STEEL WIRE MANUFACTURING
Wire drawing is a metalworking process used to reduce the cross-section of a wire by pulling the wire through a single, or series of, drawing die(s)
PROCESS OF WIRE DRAWING
Pickling
The wire is pulled through the die, its volume remains the same, so as the diameter decreases, the length increases.
% of areal reduction
Single block wire drawing machines
A bracket standing up to hold the die
A vertical drum which rotates and by coiling the wire around its surface pulls it through the die
The wire drum or "block" is provided with means for rapidly coupling or uncoupling
The block is also tapered
Snatching
Non-circular cross-section drawing
Mechanical Properties
The strength-enhancing effect
Tensile strength can be as high as 3760 MPa
Drawing dies
Tungsten carbide
Die angles usually range from 6–15 °
OPTIMIZATION OF OPERATIONS IN A STEEL WIRE
MANUFACTURING COMPANY
Process flow chart :
Wire breakages and maintenance resulted in approximately 60% of the total idle time
Downtime of any one of the KOCH machines will affect the productivity of Bekeart
No specific schedule was prepared for preventive maintenance
The time consumed and the frequency of each fault was not studied
No specific task was taken to change or to revise subassemblies or machine members design which are giving trouble periodically.
Productivity can be increased in numerous ways :
By reducing the input for the same level of output
By increasing the output with the same level of input
By combining both
By reducing down-time due to -
Wire breakages, maintenance, reducing the material input, by using better quality of goods, improved utilization of resources, reduction in working capital
GOAL: NEED TO IMPROVE THE
PRODUCTIVITY
IDLE-TIME ANALYSIS
Shift-to-shift detailed production chart of each machine
Reasoning for idle time occurrence per shift
Wire breakages were basically due to defective raw material, improper pickling and welding
Rare problems – very high time consumption
Regular problems – very less time consumption
The number of arrivals of the entity at the stores.
The number of resources required
Frequency and time of breakdown maintenance of the KOCH machines
Utilization of the KOCH machines
FINDINGS AND CONCLUSIONS
Optimum Lot Size
The objective was to reduce the blocking of the coils in the process
The optimum arrival quantity – 42
Throughput
Increasing the arrival quantity
Adding an extra forklift
FINDINGS AND CONCLUSIONS
Variables
Decision
1
% down,
KOCH1
% down,
KOCH2
% down,
KOCH3
% down,
KOCH4
% Utilization of forklift1
% Utilization of forklift2
6.6
8.6
8.8
9.1
99.9
44.5
2
1.4
2.6
2.8
3.1
100
43.5
3
Scenarios
4
5.7
8.2
8.6
9.1
79.8
99.4
1.8
2.5
3.8
3.4
79.9
99.5
5
1.6
2.5
2.9
3.0
80.0
99.5
Preventive Maintenance
