WO2001028904A1

WO2001028904A1 - Device and method for transferring adhesive laminates from a dispensing web to an acceptor web

Info

Publication number: WO2001028904A1
Application number: PCT/EP2000/009802
Authority: WO
Inventors: Christian Von Falkenhausen
Original assignee: Lts Lohmann Therapie-Systeme Ag
Priority date: 1999-10-19
Filing date: 2000-10-06
Publication date: 2001-04-26

Abstract

The invention relates to a device for continuously transferring adhesive laminate systems which enables the transfer of adhesive laminate systems from a slow-moving dispensing web to a fast-moving acceptor web during both clocked as well as continuous manufacturing operation during which the dispensing web and acceptor web are guided in a non-parallel manner. This transfer is effected without subjecting the system to tensile stresses. As a result, it is possible during continuous manufacturing operation to reduce the amount of material required due to narrow punching and to provide protruding final supports.

Description

Device and method for dispensing adhesive laminates from a dispensing web to an acceptor web

The invention relates to a device and a method for dispensing adhesive laminates from a dispensing web to an acceptor web, comprising a dispensing web that conveys the laminates to be dispensed and can be guided around a dispensing edge, and an acceptor web that is provided for receiving the laminates with possibly increased mutual distances.

In the production of plasters or labels from self-adhesive laminates, significant amounts of waste are generated during the stripping of excess material. In order to minimize this, the measure has already been taken to keep the distance between the individual laminates as small as possible. However, this endeavors to counteract the product requirement for handling to leave a protruding support edge. According to the prior art, this conflict is resolved by tightly punching out the laminates and then transferring them to a subsequent carrier, hereinafter referred to as the acceptor web, which is moved at a higher speed than the first carrier, hereinafter referred to as the donor web. The distance between the individual laminates is increased as desired after they have been transferred to the acceptor web. This means that the product requirements can be met while minimizing material consumption (see e.g. US 5,250,134).

When the laminates are transferred from a donation web that runs slowly around a fixed dispensing edge to a faster-running acceptor web, the laminates “tear off” from the donation web. This creates high tensions in the system, which can damage the products. It is known to solve the problem that arises in discontinuous production operations, for example by means of a movable dispensing edge. This method (DE 44 06 970) uses the rest phases of a clocked operation to transfer the systems. Here, while the acceptor web is stationary, the dispensing web is moved with the dispensing edge against the direction of production. This separates the laminate from the donation sheet and places it on the acceptor sheet. Laminate and acceptor web are at rest with each other and thus have the same "speed". The essence of this process is the zero relative speed between the laminate and the acceptor web. It therefore uses a property of a timed and at the same time discontinuous operation, namely the resting phase.

An example of this operating mode can be found in DE 42 32 279 Cl. It relates to a transfer process for the production of transdermal therapeutic systems, the active substance-containing layer initially being in the form of a laminate with a carrier layer and optionally further auxiliary and / or protective layers or the like as a strip-shaped web and then alone or in combination with at least one another layer is transferred in sections in the middle to a second wider web, characterized in that the strip-shaped web and the second web are moved forward step by step with different movement and rest phases and / or different step lengths and / or different speeds, and in each case in the rest phase of the trains intermittently in the same device, the section-wise division of the active substance-containing layer and optionally one or more further layers with the exception of the carrier layer transverse to the web direction into user-sized active substance-containing sections on the e second web with deduction of the carrier film, preferably at equal intervals, by means of a web direction back and forth transfer device is made.

As is known, a discontinuous production process with a rest phase and a movement phase is disadvantageous in many respects compared to continuous operation. More energy is required, the wear of all mechanical elements is multiplied, the noise level increases and productivity drops. In addition, a clocked operation with subsequent work steps at different speeds is associated with a considerable disadvantage and is justified only where the step-by-step operating mode is unavoidable.

On the basis of the aforementioned prior art and the fundamental considerations relating to the advantages of continuous operation, the invention is based on the object of specifying a device and a dispensing method which transfers the laminates without tension and in particular is sufficient for continuous operation.

The object is achieved by a device for dispensing individual adhesive die-cuts, which contains a donation sheet which lies in a donation sheet plane and can transport and deliver individual adhesive die-cut pieces in the direction of a dispensing edge, and also contains an acceptor sheet which lies in an acceptor level and individual ones can pick up and transport adhesive die cuts. Furthermore, in this device the vector V _SP standing perpendicularly on the donor path plane and the vector V ^ standing perpendicularly on the acceptor path plane lie in a plane which is perpendicular to the donor path plane and perpendicular to the acceptor path plane. The device is characterized in that the speed vector a _sp , the direction and speed of the transport of the individual adhesive die cuts on the dispensing path and the speed vector a ^, which describes the direction and the speed of the transport of the individual adhesive die-cuts on the acceptor path, are chosen such that la ^ l «cos θ is less than or equal to the magnitude of the speed vector a is _5p .

Accordingly, the method for dispensing individual adhesive die-cuts is from a donation track that lies in a donation track level to an acceptor track that is in an acceptor track level, the vector V _sp perpendicular to the donor track level and the vector standing perpendicular to the acceptor track level V ^ lie in a plane that is perpendicular to the donor track level and perpendicular to the acceptor track level, characterized in that the individual adhesive die-cuts are transported in the direction of a dispensing edge and transferred to the acceptor track, with the speed vector a _sp , the direction and the speed of the individual adhesive die cuts on the dispensing path and the speed vector a ^, which describes the direction and the speed of the individual adhesive die cuts on the acceptor path, are chosen such that

cos θ is less than or equal to the magnitude of the speed vector a _sp .

The transfer of adhesive systems from a moving donor web to another moving acceptor web works stress-free if and only if the speed of the donor web a _SP is synchronized with the speed of the acceptor web a ^ (| a ^ l - | a _sp |) = 0. This is the only way to compensate for the gain in space of the acceptor web by the loss of space in the donor web, so that an adhesive system can be transferred without tension. The transfer of adhesive systems from a slow to a fast moving web does not function without tension if the amount of the donor web speed a _{sp is} smaller than that of the acceptor web a ^: (| a _SP \ <\ a ^) (FIG. 1).

In this case, the acceptor web requests material that the donor web cannot deliver at the same time. The result is that the donated system is torn off the donor web. A carrier web change therefore only works if the web speeds are identical, that is to say if the speed of the system to be transmitted matches that of the acceptor web.

The speed is a vectorial quantity and has magnitude and direction. Thus, the above explanations relate only to the case that the movements of the donor path and the acceptor path have the same direction.

It has now surprisingly been found that the transfer of adhesive systems from a slowly moving donor web to an acceptor web that moves relatively fast functions exactly when the amount of the donor web speed | a _sp | is greater than or equal to the amount that the vector has that represents the projection of the vector a ^ onto the vector a _SP . Thus the absolute amount of the speed of an acceptor path can be greater than the absolute amount of the donor path speed | a _SP | be, but, due to the direction of the acceptor path, have an identical or even smaller amount with respect to the direction of movement of the donor path.

In other words: the speed vector a _sp , which describes the direction and the speed of the transport of the individual adhesive die cuts on the dispensing path, and the speed vector a _M , which describes the direction and the speed of the transport of the individual adhesive Die cuts on the acceptor path are chosen such that la ^ l «cos θ is less than or equal to the magnitude of the speed vector | a _sp | is.

In this way, the tension-free transfer of an adhesive laminate onto an acceptor web succeeds, which has the same, but preferably a higher web speed than the dispensing web.

FIG. 2 shows such a case that the speed vector of the acceptor path a ^ is greater than the speed vector of the donor path a _SP .

cos θ corresponds to the projection of the vector a ^ onto the vector a _SP . This vector | v _Proj | in this case is the same size as the vector a _sp .

In this view, the angle θ between the vector of the donor web speed a _SP and the vector of the acceptor web speed a ^ - hereinafter referred to as the donor angle - is in the foreground. Depending on the relative speed between the acceptor web and the donation web, a certain lower dispensing angle is required to meet the condition | a _sp |> | a ^ l «cos θ.

Figures 3 and 4 show variants in which the condition mentioned is fulfilled. Here, too, it is possible to donate plasters without tension to a faster-running acceptance path.

By choosing a suitable dispensing angle θ it is thus achieved with great advantage that a laminate to be transferred and the acceptor web have the same speed when transferring this laminate, and thus the relative speed between laminate and acceptor web vanishes and in the limit case is zero. The transfer of adhesive laminates from a slow to a fast moving web thus works without any problems if the donor web speed is equal to the amount of the projection of the acceptor web speed in the direction of the donor web movement. It is thus possible according to the invention to transfer a laminate from a slowly moving donor web to an acceptor web moving relatively faster without creating harmful tension and damage to the product.

The essence of the invention thus relates to an alignment of the donor web and acceptor web at a donor angle θ, which is selected such that the amount of a vector of the donor web speed | a _SP | greater than or equal to the magnitude of a projection _{vector of} the acceptor _{path speed} | v _proj | to the vector of the donor web speed (1). This means that adhesive laminates can be transferred in continuous or discontinuous operation and without harmful voltages in the laminate to a faster moving acceptor path without any additional aids.

An embodiment of the device provides that the angle θ is at least 5 degrees. It can preferably be 20 to 180 degrees, particularly preferably 90 to 180 degrees.

Another embodiment of the device according to the invention is characterized in that a gas supply unit is provided for deflecting the adhesive laminate.

A method for dispensing adhesive laminates from a slowly moving dispensing web to an acceptor web moving faster relative to it is characterized in that the resulting web speed difference is caused by len the receiving surface is offset at an angle to the donor track transport surface.

One embodiment of the method provides that the angle is selected so that the adhesive laminate automatically adheres to the receiving surface.

A further embodiment of the method according to the invention is characterized in that, with the aid of the gas flow from a gas supply unit, the adhesive surface of the laminate peeling off over the dispensing edge is applied away from the dispensing edge to the receiving surface of the acceptor web.

The gas flow can be provided continuously and / or pulsed.

Furthermore, the method according to the invention provides that the position of the adhesive laminate is checked with the aid of a measuring system. Finally, the measure can be provided for the speed of the donation and / or acceptor path to be checked with the aid of the measuring system.

Details, features and advantages of the invention result from the following explanation of some of the figures

Drawings of schematically illustrated exemplary embodiments.

Show it:

5 shows a side view of a donor web and an acceptor web when transferring an adhesive laminate when tension arises as a result of different web speeds of transport surfaces arranged one behind the other;

6 also in side view the invention

Transfer of a laminate from a slow loading moved donation track to an acceptor track that moved faster relative to it;

7 shows another type of transfer according to the invention of a laminate of dispensing and accepting webs moving at different speeds with the assistance of a gas flow.

FIG.5 shows a non-inventive transfer of adhesive laminate 8 from a slow moving dispensing web 1 for receiving with enlarged mutual intervals on a Akzeptorbahn 2. Of these, the donor web 1 a transport surface 1 ^■ and the Akzeptorbahn 2, a recording surface 2 'which in different speeds are aligned in parallel.

To peel off the laminate 8, the dispensing web 1 is guided around an dispensing edge 5 at an acute angle, as is known per se. As a result of the different speeds, the acceptor web tries to tear off the laminate 8 adhering to it from the dispensing web 1, which results in a tensile stress 4 between the webs, which can lead to considerable damage to the laminate 8.

6 shows an embodiment of the invention, in which a _{sp is} the vector which represents the direction and speed of the donor path (1) and a ^ is the vector which represents the direction and speed of the acceptor path (2). The angle (7) together with the dispensing angle θ, ie the angle enclosed by the two vectors, is 180 °. As can be seen in the figure, the angle (7) is greater than 90 °. The dispensing angle θ is therefore less than 90 °.

The adhesive laminate 8 is provided by means of the dispensing web 1 and peeled off at a dispensing edge 5. Because the dispensing angle θ is greater than 0 °, the adhesive underside of the laminate can stick to that in this embodiment adhere vertically extending acceptor web 2 and are pressed by the pressure roller 6 '. Dispensing angle θ and web speeds of the two webs 1, 2 are coordinated with one another in such a way that the laminate 8 is pulled off through the acceptor web 2 without tension occurring in the adhesive system.

An advantage of the embodiment according to the invention is the automatic adhesion of the laminate 8 to the acceptor web 2 due to its pressure-sensitive adhesive underside and due to the dispensing angle θ which is greater than 0 °.

FIG. 7 shows another embodiment of the invention. The dispensing angle θ between a _SP and a _b is greater than 90 °. The project xon of the vector of the acceptor path speed v _{pro; j} consequently has a negative sign, which means that the condition for all path speeds is fulfilled. In this embodiment too, the dispensing web 1 is provided via the deflection roller 6 and the dispensing edge 5 and peeled off from the carrier web 1. Because here the angle (7) (ie the complementary angle to the dispensing angle θ) is less than 90 °, the adhesive underside of the laminate 8 cannot automatically adhere to the acceptor web 2. As a result, the peeling laminate 8 must be u-steered by a suitable device in such a way that the adhesive underside is adhered to the acceptor web. As shown in FIG. 7, for example, this device can be represented by an air flow from a gas supply unit 9, which flows against the front edge of the laminate and causes the required bending of the laminate 8 by the flow energy. This air flow 9 can be applied over the entire width of the web through nozzles, or can also act "in focus" only on a specific area of the laminate. It can be advantageous to apply the high-energy gas flow in a pulsed manner, that is, to apply a flow ginn and define a flow end. If, for example, the flow impulse is only applied during the peeling phase, only the front edge of the laminate is raised until it adheres to the acceptor web 2. The acceptor web 2 then automatically pulls the rest of the laminate 8 off the dispensing web 1.

It may also be advantageous to use a special gas, e.g. nitrogen or helium, or a gas of a certain temperature, e.g. -100 ° C to 250 ° C to use.

If the air flow is operated in a pulsed manner, it may be necessary to select a specific pulse phase relative to the position of the laminate 8 on the dispensing web 1 or on the acceptor web 2. The control of this phase can be determined as a fixed setting using various parameters, for example by coupling to the angular position of a drive shaft. It is advisable to couple the pulse phase to the relative position of the laminate. This can be detected by optical, mechanical or electronic sensors or combinations thereof. An intermediate control then switches a fast-switching gas valve, as is known to the person skilled in the art. The gas pulse preferably has a duration of 1 to 90% of the donation cycle, particularly preferably 10 to 40%. The gas pulse begins e.g. before the adhesive laminate on the dispensing edge 5 is peeled off from the dispensing web 2, or at the moment of peeling off or after the beginning thereof. The laminate 8 adhering to the acceptor web 2 is then automatically pulled off through the acceptor web 2 without tension occurring in the adhesive system, as is the particular concern of the invention.

The invention is straightforward and expedient and optimally achieves the object stated at the outset.

Claims

EXPECTATIONS

1. Device for dispensing individual adhesive lanates, comprising a donation sheet which is located in an adjacent dispensing sheet and can transport and deliver individual adhesive laminates in the direction of a dispensing edge, and an acceptor sheet which lies in an acceptor sheet plane and individual adhesive sheets Can take up and transport laminates, whereby the vector V _sp perpendicular to the donor track plane and the vector V perpendicular to the acceptor track plane lie in a plane that is perpendicular to the donor track plane and perpendicular to the acceptor track plane, characterized in that the speed vector a _SP , which determines the direction and speed of the

Describes the transport of the individual adhesive laminates on the donor web, and the speed vector a ^. Describing the direction and speed of the transport of the individual adhesive laminates on the acceptor web, are chosen so that

cos θ less than or equal to the magnitude of the speed vector

| A ". | ^is -

2. Device according to claim 1, characterized. that the individual adhesive laminates contain at least one pressure-sensitive adhesive layer.

3. Device according to claim 1 or 2, characterized in that the angle between the speed vector a _sp and the speed vector a ^ is at least 5 °.

4. Device according to one of claims 1 to 3, characterized in that the angle between the speed speed vector a _sp and the speed vector a 'A _Λ K _{τ is} between 0 and 180 °.

5. Device according to one of claims 1 to 4, characterized in that the angle between the speed vector a _SP and the speed vector a ^ is between 90 and 180 °.

6. Device according to one of claims 1 to 5, characterized in that the dispensing web has an abhesive surface.

7. Device according to one of claims 1 to 6, characterized in that a gas supply unit (9) is additionally included.

8. Device according to one of claims 1 to 7, characterized in that additionally at least one device for checking the position and / or the speed of the individual adhesive laminates on the dispensing web and / or the acceptor web is included.

9. A method for dispensing individual adhesive laminates from a donation track that lies in a donation track level to an acceptor track that is in an acceptor track level, the vector V _sp perpendicular to the donor track level and the vector perpendicular to the acceptor track level in one Level, which is perpendicular to the donor track level and perpendicular to the acceptor path, characterized in that the individual adhesive laminates are transported in the direction of a dispensing edge and transferred to the acceptor path, the speed vector a _sp , the direction and the speed of the individual adhesive laminates on the dispensing web, and the speed vector a ^. which describes the direction and the speed of the individual adhesive describes the laminates on the acceptor path, so that la ^ l «cos θ is less than or equal to the magnitude of the speed vector a _SP .

10. The method according to claim 9, characterized in that the dispensing of the individual adhesive laminates from a donation track is continuous.

11. The method according to claim 9, characterized in that the donation of the individual laminates from a donation track is discontinuous.

12. The method according to any one of claims 9 to 11, characterized. that the speed of the acceptor path is greater than the speed of the donor path.

13. The method according to any one of claims 9 to 12, characterized in that the individual adhesive laminates are transferred to the acceptor web with the support of a gas stream.

14. The method according to claim 13, characterized in that the gas flow is supplied continuously.

15. The method according to claim 13, characterized in that the gas stream is supplied in a pulsed manner.

16. The method according to any one of claims 9 to 15, characterized. that the position and / or the speed of the individual adhesive laminates on the dispensing web and / or the acceptor web is checked in at least one step.