Patent ID: 12221309

It will be appreciated that in the drawings some components may not be illustrated to simplify the understanding of the figures, and that various figures may not be represented on the same scale.

DETAILED DESCRIPTION

With reference toFIG.1, a plaster10includes a carrier foil12having an adhesive surface14, and a wound pad16attached to the adhesive surface14of the carrier foil12. The wound pad16is adapted to be placed directly over a wound and held on the skin by the adhesive carrier foil12.

The carrier foil12may be formed by a transparent or skin—colored plastic film. The adhesive surface14of the carrier foil12may be formed by a layer of pressure sensitive, medical grade, hypoallergenic adhesive applied on the entire surface of the carrier foil12.

The wound pad16is adhered to the adhesive surface14of the carrier foil12. The wound pad16is made of one or more layers of gauze or other suitable material having the capacity of absorbing small quantities of exudate from a wound. The wound pad16may contain medications, e.g., disinfectant, or coagulant medications.

The plaster10may include a pair of removable protective sheets18applied over the wound pad16and the portion of the adhesive surface14of the carrier foil12which surrounds the wound pad16. The removable protective sheets18will be peeled free from the adhesive surface14of the carrier foil12at the time of application of the plaster10to a wound.

The plaster10may be packaged individually between two packaging sheets20which are joined to each other around the plaster10, e.g., by pressure sensitive adhesive, to form an envelope-shaped package.

With reference toFIG.2, an apparatus for manufacturing plasters10of the type previously disclosed is schematically indicated by numeral reference22.

The apparatus22comprises an unwinding unit24configured for unwinding continuous three-layer tapes28from respective reels26. While one of the reels26supplies a first continuous three-layer tape28, the other reel26is kept in reserve in an inoperative position. When the first reel is exhausted, the tail portion of the first continuous three-layer tape28coming from an exhausted reel26is spliced to a head portion of the second continuous three-layer tape28unwound from the replacement reel26, as it will be disclosed in the following.

With reference toFIG.3, each continuous three-layer tape28includes a continuous carrier foil30having an adhesive surface32, a continuous top protective film34applied on the adhesive surface32of the continuous carrier foil30and a continuous back protective film36applied on the surface of the continuous carrier foil30opposite the adhesive surface32.

With reference toFIG.2, the apparatus22comprises a splicing unit38which is configured for splicing a tail portion of a first continuous three-layer tape28coming from an exhausted reel26to a head portion of a second continuous three-layer tape28coming from a replacement reel26.

With reference toFIGS.2and3, the splicing unit38is configured for applying a top adhesive splicing element40across tail and head portions34′,34″ of the two continuous top protective films34and a back adhesive splicing element42on tail and back portions36′,36″ of the two continuous back protective films36. Tail and head portions30′,30″ of the two continuous carrier foils30remain not spliced.

The application of the top and back adhesive splicing elements40,42may be carried out with standard automatic splicers which are well known in the state of the art, for instance in machines for manufacturing absorbent sanitary products.

With reference toFIG.2, the apparatus22comprises a second unwinding unit44configured for unwinding from a reel46a continuous wound tape48. After being unwound from the respective reel46the continuous wound tape48is advanced longitudinally.

The apparatus22comprises a cut-and-slip unit50configured for transversely cutting the continuous wound tape48to form individual wound pads16spaced apart from each other in the longitudinal direction. The cut-and-slip unit50comprises a rotating anvil roller52and a rotating knife54cooperating with the outer surface of the rotating anvil roller52to cut the continuous wound tape48transversely to the longitudinal direction. After the transversal cut of the continuous wound tape48, the individual wound pads16are retained, e.g., by suction, on the outer surface of the rotating anvil roller52.

The apparatus22comprises a first delamination unit56configured for removing the top protective film34from the continuous carrier foil30, to expose the adhesive surface32of the continuous carrier foil30. The continuous top protective film34removed from the continuous carrier foil30is disposed as scrap, for instance in a first shredder58.

The first delamination unit56comprises an application roller60having an outer surface facing the outer surface of the rotating anvil roller52. The continuous carrier foil30passes on the outer surface of the application roller60with the adhesive surface32facing the rotating anvil roller52. On the application roller60the individual wound pads16are pressed and fixed on the adhesive surface32of the continuous carrier foil30in longitudinally spaced positions.

Downstream of the application roller60the continuous carrier foil30with the wound pads16applied thereon is transported on a conveyor62to a second delamination unit64, where the back protective film36is delaminated from the continuous carrier foil30. The continuous back protective film36removed from the continuous carrier foil30is disposed as scrap, for instance in a second shredder66.

Then, the continuous carrier foil30is cut transversely in a cutting unit68to form individual plasters10. Before transversally cutting the continuous carrier foil30, removable protective sheets (not shown) may be applied on the on the adhesive surface32of the continuous carrier foil30.

In operation, the continuous three-layer tape28unwound from the respective reel46is advanced longitudinally toward the first delamination unit56. In the first delamination unit56the top protective film34is removed from the continuous carrier foil30, to expose the adhesive surface32of the continuous carrier foil30.

In the cut-and-slip unit50the continuous wound tape48is cut transversely to form individual wound pads16longitudinally spaced from each other, which are adhered to the adhesive surface32of the continuous carrier foil30. During the normal production of plasters10, the cut-and-slip unit50cuts wound pads16having all the same dimension in the longitudinal direction and spaced apart from each other by a constant distance.

When the reel26which supplies the first three-layer tape28is exhausted, the splicing unit splices automatically the tail portion of the first continuous three-layer tape28coming from the exhausted reel26to the head portion of the second continuous three-layer tape28coming from the replacement reel26.

At the first delamination unit56, the tail and head portions of the two continuous top protective films34are spliced to each other, so that delamination of the top protective film34continues without interruptions.

Immediately after the removal of the two continuous top protective films34, the tail and head portions of the two continuous carrier foils30are not spliced to each other.

With reference toFIG.4, during the splicing operation, the cut-and-slip unit50is configured for cutting from the continuous wound tape48a splicing element70and for applying the splicing element70on the adhesive surfaces32on tail and head portions30′,30″ of the two continuous carrier foils30.

The splicing element70is made of the same material as the wound pads16and is applied on the adhesive surfaces32of the two continuous carrier foils30on the application roller60in the same way as the wound pads16. However, differently from the wound pads16, the splicing element70is applied across the tail and head transverse edges of the two continuous carrier foils30, so that the two continuous carrier foils30are spliced to each other by an element made of the same material as that forming the wound pads16.

Therefore, the same cut-and-slip unit which forms and applies the wound pads16on the continuous carrier foil30during the ordinary production of plasters is used for automatically splicing tail and head portions30′,30″ of two continuous carrier foils30at the time of a change of reels26.

A considerable advantage of this solution is that there is no need for a separate splicing unit for splicing the two continuous carrier foils30, which reduces the cost and the dimensions of the apparatus22.

In a possible embodiment, the cut-and-slip unit50is configured for cutting from the wound tape48a splicing element70having an extension in the longitudinal direction which is greater than the extension in the longitudinal direction of the wound pads16.

The splicing element70may have an extension in the longitudinal direction which is comprised between 3-6 times the extension in the longitudinal direction of the wound pads16. This increases the strength of the splicing region. The plasters10adjacent to the splicing region are disposed as wastes as customary in the field.

The apparatus22comprises a motion control system72which controls the operation of all the motor driven elements of the apparatus22. The motion control system72may be a programmable computer in which a computer program is installed, the computer program being configured for implementing a method for automatically splicing three-layer tapes28in a machine for manufacturing plasters.

In a possible embodiment the apparatus22may comprise a sensor74arranged for detecting the position of one of the top or back adhesive splicing elements40,42on the longitudinally movable first and second continuous three-layer tapes28. The detection signal generated by the sensor74may be sent to the motion control system72which controls the cut-and-slip unit50to cut and apply the splicing element70on the continuous carrier foils28in phase with the splicing region defined by the position of the top or back adhesive splicing elements40,42.

In a possible embodiment, the speed of the rotating anvil roller52remains constant while the speed of the rotating knife54of the cut-and-slip unit50is selectively variable between a first speed when cutting the wound pads16and a second speed lower than the first speed when cutting the splicing element70.

After the application of the splicing element70the speed of the rotating knife54returns to the first speed at which the wound pads16are cut.

Of course, without prejudice to the principle of the invention, the details of construction and the embodiments can be widely varied with respect to those described and illustrated, without thereby departing from the scope of the invention as defined by the claims that follow.