Maintenance Management

Maintenance ManagementMaintenance Scheduling & Life Cycle Costing for Straight Knife Cutting MachineAssignment - II

5/1/2015NIFT,Kangra

Straight Knife cutting machineIn apparel industry, more than 99% cases this knife is used. This machine is called straight knife cutting machine because its cutter is straight in shape. It is used for both woven & knit fabric. In this machine different types of straight knife are used according to the different cutting objects. This machine provides good efficiency.

Features of Straight Knife Cutting Machine The main parts of this machine are straight knife, electric motor, handle, grinder, base plate, stand/ knife holder, lubricating unit, wheel etc. Could be used to cut higher depth of fabric. Knife height is 10 cm to 33 cm. Knife stroke is 2.5 cm to 4.5 cm. Motor r.p.m. is 3000 to 4000. Auto grinder is used. Auto lubricating unit works for this machine. Different types of knife edge are used for cutting different objects. Such as, straight edge, wave edge, sew edge & serrated edge. A Handle for the cutter to direct the Knife. Knife guard is attached to the front of the knife. Sharp & heavy corners can be cut. Maximum 70% of knife height is used for fabric lay. Wheels are under the base plate to move the machine smoothly. Machine weight is around 12-15 kg. Knife cut the fabric very fast due to high speed of motor. That increases the risk of fabric damage.

M/C descriptionThe elements of a straight knife consists of A base plate Usually in rollers for easy movement. An electric motor. Handle for the cutter to direct the blade. Knife (Reciprocating motion). Knife guard. Grinding wheel used to sharp the knife during cutting. Stand. Roller wheel to move the machine over cutting table easily.

Working principleTwo kind of power are required to operate a straight knife. Motor power drives the reciprocating blade. Operator power drives the knife through the lay.The motor power needed is determined by Height of the lay. The construction of the fabric. The curvature of the line being cut. The stroke of the blade.Maintenance of straight knife cutterMachines condition will be deteriorated if it is exposed to the environment and subject to use. If these process remain unchecked and unchanged it will cause unserviceable and standstill of the machine. Industry therefore has no other way but to attend, to repair, to maintain, to set and to recondition them so as to prolong their life to the extent it is economically and physically possible to do so. So according to engineering aspect respects repair, maintenance, setting and replacement of different parts of the machines are badly needed and so on. Required Tools Flat screw driver Star screw driver Hammer Pliers Lubricating oil Grease

RepairRepair work is carried out when a component requires slight modification. To carry out such job the machine needs to be switched off first. The component under repairing, the part is fixed to its designed place and hence its correction is measured by running the machine. In a straight knife cutting machine motor, knife, knife guard, wheel, base plate wheel controller, can undergo repair job. Maintenance types required Routine maintenance: Lubrication and regular inspection are the constituents of routine maintenance. Lubrication ensures long life and safe working of all the equipment. Inspection tries to detect fault in equipment so that repairs and replacement may be undertake at right time. Scheduled maintenance: This type of maintenance provides for inspection, overhaul lubrication and servicing of the machine at predetermined dates. Overhauling of machine, cleaning of all components is normally done in this manner. It involves opening of the machine into its smallest components and carry out lubrication.Manual SettingThe setting of the machine is of immense importance. Following setting points need to be ensured before running the machine. Knife: In straight knife cutting machine, the knife is straight and it has reciprocating motor. The height of blade ranges from 1.-33 cm and the stroke of blade ranges from 2.4 - 4.5 cm. The setting of knife is very important. For smooth cutting, the knife maintenance is very necessary. Sharp edge of straight knife: The sharp edge knife may have various shapes for various extent of cutting. Such as, to cut soft and fine lay of fabric, straight edge is used to cut canvas fabric, sew edge is used to cut coarse and heavy cotton fabric, serrated edge is used. So, the sharp edge of knife should be selected according to requirements. Motor: Motor rpm expresses the speed of the machine. In straight knife cutting machine, two types of force are required i.e. for the reciprocating motion of straight knife and for the movement of knife inside the lay of fabric. The rpm is controlled by regulator of motor and the movement of knife inside the lay of fabric. Fabric height controller: Fabric height can be controlled by controlling the height of blade. Fabric height should be controlled depending on types of fabric, cutting efficiency, requirement etc.

ReplacementThe replacement is revealed when the retention on equipment is no more remains an economical proportion. A replacement is affected when the equipment is subjected to complete breakage which cannot be used even after repair or the component has become so obsolete that affects production or it has crossed its expire date. Replacement can be affected to any components of the machine at any time. In straight knife cutting machine, main component knife undergo frequent replacement. The grinding wheel, base plate wheel need not to replace very frequently, but they need to be replaced for proper function of machine. Maintenance ScheduleMaintenance schedule

Daily Schedule

09:00:00Oil CheckClean bladesDry Run

10:00:00

11:00:00

12:00:00

13:00:00

14:00:00Oil CheckClean bladesDry Run

15:00:00

16:00:00

17:00:00

18:00:00

Maintenance schedule

Weekly Schedule

01-05-2015Clean SharpenerChange BladesClean Oil gears under base plate

02-05-2015

03-05-2015

04-05-2015

05-05-2015

06-05-2015

07-05-2015

08-05-2015Clean SharpenerChange BladesClean Oil gears under base plate

Maintenance schedule

Semi - Annually Schedule

May-15Clean Carbon BrushesCheck CommuterCalibrate GearsClean Rollers

Jun-15

Jul-15

Aug-15

Sep-15

Oct-15Clean Carbon BrushesCheck CommuterCalibrate GearsClean Rollers

Nov-15

Dec-15

Jan-16

Feb-16

Maintenance schedule

Monthly Schedule

May-15Clean MotorsClean GearsBasic Servicing

Jun-15Clean MotorsClean GearsBasic Servicing

Jul-15Clean MotorsClean GearsBasic Servicing

Aug-15Clean MotorsClean GearsBasic Servicing

Sep-15Clean MotorsClean GearsBasic Servicing

Oct-15Clean MotorsClean GearsBasic Servicing

Nov-15Clean MotorsClean GearsBasic Servicing

Dec-15Clean MotorsClean GearsBasic Servicing

Life Cycle Costing

Machine Initial Cost ( Machine Cost + Setup) = 26000 INRLife in hours (6yrs.) = 15000 hrsAnnual Usage (hrs) = 2500Annual Major Cost (Blade & Spares) = 1200* 160 = 192000 (1200 per blade , changed every two days)Annual Servicing = 40000 Total Cost For 6 Years : 2,58,000 INRdg[Type text]