A method for perforating a film of plastic material in which a main film (1) is perforated whilst it is slid through a perforating device (5) by a plurality of pressurised hot gas jets having a temperature above the melting temperature of the main film, in which the hot gas jets are correlated with the sliding speed of the main film (1), and in which reinforcing bands obtained from an auxiliary film of plastic material (2) are connected to the perforated main film (1), making the reinforcing bands adhere between parallel rows of base holes; subsequently the perforated main film (1) with the reinforcing bands is stretched in the longitudinal sliding direction. During perforating, the main film of plastic material (1) is pressed against a perforating template (22), making the main film of plastic material (1) instantaneously penetrate openings of the perforating template (22) by said hot gas jets. A hot gas perforating device (5) is also disclosed, as well as an apparatus suitable for perforating and sliding a film of plastic material according to the referred method.
B29C 55/06 - Shaping by stretching, e.g. drawing through a dieApparatus therefor of plates or sheets uniaxial, e.g. oblique parallel with the direction of feed
B26F 1/26 - Perforating by non-mechanical means, e.g. by fluid jet
B32B 3/16 - Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shapeLayered products comprising a layer having particular features of form characterised by a discontinuous layer, i.e. apertured or formed of separate pieces of material characterised by a face layer formed of separate pieces of material secured to a flexible backing
B32B 3/08 - Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shapeLayered products comprising a layer having particular features of form characterised by features of form at particular places, e.g. in edge regions characterised by added members at particular parts
2.
METHOD AND APPARATUS FOR PERFORATING A FILM OF PLASTIC MATERIAL
A method for perforating a film of plastic material in which a main film (1) is perforated whilst it is slid through a perforating device (5) by a plurality of pressurised hot gas jets having a temperature above the melting temperature of the main film, in which the hot gas jets are correlated with the sliding speed of the main film (1), and in which reinforcing bands obtained from an auxiliary film of plastic material (2) are connected to the perforated main film (1), making the reinforcing bands adhere between parallel rows of base holes; subsequently the perforated main film (1) with the reinforcing bands is stretched in the longitudinal sliding direction. During perforating, the main film of plastic material (1) is pressed against a perforating template (22), making the main film of plastic material (1) instantaneously penetrate openings of the perforating template (22) by said hot gas jets. A hot gas perforating device (5) is also disclosed, as well as an apparatus suitable for perforating and sliding a film of plastic material according to the referred method.
B26F 1/26 - Perforating by non-mechanical means, e.g. by fluid jet
B29C 55/06 - Shaping by stretching, e.g. drawing through a dieApparatus therefor of plates or sheets uniaxial, e.g. oblique parallel with the direction of feed
B32B 3/08 - Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shapeLayered products comprising a layer having particular features of form characterised by features of form at particular places, e.g. in edge regions characterised by added members at particular parts
B32B 3/16 - Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shapeLayered products comprising a layer having particular features of form characterised by a discontinuous layer, i.e. apertured or formed of separate pieces of material characterised by a face layer formed of separate pieces of material secured to a flexible backing
3.
Machine for manufacturing pre-stretched extendable film rolls
A machine for manufacturing pre-stretched extendable film rolls provides for a pre-stretch unit (10) of the film (F) and a wrapping unit (100) of the film in roll provided with a series of rolls around which the advancing film is partially wrapped; the pre-stretch unit (10) provides for, in sequence, at least a first pre-stretching roll (12), a pre-stretching auxiliary roll (13) acting against the first roll (12) with the interposition of the film, and a second pre-stretching roll (14) having a speed greater than the speed of the first roll (12) to carry out the pre-stretching of the film; the wrapping unit provides for a wrapping roll (104) for wrapping the pre-stretched film; the pre-stretch unit (10) further provides for a detensioning roll (17) arranged downstream said second pre-stretching roll (14) and having a speed less than said second pre-stretching roll (14) and greater than said wrapping roll (104), so as to obtain a first detensioning of the film after the pre-stretching operation and a second detensioning of the film before the wrapping operation. A high quality pre-stretched film is obtained by this machine.
B29C 55/16 - Shaping by stretching, e.g. drawing through a dieApparatus therefor of plates or sheets multiaxial biaxial simultaneously
B29C 55/00 - Shaping by stretching, e.g. drawing through a dieApparatus therefor
B29C 55/06 - Shaping by stretching, e.g. drawing through a dieApparatus therefor of plates or sheets uniaxial, e.g. oblique parallel with the direction of feed
B65H 23/195 - Registering, tensioning, smoothing, or guiding webs longitudinally by controlling or regulating the web-advancing mechanism, e.g. mechanism acting on the running web in winding mechanisms or in connection with winding operations
A machine for producing coils of prestretched extendible film has a prestretching unit (10) for prestretching the film (F) and a winding unit (100) for winding the film in a coil provided with a series of rollers around which the advancing film winds partially; the winding unit comprises a winding roller (104) in pressing contact against the coil (R) of the prestretched film in winding progress; to obtain coils of constant diameter and high winding quality the final contact position is varied of the winding roller (104) against the coil (R) according to the length of the wound film and according to the required diameter of coil.
B29C 55/26 - Shaping by stretching, e.g. drawing through a dieApparatus therefor of tubes biaxial
B29C 55/06 - Shaping by stretching, e.g. drawing through a dieApparatus therefor of plates or sheets uniaxial, e.g. oblique parallel with the direction of feed
B65H 18/16 - Mechanisms in which power is applied to web roll, e.g. to effect continuous advancement of web by friction roller
B65H 23/195 - Registering, tensioning, smoothing, or guiding webs longitudinally by controlling or regulating the web-advancing mechanism, e.g. mechanism acting on the running web in winding mechanisms or in connection with winding operations
B65H 23/26 - Registering, tensioning, smoothing, or guiding webs longitudinally by transverse stationary or adjustable bars or rollers
B65H 18/26 - Mechanisms for controlling contact pressure on winding-web package, e.g. for regulating the quantity of air between web layers
B29C 55/02 - Shaping by stretching, e.g. drawing through a dieApparatus therefor of plates or sheets
A machine for producing coils of prestretched extendible film has a prestretching unit (10) for prestretching the film (F) and a winding unit (100) for winding the film in a coil provided with a series of rollers around which the advancing film winds partially; the winding unit comprises a winding roller (104) in pressing contact against the coil (R) of the prestretched film in winding progress; to obtain coils of constant diameter and high winding quality the final contact position is varied of the winding roller (104) against the coil (R) according to the length of the wound film and according to the required diameter of coil.
B65H 18/16 - Mechanisms in which power is applied to web roll, e.g. to effect continuous advancement of web by friction roller
B65H 18/26 - Mechanisms for controlling contact pressure on winding-web package, e.g. for regulating the quantity of air between web layers
B65H 23/195 - Registering, tensioning, smoothing, or guiding webs longitudinally by controlling or regulating the web-advancing mechanism, e.g. mechanism acting on the running web in winding mechanisms or in connection with winding operations
B65H 23/26 - Registering, tensioning, smoothing, or guiding webs longitudinally by transverse stationary or adjustable bars or rollers
A machine for producing coils of prestretched extendible film has a prestretching unit (10) for prestretching the film (F) and a winding unit (100) for winding the film in a coil provided with a series of rollers around which the advancing film winds partially; the winding unit comprises a winding roller (104) in pressing contact against the coil (R) of the prestretched film in winding progress; to obtain coils of constant diameter and high winding quality the final contact position is varied of the winding roller (104) against the coil (R) according to the length of the wound film and according to the required diameter of coil.
B65H 23/195 - Registering, tensioning, smoothing, or guiding webs longitudinally by controlling or regulating the web-advancing mechanism, e.g. mechanism acting on the running web in winding mechanisms or in connection with winding operations
B65H 23/26 - Registering, tensioning, smoothing, or guiding webs longitudinally by transverse stationary or adjustable bars or rollers
B65H 18/16 - Mechanisms in which power is applied to web roll, e.g. to effect continuous advancement of web by friction roller
B65H 18/26 - Mechanisms for controlling contact pressure on winding-web package, e.g. for regulating the quantity of air between web layers
7.
MACHINE FOR MANUFACTURING PRE-STRETCHED EXTENDABLE FILM ROLLS
A machine for manufacturing pre-stretched extendable film rolls provides for a pre- stretch unit (10) of the film (F) and a wrapping unit (100) of the film in roll provided with a series of rolls around which the advancing film is partially wrapped; the pre- stretch unit (10) provides for, in sequence, at least a first pre-stretching roll (12), a pre-stretching auxiliary roll (13) acting against the first roll (12) with the interposition of the film, and a second pre-stretching roll (14) having a speed greater than the speed of the first roll (12) to carry out the pre-stretching of the film; the wrapping unit provides for a wrapping roll (104) for wrapping the pre-stretched film; the pre-stretch unit (10) further provides for a detensioning roll (17) arranged downstream said second pre-stretching roll (14) and having a speed less than said second pre-stretching roll (14) and greater than said wrapping roll (104), so as to obtain a first detensioning of the film after the pre-stretching operation and a second detensioning of the film before the wrapping operation. A high quality pre-stretched film is obtained by this machine.
B29C 55/06 - Shaping by stretching, e.g. drawing through a dieApparatus therefor of plates or sheets uniaxial, e.g. oblique parallel with the direction of feed
B65H 23/195 - Registering, tensioning, smoothing, or guiding webs longitudinally by controlling or regulating the web-advancing mechanism, e.g. mechanism acting on the running web in winding mechanisms or in connection with winding operations
8.
MACHINE FOR MANUFACTURING PRE-STRETCHED EXTENDABLE FILM ROLLS
A machine for manufacturing pre-stretched extendable film rolls provides for a pre- stretch unit (10) of the film (F) and a wrapping unit (100) of the film in roll provided with a series of rolls around which the advancing film is partially wrapped; the pre- stretch unit (10) provides for, in sequence, at least a first pre-stretching roll (12), a pre-stretching auxiliary roll (13) acting against the first roll (12) with the interposition of the film, and a second pre-stretching roll (14) having a speed greater than the speed of the first roll (12) to carry out the pre-stretching of the film; the wrapping unit provides for a wrapping roll (104) for wrapping the pre-stretched film; the pre-stretch unit (10) further provides for a detensioning roll (17) arranged downstream said second pre-stretching roll (14) and having a speed less than said second pre-stretching roll (14) and greater than said wrapping roll (104), so as to obtain a first detensioning of the film after the pre-stretching operation and a second detensioning of the film before the wrapping operation. A high quality pre-stretched film is obtained by this machine.
B29C 55/06 - Shaping by stretching, e.g. drawing through a dieApparatus therefor of plates or sheets uniaxial, e.g. oblique parallel with the direction of feed
B65H 23/195 - Registering, tensioning, smoothing, or guiding webs longitudinally by controlling or regulating the web-advancing mechanism, e.g. mechanism acting on the running web in winding mechanisms or in connection with winding operations
9.
Spindle for winding up coreless rolls of a plastic film
A spindle (10) suitable for winding up coreless rolls (11) of a stretchable plastic film; the spindle (10) comprises a tubular body having a peripheral wall (12) defining at least one internal chamber (14) connectable to a pressurized air source. A plurality of perforations (17) extends from the internal chamber (14) of the spindle (10), through the peripheral wall (12) and a protective layer (19) of hard chrome having a sandblasted outer surface (18) with an average roughness ranging between 6 and 6.5 μm, obtained by dry sandblasting.
A spindle (10) suitable for winding up coreless rolls (11) of a stretchable plastic film; the spindle (10) comprises a tubular body having a peripheral wall (12) defining at least one internal chamber (14) connectable to a pressurised air source. A plurality of perforations (17) extends from the internal chamber (14) of the spindle (10), through the peripheral wall (12) and a protective layer (19) of hard chromehaving a sandblastedouter surface (18) with an average roughness ranging between 6 and 6.5 µm, obtained by dry sandblasting.
A spindle (10) suitable for winding up coreless rolls (11) of a stretchable plastic film; the spindle (10) comprises a tubular body having a peripheral wall (12) defining at least one internal chamber (14) connectable to a pressurised air source. A plurality of perforations (17) extends from the internal chamber (14) of the spindle (10), through the peripheral wall (12) and a protective layer (19) of hard chromehaving a sandblastedouter surface (18) with an average roughness ranging between 6 and 6.5 µm, obtained by dry sandblasting.
A method, a mandrel (10) and a device for removing coreless rolls (15) of a plastic film. The mandrel (10) comprises a tubular body having a plurality of radial holes (17), conformed with a chamber (16) for distributing pressurised air, in which a piston (22) suitable for being magnetically coupled with an external drive member (27) slides. When a roll (15) must be removed, pressurised air is supplied to the fore end of the mandrel (10), and escapes from all the holes (17) to expand the internal turns of the roll (15) which can be taken off without friction. As the roll (15) advances along the mandrel (10), the magnetically driven piston (22) progressively reduces the volume of the air chamber (16) preventing at the same time the air to escape from the holes (17) that progressively come to lie on the rear side of the mandrel (10), with consequent saving of compressed air.
One or a plurality of coreless rolls of a stretchable plastic film are wound up on a mandrel (10) having a tubular body; the mandrel (10) comprises at least a fore air chamber (14) and a rear air chamber (15) axially aligned, wherein the periph-eral wall (11) of the mandrel (10) comprises a perforated zone (16, 17) in correspondence of each air chamber (14, 15). One or a plurality of coreless rolls (B1, B2) of stretchable plastic film are wound up on the mandrel (10) at said perforated zones (16, 17) and air chambers (14, 15); the roll or rolls (B1, B2) are removed by pushing said roll or rolls along the mandrel (10), by supplying pressurised air initially into all air chambers (14, 15) during a first removal step of the roll or the rolls (B1, B2) and selectively disconnecting each chamber (14, 15) from the pressurized air source, starting from the rear air chamber (15) to the fore air cham-ber (14) at overcoming of each air chamber (14, 15) by said roll or rolls (B1, B2).
One or a plurality of coreless rolls of a stretchable plastic film are wound up on a mandrel (10) having a tubular body; the mandrel (10) comprises at least a fore air chamber (14) and a rear air chamber (15) axially aligned, wherein the peripheral wall (11) of the mandrel (10) comprises a perforated zone (16, 17) in correspondence of each air chamber (14, 15). One or a plurality of coreless rolls (B1, B2) of stretchable plastic film are wound up on the mandrel (10) at said perforated zones (16, 17) and air chambers (14, 15); the roll or rolls (B1, B2) are removed by pushing said roll or rolls along the mandrel (10), by supplying pressurised air initially into all air chambers (14, 15) during a first removal step of the roll or the rolls (B1, B2) and selectively disconnecting each chamber (14, 15) from the pressurized air source, starting from the rear air chamber (15) to the fore air chamber (14) at overcoming of each air chamber (14, 15) by said roll or rolls (B1, B2).
A coreless roll (12) of a plastic film (10) is directly wound onto a tubular spindle (11); the spindle (11) is provided with an air chamber (11P) having a perforated side wall (11W), which communicate with a pressurised air source (27). At the removal of the roll (12), the inner turns of the roll (12) are radially expanded by feeding a pressurised airflow into the winding spindle (11) and the roll (12); the pressurised air is fed for a length of time required for the removal of the roll (12).
A method and an apparatus for winding coreless and soft-core rolls (11), of film materials (10). The film (10) is made to advance, at differentiate speeds (S1, S2), between a first and a second drawing unit (12, 21) making the film (10) to perform a floating loop (19). The film (10) is fed in a controlled way, making it adhere to a grooved embossing drum (22) by an air jet (29) to emboss cross corrugations in the film (10) while it is being wound up; the corrugations of the film (10) traps air and prevents the implosion of the roll (11). A programmable electronic unit (32), controls the drawing units (12, 21) in relation to control signals (E1, E2) related to the feeding and winding up speeds (S1, S2) of the film (10), and in relation to a control signal supplied by a sensing device (28) for detecting the position of the floating loop (19).
patents
