Machine Technology and Maintenance of Textile Industry presentation.pptx

Machine Technology and Maintenance of Textile Industry

1. MTM404 Machine Technology and Maintenance of Textile Machinery Engr. Moinul Ahsan Engr. Moinul Ahsan 1

2. Course Outline Lecture Plan Lecture 01 - Maintenance Lecture 02 - Maintenance (Contd.) Lecture 03 - Lubrication Lecture 04 - Inventory Management Lecture 05 - Inventory Management (Contd.) Lecture 06 - Material Handling Lecture 07 - Material Handling (Contd.) MIDTERM Engr. Moinul Ahsan 2

3. Course Outline Lecture Plan Lecture 08 - Refrigeration and Air Conditioning System Lecture 09 - Ergonomics Lecture 10 - Occupational Safety Lecture 11 - Hazards in Textile Industry Lecture 12 - Hazards in Textile Industry (Contd.) FINAL Engr. Moinul Ahsan 3

4. Course Outline Text Book Introduction to Machine Technology & Maintenance of Textile Machinery – Dr. Engr. Abu Bakr Siddique, 1 st edition Industrial engineering and production management - Martand Telsang , 1 st edition Engr. Moinul Ahsan 4

5. Maintenance Management Any activity such as tests, measurements, replacements, adjustments and repair are performed to restore or retain a part or equipment to a specific state in which that part or equipment can perform its required functions. Engr. Moinul Ahsan 5

6. Types of Maintenance Engr. Moinul Ahsan 6

7. Preventive Maintenance In this type of maintenance, actions are periodically taken (or continuously) to functional failure and to achieve the desired level of safety and reliability for an item. These actions are performed to prevent or reduce consequences of failures. Engr. Moinul Ahsan 7

8. Periodic Maintenance It is ongoing time-based maintenance which consists of periodically inspecting, servicing, lubricating and cleaning of equipment and replacing parts to prevent sudden failure and process problems to ensure continuing working condition. Engr. Moinul Ahsan 8

9. Predictive Maintenance This is a method in which the service life of important part is predicted based on inspection or diagnosis, in order to use the parts to the limit of their service life. It is condition-based maintenance, manages trend values, by measuring and analyzing data about deterioration, designed to monitor conditions through an on-line system. Engr. Moinul Ahsan 9

10. Corrective Maintenance Repairs or other corrective actions taken after a failure has been occurred are called corrective maintenances. Unscheduled maintenance is synonymous with corrective maintenance. It improves equipment and its components so that preventive maintenance can be carried out reliably. Equipment with design weakness must be redesigned to improve reliability or improving maintainability. Engr. Moinul Ahsan 10

11. Emergency Maintenance This is based directly upon the maintenance actions raised manually on occurrence of a problem which are to be done on emergency basis. Emergency maintenance involves two types of emergencies: a) Normal emergencies b) Extra-ordinary emergencies Engr. Moinul Ahsan 11

12. Emergency Maintenance a) Normal Emergencies : Normal emergencies can happen on a daily basis whether it is a pipe break or blockage in a sewer. An effective maintenance program can reduce normal emergencies. b) Extra-ordinary Emergencies : Extra-ordinary emergencies are incidents such as high intensity rainstorms, hurricanes floods and earthquakes. They are always unpredictable occurrences. Engr. Moinul Ahsan 12

13. Reclamation Maintenance It indicates the design of new equipment Weakness of current machines are sufficiently studied. when it is observed that the maintenance of machinery is more expensive and complex. than buying a new one. then the old capital machinery or spare-parts must be replaced by a new one. Engr. Moinul Ahsan 13

14. Reactive or Break down Maintenance It is emergency unexpected breakdowns of machines or equipment. These are unpredictable or reactive type of maintenance and are more difficult to schedule than the above three categories. Engr. Moinul Ahsan 14

15. How to make Maintenance Planning (1) Preparing an asset inventory: Identifying the physical features (e.g., area, material, etc.) of all assets (e.g., schools, roads, etc.) which require maintenance. (2 ) Identifying maintenance activities and tasks: Defining the type of maintenance task (activity) to be performed on each asset and what work should be done under each activity. (3) Identifying the frequency of the task: Determining how often the activities should be performed (frequency of service). This is important particularly in preventive type of maintenance. Emergency or reactive types of repairs are unpredictable, but with good preventive maintenance, the frequency of emergency situations occurring may be reduced. Engr. Moinul Ahsan 15

16. How to make Maintenance Planning (4) Estimating the time required to complete the task: Indicating how long each task should take to complete. (5) Developing an annual work schedule: Planning what time the maintenance work for the entire year should take place. (6) Preparing and issue a work order: Identifying what, when, where and by whom maintenance work is to be done. (7) Determining a budget: Determining the costs for all maintenance activities by calculating labor hours, material, equipment, and contracting costs. Engr. Moinul Ahsan 16

17. Maintenance Tasks 1) Lubrication/servicing (all categories) - this involve any act of lubricating or servicing for maintaining inherent design capabilities. 2) Operational/visual check- it is a task to determine that an item is fulfilling its intended purpose. 3) Inspection/condition monitoring- regular examination of an item against a specific standard. 4) Restoration (all categories) - restoration is the work necessary to return the item to a specific previous standard. Engr. Moinul Ahsan 17

18. Maintenance Tasks 5) Discard (all categories) - discard is the removal from service of an item at a specified life limit. . 6) Combination (safety categories) - since this is a safety category question and a task is required, all possible areas should be analyzed. 7) No task - (all categories) - No task is required in some situations, depending on the effect. Engr. Moinul Ahsan 18

19. Lubricant Lubricant is a substance which is placed in between two mating parts which are in relative motion with each other, so that they can move, without any friction. Engr. Moinul Ahsan 19

20. Function of Lubricants To reduce the friction and wear between the contact surfaces To carry away the heat! to cool the moving elements To act as a seal for contamination To keep the surfaces clean To prevent adhesion To carry heavy loads To prevent corrosion To absorb shock and transmit hydraulic power Engr. Moinul Ahsan 20

21. Composition of Lubricants Engr. Moinul Ahsan 21

22. Types of Lubricants Engr. Moinul Ahsan 22

23. Types of Lubricants Engr. Moinul Ahsan 23

24. Properties of Lubricants Engr. Moinul Ahsan 24

25. Properties of Lubricants Engr. Moinul Ahsan 25

26. Properties of Lubricants Engr. Moinul Ahsan 26

27. Methods of Lubrication Fresh Lubrication Circulating Lubrication Engr. Moinul Ahsan 27

28. Fresh Lubrication Engr. Moinul Ahsan 28

29. Circulating Lubrication Engr. Moinul Ahsan 29

30. Principles of Lubricant Storing Outdoor Storage Indoor Storage Engr. Moinul Ahsan 30

31. Principles of Outdoor Storage Barrels should be stored on oil resistance base Barrels should be stored to keep seals moist and air tight First in first out (FIFO) policy should be adopted Store should not be situated in a dusty or corrosive atmosphere Engr. Moinul Ahsan 31

32. Principles of Indoor Storage Easy access for trolley and forklift To adopt a first in first out (FIFO) policy Good ventilation Clean walls with Lights Store should be built of fireproof materials Smooth level oil resistant floor Heating is useful to keep viscous oils Fluid Engr. Moinul Ahsan 32

33. Material Handling Material handling is defined as the handling of raw materials. semi-finished materials and finished goods. It deals with the preparation. placement and positioning of materials with a view to facilitate their storage, Preservation and movement. It is a function which facilitates the movement of materials in and outside the store house. Engr. Moinul Ahsan 33

34. Basic Elements of Material Handling There are four interdependent elements of material handling. They are: Motion Time Quantity Space Engr. Moinul Ahsan 34

35. Basic Elements of Material Handling Motion : Material handling is concerned with moving materials and finished products from location to location. Time : Material handling must assure that no production process or customer need will be hampered by having materials arrive on location too late or too early. Quantity : Material handling has the responsibility of being sure that each location revives the correct quantity of parts. Space : Storage space (both active and dormant) is a major consideration by the material handling system. Engr. Moinul Ahsan 35

36. List of Material Handling Activities Packaging (consumer) at supplier's plant Packing (protective) at supplier's plant Loading at supplier's plant Transportation to user plant Transport from one point to another within the plant. Materials are received in the plant. Stored and then moved to the series of operations until the finished product is obtained, packed and shipped. Engr. Moinul Ahsan 36

37. List of Material Handling Activities External plant handling activities. Unloading activities. Receiving Storage. Issuing materials. In process handling. In process storage. Workplace handling. Engr. Moinul Ahsan 37

38. List of Material Handling Activities Intra -departmental handling Intra plant handling Handling related to auxiliary functions Warehousing of finished goods Loading and shipping Transportation to consumer locations Interplant handling Engr. Moinul Ahsan 38

39. Functions of Material Handling To minimize the distances moved, by adopting shortest routes and at the same time handling equipment should not interfere with the production line To design containers, packages, drums etc. To economize handling and to reduce damage to the materials in transit. To utilize gravity for assisting materials movement wherever possible. Materials handling equipment should periodically be restored and checked up for repairs and maintenance. To minimize the movement involved in a production operation. Engr. Moinul Ahsan 39

40. Equipment for Material Handling Screw Conveyors Screw Mixing Conveyors Screw Feeders Drag Conveyors Ribbon & Paddle Belt Conveyors Slider Conveyors Cargo air transport Engr. Moinul Ahsan 40

41. Equipment for Material Handling Bucket Elevators Hoppers, Bins & Chutes Elevating conveyor Chain and cable conveyor Roller conveyor Cranes, elevators and hoists Trolley and platform Industrial vehicles-Trucks, Fork lifts etc. Marine carriers Engr. Moinul Ahsan 41

42. Inventory Management The Inventory Management system and the Inventory Control Process provides information to efficiently manage the flow of materials, effectively utilize people and equipment, coordinate internal activities, and communicate with customers. Inventory Management and the activities of Inventory Control do not make decisions or manage operations; they provide the information to Managers who make more accurate and timely decisions to manage their operations. Engr. Moinul Ahsan 42

43. Function of Inventory Management How inventory items can be classified How accurate inventory records can be maintained Items are counted and records updated on a periodic basis Often used with ABC analysis to determine cycle Eliminates(exclude ) shutdowns and interruptions Eliminates annual inventory adjustment Trained personnel audit inventory accuracy Allows causes of errors to be identified and corrected Engr. Moinul Ahsan 43

44. The Reasons for Inventory Control Balance the stock as to value, size, color, style, and price line in proportion to demand or sales trends. Plan the winners as well as move slow sellers Secure the best rate of stock turnover for each item Reduce expenses and markdowns. Maintain a business reputation for always having new, fresh merchandise in wanted sizes and colors. Engr. Moinul Ahsan 44

45. Types of Inventory Raw material Purchased but not processed Work-in-process or semi-finished goods Undergone some change but not completed A function of cycle time for a product Maintenance/repair/operating (MRO) Necessary to keep machinery and processes productive Finished goods (Products) Completed product awaiting shipment Miscellaneous (Products) Waste, scraps, obsolete items etc. Engr. Moinul Ahsan 45

46. Types of Inventory Lot size inventory These are maintained wherever the user makes or purchases the materials in large lots, than are needed fix this immediate purposes. Fluctuation inventory These are maintained to safeguard fluctuation in customer demand for the product or availability or material. Anticipation inventory These are needed where goods are consumed on a predictable but changing pattern through year and where it is desirable to absorb some of these changes by building and depleting inventories rather than by changing production rates. Engr. Moinul Ahsan 46

47. Inventory Control Activities Sales Forecasting or Demand Management Sales and Operations Planning Production Planning Material Requirements Planning Inventory Reduction Engr. Moinul Ahsan 47

48. Advantages of Inventory Control Improvement of customer's frictions: this is achieved through maintenance of better balance among the quantities of finished items on hand and also from better geographic development of field warehouse inventories. Improvement of labor and community relations: This results from a greater leveling of production peaks and valleys and consequent increase in stability of employment. Increase in the effectiveness of key personnel's: Effective inventory control can save considerable executive time, which otherwise would be spent on critical raw materials expediting, correcting repeated production etc. Again the effectiveness of salesman can be increased by reducing their duties of following up the home officers and in pacifying customers. Engr. Moinul Ahsan 48

49. Advantages of Inventory Control Reduction in manufacturing cost: Manufacturing costs can be reduced by: By the better utilization of labor, supervision and facilities by eliminating idle time due to raw material shortages. By making economical manufacturing runs in place of small lots. Constant rescheduling and expensive set up changes, which are needed to compensate for unbalanced inventories. By minimizing m/c down time caused by unavailability of spare parts. By reducing inventory losses due to decline in market value. By improving interdepartmental transfer facilities of material. By reducing purchase material costs by measuring requirements. By reducing inventories and inventory carrying cost. Engr. Moinul Ahsan 49

50. Advantages of Inventory Control Strengthening financial position: This is achieved by sound inventory control by preserving more liquid working capital position and reduction of overall capital requirements. Engr. Moinul Ahsan 50

51. Disadvantages of Poor Inventory Management Inability of meet delivery promises. High rate of customer turnover and order cancellation. Uneven production with frequent layoffs and rehiring. Frequent need for uneconomical production runs to meet sales requirements. Excessive machine down time because of material shortages. Periodic lack of adequate storage space. Large inventories write down because of price decline distress sales, disposal of obsolete or slow moving stock and the time. Widely varying rates of inventory losses or turn over among major inventory items. Engr. Moinul Ahsan 51

52. Reorder point (ROP) The reorder points occur when the quantity on hand drops to a pre-determined amount that amount generally includes expected demand during lead time and perhaps extra cashier’s of stock. When serves to reduce the probability of experiencing a stock out during lead time. There are determinants of the reorder point quantity: The rate of demand The lead time The extent of demand and/or lead time variability. The degree of stock out risk acceptable to management. Engr. Moinul Ahsan 52

53. Lead Time (LT) The lead time is the delay applicable for inventory control purposes. This delay is typically the sum of the supply delay, that is, the time it takes a supplier to deliver the goods once an order is placed, and the reordering delay, which is the time until an ordering opportunity arises again. Engr. Moinul Ahsan 53

54. Reorder point (ROP) If the demand and lead time are both content then the reorder point is simply: ROP = d × LT Where, d = demand rate (units per day or week) LT= lead time in day’s or weeks Engr. Moinul Ahsan 54

55. ROP with Safety Stock When variability is present in demand or lead time of creates the possibility that actual demand will exceed expected demand can sequent, it becomes necessary to carry additional inventory called safety stock. To reduce the risk of running out of inventory (a stock out) during lead time. the reorder point then increases by the amount of the safety stock . ROP= expected demand + safety stock during lead time Engr. Moinul Ahsan 55

56. ROP with Safety Stock When demand is probabilistic, Safety Stock = Z× σ dLT Where, Z = Number of standard deviations σ dLT = standard deviation of demand during lead time ROP = expected demand + Z× σ dLT Engr. Moinul Ahsan 56

57. Probabilistic Demand Engr. Moinul Ahsan 57

58. ROP Examples Demand, D = 8,000 parts per year 250 working day year Lead time for orders is 3 working days ROP = d × LT = 32 × 3 = 96 Units   Engr. Moinul Ahsan 58

59. ROP Examples The manager of a construction supply house determined from historical records that demand for sand during lead time averages 50 tons. In addition the manager determined that demand during lead time could be described by e normal distribution that has a mean of 50 tons and a standard deviation of 5 tons. Assuming that the manager is willing to accept a stock out risk at no more than 3 percent. a) What is the value of Z that will be appropriate? b) How much safety stock should be held? c) What reorder point should be used? Engr. Moinul Ahsan 59

60. Engr. Moinul Ahsan 60

61. ROP Examples Solution: The expected lead time demand = 50 tons σ LT = 5 tons Risk = 3 percent Service level = 1- risk = 0.97 From the table, using a service level 0.97, obtain a value of Z = + 1.88 Safety stock = Z× σ LT = 1.88(5) = 9.4 tons ROP = expected demand during lead time + safety stock = 50 + 9.4 = 59.4 tons Engr. Moinul Ahsan 61

62. ROP Models 2. If only demand is variable , then  dLT = and the reorder point is: ROP = Where: d =average daily or weekly demand  d = standard deviation of demand per day or week LT = lead time in days or weeks 3. If only lead time is variable , then  dLT = d LT , and then the reorder point is: ROP = Where: d = daily or weekly demand LT = average lead time in days or weeks  LT = standard deviation of lead time in days or weeks  

63. ROP models 4. If both demand and lead time are variable , then And the reorder point is: Note: each of these models assume that demand and lead time are independent

64. Psychrometric chart

65. Psychrometric Chart Need two quantities for a state point Can get all other quantities from a state point Can do all calculations without a chart Often require iteration Many “digital” psychrometric charts available Can make your own

66. Absolute Temperature Dry-bulb temperature Wet-bulb temperature Dew-point temperature Temperature

67. Psychrometric processes

68. Sensible heating

69. Example

70. Dehumidification by Cooling

71. Example

72. Psychrometric charts

73. Air Conditioning System The branch of engineering which deals with conditioning the air for industrial purpose, food processing, storage of food and other materials. Engr. Moinul Ahsan 98

74. Factors Affecting Human Comfort Engr. Moinul Ahsan 99

75. Equipment of AC System Engr. Moinul Ahsan 100

76. Summer AC System Engr. Moinul Ahsan 101

77. Winter AC System Engr. Moinul Ahsan 102

78. Ergonomics It is the study of anatomical, physiological and psychological aspects of human in working condition for optimizing the efficiency, health safety and comfort of people at work, at home and at play. Engr. Moinul Ahsan 103

79. Importance and Benefits of Ergonomics Increased productivity Increased work quality by good working environment Reduced migration of worker Reduced absenteeism Increased morale of workers Reduced potential for accidents Reduced potential for injury and ill health at work Improved performance and efficiency Increased usefulness of assets Improved work methods by motion study Avoidance of hazards Engr. Moinul Ahsan 104

80. Objectives of Ergonomics To enhance desirable human values like health, safety, ease of use etc. To improve the efficiency of operation (strength , speed, visual acuity, and physiological stresses, such as fatigue, speed of decision making, and demands on memory and perception) To reduce worker compensation costs and provide more reliable workforce To utilize the skills of many disciplines. including engineering, psychology, medical, safety, management and the employees or associates To classify difficult tasks & solve it by diversified ways To enhance performance and productivity To prevent fatigue and injury Engr. Moinul Ahsan 105

81. Objectives of Ergonomics To change the work process, environment and work management as necessary To quantify high risk or problem areas Engr. Moinul Ahsan 106

82. Elements of Ergonomics a) People b) Equipment c) Workplace environment Engr. Moinul Ahsan 107

83. Factors that play a role in Ergonomics 1. Body posture and movement: standing, sitting, lifting, pulling, pushing etc. 2. Environmental factors: illumination, noise. vibration, climate. Chemical substances etc. 3. Information and operation: information gained visually or through other senses, controls and relation between displays and control. 4. Tasks and jobs: appropriate tasks and interesting jobs Engr. Moinul Ahsan 108

84. Safety in Textile Mill Industrial hazards In the fields of industrial processes or in the industrial environment the existing unsafe conditions and unsafe personal activities are termed as industrial hazards. Engr. Moinul Ahsan 109

85. Typical Industrial Hazards a. Mechanical hazard b. Electrical hazard c. Radiation hazard d. Hazards from substance e. Work activities hazards f. Work environment hazard Engr. Moinul Ahsan 110

86. Mechanical hazard Inadequately guarded machine tools/part Defective, rough. sharp, slippery, decayed , cracked machine surface. Unsafely arranged or poor housekeeping. Poor layout, congestion blocked exits etc . Inadequate lightings and ventilations. Unsafely clothed, no goggles, gloves or masks. wearing loose garments, high heels etc. Unsafe mechanical, electrical or chemical processes. Engr. Moinul Ahsan 111

87. Electrical hazard Direct contact Indirect contact Short circuit/overload Electrostatic phenomena Source of ignition Engr. Moinul Ahsan 112

88. Radiation hazard Ultraviolet Radiation Radiation of electromagnetic waves Lasers Ionizing / non-ionizing radiation. Engr. Moinul Ahsan 113

89. Hazards from substance Toxic fluids/toxic gas/mist /fumes /dust Biological substances Explosive substances Engr. Moinul Ahsan 114

90. Work activities hazards Highly repetitive actions Stressful posture Lifting / Handling of excess weights Mechanical overload stress Visual fatigue Poor workplace design Engr. Moinul Ahsan 115

91. Work environment hazard Localized hot/cold surfaces Significant noise Significant vibration Poor lighting Hot/Cold ambient temperature Engr. Moinul Ahsan 116

92. Safety in factory premises Proper ventilation and adequate lighting provision should be present. Adequate layout of workspace is necessary for safe working. There should be proper control of overhead cranes. Sharp bends, heavy slopes, and undue steps to be considered carefully. Emergency exits must be available. Adequate control in electric installation must exist. Available first aid arrangements in different sections should be available. Engr. Moinul Ahsan 117

93. Safety against accidents from machines Dangerous parts of the machines should be enclosed in a suitable housing. Dangerous part s of the machines should be out of reach during operation. All moving parts like belts, pulleys, gears etc . should be properly guarded. There must be provision for safe working distance and interlocking. Provision of distance and interlock guards Machines should not be lubricated while running. Trainees or inexperienced staffs should not be allowed to work with complicated machines. Engr. Moinul Ahsan 118

94. Safety against fire There should be adequate provision of passages and exits. The exit door should be opened outwards. Proper warning signals must be provided. The interior doors should never be locked or bolted with workers on duly inside the enclosure, There should be provision of adequate fire fighting equipments. Training of fire fighting to all employees should be practiced. Proper electrical contacts should be maintained. Proper and safe storage of explosives should be maintained. Engr. Moinul Ahsan 119

95. Factory Act Working hours, holidays, and intervals after rest, etc. 1. Hours of work for adults- No adult worker shall be required or allowed to work in a factory for more than 48 hours in any week and for more than 9 hours in a day. 2. Relaxation of hours of work for adult-The ordinary limits on working hours of adults may be relaxed in certain special cases, e.g., workers engaged on urgent repairs or maintenance in work which must necessarily be carried on outside the limits laid down for the general working of employees. Engr. Moinul Ahsan 120

96. Factory Act Working hours, holidays, and intervals after rest, etc. 3. Payment for overtime-Where a worker works in a factory for more than 9 hours in any day or for more than 48 hours in any week, he or she shall entitled to wages due to overtime at a rate prescribed by the factory. 4. Weekly holiday-Workers are not allowed to work on government or public holidays except in case of emergency. Engr. Moinul Ahsan 121

97. Factory Act Working hours, holidays, and intervals after rest, etc. 5. Compensatory holidays-Where a worker in a factory. as a result of exemption from the ordinary provision relating to weekly holidays, is deprived of any of the weekly holidays, he or she shall be allowed, within the month in which the holidays were due to him or within the two months immediately following that month, compensatory holidays of equal number or the holidays so lost. 6. Intervals for rest for adults-The periods of work of adult workers in a factory each day shall be fixed that no period shall exceed 5 hours and that no worker shall work for more than 5 hours before he has had an interval for rest of at least half an hour. Engr. Moinul Ahsan 122

98. Factory Act Working hours, holidays, and intervals after rest, etc. 7. Prohibition of double employment-No child or, ,except in certain circumstances, an adult worker, shall be required or allowed to work in any factory on any day on which he has already been working in any other factory. 8. Prohibition of employment of children under 14- No child who has not completed his fourteenth year shall be required or allowed to work in any factory. Engr. Moinul Ahsan 123

99. Factory Act Working hours, holidays, and intervals after rest, etc. 9. Hours of work for children- No child shall be employed or permitted to work in any factory for more than four and a half hours in any day and during the period of at least twelve consecutive hours. Engr. Moinul Ahsan 124

100. Factory Act Leave with wages Leave with wages-Every worker who hit's worked for a period of 240 days or more in a factory during a 'calendar year shall be allowed during the subsequent calendar year leave with wages. Engr. Moinul Ahsan 125