EP0555928A1

EP0555928A1 - Process and machine for producing rolls of film material

Info

Publication number: EP0555928A1
Application number: EP93200369A
Authority: EP
Inventors: Pietro Di Bernardo
Original assignee: Interdibipack SpA
Current assignee: Interdibipack SpA
Priority date: 1992-02-14
Filing date: 1993-02-11
Publication date: 1993-08-18
Also published as: ITMI920310A1; ITMI920310A0; IT1254449B

Abstract

A process for producing rolls or bobbins of film material by unwounding the film from a parent bobbin of industrial diameter, and winding the same on a support, comprises the steps of:

winding said film on an expansion spindle, with the latter being in its open position, until a bobbin having the desired commercial diameter is obtained;
closing said spindle and sliding the coreless bobbin formed in that way out of it.

Description

The present invention relates to a process and a machine for producing rolls or bobbins of film material, such as, e.g., rolls of plastics, aluminum foil, and still others, material, used for wrapping miscellaneous products at household level.
The inventive idea might anyway be also applied in order to produce other roll materials not designed for use as packaging materials.
As those skilled in the art are well aware of, these rolls with commercial diameter are obtained by starting from industrial, large-diameter rolls by using machines designated as "rewinding machines".
A method and a machine for producing film material wound in roll form are disclosed, e.g., in Italian Patent No. 1,038,144; to which reference is made should further explanations be required.
A common element shared by all of the rewinding systems known from the prior art, is the use of a disposable tube, or core, generally made from cardboard, onto which the film is wound which is unwound from the industrial-diameter bobbin.
When the rewinding operation is started, the tube is installed on a tube carrier system consisting of a nose and counter-nose of the machine and, when the winding operation is ended, said tube will become part of the roll or bobbin of film material which is discharged from the rewinding machine.
The use of these disposable tubes represents a high burden, both due to the own tube cost, and to the management thereof (purchasing, storage, and so forth). The purpose of the present invention is of providing a process and a machine for producing rolls of film material, which do not require the use of a disposable tube or core in order to rewind the film material from a bobbin of industrial diameter, into a commercial-diameter bobbin.
Said purpose is achieved, according to the present invention, by providing a process for producing rolls or bobbins of film material by unwounding the film from a parent bobbin of industrial diameter, and winding the same on a support, which process is characterized in that it comprises the steps of:

winding said film on an expansion spindle, with the latter being in its open position, until a bobbin having the desired commercial diameter is obtained;
closing said spindle and sliding the resulting core less bobbin out of it.

A machine for implementing the process disclosed above is characterized in that it comprises an expansion spindle (18) on which the film which is being unwound from said parent bobbin (22) is wound up.
The structural and functional characteristics of the invention, and its advantages over the prior art will be still more evident from an examination of the following disclosure, made by referring to the accompanying schematic drawings, which display an exemplifying machine for implementing the process according to the present invention. In the drawings:

-- Figure 1 shows a partially cutaway, sectional side elevation view illustrating a rewinding machine according to the present invention;
-- Figure 2 shows a front elevation view of the machine of Figure 1;
-- Figures 3 and 4 display two operating schematics respectively illustrating the starting and ending steps of machine operations;
-- Figure 5 shows a detail illustrating a first embodiment of an expansion spindle useable with the machine according to the present invention;
-- Figures 6 and 7 show two cross-sectional views illustrating the spindle of Figure 5 in its open, film-winding position, and respectively in its closed, bobbin-discharge position;
-- Figure 8 shows a detail illustrating a further embodiment of a suitable spindle for use on the machine according to the present invention; and
-- Figures 9 and 10 show two cross-sectional views illustrating a further possible embodiment of the spindle, in its open, film-winding position, and respectively in its closed, bobbin-discharge position.

Figures 1 and 2 of the accompanying drawings display a rewinding machine (10) equipped, for non-limitative emplifying purposes, with two identical operating units (11), (12). The invention will of course be disclosed by referring to only one of said operating units (11), (12).
The operating units (11), (12) are installed on a framework (13) and each of them comprises a frame (14) provided with a lifting handle (15), and hinged in (16) in such a way as to be able to swing according to the directions shown by arrows (17).
Typically, the frame (14) bears an expansion spindle (18) actuated by a motor means (19), with which a driven return roller (20) coated with a relatively soft material, e.g., rubber, and an also driven pressure roller (21), cooperate.
With the reference numeral (22) a so-said "parent bobbin" of industrial diameter is displayed, from which a certain length of film must be unwound, which is then wound, to a commercial diameter, around the expansion spindle (18). With said parent bobbin (22) a so-said "meter counter" (23) cooperates.
Referring to Figures 3 and 4, according to the process of the invention the film, unwound from the parent bobbin (22), is caused to run through the return and pressure rollers (20) and (21) respectively, in order to be wound around the expansion spindle (18), which is in its open, film-winding position (Figures 6 and 9).
When the winding operation is complete, i.e., when on the expanded, viz., open spindle (18) such a film length is wound as to constitute a bobbin (24) (Figure 4) of commercial diameter, the same spindle (18) is closed again (Figures 7 and 10) and the bobbin (24) is slid out of it.
In that way, a commercial core less bobbin is obtained, which is perfectly stable and from which, in use, any desired film length can be unwound and separated with no problems.
It should be observed that providing, in a characteristic way, the driven return roller (20), with which the pressure counter-roller (21) cooperates, prevents air pockets or bubbles, which would yield a lower-quality product, from being undesirably formed between adjacent film turns.
For that purpose, the level of pressure applied by the counter-roller (21) to the return roller (20) can be adjusted by means of a handle (25).
Different embodiments of expansion spindle (18) can be provided for, as illustrated, for exemplifying purposes, in Figures 5-10 of the accompanying drawings.
The spindle (26) displayed in Figures 5-7 is installed between a thrust nose (27) and a shoulder counter-nose (28).
The drawing shows a cut away, cross-sectional view, and on the right hand side, the spindle is depicted in its open position during the film winding step, whereas on the left the spindle is depicted in its closed position, allowing the formed bobbin to be slid out of it.
On the contrary, Figure 8 of the accompanying drawings displays a spindle (29) which is constrained to the apparatus by means of an articulation (30).
In that way, when the rewinding operation is ended, the spindle is moved to its position shown in the drawing, and is closed again, so as to make it possible the formed bobbin (24) to be slid out of it.
Figures 9 and 10 schematically show other possible embodiments of an expansion spindle.
Thus, the purposes recited in the preamble to the disclosure are achieved.

Claims

Process for producing rolls or bobbins of film material by unwounding the film from a parent bobbin of industrial diameter, and winding the same on a support, characterized in that it comprises the steps of:
- winding said film on an expansion spindle, with the latter being in its open position, until a bobbin having the desired commercial diameter is obtained;

- closing said spindle and sliding the resulting coreless bobbin out of it.
Machine for implementing the process according to claim 1, characterized in that said machine comprises an expansion spindle (18) on which the film which is being unwound from said parent bobbin (22) is wound up.
Machine according to claim 2, characterized in that with said expansion spindle (18) a return roller (20) and a pressurizing counter-roller (21) cooperate.
Bobbin of film material, when obtained by means of the process and the machine according to the preceding claims.