Spinning
Maintenance and Management
Sanyog Chandpurkar
Department of Textile
Technology
Shri Guru Gobind Singhji
Institute of Engineering and Technology, (SGGS I E&T ), Vishnupuri,Nanded,
(Maharashtra State, India)
ABSTRACT
Machines play a major role in
determining the productivity of an industry, the quality of its products, power
consumption and working atmosphere. All these factors are dependent on the
mechanical condition of the machine in spinning units it is also very important
that the condition of the major machines is maintained by systematic and
well-planned maintenance practice. This chapter deals with such important
aspects of maintenance management as maintenance scheduling. Maintenance costs,
the efficiency of maintenance function assessment of quality of maintenance
etc. modern practices such as total productive maintenance (TPM). 5s and
computerized maintenance management have also been covered. Proper maintenance
management helps companies to improve profitability. Product quality and
customer relationship.
INTRODUCTION
In case of modern textile machinery,
with their rising cost, complications, and automation, the necessity of
maintenance has become very severe.The machine plays a very important role in
determining the productivity of the mill, quality of products, power
consumption & so on. Hence, in spinning units, it is important that
condition of major machines is maintained by systematic and well-scheduled maintenance
practices.Also, there is some economic pressure, which forces mill to use the
high capital of machinery to full extent, so that it will face competitors. Due
to the importance of maintenance, it can be considered as ‘heart of
productivity’. If maintenance and replacement of breakdown parts are neglected,
then it may cost more than cost possible by good maintenance.
Objective of Maintenance
- To maintain machines at maximum operating speed and efficiency.
- To minimize the maintenance cost.
- To ensure best possible quality of output product.
- To reduce lead time and waste occurs due to the breakdown of parts.
Types of Maintenance:
There are two main types of
maintenance:
- Breakdown Maintenance
- Planned Maintenance
Breakdown Maintenance
The breakdown may occur at any time
unexpectedly and handling such breakdowns is known as ‘breakdown maintenance’.
In this type, attention is given to machine for maintenance only when the
breakdown of parts occurs.
Planned Maintenance:
In this type, maintenance is carried
out as per predetermined plan. It has following five types:
1-Routine Maintenance
This maintenance type is performed to
ensure efficiency of the machine. It is carried on the basis of a predetermined
schedule. General lubrication, cleaning, cot replacement, cots buffing,
clothing, grinding etc. fall under the category.
2-Preventive Maintenance
As the title indicates, it is
performed to prevent damage to parts and machines. In this case, faults are
discovered and remedial action is taken before it affects production and
quality. For this method, a skilled technician is required, with the standard
checklist and with proper tools, equipment, gauges.
3-Predictive Maintenance
From this method, we will come to
know, what is happening with machine parts, during actual operation of the
machine. It assesses the effectiveness of routine & preventive maintenance.
4-Remedial Maintenance
In this, the parts of the machine are
studied and change in design, material, a method is done as per requirement,
for improving operation. Design, material & method selected should be such
that, it should withstand increased loads, speeds with the reduction in wear
& tear.
5-Restorative Maintenance
It is also known as
‘semi-overhauling’. In this method, drastic change in the machine by replacement
of a major part is done. This type is expensive and time-consuming. The
advantage of this can be taken for automation of particular machine.
LITERATURE SURVEY
Maintenance
The maintenance function of a company
run on modern principles gives major weightage to production availability, to
machine performance rates, to cost of operations and of maintenance.Maintenance
of machines includes all efforts directed to keep all the machines in good
health at minimum cost. This leads to smooth and efficient working of an
industrial plant, thus helping to improve the productivity and hence the
profitability of company.Effective maintenance is defined as that which gives
the maximum level of availability as well as performance of plant. This is
achieved through maintenance management, involving planning, organizing,
control and execution directed at specified objective that ensure so that the
company achieves its business objectives.
A sound maintenance policy should have
the following objective in a spinning mill.
- To maximize the service life of all assets i.e. production machinery and ancillary equipment’s.
- To assure optimum availability of installed machinery so that the maximum profitable return on investments can be achieved.
- To ensure full safety for personnel dealing with machinery and equipment’s.
- To permit the highest production rates consistent with good yarn quality.
- To ensure minimum incidence of faults in the yarn being sold.
Condition Monitoring
Condition monitoring is another method
used for planned replacement. This can be used wherever the failure development
process can be accessed; where the failure mechanism gives some form of early
warning signal through detectable changes in the condition of the machine part.
This detection can be visual etc or with the help of condition monitoring tool.
Three requirements must be fulfilled
for the use of condition monitoring process.
- The rate of deterioration must be slow enough to permit detection of failure development, and then to make use of the result to plan and to rectify the fault before failure occurs.
- The deterioration process must exhibit sufficient and detectable change in condition parameters that are relevant.
- Proper measuring equipment / tool or adequate competence must be available to detect and to interpret the condition.For basic method can be used to do this, and these involve measurement/ assessment of the component function by different means: visual inspection, leakage, thermal, vibration and noise. The component is checked tom make sure that it perform the required function.
Machinery Audit
It means a thorough examination of the
mechanical condition of the machine in order to rectify the defect or improve
the quality of the product. Machinery audit helps in improving the existing
maintenance procedure. It also helps in early detection and prevention of
mechanical fault, which may go unidentified, undetected for too long if there
is a total reliance on instrumental examination of the machine.
Machinery audit should generally cover the following
aspects.
A critical review of current
maintenance program such as method of operations, maintenance schedule,
inspection procedure, staff employed and organization.
A detailed investigation of the
machine condition in different departments like machine alignment, wear and
tear of components, damage etc.
General aspects relating to
maintenance tidiness, housekeeping, tool and equipment used.
Records
Proper maintenance schedule is always
following by a suitable record keeping which is essential for preventive routine/normal
and forecast maintenance. For these reasons following records should be
maintained.
- Machinery history register
- Schedule register
- Corrective action register
- Indent register
- Maintenance cost record
- Budget
- These records help in deciding
- Frequency of inspections/checkups.
- Extent of reduction in fault reoccurrence.
- Wear and tear of parts.
- Cost incurred.
Analysis
Maintainability needs to be assessed
through analysis after every one or two year, and improved further on the basis
of such analysis.
The purpose of analysis is as follows:
- To reduce the down time.
- To reduce work load.
- To assure product quality.
- To improve work environment and safety for maintenance.
- Important points to be considered during annual analysis are:
- To uncover any special needs for the system for streamlining the performance of maintenance.
- To identify tools and remedies necessary for improved maintenance.
- Such detailed analysis would assist in determining the overall effectiveness of maintenance schedule in a better way.
SAFETY IN MAINTENANCE
Industrial production is a process
depending on men and machine. In textile mill, men and machine are to sides of
a coin: smooth functioning of the mill depends on science, technology and
engineering on one hand. Studies have shown that accidents occurs mainly due to
unsafe actions, unsafe conditions and carelessness negligence. The textile industry
is today equipped with complicated and fast moving production machines. So it
necessary that everyone follows safety precautions in order to prevent
accidents.
Accidents: Causes and Prevention
An accidents is unplanned and
unexpected event that causes injury to a persons or persons and damage to property
and damage to environment.Accidents occur as a result of unsafe action or due
to exposure to unsafe mechanical and physical condition. Accidents can also
happen due to human failure.To prevent accidents, one should examine how they
are caused, and determine what the exact causes are, and then take appropriate
actions to eliminate the identified causes. Two major factors can give rise to
accidents.
Unsafe actions
Unsafe actions may be result of lack
awareness or lack of knowledge about the right practice or lack of skill on the
part os a Worker.
Attitude
Studies have shown that more accidents
are caused due to negative attitude and then due to bad, unsafe habits at
workplace.
- Over confidence: ‘It could never happen to me’
- Stubbornness: ‘I will do it in my own way’
- Sarcasm: ‘why should I bother about it’
- carelessness: what safety! Safety is kid stuff.
Unsafe mechanical/ physical condition.
- Inadequate illumination
- Lack of or inadequate personal protection.
- Poor housekeeping; defective condition, rough, sharp, slippery etc.
- Inadequate guarded machine parts etc.
Electrical safety
- Failure to take precaution against electrical hazards may lead to serious injuries. Statistics show that 15% to 20% of electrical accidents turn out to be fatal. The most common electrical injuries are shock or burn.
- Tips on electrical safety
- Permit only qualified persons to undertake electrical repairs.
- Do not take short cuts follow safe procedure.
- Ensure that extension wire is free from cuts, damage insulation, kinks or joints.
- Check that the pins of socket are not loose.
- Ensure easy access to shut off power supply.
Precautions during running machine
- Do not touch the running portion of any machine
- Never open or remove safety covers on running machine
- Do not wear loose clothing-loosely fitting jackets, long sleeves etc.
- Never put any tool or science or comb etc. in an open
Implementation stage
There is no readymade formula for
implementing TPM in an organization. Also overnight implementation is not
possible. Top management should have patience to get the full benefit of TPM.
Each organization should establish and develop implementation methodology
depending on the requirement, available resources and complexity of the
maintenance operation to make the project viable. However, some of the
important aspects pertaining to implementation of TPM are discussed here under:
Good housekeeping:
TPM starts with Good housekeeping in
workplace. An organization can establish and maintain a good housekeeping based
on 5S principle, which includes:Seiri ( ie, Sorting out the unnecessary items
from the necessary items thus saving in space, Seiton ( ie, defining storage
space place for every item, which lead to saving of time in searching spare
parts, accessories.) Seiso (ie, thorough cleaning of workstation. This results
in safer work place, reduced contamination in the output and less quality
complaint) Seiketsu (ie, Standardization of the above mentioned activities,
resulting in improvement in the house keeping. Shitsuke (this implies
sustaining the improvement to make the work place more disciplined and organized).
Preparation and adherence of maintenance manual:
In order to bring transparency in the maintenance
process and to make it systematic a maintenance job manual for each production
department/section is to be prepared .The maintenance manual clearly specify to
the extent possible the following:
- The type of autonomous maintenance to be carried out by the trained machine operator.
- Activities related to condition based monitoring and predictive maintenance to be carried out.
- Need based preventive maintenance plan and schedule of each activity.
- Required level of inventory of critical items and their Economic order Quantity and lead time for procurements consistent with Lean Manufacturing System.
- Work instruction for the maintenance personnel.
- Man hour required to carry out each operation.
- Necessary records to be maintained for future reference.
Coordination with SQC department:
The activities of the SQC department
need to be reoriented to synchronize with the maintenance activities. This will
help the management to review the effectiveness of maintenance operations and
make necessary changes wherever required.
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