JPH04308240A - Device for thermally treating moving yarn - Google Patents

Abstract

PURPOSE: To provide the subject device designed to furnish a heating unit placed in a thermal insulation material with a specific groove through which a yarn is to be passed so as to effect uniform heat treatment of the yarn. CONSTITUTION: This device has such a scheme that a heating unit 1 is placed in a thermal insulation material 13 and, in the longitudinal direction of the heating unit 1, a groove 2 is furnished through which a yarn 5 is to be passed, and provided with a zone A where the yarn is subjected to temperature rise by radiation while moving inside the wall of the heating unit 1 and apart from the wall and a zone B where the yarn is heated by thermal transfer on its contact with the wall of the heating unit. By the way, a yarn is guided into the groove 2 through guide members 3, 4.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION The present invention relates to an improvement in a device for the heat treatment of moving yarns, in particular for the purpose of imparting shrinkage and/or capacity increase and/or elasticity properties to them. It is related to heat treatment.

0002

BACKGROUND OF THE INVENTION In the following part of the specification, the usual expression "oven" refers to the production of both continuous filaments, monofilament or multifilamentary, and fibers of spun yarn. Used for equipment designed to be able to be used for processing. In all methods for the treatment of moving yarns where heat treatment is required, the main problems asserted are rapid heat transfer, heat for uniform penetration into the core and heat over the entire length of the yarn as well. It is a question of penetration. In fact, as is well known, the processing temperature and its uniformity have a very large influence on the properties of the yarn.

It is well known that heat treatments vary depending on the material being treated, the yarn count and the speed of the yarn passing through the oven. Therefore, it can be easily understood that finer yarns achieve faster results than higher count yarns. Similarly, the yarn cannot be processed at temperatures above a certain temperature limit without degrading its grade. Consequently, this problem of heat exchange is a very important problem in the textile technology field, so that a large number of solutions have been devised to solve it. These solutions use three major principles of heat exchange: convection, radiation and conduction.

[0004] In addition to this problem of good heat transfer, there is the problem of supporting the yarn under special tension due to the processing carried out. Thus, for example, in the case of the illustrated operation, which is possible in conjunction with the interweaving operation, the yarn is held under maximum tension, since the tension necessarily decreases when, on the other hand, it is required to perform a contraction of the yarn. There is a need to. Finally, the problem arose of increasing the production speed of weaving machines, which increased from 20 or 30 meters per minute 30 years ago to 1000 meters per minute today.

Among the solutions proposed to provide very high uniformity in heat exchange and to facilitate the problem of temperature limitation from location to location on the machine, so that the entire production line is uniform. There has long been research into performing heat treatments that can be applied as a "sequential" by ovens built over the length of several separate heat treatment zones that follow one another. Among these solutions, French patents 1,20
The problem is described in the specification of No. 4,634,
Therein, in the same oven, two consecutive processes are carried out. In one of them, the yarn is processed where the yarn is transported at a temperature significantly higher than that of the normal temperature. And this is done for a sustained period of time so that the thread is not damaged. After this initial stage, stable processing occurs at normal temperatures. Such a solution requires equipment of complex design, the effect of which is to allow a considerably reduced oven length for a given running speed. However, it is difficult to put into operation. A similar solution is also described in French Patent No. 1,216,847 and Certificate of Addition 76,861.

[0006] For other types of heat treatment, different heat exchange sequences are required. For example, slowly increasing the temperature of the yarn, uniformity achieved by a larger thermal shock, or a combination of different such measures. These have now been discovered and it is this that forms the object of the present invention. This is a new type of oven with a particularly simple design, which solves all of these problems.

[0007]

[Means for solving the problem] In the normal method,
A new type of oven according to the invention for heat treatment of yarns,
For example, texturizing
ing) and during stretching operations are of the type constituted by inclusions of thermal insulation. The insulation surrounds the heating unit, which has an inner longitudinal groove through which the yarn is treated. The thread guiding means are located at the top and bottom of the oven, in order to ensure the alignment of the thread. And the groove has, over its length,
It has a cross section such that the thread moves inside the wall and away from the wall. In this area an increase in temperature is given by radiation, and in other parts of the oven it comes into contact with the walls. The heat is transferred by contact (or conduction). According to an embodiment of the invention, the actual heating element has the shape of a cylindrical block;
It is penetrated along its length by a groove. This groove is also cylindrical. A region for heating by contact is provided by being arranged inside the groove, that part having good conduction of heat. The portion is supported opposite the inner surface of the groove and has a thread-supporting surface. This surface is arranged substantially along the axis of the groove.

According to an embodiment of the invention, the heating unit is constructed of ceramic (or other similar material) and the resistive element is embedded in the wall. The part that serves as the support surface is constructed of a material that has good thermal conductivity for that part. This material may include, for example, stainless steel, ceramic or other materials. The effect of such a design is that it is possible to construct a region for separating heating by radiation and conduction, a region that can be connected in any way by a simple arrangement of parts that serve as central inner supporting surfaces. It is possible. The oven is thus constructed with an inlet area for heating by radiation and a subsequent area for heating by conduction (contact). Or, conversely, it can be thought of as having inner and outer regions for heating by radiation and a central region for heating by conduction.

Furthermore, such ovens are either completely closed or have long slits (so-called "open" ovens). Other embodiments are also contemplated. For example, the oven may be constructed from a single unit with two different regions formed by two cylindrical grooves with different diameters. The two regions are arranged within each other's extensions, and the thread is in contact with the surface of the groove of smaller diameter and is held away from the surface of the other groove of larger diameter. There is. This allows for the two types of heating provided by the present invention: radiation and contact (or conduction). Also, a method has been considered in which one basic unit is placed next to the other. Each unit allows one type of heating.

[0010] The dimensions of such an oven and the range of temperatures that it can provide are adapted depending on the operation of the process to be carried out. As indicated, fals
e-twisting) for the loom, the length is 0.3
between 0 and 1,50 meters and the temperature is 30
It is between 0°C and 1000°C. Preferably, the length of contact heating is between 25 and 75% of the total length of the oven. Furthermore, in the area of contact, the path of the thread can be either straight or curved, depending on the geometry of the process.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS The invention and its advantages will be further understood by reference to the examples and drawings described below. However, these examples and the accompanying drawings are not intended to limit the invention. In FIGS. 1 and 2, which illustrate the invention, only the actual heating elements of the oven of the invention are depicted. The insulation inclusions, heating and control elements commonly found in ovens are used and will not be described here for clarity. According to the figures shown, such means are described in the closest prior art French patent no. 1,515
, No. 673.

According to FIGS. 1 and 2, the heating member of the oven of the present invention is composed of a heat insulating member 13 shown by a dashed line in FIG. 1, and a unit 1 made of ceramic. This unit 1 is pierced over its entire length by a groove 2 of circular cross-section, which is either completely closed or has longitudinal slits as shown in FIG. . Thread 5
Guide members 3, 4 for are arranged at the top and bottom of the unit. The heating member is heated by a normal method.
It is located inside the wall of unit 1. These heating elements either conduct a uniform temperature over the entire length of the oven or have areas of different temperatures.

According to the invention, the inner cross-sectional part 2 of the axial groove forms an area A in which the thread 5 is kept away from the inner wall 6 of the groove 2.
and a region B where the thread 5 is heated by contact. The area B heated by contact is provided by introducing a part 7 formed inside the groove 2, as shown in the described embodiment. Such a section 7 is made, for example, of stainless steel (or other equivalent material such as ceramic) and has a cross-section such that it is uniformly supported against the inner wall of the conduit 6; It has a surface 8 arranged substantially along the running axis of the thread 5. This support surface 8 can be either straight or curved. It is preferred that the lower surface 8 with which the thread 5 contacts is both planar and curved (the cross-section of the formed member has the substantial shape of a "bean"). Good positioning of the thread during its movement, especially when performed at fairly high speeds.

[0014] Such an oven design is particularly used for the construction of compact machines for weaving, especially for teasing machines as shown in FIG. In such a machine, the oven of the invention, designated by F, more commonly referred to, is arranged between a cooling area, after which a false twisting spindle 12 is arranged, and a delivery device 10 for the yarn 5. has been done. In such a case, oven F is designed in the manner described in FIGS. 1 and 2. It is heated in its exit region B by conduction, while at the same time in region (A) the thread is heated by radiation. In region A, there is no contact with the wall and the temperature rises rapidly, in region B, allowing enhanced heat exchange,
It also provides guidance and positioning of the thread in the area of the oven for heating by radiation, which makes it possible to shorten the length of the oven given. The oven F as shown has a length between 0.3 and 1.5 meters, a temperature between 300°C and 1000°C, and the diameter of the internal conduit 2 is 12 mm. .

The present invention is not limited to the preferred embodiments described herein, but also includes various modifications within the same spirit of the invention. Therefore, in the description of the invention, although it is described for the treatment of a single yarn, it is also possible to envisage an oven configuration that makes it possible to process two yarns at the same time. be.

[0016]

Effects of the Invention The present invention provides a heating unit surrounded by a heat insulating material, a groove formed in the longitudinal direction of the heating unit in which the yarn is treated by passing through it, and a groove provided at the upper and lower sides of the oven. an apparatus for heat treating a moving yarn of the type comprising means for guiding the temperature of the yarn through the length of which the yarn moves inside the wall and away from the wall to increase the temperature imparted by the radiation; area to increase;
Since it is a device for heat treatment of a moving yarn, which has a remaining area in contact with the wall and where heat exchange is performed by contact (conduction), it has the effect that the yarn can be uniformly heat treated.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the structure of an oven according to the present invention.

FIG. 2 is a longitudinal sectional view showing the structure of an oven according to the present invention.

FIG. 3 is a front view showing the operating arrangement of a false twisting machine equipped with an oven according to the invention;

[Explanation of symbols]

1 Unit 2 Groove 3, 4 Guide member 5 Thread 6 Inner wall 13　　　　　　　　　　　　　Insulating material

Claims (7)

[Claims] 1. A heating unit (1) surrounded by a heat insulating material, a groove (2) formed in the longitudinal direction of the unit and in which the yarn (5) is passed through and treated inside, and a groove (2) at the top and bottom of the oven. and means (3, 4) for guiding said thread (5), wherein said groove (2) is provided throughout the length of the thread (5). a region (A) in which the particles move inside and away from the wall, increasing the temperature given by radiation; and a remaining region (B) in contact with said wall, where heat exchange is carried out by contact (conduction). An apparatus for heat treatment of moving yarn, characterized in that it has. 2. The heating unit (1) is cylindrical in shape and is pierced through its length by a cylindrical groove (2), said area (B) for heating by contact being made of a thermally conductive material. provided by placing a good part (7) inside said groove, which part is supported opposite the inner surface of the groove 2 and has a support surface (8) for the thread (5); 2. Device for heat treatment of moving yarns according to claim 1, characterized in that this surface is arranged along the axis of the groove. 3. The heating block (1) is made of ceramic, the resistance element being embedded in the wall, and the part (7) serving as the support surface being made of stainless steel or, for example, ceramic. 2. Device for heat treatment of moving yarns according to claim 1, characterized in that it is made of a comparable material such as. 4. Device for heat treatment of moving threads according to claim 1, characterized in that the unit (1) is completely closed. 5. Device for heat treatment of moving yarns according to claim 1, characterized in that the unit (1) has a slit in the longitudinal direction. 6. The heating unit (1) consists of a unit with two grooves of different diameters, each of which is arranged in the other extension, and the thread is arranged on the surface of the groove of smaller diameter. 2. The moving thread according to claim 1, characterized in that it is in contact with the surface of the groove and is kept at a distance from the surface of the other grooves of large diameter, making it possible to carry out two types of heating: radiation and contact (or conduction). Equipment for heat treatment of. 7. Device for heat treatment of moving yarns according to claim 1, characterized in that the heating unit (1) is composed of juxtaposed units making it possible to carry out two different types of heating. Device.