Decatizing of fabrics

Decatizing apparatus comparison a heated cylinder and a backing cloth applied against the cylinder by means of a thrust belt under high tension. The material to be treated passes between the cylinder and the backing cloth. The cylinder is freely rotatable and is driven by passage of the material, the backing cloth and the thrust belt.

BACKGROUND OF THE INVENTION 
(1) Field of the Invention 
The present invention relates to the continuous decatizing of woven, 
knitted and other fabrics. 
(2) Description of the Prior Art 
There has been proposed a decatizing process in which the material to be 
treated is pressed between a rotated, heated, cylinder having its own 
drive system, and a heated trough in order to consolidate the material. 
The cylinder entrains the material and drags it over and beyond the 
trough. As a result of this treatement, the material has a shiny surface 
at least on the side of the material facing towards the trough. 
This previously proposed process is disadvantageous in that the material is 
elongated longitudinally during the treatment. Elongation of the material 
of the order of magnitude of 2 to 5% occurs. The purchasers of the 
material, will, however, accept a maximum tolerance of plus or minus 1%. A 
material which shrinks by more than plus or minus 1% during the so-called 
"ironing test," is useless for further processing since it causes 
shrinkage folds or creases in a garment made from the material. The cloth 
manufacturer can reduce the internal strain condition of the material to 
the acceptable value, only by a shrinking process. However, this shrinking 
process, which is usually performed by a steaming operation, adversely 
affects the previously obtained pressing and decatizing effect. 
For these reasons, a compromise solution is implemented by using a very low 
contact pressure between the material and the cylinder. Although in this 
manner, the elongation of the material is kept within permissible limits, 
the resulting pressing effect leaves much to be desired. 
There has also been proposed a decatizing process using apparatus 
comprising a heated cylinder, an inner backing cloth which is conveyed 
over a humidifying device prior to reaching the cylinder, and an outer 
backing cloth which surrounds the cylinder, the material to be treated, 
and the inner backing cloth in the area of the cylinder. There is no 
significant contact pressure applied between the material and the cylinder 
with the result that the material is not properly finished. Also, owing to 
the absence of applied pressure the material is likely to slip which 
results in an unacceptable elongation of the material and in a moire 
effect on the material, this latter effect being caused by slip between 
the cylinder and the backing cloths. 
SUMMARY OF THE INVENTION 
According to the invention, there is provided a method for the continuous 
decatizing of a fabric material using a rotatable, heated, cylinder, a 
moisturizing device, a backing cloth, said backing cloth passing across 
the moisturizing device and around the cylinder. The material is fed 
between the cylinder and the backing cloth with the material being in 
direct contact with the surface of the cylinder, and a thrust belt is 
provided under high tension to thrust the backing cloth and the material 
against the cylinder.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
As shown in the drawing, the apparatus comprises a heated cylinder 1, which 
is freely rotatable, the cylinder 1 being rotated simply by passage of the 
material 2 to be decatized, an associated backing cloth 8 and a thrust 
belt 9. The surface of this cylinder 1 has a mirror finish and is 
completely smooth. The cylinder 1 is heated to a constant, but 
controllable, temperature of 110.degree. to 180.degree. C., and is 
journalled in ball-bearings in a smooth-running manner. 
The material 2 is fed from a stack (not shown) over a series of rolls 
including a feed roll 3, and a roll 4, over a moisturizing device 5, 
around a part of the cylinder 1, and around a drive roll 6 and is then fed 
to a folding device (not shown). 
The moisturizing device 5 may, for example, comprise a perforated box from 
which steam, and in particular saturated steam, flows out freely. 
Alternatively the moisturizing action can be effected by means of fine 
spray of water. The moisturizing device 5 acts to improve the pressing and 
decatizing action. 
The feed roll 3 acts to draw the material 2 off the stack with a minimum 
tension. A stationary rod 7 which is intended for manually straightening 
material having a distorted weft, is situated between the two rolls 3 and 
4. The material 2 passes over this rod 7, during its passage from the 
stack to the cylinder 1. 
The backing cloth 8 consists of an endless and seamless belt of satin, felt 
or other suitable material. Among other purposes, the backing cloth acts 
as a conveyor belt for the material 2. 
A part of the cylinder 1 is surrounded by the thrust belt 9 which is formed 
from a strip and is free of projections at the point of connection of the 
two ends of the strip. The thrust belt 9 consists of, for example, a 
high-strength synthetic felt, metal, or rubber with a reinforcing insert 
and the like, and is intended to bear and transmit high tensile forces. 
The thrust belt 9 is entrained around the drive roll 6 and freely 
rotatable rolls 10 and 11. The rolls 6 and 11 are heated and maintain the 
thrust belt 9 at the treatment temperature. A tensioning device 12 which 
enables the tension of the thrust belt 9 to be adjusted steplessly and to 
be kept constant throughout the decatizing operation is incorporated on 
the path of movement of the thrust belt 9. 
The roll 10 also serves the purpose of laterally guiding the thrust belt 9. 
Contact sensors 13 which are situated at either side of, and spaced from, 
the thrust belt 9, effect an axial displacement of the roll 10 via 
electrical or pneumatic switching elements (not shown). An inclined 
setting of the roll 10 is produced by such axial displacement, so that the 
thrust belt 9 is consequently displaced sideways. In this manner the 
thrust belt 9 can be maintained in a central position at all times. 
The backing cloth 8 acts to prevent the thrust belt 9 from marking the 
material 2. The backing cloth 8 which has a dense and smooth surface, is 
interposed between the thrust belt 9 and the material 2 and does not leave 
on the material 2 any imprints of the comparatively coarse structure of 
the thrust belt 9. The high radial stress exerted on the material 2 by the 
thrust belt 9 is thus transmitted to the material 2 by the backing cloth 
8, and the material 2 is pressed against the periphery of the cylinder 1. 
The material 2 is conveyed across the moisturizing device 5 and around the 
cylinder 1 without elongation by virtue of the fact that the material 2 is 
supported and moved by the backing cloth 8; the displacement of the thrust 
belt 9, the backing cloth 8, and of the material thus occur completely 
free of slipping in these two areas. 
The backing cloth 8 moves along a common path with the thrust belt 9 in the 
pressing area of the cylinder 1; outside this area and behind the drive 
roll 6, the backing cloth 8 and the thrust belt 9 follow separate paths, 
the backing cloth 8 passing over guide rolls 14, 15 and 16 and a 
tensioning roll 17. 
Brushes 18, 19 are associated with the thrust belt 9 and the backing cloth 
8 to ensure that the surface of the belt 9 and the surface of the backing 
cloth 8 remain free of dirt and fluff and other matter. 
The material 2 is also brushed on both sides prior to the moisturizing and 
pressing actions. This is effected by means of brushes 20, 21. Each of the 
brushes 18 to 21 is equipped with a box 22 to 25, respectively, for 
receiving matter removed by the brushes, the boxes 22 to 25 being in 
communication with a suction device (not shown). 
The apparatus described may be used as a thermal printing machine, in which 
transfer paper or thermal printing paper is fed through the apparatus 
synchronously with the material 2 and the backing cloth 8. In this case, 
however, the force applied by the tensioning device 12 is reduced, so that 
the pressure between the material 2, the paper and the cylinder 1 does not 
become excessive. 
The apparatus operates in the following manner: 
The material 2 fed from the stack is conveyed by the backing cloth 8 in 
stress-free and slip-free manner over the roll 3, the rod 7 and the roll 4 
and over the moisturizing device 5. In view of the freedom from slipping, 
there is thus no speed differential between the material 2 and the backing 
cloth 8. 
Following moisturization, the material 2 is conveyed into the pressing area 
of the heated cylinders 1. The material 2 is pressed and steamed by the 
thrust belt 9 via and the backing cloth 8. The displacement of the thrust 
belt 9, the backing cloth 8, the material 2, and the cylinder 1 is 
effected by frictional engagement of the thrust belt 9 with the drive roll 
6, and no relative displacement occurs between the thrust belt 9, the 
backing cloth 8, the material 2 and the cylinder 1. The material 2, which 
is thus ironed and pressed, has improved handling properties and is not 
liable to shrinkage, and is fed from the roll 6 to a folding device (not 
shown), in a state suitable for use. 
In the apparatus particularly described, the material is conveyed and 
processed without elongation and due to the absence of elongation the 
finished material has good properties. Also, the material is free from a 
moire effect due to the high pressure applied by the thrust belt and due 
to the fact that the cylinder lacks its own drive means. 
The endless and slip free backing cloth of satin or other appropriate 
material, which moves with the thrust belt, fulfils two important 
functions. On the one hand, the backing cloth which has a very dense and 
smooth surface, does not mark the material so that the relatively rough 
surface of the thrust belt is not impressed on the surface of the 
material; on the other hand, the backing cloth serves the purpose of 
stretch-free conveyance of the material. 
The material is moved through the moisturizing zone free of elongation by 
means of the backing cloth, which acts as a conveyor belt. The steaming or 
other moisturizing operation, which has beneficial effects on the final 
condition of the material, is, in the previously proposed apparatus 
accompanied by an unacceptable elongation of the material. As is known, a 
steamed material is extremely delicate and easily deformable, so that not 
only an elongation of the material, but at the same time also a decrease 
in the width of the material, must be expected as a consequence of this 
elongation. These effects do not, however, arise in the apparatus 
described since the material is carried through the moisturizing zone by 
means of the backing cloth and also because the feed roll draws the 
material from the stack and feeds it to the backing cloth. 
Elongation of the material does not occur throughout the contact period, 
since all the parts move without slipping. Evaporation of moisture occurs 
from the material on the cylinder with the result that both a pressing and 
a decatizing action is effected due to the high contact pressure between 
the material and the cylinder along a relatively large path length.