GB1578327A - Heating or cooling extruded materials - Google Patents

Description

(54) HEATING OR COOLING EXTRUDED MATERIALS (71) We, STANDARD TELEPHONES AND CABLES LIMITED, a British Company, of 190 Strand, London, W.C.2R lDU, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to arrangements for heating or cooling extruded materials and in particular to heating or cooling arrangements which do not impart a tensile stress on the extrudate.

Interstage and final cooling of hot wire and plastics coatings deposited thereon is necessary in order to condition the product for subsequent operations and to facilitate reeling and packaging. Similarly heat treatment of freshly drawn wire is often necessary to anneal the wire prior to subsequent coating with plastics material.

Most heater or cooler systems at present in use impart unwanted tensile loads to the workpiece due to the viscous and inertial drag of the heat transfer fluid as it is accelerated from rest to a velocity ap proaching that of the extrudate. The techniques employed to minimise this problem are generally inefficient and employ long heating or cooling troughs which must be threaded prior to extrusion or amount of factory floor space.

The object of the invention is to minimise or to overcome these disadvantages.

According to the invention there is provided an arrangement for heating or cooling a wire or wire product as hereinafter defined, the arrangement including a tubular body having one or more branch tubes for the injection of a heat transfer fluid, a jet secured in the tube adjacent one end, said jet having an axial bore for receiving the wire or wire product, a hollow conical throat leading to the bore, and a raised annular exit nozzle at the exit of the bore, a tubular valve member slidably mounted in the bore of the tubular body, the valve having an axial bore for receiving the wire or wire product, a cylindrical body portion of smaller diameter than the bore of the tubular body, a conical nose portion at one end extending into the throat of the jet, and an enlarged diameter portion at its other end, the enlarged diameter portion being a freely sliding fit in the bore of the tubular body, abutment means for limiting movement of the valve, and guide means for centering the wire or wire product in the axial bores of the valve and the jet, wherein the one or more branch tubes are disposed so as to inject the fluid into the bore of the tubular body and on to the cylindrical body of the valve adjacent the enlarged diameter portion of the valve, and wherein the valve and the jet throat are so arranged that the heat transfer fluid is directed through the jet bore parallel to the axis of the wire or wire product.

The term "wire or wire product" as employed herein is understood to include a glass or silica fibre.

The arrangement may be employed for cooling plastics coated wires following melt extrusion coating, or for heating and/or cooling uncoated metal wires following drawing down. In a further application the arrangement may be used for cooling annealed uncoated wires produced for example by the processes described in our published specifications Nos. 1,406,317 and 1,466,373. The arrangement is of particular advantage on a tandem wire drawing/extrusion coating line in which it is generally necessary to anneal the drawn wire prior to coating with extruded plastics material.

An embodiment of the invention will now be described with reference to the drawing accompanying the Provisional Specification in which the single figure shows a cross-section of an arrangement for heating or cooling an extruded or drawn wire or wire product.

Referring to the drawing, the arrangement includes a substantially tubular housing 11 which is mounted adjacent the extruder head or wire drawing die (not shown) or at some other point along the extrusion or drawing system line. The housing 11 supports along its central bore 12 a coaxial arrangement comprising a jet 13, a float valve or piston member 14 and a gland screw 15 provided with a ceramic wire guide 16. The jet 13, the valve 14 and the screw 15 each have an axial bore, 17, 18 and 19 respectively, adapted to receive an extruded wire or wire product 20, there being a small clearance between the wire 20 and the surface of each bore.

The jet 13 has a conical throat 21 leading to the axial bore 17 and has an exit nozzle formed by an annular raised portion 22.

The jet 13 is secured in the body 11 either as a press fit or as shown in the drawing, by a snap ring 27 located in a circumferential groove 28, in the bore 12 of the housing. The valve 14 has a conical nose portion 24 which enters the throat 21 of the jet 13 so as to direct the heat transfer fluid, e.g. water or a gas injected via the pipe 25 parallel to the axis of the wire 20.

The valve 14 is free to slide within the housing 11 and is provided with a fluid tight O-ring seal 26. In operation the pressure of the fluid directed into the housing pushes the valve 14 into abutment with the gland screw 15 as shown in the drawing.

In use the arrangement is mounted adjacent the head of an extruder or the die of a wire drawing machine or at some other point along the line at which the wire heating or cooling is required. The wire 20 is threaded through the ceramic guide 16 and through the gland screw 15, the valve 14 and the jet 13. The wire 20 is drawn in the direction of the arrow A and heat transfer fluid, e.g. water, at a controlled temperature, is fed to the wire via the tube 25. By controlling the fluid pressure at the tube 25 and by adjusting the gland screw 15 so as to control the gap between the valve cone 24 and the jet throat 21, the fluid velocity through the bore 17 of the jet 13 may be adjusted to match the velocity of the wire 20. If, as is usually the case, the heat transfer fluid is water, the annular raised portion 22 of the jet 13 may advantageously be profiled so as to direct the water stream in contact with the wire after it leaves the jet. In this way maximum heat transfer is obtained.

In some applications the surfaces of the valve cone 24 and the jet throat 21 may be provided with grooves and/or ridges to direct the fluid along the wire 20.

In further applications two devices may be used for annealing and cooling uncoated wires. The devices are arranged in tandem, the first employing a hot gas to anneal the wire and the second employing water for cooling.

A similar arrangement may be employed for heating or cooling extruded materials having a non-circular cross-section, the bores 17, 18 and 19 being shaped accordingly. In other applications the entire arrangement may be split longitudinally to permit fitting to an extrusion line when extrusion is in progress. Means are provided to secure the various portions of the apparatus together.

The arrangement is adapted to the annealing of a drawn wire by the use of a suitable heat transfer fluid such as superheated steam.

In another application the arrangement may be used for cooling and annealing a plastics coating applied to a glass fibre by an extrusion process.

WHAT WE CLAIM IS: 1. An arrangement for heating or cooling a wire or wire product as hereinbefore defined, the arrangement including a tubular body having one or more branch tubes for the injection of a heat transfer fluid, a jet secured in the tube adjacent one end, said jet having an axial bore for receiving the wire or wire product, a hollow conical throat leading to the bore, and a raised annular exit nozzle at the exit of the bore, a tubular valve member slidably mounted in the bore of the tubular body, the valve having an axial bore for receiving the wire or wire product, a cylindrical body portion of smaller diameter than the bore of the tubular body, a conical nose portion at one end extending into the throat of the jet, and an enlarged diameter portion at its other end, the enlarged diameter portion being a freely sliding fit in the bore of the tubular body, abutment means for limiting movement of the valve, and guide means for centering the wire or wire product in the axial bores of the valve and the jet, wherein the one or more branch tubes are disposed so as to inject the fluid into the bore of the tubular body and on to the cylindrical body of the valve adjacent the enlarged diameter portion of the valve, and wherein the valve and the jet throat are so arranged that the heat transfer fluid is directed through the jet bore parallel to the axis of the wire or wire product.

2. An arrangement for heating or cooling a wire or wire product substantially as described herein with reference to the drawing accompanying the Provisional Specification.

3. A tandem wire drawing/extrusion

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

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. Referring to the drawing, the arrangement includes a substantially tubular housing 11 which is mounted adjacent the extruder head or wire drawing die (not shown) or at some other point along the extrusion or drawing system line. The housing 11 supports along its central bore 12 a coaxial arrangement comprising a jet 13, a float valve or piston member 14 and a gland screw 15 provided with a ceramic wire guide 16. The jet 13, the valve 14 and the screw 15 each have an axial bore, 17, 18 and 19 respectively, adapted to receive an extruded wire or wire product 20, there being a small clearance between the wire 20 and the surface of each bore. The jet 13 has a conical throat 21 leading to the axial bore 17 and has an exit nozzle formed by an annular raised portion 22. The jet 13 is secured in the body 11 either as a press fit or as shown in the drawing, by a snap ring 27 located in a circumferential groove 28, in the bore 12 of the housing. The valve 14 has a conical nose portion 24 which enters the throat 21 of the jet 13 so as to direct the heat transfer fluid, e.g. water or a gas injected via the pipe 25 parallel to the axis of the wire 20. The valve 14 is free to slide within the housing 11 and is provided with a fluid tight O-ring seal 26. In operation the pressure of the fluid directed into the housing pushes the valve 14 into abutment with the gland screw 15 as shown in the drawing. In use the arrangement is mounted adjacent the head of an extruder or the die of a wire drawing machine or at some other point along the line at which the wire heating or cooling is required. The wire 20 is threaded through the ceramic guide 16 and through the gland screw 15, the valve 14 and the jet 13. The wire 20 is drawn in the direction of the arrow A and heat transfer fluid, e.g. water, at a controlled temperature, is fed to the wire via the tube 25. By controlling the fluid pressure at the tube 25 and by adjusting the gland screw 15 so as to control the gap between the valve cone 24 and the jet throat 21, the fluid velocity through the bore 17 of the jet 13 may be adjusted to match the velocity of the wire 20. If, as is usually the case, the heat transfer fluid is water, the annular raised portion 22 of the jet 13 may advantageously be profiled so as to direct the water stream in contact with the wire after it leaves the jet. In this way maximum heat transfer is obtained. In some applications the surfaces of the valve cone 24 and the jet throat 21 may be provided with grooves and/or ridges to direct the fluid along the wire 20. In further applications two devices may be used for annealing and cooling uncoated wires. The devices are arranged in tandem, the first employing a hot gas to anneal the wire and the second employing water for cooling. A similar arrangement may be employed for heating or cooling extruded materials having a non-circular cross-section, the bores 17, 18 and 19 being shaped accordingly. In other applications the entire arrangement may be split longitudinally to permit fitting to an extrusion line when extrusion is in progress. Means are provided to secure the various portions of the apparatus together. The arrangement is adapted to the annealing of a drawn wire by the use of a suitable heat transfer fluid such as superheated steam. In another application the arrangement may be used for cooling and annealing a plastics coating applied to a glass fibre by an extrusion process. WHAT WE CLAIM IS:

1. An arrangement for heating or cooling a wire or wire product as hereinbefore defined, the arrangement including a tubular body having one or more branch tubes for the injection of a heat transfer fluid, a jet secured in the tube adjacent one end, said jet having an axial bore for receiving the wire or wire product, a hollow conical throat leading to the bore, and a raised annular exit nozzle at the exit of the bore, a tubular valve member slidably mounted in the bore of the tubular body, the valve having an axial bore for receiving the wire or wire product, a cylindrical body portion of smaller diameter than the bore of the tubular body, a conical nose portion at one end extending into the throat of the jet, and an enlarged diameter portion at its other end, the enlarged diameter portion being a freely sliding fit in the bore of the tubular body, abutment means for limiting movement of the valve, and guide means for centering the wire or wire product in the axial bores of the valve and the jet, wherein the one or more branch tubes are disposed so as to inject the fluid into the bore of the tubular body and on to the cylindrical body of the valve adjacent the enlarged diameter portion of the valve, and wherein the valve and the jet throat are so arranged that the heat transfer fluid is directed through the jet bore parallel to the axis of the wire or wire product.

2. An arrangement for heating or cooling a wire or wire product substantially as described herein with reference to the drawing accompanying the Provisional Specification.

3. A tandem wire drawing/extrusion

coating system when fitted with one or more heating or cooling arrangements as claimed in Claims 1 or 2.