FR2467674A1 - Heat-shrinkable, flocked fabric tubes, - produced for covering rollers on e.g. textile machines - Google Patents

Abstract

The production of flocked, heat shrinkable synthetic fabric tubing comprises removing the flat tube from a supply, opening it to circular form, coating its outer surface with a binder layer, and encrusting the binder with synthetic fibre flocking by electrostatic process. The flocking stands perpendicular to the outer surface of the tube. The tube is dried, brushed and/or cleaned before winding or folding for storage. The tubing is intended for heat shrinking on to rollers for use in textile spinning and printing machines and machines for handling paper webs. A rapidly replaceable covering for treatment rollers may be shrunk into position by hot air or steam.

Description

The present invention relates to a continuous manufacturing process for a tube made of flocked heat-shrinkable synthetic material, a device for implementing this method, as well as the use of the tube obtained.

Textile machines, in particular spinning machines, machines used in graphic art and machines equipped with a device for transporting paper webs, use a large number of cylinders coated with a textile tube. The cleaning cylinders, intended to collect the lint in the textile machines, the inking or wetting rolls of the graphic reproduction machines and the rolls of paper tape conveyors comprise a textile covering generally consisting of a knitted tube or cloth or a ribbon stuck on the cylinder. Textile tubes have the disadvantage of wearing out quickly and of causing a knitting or fabric marking. The coatings obtained by gluing a tape eliminate this drawback, but are long to install and risk marking at the join. However, these coatings have a relatively short life, which implies their replacement at regular intervals. The replacement of the coatings glued to the cylinders therefore involves a relatively long downtime of the machines, which represents another major handicap, the consequence of which is to increase production costs.

The present invention proposes to overcome the aforementioned drawbacks by providing a means for rapid replacement of the textile coverings of cylinders used in different machines, by providing flocked heat-shrinkable tubes, intended to be placed on these cylinders. This operation is done by cutting a section of tube of appropriate dimensions, its positioning on the cylinder to be coated and its fixing on this cylinder is carried out by application of a hot air or hot water pulse causing retraction heat shrink tubing.

For this purpose, the manufacturing method according to the invention is characterized in that a supply device, where it is initially stored, is continuously withdrawn from a tube made of heat-shrinkable material in a flattened and wound form, in that said pipe is transported through a shaping station to open it and give it a circular cross-section, in that said shaped pipe is then passed through a spraying station where its peripheral surface is coated with a layer of binder, in that the pipe is passed through an electrostatic flocking station, in which synthetic strands are embedded in the binder in directions substantially perpendicular to the peripheral surface of the pipe , in that the binder is solidified and the strands fixed by passing the pipe through a drying station, and in that the flocked pipe is transported through a surface treatment station e, before storing it in coiled and flattened form in a storage magazine.

The machine for implementing this process is characterized in that it comprises a first storage magazine for a pipe made of flattened heat-shrinkable material and wound on a flat circulating coil rotating around a central axis perpendicular to the plane of its sides, a station for shaping the pipe comprising a cylindrical mandrel disposed inside the pipe, a station for spraying a binder comprising at least one nozzle arranged to spray a uniform layer of binder on the peripheral cylindrical surface of the pipe, an electrostatic flocking station arranged to create an electric field intended to attract the synthetic cut fibers and embed them in the binder perpendicular to the peripheral surface of the pipe, a hot-drying tunnel to solidify the binder, a second storage store comprising a flat circular take-up spool, substantially identical to the spool of the first storage magazine, and drive means for ur continuously drive said take-up reel around its axis perpendicular to the plane of its sides.

According to a preferred embodiment of the method according to the invention, the surface treatment followed by the flocked tube consists of mechanical brushing and / or cleaning with a jet of compressed air.

During its treatment, the heat-shrinkable plastic pipe used as a raw material for the manufacture of the flocked tube, is driven in slow and continuous rotation about itself, around its longitudinal axis. To perform this rotation, the two storage magazines serving, one, to store the heat-shrinkable plastic pipe and the other, the second, to store the flocked tube obtained by the process according to the invention, include means drive to drive them in synchronous rotation about a central axis parallel to the plane of the faces of the flat coils they contain. These storage magazines preferably include two flanges mounted parallel to each other, to constitute the support of the corresponding flat coil disposed between them, this support being integral with a rotary drive axis parallel to their plane. The drive axes of these supports are interconnected by a mechanism intended to ensure their synchronous drive by means of a single drive motor, or a similar device.

In addition, the support of the storage magazine, containing the take-up reel, carries a motor for driving said reel, the rotation of the reel of the first storage tank, in view of the unwinding of the heat-shrinkable plastic pipe, being provided by the traction exerted on the finished tube during its winding on the take-up reel.

To make the opening of the hose initially wound in flattened form on the reel of the storage magazine, the cylindrical mandrel comprises a cylindrical head whose front edge or leading edge is rounded, and whose diameter is slightly less than or substantially equal to inner diameter of the pipe. This head is mounted at the end of a central rod which also carries a cylindrical part mounted at the rear of the head and having a diameter substantially equal to that of the head. The end of the central rod opposite the head carries an articulated part comprising two lateral support rollers, intended to cooperate to ensure the maintenance in the longitudinal position of the mandrel inside the pipe. These rollers have a suitable additional side surface to avoid crushing the pipe.

The present invention will be better understood with reference to the description of an exemplary embodiment and the accompanying drawings, in which
FIG. 1 represents a schematic view of an installation for implementing the method according to the invention,
FIG. 2 is a more detailed view of part of the installation of FIG. 1, in particular illustrating the storage stores and the pipe shaping station, and
Figures 3A and 3B show detailed partial views of the pipe shaping mandrel.

Referring to fig. 1, the machine according to the invention, shown schematically in this figure, comprises a first circular flat coil 10 serving as a storage magazine for a pipe 11 made of a heat-shrinkable synthetic material, and which is wound in flattened form on the coil 10. After passing between two guide rollers 12, the pipe 11 passes through a shaping station 13, where it is open so as to present at its outlet a section of circular shape. The thus opened pipe 14 then enters a station 15 for spraying a binder, where it is coated over its entire periphery with a layer of binder used for fixing strands of synthetic fibers, which will be embedded perpendicular to its peripheral surface. in the flocking station 16 succeeding station 15. To fix these strands and solidify the binder, the tube passes through a drying tunnel 17 where it is heated to a temperature sufficient to solidify the binder, but insufficient to cause the shrinkage of the material heat shrinkable from which it is formed. Finally, a mechanical processing station 18 allows the cleaning of the flocked tube obtained and the elimination of the strands which have not become encrusted on the peripheral surface of the tube. This treatment can be in the form of mechanical brushing and / or flooding with a jet of compressed air. On leaving station 18, the flocked tube passes through two rollers 19 which flatten it and allow it to be wound up on the take-up reel 20 which constitutes the second storage magazine.

With reference to fig. 2, the coil 10 used to store the raw material comprises two flanges 21 mounted parallel to each other, so as to constitute a support 22 for the coil 10 rotating around its central axis 23, the two ends of which are retained by the flanges 21. The support 22 is connected to the free end of a drive axis 24 of a drive motor 25, with the aim of driving the storage magazine for the pipe in continuous rotation about a longitudinal axis perpendicular to the axis 23 of the coil 10. The motor 25 and its drive axis 24 are mounted on a fixed console 26, which cooperates with a fixed console 27 to support the entire storage warehouse for the raw material pipe.

To facilitate understanding, the storage magazine for the finished flocked tube has been turned ninety degrees relative to the first storage magazine. As before, this magazine has two flanges iii which serve as support 22 'for the coil 20 rotating around a central axis 23'. The support 22 'is mounted at the end of a drive shaft 24' which is connected by a drive mechanism, which will be described below, to the drive axis 24 of the motor 25. The support 22 'is again suitably mounted on two brackets 26' and 27 ', which allow the rotation of this support in synchronism with the support 22 of the first storage magazine. The support 22' also carries a geared motor group 28 connected to the axis 23 'of the coil 20, to drive the latter in continuous rotation and cause the displacement of the pipe 14 through the whole machine.

To ensure the synchronous rotational movement of the two storage magazines around the longitudinal axis 29 of the pipe 14, the drive axis 24 carries a pulley 30 identical to a pulley 30 'carried by the axis 24', these two pulleys being respectively connected by belt or chain to two pulleys 31 and 31 'coupled together, for example by means of a rod 32 serving as a common axis and mounted on bearings 33 and 33'.

The shaping station 13 essentially comprises a mandrel 34, which will be described in more detail with reference to the following figures, housed inside the pipe 14, and the rear end of which (in the direction of travel of the pipe) takes bearing on rollers 35 fixed in position and rotating around axes perpendicular to the longitudinal axis 29 of the pipe 14.

With reference to fig. 3A and 38, the shaping mandrel comprises a central rod 37, the front end of which carries a substantially cylindrical shaping head 38, the leading edge 39 of which is rounded or possibly frustoconical. At the rear of the head 38 is mounted a cylindrical part 40, the diameter of which is substantially equal to that of the head 39, slightly less than or substantially equal to the internal diameter of the pipe 14. The rod 37 ends, at its rear end, by a ball joint 41 intended to be housed in a suitable cavity 42 of an end piece 43. The ball joint 41 carries two pins 44 intended to engage in two longitudinal grooves 45 of the cavity 42.

The free end of the part 43 has two lateral recesses 46 intended to accommodate two rollers 47, the peripheral surface of which is curved so as to adapt to the internal surface of the pipe 14 and prevent it from being crushed. The rollers 47 bear against the peripheral surface, of concave shape, of the rollers 35, the pipe 14 being caught between the respective peripheral surfaces of these rollers. The rollers 47 rotate freely around the fixed axes 48 integral with the end piece 43.

The heat-shrinkable blocked tubes obtained by the process according to the invention and thanks to the machine of the invention are then cut into segments of desired length and adapted on the cylinders of the machines requiring a textile coating such as the inking or wetting cylinders of the machines. of graphic art, or the cleaning cylinders of textile machines. It is enough to thread the segment of tube on the cylinder and to apply a hot air impulse, for example using a small heating fan, to cause the retraction of the plastic tube and its firm fixing to the periphery of the cylinder.

Of course, the present invention is not limited to the embodiment described, but can undergo different modifications and present different variants obvious to those skilled in the art.

Claims (12)

CLAIMS [ONS 1. A method of continuously manufacturing a tube of flocked heat-shrinkable synthetic material, characterized in that a supply device where it is initially stored is taken continuously, a tube of heat-shrinkable material in a flattened form and wound, in that it conveys said pipe through a shaping station to open it and give it a circular cross-section, so that said shaped pipe is then passed through a spraying station where its peripheral surface is coated with a layer of binder, so that an electro-flocking flocking station is passed through the pipe, Jaris which bl :: iIIb byllLilét i4UeS become embedded in the binder in substantially directions perpendicular to the peripheral surface of the pipe, in that- the solidification of the binder and the fixing of the strands is carried out by passing the pipe through a drying station, and in that the florked pipe is transported through a surface treatment station, before storing it in coiled and flattened form in a storage warehouse. 2. Method according to claim 1, characterized in that the surface treatment, undergone by the flocked tube, consists of mechanical brushing and / or cleaning with a jet of compressed air. 3. Method according to claim 1, characterized in that the pipe is driven in slow rotation and continues on itself during its treatment, the axis of this rotation being the longitudinal axis of this pipe. 4. Machine for implementing the method according to claim 1, characterized in that it comprises a first magazine for storing a pipe made of heat-shrinkable material which is flattened and wound on a flat circular coil rotating around a perpendicular central axis in the plane of its sides, a station for shaping the pipe comprising a cylindrical mandrel disposed inside the pipe, a station for spraying a binder comprising at least one nozzle arranged to spray a uniform layer of binder on the surface cylindrical peripheral of the pipe, an electrostatic flocking station arranged to create an electric field intended to attract the synthetic strands and to embed them in the binder perpendicular to the peripheral surface of the pipe, a hot-drying tunnel to solidify the binder, a second storage store comprising a flat circular take-up spool, substantially identical to the spool of the first storage magazine, and driving means ement to continuously drive said take-up reel around its axis perpendicular to the plane of its sides. 5. Machine according to claim 4. characterized in that it comprises drive means for driving in synchronous rotation the two rna kids storage around a central axis parallel to the plane of the faces of the flat bo bines, so as to cause a continuous axial rotation of the pipe during its treatment. 6. Machine according to claim 4, characterized in that the two storage magazines each have two flanges mounted parallel to one another, to form a support for the respective corresponding coils, disposed between these flanges, these supports being integral a rotary drive axis parallel to the planes of the flanges. 7. Machine according to claim 4, characterized in that the drive axes of the two supports of the coils of the two storage magazines are interconnected by a device intended to ensure their synchronous drive. 8. Machine according to claim 4, characterized in that the support of the second storage magazine containing the receiving coil carries a motor for driving said coil, the rotation of the coil of the first storage magazine, for the unwinding of the pipe , being provided by the traction exerted on the pipe by its winding on the take-up reel. 9. Machine according to claim 4, characterized in that the cylindrical mandrel comprises a cylindrical head, whose front edge is rounded and whose diameter is substantially equal to that of the internal diameter of the pipe, this head being mounted at one end d 'a central rod, a cylindrical piece mounted at the rear of the head and also having a diameter slightly smaller or substantially equal to the inner diameter of the pipe, and a rear end piece articulated on said rod and comprising two rollers lateral supports, intended to cooperate with two rollers external to the pipes and serving as a stop to maintain the mandrel longitudinally in position inside the pipe. 10. Use of the heat-shrinkable flocked tube obtained by the process of claims there 3, cut into segments of appropriate length for coating the cylinders in graphic art machines. 11. Use of the heat-shrinkable flocked tube obtained by the method according to claims I to 3, cut into segments of appropriate length for coating the cleaning cylinders in textile machines. 12. Use of the heat-shrinkable flocked tube obtained by the process of claims 1 there, cut into segments of appropriate length, for coating the transport cylinders of paper strips.