EP2669094A1

EP2669094A1 - Printer for fabric

Info

Publication number: EP2669094A1
Application number: EP12170138.7A
Authority: EP
Inventors: Paolino Gastoldi
Original assignee: La Meccanica Costruzione Macchine Tessili SpA
Current assignee: La Meccanica Costruzione Macchine Tessili SpA
Priority date: 2012-05-31
Filing date: 2012-05-31
Publication date: 2013-12-04

Abstract

It is provided a printer for fabric (10) comprising a printing unit (20) adapted to carry out printing of the fabric (10); a conveyor apparatus (30) adapted to dispose the fabric (10) close to the printing unit (20) and defining a rest surface (30a) of the fabric (10); and a pressure member (60) adapted to press the fabric (10) against the rest surface (30a).

Description

The present invention relates to a printer for fabric of the type pointed out in the preamble of the first claim.
In particular, the invention relates to a printer for fabrics of natural origin such as cotton or linen and/or fabrics of synthetic origin, such as polyester and Lycra^®. More particularly, the invention relates to a fabric printer of the inkjet type.
It is known that printers presently in use contemplate the presence of an unrolling group adapted to unroll the fabric from a reel and lay it down and a conveying group receiving the fabric from the unrolling group and taking it to the printing unit where printing of the fabric is carried out.
In detail, the fabric is disposed on a roller belonging to the conveying group and moved forward until a fabric portion reaches the printing unit carrying out printing of this fabric portion.
When printing of this portion has been completed, the roller moves the fabric forward in such a manner that a new fabric portion is disposed in correspondence of the printing unit that is therefore able to print the second portion.
The known art mentioned above has some important drawbacks.
A first important problem is represented by the fact that the fabric printing is particularly inaccurate and often has such faults that the fabric has to be rejected. Another problem consists in that, in an attempt to reduce the print defects, presently known printers are caused to work at particularly low rates bringing about reduced production volumes.
A further problem therefore results from the poor efficiency of known printers and the high production costs.
Under this situation, the technical task underlying the present invention is to conceive a printer for fabric that is able to substantially obviate the mentioned drawbacks.
Within the scope of this technical task it is an important aim of the invention to provide a printer characterised by high printing accuracy.
Another important aim of the invention is to obtain a printer ensuring high production rates and almost zero working rejects.
It is a further aim of the invention to provide a printer enabling low production costs and high efficiency.
The technical task and the aims specified are achieved by a printer for fabrics as claimed in the appended Claim 1.
Preferred embodiments are highlighted in the sub-claims.
The features and advantages of the invention are hereinafter clarified by the detailed description of a preferred embodiment of the invention, with reference to the accompanying Fig. 1 showing a sectional view of a printer for fabric according to the invention.
With reference to the mentioned figures, the printer for fabric according to the invention is generally identified by reference numeral 1.
It is adapted to be used for printing, preferably by inkjet, a fabric 10, paper or other similar material. In particular, printer 1 is adapted to carry out printing of a synthetic fabric, such as polyester and Lycra^®, or a natural fabric such as cotton and linen.
Printer 1 briefly comprises a printing unit 20 adapted to carry out printing of the fabric 10 or the like; a conveyor apparatus 30 adapted to dispose the fabric 10 close to the printing unit 20 and defining a rest surface 30a for the fabric 10; a loading or supply system 40 adapted to dispose the fabric 10 on the rest surface 30a; and a supporting structure 50 adapted to maintain said components of the printer 1 in a correct position.
The loading system 40 can be identified by an unrolling group, known by itself, adapted to unroll a fabric reel 10 and that, by virtue of suitable rollers 41, is able to tension the fabric 10 and dispose it in such a manner as to facilitate printing by the printing unit 20.
This unit 20 is preferably of the inkjet type, known by itself.
It therefore comprises a support 21 adapted to carry the different components of the printing unit 20 itself in the correct position; a head 22 provided with nozzles 22a adapted to eject ink droplets 22b onto the fabric 10; a guide 23 defining a sliding direction for the head that is preferably substantially perpendicular to the advancing or feeding direction of the fabric or the like; and a translation motor 24 adapted to translate the head 22 along this sliding direction so as to enable the head to print a portion to be printed characterised by a given printing length, calculated according to the advancing direction.
In order to operatively connect the loading system 40 to the printing unit 20, printer 1 is provided with the conveyor apparatus adapted to take fabric 10 from system 40 to unit 20.
The conveyor apparatus 30 is a continuous conveyor such as a band, roller or slat conveyor. Preferably, the conveyor apparatus 30 is a band or belt conveyor.
It therefore comprises a belt 31, i.e. a conveyor belt defining the rest surface 30a; two supporting cylinders 32 in engagement with the belt 31 so as to define a substantially flat rest surface 30a; and a suitably electric motor associated with one of the supporting cylinders 32 so as to move the belt 31 defining an advancing direction of the fabric.
The belt 31 has a width calculated along a direction parallel to the rest surface 30a and perpendicular to the advancing direction, at least as large as the width of fabric 10 so as to define a suitable surface 30a for the fabric 10.
In some cases, the conveyor apparatus 30, in addition to said cylinders 32, can be provided with one or more additional cylinders, not shown in the figure, in engagement with belt 31 and disposed inside the loop defined by the belt 31 so as to give greater steadiness to the belt 31 itself and therefore avoid deformation or warping of the rest surface 30a.
In addition, belt 31 has an adhesive layer to enable the fabric 10 to adhere to the rest surface 30a, and disposed at least on a portion of the rest surface 30a and, preferably, almost the whole rest surface 30a. In detail, the adhesive layer consists of a permanent adhesive made up of acrylic-vinyl copolymers, and it is in particular ATRAFIX MLIK^®.
Printer 1 advantageously comprises a pressure member 60 disposed at the conveyor apparatus 30 and, more specifically, between the printing unit 20 and loading system 40, which member 60 is adapted to press the fabric 10 against the rest surface 30a. Preferably, the pressure member 60 is disposed in the vicinity of the loading system 40 so that the fabric 10 is pressed against the rest surface 30a immediately after being laid on the belt 31.
The pressure member 60 comprises a presser 61 adapted to press the fabric against the rest surface 30a and at least one actuator 62 adapted to move presser 61.
In particular, member 60 is provided with a single actuator 62 disposed laterally of the conveyor apparatus 30 and at least one guide 63 adapted to secure correct movement of presser 61 and disposed on the opposite side from actuator 62 relative to the belt 31. In particular, the pressure member 60 is provided with two guides 63 one of which is disposed at actuator 62 (see Fig. 1) and the other on the opposite side from actuator 62 relative to the belt 31.
Actuator 62 is adapted to translate presser 61 along a translation trajectory 62a having a component substantially perpendicular to the rest surface 30a and, in particular, along a translation trajectory 62a substantially perpendicular to the rest surface 30a and, therefore, fabric 10. Thus, it may consist of a straight actuator, preferably of the pneumatic type such as a piston, a powered guide or other similar mechanism adapted to perform said function.
Presser 61 comprises a plate 61a or other similar element defining a pressure surface 61b parallel to the rest surface 30a and substantially conforming in shape to a portion of the rest surface 30a so as to substantially overlap such a portion of the rest surface 30a. Preferably, the pressure surface 61 b substantially has an extension at least as large as that of the printing portion of unit 20. More preferably, the length calculated in the advancing direction of the pressure surface 61 b is greater than said printing length.
It therefore has a width, calculated along a direction parallel to surface 30a and perpendicular to the advancing direction, at least as large as the width of fabric 10, in particular at least as large as the width of the belt 31.
Finally, the pressure member 60 advantageously contemplates the presence of a counter-plate or abutment 64 rigidly connected to the supporting structure 50 and adapted to be disposed on the opposite side from presser 61 relative to fabric 10 so as to absorb the force applied by presser 61. In detail, the abutment 64 is disposed in such a manner that, when presser 61 abuts against fabric 10, a portion of the fabric 10 and part of belt 31 is enclosed between the abutment 64 and presser 61.
Said counter-plate or abutment 64 can consist of a plate or other similar element adapted to define a contact surface substantially coincident with the pressure surface 61 a.
Printer 1 carries out an innovative printing process for fabric.
This printing process for fabric comprises an unrolling step in which fabric 10 is unrolled from a reel and made available for the conveyor apparatus 30; a feeding step adapted to make fabric 10 reach the printing unit 20 substantially in a taut condition; and a printing step in which the printing unit 20 carries out printing on fabric 10.
In the feeding step, at least two sub-steps can be identified, i.e. at least one advancing sub-step, and at least one pressure sub-step, adapted to be performed substantially simultaneously or in succession.
As soon as fabric 10 is disposed on belt 31, the fabric 10 is moved until it reaches the pressure member 60 where the pressure sub-step takes placed. In detail, this movement is carried out by steps, i.e. in a non-continuous manner and, more specifically, at a feed pitch substantially as long as the printing length.
In detail, during this pressure sub-step, actuator 62 moves presser 61 along the translation trajectory 62a making presser 61 come into contact with the first portion of fabric 10 and press it against the rest surface 30a with a pressure force having at least one component substantially perpendicular to surface 30a and, more preferably, with a pressure force substantially perpendicular to the rest surface 30a.
When pressure on fabric 10 is over, actuator 62 moves presser 61 away from fabric 10 moving presser 61 along the translation trajectory 62a in the opposite way relative to the preceding motion of presser 61.
At this point, the pressure sub-step is terminated and an advancing sub-step begins in which the first portion of fabric 10 moves forward by a stretch substantially corresponding to the printing length so that presser 61 is able to submit a new portion of fabric 10 to the pressure sub-step.
After a given number of advancing movements, a portion of fabric 10, previously treated by presser 61, comes in correspondence of the printing unit 20 while, simultaneously, another portion of fabric 10 reaches the pressure member 60.
At this point, a printing step takes place, in which the first portion is printed and, simultaneously, a new pressure sub-step occurs in which said second fabric portion is pressed between presser 61 and abutment 64 and then suitably stretched out on the rest surface 30a.
In detail, the printing step and the pressure sub-step are performed substantially simultaneously so that, during both sub-steps, the fabric is substantially immobile and therefore adapted to be pressed against abutment 64 and printed by unit 20. The invention achieves important advantages.
A first important advantage is represented by the fact that, due to printer 1, printing of fabrics 10 is particularly accurate and substantially without faults.
In particular, this important result has been obtained in an innovative manner by virtue of the innovative presence of the pressure member 60: the fabric comes to the printing unit 20 perfectly stretched out and therefore without small creases and gathering effects that usually cause deterioration in printing.
This perfect planar appearance is due to presser 61 that by applying a force perpendicular to the rest surface 30a, ensures that the fabric is perfectly planar on belt 31.
This perfect extension is also obtained due to the presence of abutment 64 that, by preventing deformation of belt 31 and fabric 10 during the pressing action by presser 61, ensures laying down of fabric 10 almost perfectly on belt 31 so that said fabric reaches the printing unit 20 without creases and pleats.
Another advantage is represented by the fact that printer 1, due to the fact that fabric 10 is almost perfectly taut when it reaches the printing unit 20, is characterised by particularly high working rates and therefore can ensure greater production volumes as compared with presently known fabric printers.
In particular, this advantage results from the fact that the pressure member 60 ensures perfect laying of fabric 10 and therefore enables the printing unit 20 to have a printing surface almost perfect, bringing about particularly high working rates. Another advantage is the fact that printer 1 ensures a production without rejects and therefore of high efficiency and reduced production costs.
Also important is the fact that, being the advancing pitch of fabric 10 shorter than the pressure surface 61 b, there is a small portion of fabric 10 that is pressed twice by presser 61, which ensures uniform stretching out of the whole fabric 10 supplied from the reel.
The invention is susceptible of variations falling within the scope of the inventive idea. In particular, the pressure member 50 can be provided with a presser 51 substantially consisting of a cylinder adapted to rotate about a rotation axis substantially parallel to the rest surface 30a so as to press fabric 10 against the surface itself and therefore ensure an almost perfect printing operation. In this case, the printing process and, more specifically, the feeding step contemplates that the advancing sub-step and pressure sub-step be performed substantially simultaneously.

Claims

A printer (1) for fabric (10) comprising a printing unit (20) adapted to carry out printing of said fabric (10); a conveyor apparatus (30) adapted to dispose said fabric (10) close to said printing unit (20) and defining a rest surface (30a) for said fabric (10); and characterised in that it comprises a pressure member (60) adapted to press said fabric (10) against said rest surface (30a).
A printer (1) as claimed in claim 1, wherein said pressure member (60) comprises a presser (61) adapted to press said fabric (10) against said rest surface (30a) and at least one actuator (62) adapted to move said presser (61).
A printer (1) as claimed in the preceding claim, wherein said at least one actuator (62) is adapted to move said presser (61) along a translation trajectory (62a) having a component substantially perpendicular to said rest surface (30a).
A printer (1) as claimed in the preceding claim, wherein said pressure member (60) comprises an abutment (64) adapted to be disposed on the opposite side from said at least one actuator (62) relative to said fabric (10).
A printer (1) as claimed in one or more of claims 2-4, wherein said translation trajectory (62a) is substantially perpendicular to said rest surface (30a).
A printer (1) as claimed in one or more of claims 2-5, wherein said actuator (62) is disposed laterally of said conveyor apparatus (30).
A printer (1) as claimed in the preceding claim, wherein said pressure member (60) comprises at least one guide disposed on the opposite side from said actuator (62) relative to said conveyor apparatus (30).
A printer (1) as claimed in one or more of the preceding claims, wherein said conveyor apparatus (30) at least at a portion of said rest surface (30a) has an adhesive layer adapted to make said fabric (10) adhere to said rest surface (30a).
A printer (1) as claimed in the preceding claim, wherein said adhesive layer is made up of acrylic-vinyl copolymers.
A printer (1) as claimed in one or more of the preceding claims, wherein said conveyor apparatus (30) comprises a belt (31) defining said rest surface.
A printing process for fabric comprising a printing step in which printing of said fabric (10) is carried out; a feeding step preceding said printing step, comprising at least one advancing sub-step in which said fabric (10) is moved forward along a rest surface (30a); and characterised in that said feeding step comprises at least one pressure sub-step in which said fabric (10) is pressed against said rest surface (30a).
A printing process as claimed in the preceding claim, wherein in said at least one pressure sub-step, a pressure force is applied to said fabric (10) which has at least one component substantially perpendicular to said rest surface (30a).
A printing process as claimed in the preceding claim, wherein said pressure force is substantially perpendicular to said rest surface (30a).-
A printing process as claimed in one or more of claims 11-13, wherein said at least one advancing sub-step and at least one pressure sub-step are performed substantially in series.
A printing process as claimed in one or more of claims 11-14, comprising a printing step in which printing of said fabric is carried out and in which said printing step and at least one pressure sub-step are performed substantially simultaneously.