DE10104002A1 - Process for tempering plastic films to be glued and device for gluing plastic films with temperature-controlled transport roller - Google Patents

Abstract

Process for adjusting the temperature of the plastic film to be glued, which is preferably in the form of notes (8), on flat-lying hose or workpieces (2) made of plastic film, e.g. B. from valve labels on the drawn-up floor squares or from bottom cover sheets to the added bottoms of cross-bottom valve bags, DOLLAR A, the hose or workpieces being conveyed by a conveyor with a plate or a table (1) and a gap between a counter-pressure element, preferably a counter-pressure roller ( 4) and a suction cylinder (6), and DOLLAR A, the plastic film to be bonded being fed and transferred to the suction cylinder (6) by a conveying cylinder (7), DOLLAR A, the plastic film to be bonded being heated in the roll nip already at the transpsort , DOLLAR A Furthermore, a device for carrying out the method is presented, which has a heatable conveyor roller.

Description

The invention relates to a method for tempering to be glued Plastic films according to the preamble of claim 1 and a device for gluing plastic notes according to the preamble of claim 9.

Method and devices for gluing plastic film on tubular or workpieces, which often also consist of plastic film, are made of Literature known. When gluing several thermoplastic elements with each other, it is often useful to heat these elements and thus at least to loosen their surface.

In this context, the term gluing includes several different ways of joining plastic films summarized, in which the process temperature plays a role. Mostly - as already mentioned above - the surface of the plastic film plasticized or melted by heating and then under Pressure glued or welded.

However, the term bonding also includes classic gluing understood, which is another substance - which is an adhesive can act - additionally applied to one or both foils. at This substance can be an adhesive that is initially in liquid Form is present and then hardens, act. The third substance can also - optionally together with the film surfaces - tempered and on a suitable temperature for bonding. In this case, too the two foils are finally joined together under pressure.  

According to the current state of the art, notes and workpieces are in brought together a nip. The heating of the contact surfaces the elements to be bonded are also made within the nip Hot air.

In order to achieve reliable reproducible results, DE 198 18 720 shows a device where the temperature of the already glued Elements measured after passing through the nip as actual value becomes. The temperature of the hot air flow is based on this actual value adjusted.

The setting of the adhesive temperature only by a suitable air flow however, has disadvantages. So it sometimes takes a few hours for that Roll gap adjacent components of the device the working temperature achieved. The film is therefore only in the immediate vicinity of the Roll nip exposed to the temperature influence of the air flow. It is therefore, the speed of passage of the film through the To reduce the nip during the running-in phase so that the film assumes the desired temperature.

It is the object of the present invention to shorten this running-in phase, so that the device can work faster at high speed. The object of the invention is achieved by the plastic film already is tempered before reaching the nip.

This procedure can a. be performed by parts of the Conveying device, which the plastic film to be glued into the nip transported, tempered and in this way the temperature of the film is set.

The temperature control can be limited, for example, to a conveyor roller, however, it can also be on the vacuum roller, or in the machining direction Conveyor roller upstream conveyor or storage elements or Deflection rollers or bands of tapes are made with the Interact conveyor roller. Also a combination of the tempering of the the aforementioned elements is conceivable. Also an integration of additional ones heatable or temperature-controllable elements, which are neither a transport  or storage function, but during transport or storage in mechanical contact with the film to be glued is possible. All of these possibilities are defined by the term "devices which the Transport or store film "in the characterizing part of claim 2 includes.

In addition to the aforementioned shortening, the advantages of the invention include Run-in phase also efficient use of the energy used because the Air previously used is a relatively expensive form of heat energy transfer represents.

The method according to the invention can be used with other methods Setting a suitable melting or adhesive temperature, such as for example the already mentioned heating of the film in the nip by hot air or by heating the workpieces in front of the nip, combine.

Since the use of various heatable elements, the occurrence of friction or process heat and the ambient temperature can cause In this application, cooling is required instead of heating related to the word tempering, which means both heating and cooling includes.

The temperature transfer from one proves to be particularly expedient Casting material produced conveyor roller on the plastic film, since rollers this type have a high heat capacity, therefore one for a stable one Bring process advantageous thermal inertia and also relative be in long contact with the film to be glued.

Further advantages and advantageous embodiments of the invention result itself from the further claims and the subsequent ones objective description.

Embodiments of the invention are described below with reference to the Drawings explained in more detail. In this shows  

Fig. 1 is a side view of a device for applying and sticking notes on workpieces in a schematic representation, in which hot air is additionally blown into the nip

Fig. 2 is a plan view of a cross floor with a glued ground cover sheet and

Fig. 3 is a raised floor with a valve label glued to a corner.

Fig. 4 shows a detail from a side view as in Fig. 1, in which a heating coil is also sketched in the transport cylinder.

In a frame, not shown, a table top 1 is supported, on which, in the direction of arrow A, flat-lying plastic tube pieces with open or closed bottoms are conveyed by conveying devices, not shown. In the case of the hose sections 2 which are conveyed at a mutual distance from one another, the added floors or the raised floors are folded into the plane of the flat hose sections in the manner shown in FIGS. 2 and 3. In a transverse gap 3 of the table 1 , a counter-pressure roller 4 and a suction roller 5 are mounted in the machine frame, which together form a pair of conveyor rollers and whose roller gap lies in the area of the plane of the top of the table 1 . The suction cylinder 5 is provided in its jacket at approximately equal angular intervals with rows of suction air holes 6 . The interior of the suction cylinder 6 , the suction air is discharged in the usual way through a rotary feedthrough, not shown.

Above the suction cylinder 5 , a knife and conveying cylinder 7 is mounted in the machine frame, against which the pieces of paper 8, separated from an endless plastic web (not shown), are pressed by a strand 9 of an endless band of tapes 10 which circulate deflection rollers 11 , 12 , 13 mounted above the machine frame , of which the roller 13 can also be driven. The knife and feed cylinder 7 is provided in the usual way with a knife 14 running along a surface line.

In front of the nip of the cylinder pair 4 , 5 , a sheet 16 ends, which is used for temperature control and thus for setting the suitable temperature of the tube pieces 2 . For this purpose, this sheet can dissipate or supply thermal energy to the tube pieces. In the following, however, this sheet is referred to as cooling sheet 16 for the sake of simplicity. This cooling plate 16 is provided with an upwardly angled inlet side 17 . The cooling plate 16 , 17 is provided in a meandering and / or serpentine shape with coolant or heat medium tubes through which a medium flows. This medium, for example water, is introduced into the connector 18 through hose lines, not shown, and is drawn off again from the discharge connector 19 . Above the cooling plate 16 , 17 , an inclined guide 20 is held in the machine frame, on which a heating unit 21 can be moved back and forth between stops 22 , 23 of the guide 20 by a pressure medium piston cylinder unit 24 . The heating unit is provided at its front end with a pipe 25 for blowing out warm air. A rotary slide valve 26 is arranged in the tube 25 , the slide valve can be moved into an open and closed position and intermediate positions by an actuating lever 27 . To actuate the lever 27 , a pressure medium piston cylinder unit 28 is provided, which is articulated on the one hand on the hot air unit 21 and on the other hand on the actuating lever 27 . An output of the rotary valve 26 opens into a tube 29 which carries a slot die 30 which is directed into the gap between the rollers 4 , 5 . The other output of the rotary valve 26 opens into a tube 32 which opens into the open or discharges the hot air.

The suction cylinder 5 takes the notes 8 in the manner shown from the knife and conveyor cylinder 7 and places them in the correct position on the continuous bag workpieces. Hot air is blown through the slot die 30 into the roll gap in which the slip 8 and the workpiece 2 are located at controlled times, which plasticizes the plastic material or melts in such a way that the slip 8 sticks to the workpieces 2 .

The hot air supply is controlled cyclically by the pressure medium piston cylinder unit 28 by a control device. Furthermore, the slot die 30 can be adjusted by the pressure medium piston cylinder unit 24 in the desired manner in its distance to the nip.

In the embodiments shown in FIGS . 1 and 4, in addition to the hot air supply, the temperatures of the suction cylinder 6 , the feed cylinder 7 and the cooling plate 16 can be regulated. In extreme applications, it may even be necessary to blow cold air into the nip instead of hot air. The volume of air blown in per time unit is another parameter for the temperature setting.

FIG. 2 shows a workpiece consisting of an added cross bottom onto which a bottom note 8 'is glued.

From Fig. 3 a sack workpiece 2 with still open bottoms can be seen, in which the valve label 8 "is glued onto the leading corner fold of the one bottom, which results in a valve hose in a known manner when the side folds are folded in.

The device shown in FIG. 1 is provided twice on both sides of the table 1 , if at the same time both bottoms formed on the tube piece 2 are to be provided with bottom cover sheets 8 '.

Immediately behind the pair of rollers consisting of the counter-pressure roller 4 and the suction roller 5 , the temperature of the bonded area of the tube pieces 2 is measured by a temperature sensor, in the exemplary embodiment shown by an infrared pyrometer 43 , which is arranged in the machine frame at a predetermined distance above the outgoing workpieces. The measurement signals of the temperature sensor 43 are fed to the control and regulating unit 40 through a signal line 44 .

In this embodiment, this control and regulating unit regulates the temperatures of the rollers 6 and 7 and of the cooling plate 16 via signal lines (not shown) and by means of heating or cooling elements (not shown).

Only the control elements for the temperature of the heating unit 21 or the air heated by it, which serves for the bonding, is shown in the drawing.

The temperature signals of the temperature sensor 43 are fed through a signal line 41 to the control and regulating unit 40 consisting of a computer. This control and regulating unit 40 controls the temperature of the blown out heated air through a control line 42 , which increases or decreases the temperature of the electrical heating elements of the heating unit 21 accordingly.

The temperature of the table 1 is measured behind the nip of the rolls 4 , 5 by a temperature sensor 45 , the signals of which are fed to the control and regulating unit 40 via a signal line 46 . The temperature sensor 45 essentially detects the temperature of the device, so that the temperature of the hot air blown out of the slot die 30 can be preset via the control and regulating unit.

Irrespective of the regulation described, the temperature of the hot air blown out of the slot die 30 can also be set manually on the control and regulating device, which can be expedient for presetting the temperature.

Fig. 4 shows a section of a side view as shown in Fig. 1. However, the exemplary embodiment shown in FIG. 4 includes a heating coil, which is represented by the serpentine line 50 . This exemplary embodiment merely outlines, by way of example, a possibility of heating or tempering a cylinder.

Claims (9)

1. Process for tempering plastic film to be glued, which is preferably in the form of notes ( 8 ), on flat-lying hose or workpieces ( 2 ) made of plastic film, for. B. from valve labels on the open squares or from bottom cover sheets to the added bottoms of cross bottom valve sacks,
wherein the hose or workpieces are conveyed by a conveyor device with a plate or a table ( 1 ) and fed into a gap between a counter pressure element, preferably a counter pressure roller ( 4 ) and a suction cylinder ( 6 ) and
wherein the plastic film to be glued is fed and transferred to the suction cylinder ( 6 ) by a conveyor cylinder ( 7 ),
characterized in that
the plastic film to be bonded is already tempered during transport into the nip. 2. The method according to claim 1, characterized in that at least part of the devices which the film to be glued convey or store, is tempered so that a direct heat transfer between the tempered devices and the one to be glued Plastic film takes place. 3. The method according to claim 2, characterized in that the devices to be tempered, which convey or store the film to be bonded, are tempered or heated with one or more of the different methods:
through electrical heating elements
by supplying preheated liquid
through peeling animal elements
by heating cartridges 4. The method according to any one of the preceding claims, characterized in that a further adjustment of the temperature of the plastic film and the hose or workpieces is carried out by blowing air into the area of the nip between the counter-pressure roller ( 4 ) and the suction cylinder ( 6 ). 5. The method according to any one of the preceding claims, characterized in that only the conveyor cylinder ( 7 ) can be tempered by the conveyor devices. 6. The method according to any one of the preceding claims, characterized in that of the conveyor devices, only the conveyor cylinder ( 7 ) and the suction cylinder ( 5 ) can be tempered. 7. The method according to any one of the preceding claims, characterized in that even the hose or workpieces before reaching the Roller gap are tempered. 8. The method according to any one of the preceding claims, characterized in that
the temperature of the glued area of the workpiece is measured as an actual value immediately after the gluing and the temperature of the temperature-adjustable conveying devices and
where appropriate, the air blown into the nip and
if necessary, the hose and workpieces
is determined and set as the setpoint. 9. Device for gluing plastic films, preferably of paper ( 8 ) made of plastic film on flat lying hose or workpieces made of plastic film z. B. from valve labels on the open squares or from bottom cover sheets to the added bottoms of cross bottom valve bags, consisting of
a frame with a plate or a table ( 1 ) over which the tubular or valve bags are conveyed,
a pair of rollers arranged at one end or in a nip of the table, comprising a counter-pressure roller ( 4 ) and a vacuum roller ( 5 ), the roller nip of which is largely aligned with the table surface,
a conveyor cylinder ( 7 ) which transfers the plastic film to be glued to the suction cylinder,
characterized in that
the delivery cylinder is equipped with devices for its temperature control.