DE10056322A1 - Breaking an adhesive connection, e.g. between a windscreen and its surrounding frame, comprises using an infra-red source to thermolytically destroy the adhesive bond - Google Patents

Abstract

A process for breaking an adhesive connection composed of a thermolytically destructible adhesive located between a sheet of glass and a metal frame comprises using infra-red radiation. An infra-red source is applied to the screen to thermolytically break down the adhesive connection. The infra-red source is applied for a predetermined time and then the screen is removed without damage. A process for breaking an adhesive connection composed of a thermolytically destructible adhesive, especially a thermoplastic polyurethane or similar, located between a sheet of glass and a metal frame comprises using infra-red radiation. An infra-red source is applied to the screen to thermolytically break down the adhesive connection. The infra-red source is applied for a predetermined time and then the screen is removed without damage. The heat source consists of numerous elements in modular form, and the radiation is focussed on the adhesion area. The arrangement used comprises a metal holder, an infra-red source, and a positioning unit.

Description

The invention relates to a process for dissolving an adhesive bond according to the Preamble of claim 1 and a device for carrying out this Method according to the preamble of claim 13. Furthermore, the invention is directed to a method for non-destructive removal by means of an adhesive connection with a mounting disk connected according to the preamble of claim 2.

To secure attachment to ensure at least parts are now the Glazing of motor vehicles in a frame-like mostly made of metal Bracket is glued. Polymer adhesives are usually used as adhesives, in particular highly modular thermoplastic polyurethane glue used. Popular this type the mounting especially for the fixation of the front and rear windows Motor vehicles. The adhesives used and the design of the bracket in the Bonding area must have a high mechanical strength and stability to environmental influences of diverse provenance in order for a long time to guarantee a secure hold of the disc in the holder. However proves removing the glued-disc from the holder problematic, especially if it is to be complete and without destroying the disc. particularly for Improve the recycling rate of the overall vehicle, as in Germany For example, is prescribed in the old car regulation of 1.4.1998, and by the in glass content contained car completely as possible for recycling to Providing is a non-destructive removal of the glazing desirable. Likewise, the glazing is to the dissolution often Repair purposes required to keep the windows as possible.

Heretofore, for removing by means of an adhesive connection with a holder connected panes, two different processes have been used. The first method is based on the mechanical separation of the disc and Mounting, in particular by sawing out of the disc. For example, in the DE 44 45 095. The use of a high frequency jigsaw. This The conventional way of disassembling the window becomes time and thus costly that the gap between the disc edge and bracket today's vehicles are kept very low. Furthermore, there is a relatively large Chance that the disk will be destroyed. If the distance of the disc Connection is done with repairs, is also disadvantageous that when Sawing out can easily cause paint damage to the body of the car can.

The second method is inductive heating of metal and is, for example, from the DE 38 23 952 known. In induction heating metal when there is a a sufficiently strong electromagnetic field is used around the support to heat in the bonding area, and thus a destruction of the Establish adhesive connection. However, this procedure can only work if the bracket in the entire gluing area made of a metallic material consists. This is in the use of plastic mounting parts do not. Further there is a risk that the heating of the metallic support to a warpage with irreversible deformities, especially also on other body parts leads. Next there may be a transfer of forces from the support to the Your windows through which a fraction of the disk can be caused.

Summary of the invention

Starting from this prior art, the object of the present invention the basis for a quick, simple and safe solution in one Gluing area arranged between a disc and a bracket To enable adhesive connection from a thermally destructible adhesive.

This object is achieved by a method with the features of claim 1 and by an apparatus for performing this method having the features of Claim 13 is released. This will provide a non-destructive removal of a by means of a Adhesive connection with a bracket connected disc according to the characteristics of the allows claim 2.

According to the method of one of the holder for a predetermined time interval Disc surface area is remote by an infrared source thermal energy into introduced the adhesive connection and thus thermally destroyed the adhesive connection. During the thermolytic destruction, the chemical structure of the adhesive changed irreversibly so that it loses its adhesive properties. As special effective infrared radiation in the near infrared range has proven to be. The Method is effective in a large class of polymer adhesives that are not too have high temperature stability. Here, the most come in Polyurethane glue used in the auto industry in question. The process is in all Disc shapes and bracket geometries and can also be used if only there are small gaps between the edge of the pane and the holder. You can also Parts of the bracket are made of plastic. Since there is no direct energy input into the Holder is required to be generated by heating the deformations Handle completely or largely avoided. It is preferable here radiation used in the near infrared range.

In the method for non-destructive removal by means of an adhesive connection connected from a thermolytically destructible adhesive with a holder Disc, according to the invention, after the connection has been dissolved, the disc becomes captured and removed from the bracket. Since a detection of the disc according to the invention is carried out only in the second step consists in removing the Disc only a very low risk of damage or destruction.

If according to a further embodiment of the invention, the infrared source of a Plurality of sub-elements, which are preferably in groups of Modules forming sub-elements are combined, the introduction can be the infrared radiation more readily to the respectively present disk shape, and Bracket geometry, adjust.

If, according to further claims spatial and / or temporal parameters of the infrared Radiation or their entry be varied at or above the disc surface, an optimal adaptation to the respective circumstances of the application of the method and thus a high degree of flexibility achievable.

In a preferred embodiment of the invention, at least one predetermined time interval after the start of introduction of the infrared radiation in or by the disk surface area air masses from the vicinity of the Splicing area removed and / or, if appropriate, fed to a purification.

This makes a contribution to occupational safety and environmental protection, since at thermolytic caused destruction of the adhesive bond toxic substances can.

The device according to the invention includes an infrared radiation device, which has an infra-red emitting infrared source to the Infrared radiation into a side remote from the support disc surface area for thermolytic destruction of the adhesive bond contribute.

According to a preferred embodiment of the device, the infrared source has a Surface having a shape on which a contour of the splicing area and / or the shape of a disc surface area at least in the Bond area is congruent. This makes it particularly easy to use and achieved a higher efficiency in the introduction of infrared radiation.

In further embodiments of the invention, the infrared source of a A plurality of sub-elements, of which preferably groups in preferably Box-shaped modules are combined. This is even easier handling and better adaptation to different lens shapes and Bracket geometries reached.

If the sub-elements in a further embodiment of the invention and / or the Modules are flexibly connected to one another, making them even faster Adaptability of the device to different lens shapes and / or Bracket geometries reached.

In a further embodiment of the device, reflector means for Focusing of infrared radiation is provided, which makes it more efficient to use is achievable.

Further features and advantages of the present invention result from further dependent claims and regardless of their summary in the Claims from the following description of preferred inventive Embodiments in conjunction with the accompanying drawings.

The drawings show in schematic form:

Fig. 1 is an infrared irradiation means, and glued into a holder disc in a cross-sectional representation,

Fig. 2 is a module chain arranged in the warp direction infrared lamps,

Fig. 3 is a module chain with transverse to the chain direction infrared lamps.

Fig. 1 shows a cross-sectional view of a box-shaped module 10 an infrared irradiation device with an infrared source, the emitting part elements six infrared radiation 21 lamps 20 has, and at a distance d from the surface 31 of a disc 30, in this case the windscreen of laminated glass of a motor vehicle , is located. The distance d refers to a formed by a protective cover 11 of the module 10 surface 10 is emitted through which infrared radiation from the lamps 21 twentieth The protective cover 11 may consist for example of quartz or a wire mesh.

The disc 30 is adhered with an adhesive in a frame-like bracket 40th The adhesive forms an adhesive connection 50 between the pane 30 and the holder 40 in a bonding area 33 of the pane 30 . The contour of the bonding area 33 is determined by the mounting geometry and varies between different types of motor vehicles as well as the shape of the window surface 31 . A highly modular polymer adhesive which is photosensitive to infrared radiation, for example based on polyurethane, is preferably provided as the adhesive.

A spacer 42 , which can also be made of polyurethane, for example, is used to position the disk 30 in the holder 40 relative to a flank section 46 . The bracket 40 merges into a front section 44 of the body or into the roof of the motor vehicle.

The bracket 40 has a profiled structure on 43rd For example, these can be openings into which adhesive can penetrate, so that a toothing 45 is formed by the adhesive connection 50 , in which the teeth protrude into the openings and lead to an improved hold of the adhesive connection 50 in the holder 40 . It goes without saying that other forms of the holder are also possible, in particular those without a profile structure. Between the disk rim 32 and an edge portion 46 of the holder 40 there is a gap 47th The spacer 42 prevents contact of water or other environmental media with the adhesive connection 50 . The holder 40 , like a side edge of the pane 30 , not shown here, is normally covered by body parts 41 .

The module 10 has a suction device 16 leading suction tubes 15 with the air masses, which contain toxic substances 50 resulting in the destruction of the adhesive bond, filtered off with suction and / or can be cleaned.

In addition to the lamps 20 , ceramic or quartz emitters, infrared diodes or infrared lasers can also be used as the infrared source.

To focus the infrared radiation 21 on the bonding area 33 , mirror-like reflectors 13 are arranged inside the module 10 behind the lamps 20 . The module 10 also has an interior partition wall 14 between a rear wall 17 and the reflectors 13 . In the area of the module 10 between the rear wall 17 and the interior cover 14 control and power supply systems can be accommodated the infrared source.

A positioning arm 60 is disposed on the rear wall 17 of the module 10th In the area of the protective cover 11 , sensors 61 are provided, the signals of which can be fed to a control system. The positioning of the module 10 relative to the disc 30 to the infrared radiation 21 to bring the present invention may be done for example by a robot or the like, the positioning arm 60 controlled by a sensor moved. Correct positioning can be facilitated by applying markings to the pane 30 in the area of the adhesive area 33 .

According to the invention, continuous or pulsed infrared radiation, preferably in the so-called near infrared, can be used. At this time, particularly in special glazing, the emitted infrared radiation 21 to be increased in a suitable manner from a minimum value to a maximum value, to keep sufficiently low the mechanical tension in the disc 30th It is further provided that the time interval during which the infrared radiation 21 is applied as a whole is to be dimensioned such that the heating of the holder 40 and of the body elements 41 , 44 surrounding it is small and the deformations which are produced are tolerably small. Is advantageous if the wavelength range of the light emitted from the lamps 20 infrared radiation in the near infrared, that is approximately 0.8 to 1.5 microns. However, lamps with infrared radiation with a different wavelength range can also be used.

According to the invention the adhesive bond is heated to a temperature of 50 by the light emitted from the lamps 20 infrared radiation 21, wherein the adhesive bond 50 forming adhesive is thermolytically destroyed. The adhesive loses its adhesive properties and the adhesive connection 50 between the pane 30 and the holder 40 is broken. The disk 30 can then readily from the holder 40 to be removed. Various means which are known per se and are not illustrated are provided for this purpose, for example adhesive suction bells or splitting knives engaging in the gap 47 .

A higher absorption of infrared radiation 21 in the disc 30 can be achieved when the disc 30 in the splicing area of the absorbent 33 with a infrared radiation coating z. B. is blackened or if the disc 30 absorbs infrared radiation more even in this area. The heat thus generated by absorption contributes to the thermolytic destruction of the adhesive bond 50 . This is particularly advantageous when used if the adhesive connection consists of an adhesive that is not or only slightly photosensitive in the infrared range.

In order to prevent undesired heating of the pane 30 and / or the holder 40 in areas adjacent to the bonding area 33 , a cover area can be covered with a cover that is impermeable to infrared radiation, for example consisting of aluminum foil or a heat protection foil. This particular paint damage can be avoided.

If only a single module 10 is used to detach the adhesive connection 50 , there is initially only a solution in a partial section of the adhesive area 33 , since only the assigned part of the adhesive connection 50 is destroyed in a first time interval. In the following time intervals, further sections of the adhesive connection 50 are successively destroyed.

In a preferred embodiment of the invention of the module 10 , 6 lamps 20 are provided , for example with a total connected load of 20 to 30 kW. However, modules with a lower power input, for example, 1 kW per lamp can be used. For example, power densities of 800 to 900 kW / m2 or 200 kW / m2 are used. The power of the module can, for example, be varied continuously and linearly from zero to the maximum connected load.

The required heating time depends inter alia on the total energy density, which is generated by the module 10, and may extend from a few seconds to about a minute. A favorable distance d between the pane surface 31 in the bonding area 33 and the protective cover 11 is between 10 and 20 cm for the parameters specified. With a smaller value of the distance, the heating time is reduced accordingly, while with a larger value the distance increases accordingly. Within the specified time intervals, the specified parameters of the heating module can quickly reach temperatures of up to 300 ° C in the bonding area 33 , which are sufficient to reliably remove, for example, bonds made of polyurethane, which decomposes at approximately 180 ° C.

Figs. 2 and 3 show respective views of apparatus with which, for example, the entire adhesive bond can be substantially solved simultaneously 50 in the upper or lower area of a windshield of a motor vehicle. Corresponding components of the devices have the same reference numerals as in Fig. 1. The module chains 18 shown in Fig. 2 and 3 show two different embodiments of positioning arms 60 on.

A chain module 18 is preferably each formed of flexibly interconnected modules 10th For the formation of a flexible connection between the individual modules 10 , for example swivel joints 12 or the like can be used. The flexible connection of the modules 10 enables an optimal adjustment of the spatial power density of infrared radiation to the contour of the splicing area 33 and to the shape of the wafer surface 31st Arranged at a distance D from the disk surface 31 of modules 10 may all emit infrared radiation 21, whereby a correspondingly wide-ranging solution of the adhesive connection can be done 50th

FIG. 2 shows an embodiment of the module chain 18 in which lamps 20 are arranged with their longitudinal axis along the chain direction. To ensure a minimum distance between the protective cover 11 and the pane surface 31 , a spacer 62 is provided on a module 10 .

FIG. 3 shows an embodiment of the invention in which the lamps 20 lie with their longitudinal axis perpendicular to the direction of the module chain 18 . In the latter embodiment, the length of the lamps 20 is expediently adapted to the width s of the bonding area 33 .

The use of modules 10 which are flexibly connected to one another in the module chain 18 enables simple adaptation to different disk shapes and mounting geometries. This can also be achieved by the lamps 20 themselves are flexibly connected to each other.

Alternatively, however, embodiments having rigidly interconnected modules 10 are included in the invention.

In a further, but not visually illustrated embodiment of the invention a number of modules arranged in a shape that is congruent to the contour of the Splicing area and to the surface in the entire bonding area of a Disc with a frame-like holder. This enables a simultaneous solution to the entire adhesive connection between disc and bracket.

Claims (22)

1. Method for releasing an adhesive connection from a thermolytically destructible adhesive, preferably from thermoplastic polyurethane or the like, which is arranged in a bonding area between a pane made of glass or the like and a preferably frame-like holder, preferably made of metal, preferably for glazing of motor vehicles, characterized in that by means of an infrared source for a predetermined time interval in a preferably of the holder disc surface region remote infrared radiation, preferably near infrared, is introduced and the adhesive connection is so thermolytically destroyed. 2. A method of non-destructive removal of a glass or the like existing pane, preferably a glazing of motor vehicles, preferably, or the like from a metal consisting preferably frame-like holder in a splicing area by means of an adhesive connection of a thermolytically destructible adhesive, preferably polyurethane, with the , support is connected characterized in that the following steps are performed: - means of an infrared source for a predetermined time interval in a preferably of the holder disc surface region remote infrared radiation, preferably near infrared, is introduced and thus the adhesive bond between the pane and holding thermolytically destroyed, - the disc is then mechanically collected and removed from the holder. 3. The method according to at least one of the preceding claims, characterized characterized in that the infrared source is preferably a plurality of juxtaposed sub-elements, wherein preferably Groups of sub-elements are combined in box-shaped modules. 4. The method according to at least one of the preceding claims, characterized in that the infrared radiation on the splicing area is focused. 5. The method according to at least one of the preceding claims, characterized in that in a first time interval the infrared radiation on Sub-sections of the bond area is focused and in subsequent Time intervals to focus on other sections of the Bonding area takes place. 6. The method according to at least one of the preceding claims, characterized characterized in that the disc and / or the holder at least in one adjacent to the bonding area coverage with a for Infrared-impermeable cover, for example made of aluminum foil or the like is covered. 7. The method according to at least one of the preceding claims, characterized in that the power density of the emitted infrared radiation is varied with time, in particular slowly from a low value up to a predetermined maximum value or that a pulse radiation is used. 8. The method according to at least one of the preceding claims, characterized in that the power density of infrared radiation, a Contour of the bond area and / or the shape of the pane surface in the Adhesion area has adapted spatial variation. 9. The method according to at least one of the preceding claims, characterized in that the disc at least in the bonding region Has focus markings. 10. The method according to at least one of the preceding claims, characterized in that the disk in a surface region, at least in the Bonding region, an infrared radiation absorbing coating, includes, for example, blackening or the like. 11. The method according to at least one of the preceding claims, characterized characterized in that at least in a predetermined time interval The beginning of the introduction of the infrared radiation air mass, at least from the Removed near area of the bonding area, for example, vacuumed and / or a cleaning can be supplied. 12. An apparatus for dissolving an adhesive bond of a thermolytically destructible adhesive, preferably polyurethane, in a Bonding region existing between one or the like made of glass Disk and a preferably made of metal preferably frame-like mount is arranged, characterized in that Infrared radiation device is provided with infrared radiation, preferably radiation in the near infrared region, emitting infrared source remote to infrared radiation in a preferably of the holder Disk surface area for thermolytic destruction of the Introduce adhesive connection. 13. The apparatus according to claim 12, characterized in that Positioning means are provided with which the positionable infrared irradiation device relative to the disk surface. 14. The apparatus according to claim 12 or 13, characterized in that the infrared source has a surface with a shape which to a Contour of the splicing area and / or the form of a Pane surface area is congruent at least in the bonding area. 15. The device according to at least one of claims 12 to 14, characterized in that the infrared source comprises a plurality of subelements includes. 16. The device according to at least one of claims 12 to 15, characterized in that groups of sub-elements of the infrared source in preferably box-shaped modules are combined. 17. The apparatus according to claim 16, characterized in that the modules flexible, for example by means of hinges or the like, with each other are connected. 18. The device according to at least one of claims 12 to 17, characterized in that reflector means for focusing the infrared radiation, for example mirrors or the like are provided. 19. The device according to at least one of claims 12 to 18, characterized characterized that lamps emitting infrared radiation as the infrared source, Ceramic or quartz heaters, infrared diodes or infrared - Laser provided are. 20. The device according to at least one of claims 12 to 19, characterized in that the infrared radiation device is a comprising protecting cover, pass through the infrared radiation and to a Disc surface area, preferably emitted on the bonding area can be. 21. Device according to one of claims 12 to 19, characterized in that means for ensuring a minimum distance between Protective cover and the disc surface are provided. 22. The device according to at least one of claims 12 to 21, characterized characterized that means for vacuuming and / or cleaning with air masses contaminated with toxic substances are provided.