Patent Application
20050132665
This application claims priority under 35 U.S.C. 517 119 from European Patent Application No. 03425768.3, filed Nov. 28, 2003. The prior application is incorporated herein by this reference.
The present invention relates to a device for manufacturing wrapping sheets provided with related handles.
In particular, the present invention relates to a device for manufacturing wrapping sheets for packaging paper rolls taken individually or in groups constituted by a plurality of paper rolls, positioned adjacent to each other and aligned, whereto the present description shall explicitly refer without thereby losing its general nature.
According to the prior art in the paper roll industry, the paper rolls are packaged within related wrapping sheets, each of which is obtained from a first strip of heat-sealable material, is wrapped around one or more paper rolls to form a paper roll package, and is associated to a handle able to allow the consumer conveniently to grip the package itself.
Generally, the handles are obtained from a second strip of heat-sealable material, whose width is smaller than the width of the first strip, is superposed to the first strip, and is joined to the first strip by means of a coupling device that is normally able to seal or glue the two strips.
Once the two strips are joined and a third strip of heat-sealable material is obtained, the wrapping sheets and the related handles are obtained in succession by cutting the third ribbon transversely to a direction of advance thereof.
The known devices described above have some drawbacks, mainly deriving from the tact that the solutions adopted by said devices for joining the aforesaid first and second strip are relatively complex and entail in one case heat-shrinking phenomena, which occur at the end of the sealing operation, are located solely in the area of superposition of the two ribbons, and can, therefore, cause said superposition area to be shortened and narrowed relative to the remaining part of the wrapping sheet, compromising the correct formation of the roll package, and in the other case the known problems connected with the use of glue.
An object of the present invention is to provide a device for manufacturing wrapping sheets provided with related handles which is free from the aforesaid drawbacks and is simple and economical to construct.
According to one embodiment, a device for manufacturing wrapping sheets provided with related handles, the wrapping sheets and the handles being obtained from a first and, respectively, a second strip of heat sealable material, the device comprising a station for coupling the first strip with the second strip; feeding means to feed the first and the second ribbon to said coupling station; and coupling means to couple the first and the second strip to each other and form a third strip; and being characterised in that said coupling means comprise electric means for charging the first and the second strip with respective electrical charges of opposite sign.
The present invention shall now be described with reference to the accompanying
With reference to the accompanying
The sheets 2 and the handles 3 are obtained from respective strips 6, 7 of heat-sealable material, whereof the strip 6 has a width greater than the width of the strip 7, which strips are unwound from respective reels 8, 9 by means of a known unwinding device 10 comprising at least a pair of unwinding rollers positioned substantially in contact with each other with the interposition of the strips 6, 7 and, for each strip 6, 7, respective plurality of transmission rollers 12.
The strips 6, 7 are fed through the device 10 to a coupling station 13 provided with a coupling unit 14 comprising an electrical device 15 able electrically to charge the strips 6, 7 with respective electrical charges of opposite sign and to cause the adhesion of the entire strip 7 on the strip 6 due to the electrostatic attraction force generated by said electrical charges. The device 15 comprises, for each strip 6, 7, a respective electrostatic generator 16 or ioniser or a generator 16 for each of the strips 6, 7 and a ground connection 17 for the other strip 6, 7.
The unit 14 further comprises a pair of presser rollers 18 positioned downstream of the device 15 in a direction 19 of advance of the strips 6, 7 to press the strips 6, 7 firmly against each other and form a third strip 20 of heat-sealable material, which is fed to a known cutting device 21 able to engage the ribbon 20 transversely to the direction 19 and to separate in succession from the strip 20 the sheets 2 and the related handles 3.
Lastly, each sheet 2 and the related handle 3 are fed to a wrapping unit 22 defining, together with the device 1, a packaging machine 23, and are wrapped around a related group 4 of rollers 5 in such a way as to form an external wrapper 24 with two mutually opposite end superposition areas 25, each of which is folded substantially in contact with the rollers 5 with the interposition of a free end 26 of the related handle 3, and is stabilised by means of a respective sealing operation.
It should be specified, lastly, that at the output from the unit 22 the effect of the electrostatic attraction between each sheet 2 and the related handle 3 ceases, so said handle 3 remains connected to the wrapper 24 solely in correspondence with its ends 26.
The operation of the device 1 is readily apparent from the above description and requires no additional explanations.
| Number | Date | Country | Kind |
|---|---|---|---|
| 03425768.3 | Nov 2003 | EP | regional |
