GB2038893A

GB2038893A - Device for Heat Treatment of Man-Made Fibres

Info

Publication number: GB2038893A
Application number: GB7943354A
Authority: GB
Original assignee: Elitex Zavody Textilniho; Elitex
Current assignee: Elitex Zavody Textilniho; Elitex
Priority date: 1978-12-21
Filing date: 1979-12-17
Publication date: 1980-07-30
Also published as: CS203613B1; DE2950094A1

Abstract

The present invention relates to a device for heat treatment of man- made fibres by direct and substantially permanent contact of the fibre with a contact heating surface. The disadvantages encountered in hitherto known devices, i.e. reduced strength of the fibre after treatment and rather high intricacy in design of the device, are avoided in the present invention in that the heating body 1 is provided with a longitudinal groove 3 of which the bottom forms a contact heating surface, and a detachable metal lid 5 is tightly placed to the heating body along the whole length of the groove. The detachable metal lid may be formed of a thin tape tensioned by axial tension, and said lid may be provided with openings connected to an exhaust channel for the heat treatment products. <IMAGE>

Description

SPECIFICATION Device for Heat Treatment of Man-made Fibres The present invention relates to a device for heat treatment of man-made fibres by direct and substantially constant contact of the fibre with a contact heating surface.

Heating of fibres very frequently forms part of textile technological processes for enhancing the serviceability of man-made fibres, which are hereinafter referred to simply as fibres.

It is usually impossible, for various reasons, to curve the fibre path. Therefore, the heating bodies in modern high speed machines for processing fibres are very long, this being considerably disadvantageous from the viewpoint of both design and economy.

Raising the heat-transfer coefficient to the fibre is one of the possible methods of reducing the length of said heating bodies.

In the devices hitherto known, a very high heat-transfer coefficient is achieved with contact bodies, in which the fibre is heated by direct contact with a convex heated metal surface.

However, at a higher curvature of said surface, the resulting fibre shows interior strength and, in the course of actual heating, fibre breakage is frequently encountered.

In the case of slot heat treatment in a space between two plane surfaces, the fibre is not mechanically stressed and its strength is higher.

The value of the heat-transfer coefficient might be even higher than with contact heating, if the fibre is oscillated in a certain manner during heating.

The disadvantage of this heat treatment principle consists in the devices hitherto known in their higher intricacy as to design.

The above disadvantages of the devices hitherto known are mitigated by the device according to the present invention, of which the subject matter consists in that a longitudinal groove is made in the heating body, the bottom of said groove forming a contact heating surface, a detachable metal lid being tightly placed thereto along the whole length of the groove.

The present device had a higher heating effect, which makes it possible to raise the radius of curvature of the contact surface in the plane of the fibre axis, the mechanical stressing of the fibre by friction about the contact surface thus being reduced and the resulting fibre showing a higher strength.

Further advantages and features of the present invention are specified in the following description of an embodiment, given by way of example, which is diagrammatically shown in the accompanying drawings, of which Fig. 1 -- represents a transverse section through the device; Fig. 2 - shows the lid and the contact body in dismantled condition.

In the heating body 1, which is heated by a suitable heating means 2, is formed a longitudinal groove 3, the bottom of which forms a contact heating surface 31. A fibre 4 is guided inside the groove 3, which is covered along the whole length of the heating body 1 by a detachable lid 5, the lid 5 being permanently placed during operation against a bearing surface 6 formed on the heating body 1, which is mounted in a housing 7 filled by thermal insulation material 8.

The lid 5 is formed in this embodiment by a thin metal tape, e.g. copper tape, which is mounted on pulleys 9,9' with its ends connected by a spring 10. The pulleys 9,9' are mounted pivotally on pivots mounted in the insulation housing 11 of lid 5.

The lid 5 in the form of a thin copper tape is maintained in tensioned condition by means of the pulleys 9,9' and spring 10. After heating up the heating body 1, the fibre 4 is inserted by a device (not shown) into the groove 3 and is started to be withdrawn by a device (not shown), thus being placed well against the heating surface 31. Thereupon, the operator places lid 5 by means of a suitable lever system including the appurtenant insulation housing 11 and further devices on to the curved bearing surface of heating body 1 and presses said lid 5 thereagainst so as to form a good thermal contact between lid 5 and said bearing surface 6. As lid 5 has a negligible mass and good heat conductivity, it is heated up to the temperature of the contact surface within a few seconds and begins to participate in the heat transfer into fibre 4.

In contact bodies hitherto known, a rather thick boundary layer is maintained within the surrounding of the fibre part to be heated up with a low thermal capacity and a low heat transfer into the fibre. In the present invention, in contrast, a metal surface is placed in the vicinity of the fibre, thereby conducting heat intensively heat to the adjacent fibre part.

In accordance with calculations performed, the overall intensity of heat transfer into the fibre in the device according to the present invention is higher by at least 30 per cent when compared with commonly used contact heating bodies.

A further advantage consists in the possibility of intensive withdrawal of vapours from a closed texturing space with substantially smaller volumes of air sucked off from the separate texturing units.

The device according to the present invention can be applied, without changing its principle of function, also for contacting-conductive cooling of man-made fibres upon their texturing by false twist, or in other similar thermal processes. The contact surface and the detachable lid are maintained, the thermal insulation being replaced by a device of dissipating heat either only from the contact surface or also from the lid.

Claims

1. Device for thermal treatment of man-made fibres by direct and substantially permanent contact of fibres with a contact heating surface, the device comprising a heating body in which is formed a longitudinal groove, the bottom of the groove forming a contact heating surface, and a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Device for Heat Treatment of Man-made Fibres The present invention relates to a device for heat treatment of man-made fibres by direct and substantially constant contact of the fibre with a contact heating surface. Heating of fibres very frequently forms part of textile technological processes for enhancing the serviceability of man-made fibres, which are hereinafter referred to simply as fibres. It is usually impossible, for various reasons, to curve the fibre path. Therefore, the heating bodies in modern high speed machines for processing fibres are very long, this being considerably disadvantageous from the viewpoint of both design and economy. Raising the heat-transfer coefficient to the fibre is one of the possible methods of reducing the length of said heating bodies. In the devices hitherto known, a very high heat-transfer coefficient is achieved with contact bodies, in which the fibre is heated by direct contact with a convex heated metal surface. However, at a higher curvature of said surface, the resulting fibre shows interior strength and, in the course of actual heating, fibre breakage is frequently encountered. In the case of slot heat treatment in a space between two plane surfaces, the fibre is not mechanically stressed and its strength is higher. The value of the heat-transfer coefficient might be even higher than with contact heating, if the fibre is oscillated in a certain manner during heating. The disadvantage of this heat treatment principle consists in the devices hitherto known in their higher intricacy as to design. The above disadvantages of the devices hitherto known are mitigated by the device according to the present invention, of which the subject matter consists in that a longitudinal groove is made in the heating body, the bottom of said groove forming a contact heating surface, a detachable metal lid being tightly placed thereto along the whole length of the groove. The present device had a higher heating effect, which makes it possible to raise the radius of curvature of the contact surface in the plane of the fibre axis, the mechanical stressing of the fibre by friction about the contact surface thus being reduced and the resulting fibre showing a higher strength. Further advantages and features of the present invention are specified in the following description of an embodiment, given by way of example, which is diagrammatically shown in the accompanying drawings, of which Fig. 1 -- represents a transverse section through the device; Fig. 2 - shows the lid and the contact body in dismantled condition. In the heating body 1, which is heated by a suitable heating means 2, is formed a longitudinal groove 3, the bottom of which forms a contact heating surface 31. A fibre 4 is guided inside the groove 3, which is covered along the whole length of the heating body 1 by a detachable lid 5, the lid 5 being permanently placed during operation against a bearing surface 6 formed on the heating body 1, which is mounted in a housing 7 filled by thermal insulation material 8. The lid 5 is formed in this embodiment by a thin metal tape, e.g. copper tape, which is mounted on pulleys 9,9' with its ends connected by a spring 10. The pulleys 9,9' are mounted pivotally on pivots mounted in the insulation housing 11 of lid 5. The lid 5 in the form of a thin copper tape is maintained in tensioned condition by means of the pulleys 9,9' and spring 10. After heating up the heating body 1, the fibre 4 is inserted by a device (not shown) into the groove 3 and is started to be withdrawn by a device (not shown), thus being placed well against the heating surface 31. Thereupon, the operator places lid 5 by means of a suitable lever system including the appurtenant insulation housing 11 and further devices on to the curved bearing surface of heating body 1 and presses said lid 5 thereagainst so as to form a good thermal contact between lid 5 and said bearing surface 6. As lid 5 has a negligible mass and good heat conductivity, it is heated up to the temperature of the contact surface within a few seconds and begins to participate in the heat transfer into fibre 4. In contact bodies hitherto known, a rather thick boundary layer is maintained within the surrounding of the fibre part to be heated up with a low thermal capacity and a low heat transfer into the fibre. In the present invention, in contrast, a metal surface is placed in the vicinity of the fibre, thereby conducting heat intensively heat to the adjacent fibre part. In accordance with calculations performed, the overall intensity of heat transfer into the fibre in the device according to the present invention is higher by at least 30 per cent when compared with commonly used contact heating bodies. A further advantage consists in the possibility of intensive withdrawal of vapours from a closed texturing space with substantially smaller volumes of air sucked off from the separate texturing units. The device according to the present invention can be applied, without changing its principle of function, also for contacting-conductive cooling of man-made fibres upon their texturing by false twist, or in other similar thermal processes. The contact surface and the detachable lid are maintained, the thermal insulation being replaced by a device of dissipating heat either only from the contact surface or also from the lid. Claims

1. Device for thermal treatment of man-made fibres by direct and substantially permanent contact of fibres with a contact heating surface, the device comprising a heating body in which is formed a longitudinal groove, the bottom of the groove forming a contact heating surface, and a detachable metal lid which in use is tightly placed against the heating body along the whole length of groove.

2. Device as claimed in claim 1, in which the detachable metal lid is formed of a thin tape tensioned by axial tension.

3. Device as claimed in claim 1 or claim 2, characterised in that openings connected to a channel for exhausting products of heating are arranged along the lid.

4. A device for thermal treatment of man-made fibres substantially as herein described with reference to the drawings.