heating units.

By the effectiveness The inductive heater is made with thermally activated adhesives another class of adhesives for Parts identification made accessible in mechanical engineering. Ever the invention extends the spectrum of usable adhesives. It can used smaller amounts of adhesive and thus the tendency for adhesive leakage reduced at the edge of the label and the shear stability can be increased. The often problematic adhesion of gray cast iron labels is improved. In general, a very good initial adhesion of the labels is achieved.

Further allows the invention the exact adaptation and bonding of labels made of shrink film on surface reliefs, Component bulges on machine shafts for corrosion protection, etc. By preferably rubber-elastic design the front part of the pressure stamp becomes a high flexibility in terms of Underground vaults reached.

Further can the contact surface advantageously adapted to the shape of the ground be on which the label is to be applied. At a in a sense (nearly) as a negative of the subsurface formed pressure surface offers both a rigid as well as an elastic design of the front part of the pressure ram at.

There the device according to the invention very compact executable is, great ones arise Handling advantages. Exactly to the respective underground curvature and / or Label shape and / or size matched Inductors and pressure surfaces can be adjusted accordingly adapted, easy attachable to a base unit Be integrated units.

A Label dispenser, of which the pressure stamp The labels can be integrated into the device or be attached to this modular.

Furthermore, the device according to the invention may advantageously be designed as a compact tool which is similar to a pneumatic impact wrench to handle. The supply lines are then led from a central station, for example, to the ceiling of the assembly hall. Such a thing Tool may be suspended from a cable system to reduce the masses to be moved during handling.

Of course you can too electrical supply lines and vacuum supply lines for a suction unit, which Receiving labels from a template, advantageously from above be led forth to the device.

at manual operation of the unit containing the pressure stamp can preferably visual (e.g., light) or acoustic displays for the desired one or actual Contact pressure, the Operation of the inductor and the end of the intended Anpreßzeit provided be.

Next Semi-automatic labeling with man control can also be a fully automatic operation with sensor control in in-line operation particularly be efficient.

Based the associated Drawings are examples of preferred embodiments of the present invention Invention in more detail below explained. at The drawings are purely schematic, strong simplified and not to scale illustrations, In particular, the thickness of the labels is greatly exaggerated for reasons of clarity shown. Corresponding elements are in the individual Figures are each provided with the same reference numerals.

1 shows a side view of a pressure stamp of a labeling device according to the invention.

2 shows the pressure stamp 1 with a front part adapted for round labels from the side of the contact to the label (ie from the right in FIG 1 ).

3 shows the pressure stamp 1 with a front part adapted for substantially rectangular labels from the side of the contact to the label (ie from the right in FIG 1 ).

4a shows the pressure stamp 1 with a sucked label just prior to application to a domed, metallic workpiece.

4b shows the pressure stamp 1 with label immediately upon application to the domed, metallic workpiece.

5a shows a Anpreßstempel the in 1 shown type when picking up a label from a completely movable dispensing unit.

5b shows the pressure stamp and the completely movable dispensing unit 1 after picking up a label.

The in 1 illustrated punch 1 has a replaceable rubber-elastic stamp front part 2 with embedded inductor 3 on, which may have different, the basic shape of one or more conductor loops varying designs.

A trained for a round label form stamp front part 2 is in 2 shown. In the center this has a vacuum plate 4 with several suction openings 5 for picking up the label to be dispensed 6 , Indicated by dashed lines is also the position of the spiral inductor 3 ,

A trained for a substantially rectangular label form stamp front part 2 is in 3 shown. In the center this also has a vacuum plate 4 with several suction openings 5 for picking up the label to be dispensed 6 , Indicated by dashed lines is also the position of the meandering inductor 3 ,

As in 4a This is shown in the area of the vacuum plate 4 (in 4a / 4b not shown) received label 6 by moving the pressure stamp 1 in the lateral for the label 6 certain position in front of a metallic workpiece 7 with a curved surface, for marking the label 6 serves.

Then presses the pressure stamp 1 the label 6 with its adhesive coating (not shown) axially against the surface of the workpiece 7 , When pressed, the front part fits 2 due to its rubber elasticity to the surface curvature of the workpiece 7 at. During pressing, the inductor becomes 3 supplied with electrical AC voltage. The hereby in the near-surface, hatched indicated area 8th of the workpiece 7 Induced eddy currents cause an ohmic heating of the workpiece surface at the point to be labeled. The resulting softening of the adhesive coating (not shown) of the label 6 Ensures a greatly increased adhesion between label after the labeling process 6 and workpiece 7 ,

5a and 5b show the interaction of the pressure stamp 1 with an alternately completely movable donation unit 12 during a work cycle. The donation unit 12 donates a label 6 from a donor role 10 in front of the vaccum plate 4 (in 5a / 5b not shown) showing the label 6 absorbed by suction. This will be the label 6 from a carrier tape 9 dispensed from Abziehmaterial on which a plurality of labels is arranged. After dispensing the label 6 becomes the donation unit 12 in the direction of the arrow 13 moves, and the application of the label 6 on the object to be labeled by means of the Anpreßstempels 1 may happen. Subsequently, the dispensing unit moves in the opposite direction of the arrow 13 back to the position of 5a and the process begins again. The empty carrier is cyclically on the take-up reel 11 wound up, creating a new label 6 placed in Abspendeposition.

As well as a movable donation unit 12 is of course the kinematic reversal feasible, ie a fixed dispensing unit in combination with displaceable pressure unit.

Claims (11)

Labeling device, comprising a pressure stamp ( 1 ) with integrated inductor ( 3 ) for heating an electrically conductive object to be labeled ( 7 ). Labeling device according to claim 1, wherein the pressure stamp ( 1 ) at least one suction opening ( 5 ) having. Labeling device according to one of the preceding claims, wherein the pressure stamp ( 1 ) has a rubber-elastic pressing portion. Labeling device according to one of the preceding claims, wherein the pressure stamp ( 1 ) is at least partially interchangeable. Labeling device according to one of the preceding claims, comprising a dispensing unit ( 12 ) for dispensing labels ( 6 ) of a carrier web ( 9 ). Labeling device according to claim 5, wherein the dispensing unit ( 6 ) is displaceable alternately. Labeling device according to one of the preceding claims, comprising a semi-automatic or fully automatic control unit. Labeling device according to one of the preceding claims, wherein the pressure stamp ( 1 ) is pneumatically movable. Labeling device according to claim 8, comprising a Pneumatic connection for an external compressed air supply. Labeling device according to one of the preceding claims, wherein a top suspension above Cable system is provided. Method for labeling an electrically conductive object ( 7 ), the object ( 7 ) in its area to be labeled during the pressing of an adhesive coated label ( 6 ) is heated inductively.