WIRE DRAWING
Objective

To know how copper and aluminum drawing is done, and also to understand the machine setting and how the machine operates.

Introduction

Wire drawing is the process by which a metal rod is forced through a series of varying cross section die(s) and hence the metal rod cross sectional area is varied so as to obtain the desired shape and size. In Kenwest cables company their are 3 wire drawing machines namely:- 1. M55 2. H20 3. M85
1.M55
This is the main copper drawing machine and the one which can handle the 1st drawing process which is hard drawing. The raw material used is usually copper rod of 7.9mm thickness as the hard drawing material. The M55 can also handle further copper drawing like the H20.

Operation procedure

The M55 has several units namely:- a) stand b) block c) drawing basin d) annealer e) spooler

a) stand
It is responsible in guiding the copper rod being fed to the block or drawing basin. If its hard drawing its fed to the block but when its further drawing its directly fed into the drawing basin. This is because at the block section the die obtained may have a larger diameter than the copper rod in the case of further drawing hence the block is not required.

b) Block
It is functional when hard drawing takes place. The 1st die is usually located in this section (the block section) hence drawing process begins at the block section. The copper rod being fed is usually about 7.9mm in diameter which is the diameter of the hard drawing copper. Animal fat is used in this section which acts as a lubricant to ease the process of the copper rod passing through the die. Jam oil cannot be used in this section because the block section does not have a system that supplies jam oil and recycle the jam oil for effective and efficient use.A thing to note is that the dies are made of a strong material called tungsten carbide hence are not easily worn out.This is because they experience a lot of frictional forces from the copper wire being forced through it.

c) Drawing basin
This is where the main drawing process is done. It contains several number of dies 7 to be exact. These dies are arranged in such a way that their cross sectional area reduces from one successive die to the next. This organized arrangement aids in the ease of cross sectional area reduction and to avoid breaking of the wire as it is being drawn. In the drawing process not only is the wire reduced in diameter but also its elongated in the process. Pulleys are found in this section and they are mainly used to provide space for elongation and the movement of the wire during the drawing process. The pulleys also aid in the alignment of the wire as its being drawn. Jam oil is used in the drawing basin and its used as a coolant and a lubricant. Jam oil has a high boiling point temperature making it a good coolant and its slimy nature makes it a good lubricant. If the machine runs for a very long time eventually the coolant will become hot thereby the heat exchanger is used to cool the jam oil through a counter flow process where cold water and jam oil are passed in opposite directions in 2 parallel adjacent pipes one carrying jam oil the other carrying cold water thereby reducing jam oil temperature.
The motor is responsible for the movement of the pulleys in the drawing basin to move. The rotary motion of the motor is transferred to a shaft using belts. Subsequently the shaft is connected to a gear box which contains gears which in turn is connected to a set of pulleys. The gears are used to vary the speed of the pulleys.

d) Annealer
Annealing is the process by which a conductor is made more ductile and its conductivity is increased by passing it through an anode and a cathode. The type of electric current used is the DC (Direct current).The AC (Alternating Current) produced is converted by the transformer to DC which is required and its transferred to the annealer through bus bars, to the anode and cathode. This section contains pulleys that aid in the movement of the copper rod. The steam generated from the boiler is transferred to the annealer. Its work is to prevent copper from being oxidized to form copper (ll) oxide which is black in colour.
At this annealer section a compressor is used in that it is responsible for supplying dry compressed air to the wire which in turn causes the wire to dry up.

Immediately after the annealer section their is another system of pulleys whereby the lower pulley has the freedom to move up and down or rather in a vertical motion, depending on the tension of the copper wire on the pulleys. The lower movable pulley is known as the dancer pulley. The dancer pulley aids in regulating the tension on the copper wire and preventing it from snapping. When the tension on the copper wire is high the dancer pulley moves up and when the tension on the copper wire is low the dancer moves down. e) spooler
This is where the take up stand is mounted and its mounted using a hydraulic mechanism. There is a traverse which is used to arrange the wire winded on the spool in an evenly distribute d manner. The control panel is located at the spooler section. The hydraulic pump present is responsible for the spool rotation and traverse movement. The traverse also has a limiting switch which basically limits the scope of its movement as it moves horizontally. This aids in better distribution of the copper windings on the spool.

2. H20
The H20 machine is similar to the M55 machine in that they are both used for drawing copper wires and have the same features. However the H20 machine is used for further drawing and cannot do hard drawing. The H20 machine also produces flex wires which are very small in diameter but the M55 cannot produce such small diametered copper wires. The H20 machine doesn't have the block section as compared to the M55 machine. The H20 machine had 21 dies.

Operation procedure

The H20 has several units namely:- a) stand b) drawing basin c) annealer d) spooler

a) Stand
This is where the pay off spool is fixed.

b) Drawing basin
This is where the drawing of the wire takes place and its a very important process. This section contains 21 dies and it also has pulleys which aid in the movement of the copper wire. Jam oil is usually filled in this basin which acts as a lubricant and as a coolant.

c) Annealer
Annealing is the process by which a conductor is made more ductile and also increases its conductivity.
The steam generated is usually used to prevent the copper wire from being oxidised to form copper (ll) oxide which is black in colour. The compressed air is used to dry the copper wire.There is also a system of pulleys in this section which aid in the movement of the copper wire. It also has a dancer pulley that is used to control the tension of the wire so as to prevent snapping of the wire.

d) spooler
This where the take up stand is mounted . There is a traverse which is used to arrange the wire winded on the spool in an evenly distributed manner. The control panel is located at this section. 3. M85
This is a drawing machine which is used in the drawing process of aluminium rods. It is used for hard and further drawing processes. Oil is used instead of jam oil in this drawing machine.

Operation procedure

The M85 has several units namely:- a) stand b) block c) drawing basin d) spooler e)Furnace

a) stand
This is where the pay off spool is fixed.

b)block
It is used in directing the aluminium wire to the drawing basin and it also contains a die............ ¥(check for more info) ¥

c) Drawing basin
This is where the drawing of the wire takes place and its a very important process. This section contains ....... dies and it also has pulleys which aid in the movement of the aluminium wire. Oil is usually filled in this basin which acts as a lubricant and as a coolant.

d)spooler
This is where the take up stand is mounted. There is a traverse which is used to arrange the wire winded on the spool in an evenly distributed manner. The hydraulic pump present is responsible for the spool rotation and traverse movement. The traverse also has a limiting switch which basically limits the scope of its movement as it moves horizontally. This aids in better distribution of the aluminium windings on the spool.

e) Furnace
This is where the aluminium wire is heated in a furnace at very high temperatures so as to increase its ductility and conductivity. This process is usually optional depending on whether the customer wants a ductile or hard aluminium.

Conclusion
1. M55 machine produces copper wires having diameters :- 1.38mm, 0.67mm, 0.85mm, 1.04mm, 1.35mm, 1.70mm, 2.14mm, 1.53mm, 1.78mm, 2.14mm and 2.52mm

2.H20 machine produces copper wires having very small diameters which makes the flexible hence their name flex wires.The sizes produced are :- 0.20mm, 0.25mm, 0.30mm, and 0.40mm.

3.M85 machine produces aluminum wires having the diameters:-

BUNCHER
Objective

To know and understand the machine setting and how the machine operation takes place.

Introduction

Bunching is the process of twisting several wires together through a die. In Kenwest cables company their are 2 buncher machines namely:- 1.Buncher 800 2.Buncher 1000

1.Buncher 800
It is more technologically advanced as compared to the buncher 1000. It has a high bunching speed as compared to the buncher 1000. The brakes are pneumatically operated. Every motor has its limit switch and a pressure regulator which is usually set to 2 bars. The pressure regulator aids in changing or varying the tension of the wire. It has 8 bar stands and a maximum of 7 are used hence their is an extra bar stand incase any others fails.

2.Buncher 1000
Its slower in speed as compared to the buncher 800. It has 8 bar stands which are for singles and 60 stands which are for flexible wires which have very small cross section.

Operation procedure This is the operational procedure of a buncher machine (buncher 800 and buncher 1000). Once the raw materials are received the set up of the machine is done and it includes the steps below:- 1. To determine the appropriate die(s). 2. Loading the conductors on the stands (pay off spool) 3. Changing the gears so as to attain the appropriate lay ie the magnitude of twist. 4. Load an empty take up spool. 5. Initiate the arrangement of the wires from pay off spool to the take up spool in a logical sequence. 6. Ensure everything else is in order. 7. Start the machine and monitor the entire process incase of any malfunctions.

Analysis

Selection of the die is governed by the cross sectional area of the twisted wires. The die cross sectional area should be slightly higher than the twisted wires cross sectional area.
For example
How to determine the cross sectional area of the twisted wire given the diameter of one wire where 7 similar wired are twisted together.

Draw diagram

As illustrated the diameter of the whole twisted wire will be given by 3 × diameter of one wire.

Diameter of twisted wired= 3×diameter of one wire

Conclusion

Buncher 800 produces copper wires with the dimensions given below:-

Total area of bunch wires | Area of single wire | Number of wires | 2.5mm2 | 0.67mm2 | 7 | 4.0mm2 | 0.85mm2 | 7 |

Buncher 1000 produces copper wires with the dimensions given below:-

Flexible cables Total area of bunch wires | Area of single wire | Number of wires | 0.5mm2 | 0.20mm2 | 16 | 0.75mm2 | 0.20mm2 | 24 | 1.0mm2 | 0.20mm2 | 32 | 1.5mm2 | 0.25mm2 | 30 | 2.5mm2 | 0.25mm2 | 50 |

EXTRUDER

Objective

To know and understand the machine setting and how the machine operation takes place.

Introduction

Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section.
Hot extrusion is a hot working process, which means it is done above the material's recrystallization temperature to keep the material from work hardening and to make it easier to push the material through the die. Most hot extrusions are done on horizontal hydraulic press.
In Kenwest cables company their are 3 extruder machines namely:- 1.BM80 2.BM30 3.Mapre
1.BM80
The screw and barrel method is employed as the method of movement of the polymer.
2.BM30
It uses gravity as the method of movement of the polymer to the crosshead. It is mainly used when making the green yellow insulation coating.
3.Mapre
It is the most advanced machine for extrusion at Kenwest cables. Its processes are all controlled for a control panel where by if one operation is not functioning or is not properly set the whole operation will not take place.

Operation procedure

The extrusion process begins with bear wire or cable being fed into the extruder. The insulation or polymer substance is fed into the hopper and in solid form it is then heated as it is pushed to the crosshead by way of screw and barrel as the screw turns it pushes the material to the crosshead. The crosshead holds a die which controls the shape and size of the wire or cable. By the time the polymer enters the crosshead it is in its liquid state. An embosser may be used if necessary at this stage. The embosser is to make engraved markings on the insulated cable mostly the are alphanumerical. The insulated material then goes into a chilled bath of water to cool and help retain its shape and size.Once the cable is cooled it is then dried and passed through a caterpillar or capstan which aids in the movement of the wire.The caterpillar helps in moving very thick and heavy cables while capstan is used to assist in the movement of thin and light cables. Then the wire is tested for defects with a spark tester. Then it is passed to a diameter control to check the consistency of the diameter of the insulated wire.
The wire is then passed to a printer where printed text or information is written on the insulated wire. The wire is then passed through a pulley system whereby a dancer pulley is one of the pulleys. Its work is to reduces tension in the wire as its being fed to the drum or spool. A traverse is used to direct the wire in an organised manner onto the pay off spool.
Note: In a case where double insulation is required chalk dust is used as it helps to prevent the two insulation coats to merge hence forming one single coat.

ARMOURING

Objective

To know and understand the machine setting, how the machine operation takes place and the properties of GI and working with galvanized steel wire.

Introduction

This is the process by which a cable is insulated using steel that is twisted on the insulated PVC coating of a wire cable. Their are 4 types of steel wire sizes namely:- 0.9mm, 1.25mm, 1.6mm, 2.0mm.

Operation procedure

The armouring process initiates from when a wire cable is wound on a drum and its fed into the machine where it is passed through a die. The wire originating from the pay off spool is armoured with steel before it passes through the die. The die however is used to ensure that the steel is held firmly and is directed on the cable. The armoured cable is then passed through some pulleys that are used to ensure proper or effective contact with the sensor pulley. The sensor counts the number of revolutions made and also the distance covered by the cable.
Their is a capstan where the armoured cable is wound on before its fed to the drum. It has fixed traverse which guides its alignment as its fed to the take up spool or drum. The twist alignment obtained from the armouring process is brought about by the rotation of the steel wires on the cable in either a clockwise or anticlockwise direction and this changes the twist alignment. The switching of the rotation is caused by the bevel gears present. The switching from one gear to the other causes a change in the direction of rotation hence causing a subsequent change in the twist alignment. The presence of the spur gears that can be changed are responsible for the spacing of the steel wires armoured on the cable.
Their is also a speed regulator which regulates the speed. Its working principle is that when the plate electrodes are immersed into the water and the gap between plate electrodes and the base conductor is decreased then the speed increases in that the conductivity increases as the gap is decreased. When the plate electrode gap is increased the speed decreases because the conductivity reduces to the extent that when the plate electrodes are removed from the water the machine speed will gradually decrease in speed until it comes to a halt.
The machine is driven by one big motor where by shafts,pulleys,belts and gears are used to change direction of motion and aid in the motion of the moving parts. It has a small motor that is connected to a chain and its responsible for moving the take up spool in a vertical manner.

Analysis

The die size is determined by finding the summation of the initial cable diameter before armouring and the twice the diameter of the steel wire used in the amouring process.

¥(Draw illustration if possible and the GI properties)¥

Conclusion

The importance of armouring is to prevent mechanical or physical damage of the wire cables because they are mainly used in underground or buried in the ground. Due to this they are exposed to damages.

LAYING AND TWISTING

Objective

To know and understand the machine setting and how the machine operation takes place.

Introduction

This is the process by which two or more wires are intertwined together and are also formed into certain shapes if need be.

Operation procedure

The wires or cables to be twisted are fixed on their appropriate spool location in accordance to their cable insulation color. Then the wires are twisted together.
The twisted cables are then passed through a die which enables the effective twist on the cables this is to align the wires that are twisted. Then it is passed through a shaper where it is shaped to its required shape. Then it is passed through the sensor which counts the number of revolutions and subsequently the distance covered by the moving cable and its indicated in a meter reading.
The cable is then covered with plastic paper which is twisted in the opposite direction of the wire cables so as to prevent unnecessary unwrapping. The importance of the wrapping is to prevent mixing of the already coated cables when they are undergoing another coating in the extruder. (This process of wrapping with plastic paper is optional depending on whether the wire cables are coated or not ).
The cable is then wound on a capstan which has a traverse that's fixed. The traverse ensures effective alignment of the distribution of the cable to the collecting drum. The capstan is used to assist in the movement of the wire to the drum.
Their is also a speed regulator which regulates the speed. Its working principle is that when the plate electrodes are immersed into the water and the gap between plate electrodes and the base conductor is decreased then the speed increases in that the conductivity increases as the gap is decreased. When the plate electrode gap is increased the speed decreases because the conductivity reduces to the extent that when the plate electrodes are removed from the water the machine speed will gradually decrease in speed until it comes to a halt.
It has a control panel where its operations are controlled. It also has a gear system which assists in the effective lay of the wire cables being twisted.
It has a small motor and a big motor. The small motor is connected to a chain and its purpose is to aid in the movement of the movement of the drum in a vertical manner. The big motor is the one responsible for powering the whole motor.

Conclusion

The importance of laying or twisting is to provide the required shape of the cables being twisted and also to cover the cables with plastic paper which is important during the extrusion process.

COILING

Objective

To know and understand the machine setting and how the machine operation takes place.

Introduction

This is the process of winding of a wire cable onto a spool. The winding on the spool is usually measured in length or in weight. The wires which have no insulation are measured in weight while the wires which have an insulation are measured in length. There are two types of coiling machines namely:- i. Rear semi auto coiler ii. Coiling machine 1 and 2

Operation procedure

i. Rear semi auto coiler
The spool is taken to the stand as the take up spool where its loaded and ready for coiling process to initiate. The wire cable is connected to a system of pulleys whereby their is a dancer pulley where by the main purpose o the dancer pulley is to shift or allow less tension on the cable to avoid breakage of the cable. The door of this section has a limiting switch which when the door is opened it triggers and causes the machine to halt.
From the pulley section it is moved to the spark tester whereby its main function is to detect the non insulated section of the cable. From this point it is connected to a system of pulleys whereby it is directed to the winding section.
The winding section is where the winding or the coiling of the wire is done. It has 2 winders which are automated in that when one is moving the other is stationary and vice versa. It helps in saving time when the coiled wire is being removed the other winder continues winding. It has a door which is connected to a limiting switch such that when operating on one winder the other doesn't function.
Its powered by a coupling magnetic motor on a shaft that is responsible for the sequential non simultaneous operation of both the winders in that both winders cannot rotate at the same time. ii. Coiling machine 1 and 2
Their are two coiling machines namely coiling machine 1 and 2. It has a stand where the take up spool is placed and the wire is passed through a traverse which is used to position or ensure proper or effective alignment of the wire distribution to the pay off spool.
The wire passes through a meter reader which is responsible for measuring the length of the wire wound. It is however finally wound on a pay off spool.