Core gluing device for a rewinding machine and related method

Abstract

A core gluing device for a rewinding machine comprises a conveyor (1) designed to convey cores (10a, 10b, 10c) along a core conveying surface (A-A), a gluing unit (2) comprising a first gluing roller (22) which picks up the glue from a glue container (20) and a second gluing roller (26) opposed to the first gluing roller, so that each core (10a, 10b, 10c) can pass between the two gluing rollers (22, 26) for application of a trace of glue (100b, 100c) on it. The gluing rollers (22, 26) are driven at different speeds to control the width of the trace of glue to be applied to the core, and positioning devices (4) are provided, arranged downstream of the gluing devices (2) and upstream of a log winding unit (6) of the rewinding machine for the correct positioning of the core (10c) with the related trace of glue (100c), before insertion between the winding rollers.

Description

BACKGROUND [0001] The present invention refers to a device and to a method for gluing cores of a rewinding machine. [0002] As is known, a rewinding machine is used for the formation of reels of sheet material originating from large parent reels. [0003] Generally the sheet material is wound on tubular cores, which are appropriately fed towards the winding unit of the rewinding machine. For this purpose, upstream of the winding unit of the rewinder there is a gluing unit which applies a strip of glue on the outer surface of the cores. In this way, when the core comes into contact with the winding rollers, the end edge of the sheet material grips the glue deposited on the core, permitting winding of the sheet material on the core for formation of the reel. [0004] The European patent EP 0.697.988 describes a gluing unit of the overflow type. The glue comes out of a slot positioned according to a directrix of the core by overflowing and is applied on the cores when they pass over the slo...

AI Technical Summary

Benefits of technology

[0012] An object of the present invention is to eliminate the drawbacks of the prior art by providing a core gluing device that permits the control of the amount and of the extent of the glue applied on the cores and at the same time to ensure a correct positioning of the cores at the rewinding machine inlet.

[0013] A further object of the present invention is to provide a core gluing device that can guarantee a regular distribution of the glue on the cores regardless of the type of glue used.

[0014] A further object of the present invention is to provide a core gluing device that ensures a high glue application speed on the cores.

[0019] a higher gluing speed with consequent increase in the performance of the machine,

[0025] Advantageously, elements are fitted on the first gluing roller, which pick up the glue contained in the glue container and apply the glue on the cores. Said elements are interchangeable and can be easily replaced according to the form of the trace of glue required for application on the cores.

Problems solved by technology

It operates irregularly with high density glues, requires frequent maintenance for cleaning, and does not permit adjustment of the amount of glue applied.

Due to the up-down times of the bar and to the time it remains in the tank to pick up the glue, the speed of the glue distribution unit is limited and therefore the production capacity of the rewinding machine is limited.

Said gluing system with synchronised rollers also has the drawback that the glue is applied only on one generatrix of the core and that the width of the glue application area cannot be varied.

It should also be considered that all the gluing systems of the prior art have problems with the correct positioning of the cores at the winding unit inlet.

Images