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How to Maintain circular knitting machines
[ Time:2020-08-18 15:35:09  Visits:537  Size: Large Medium Small ]
Maintenance of the knitting machine
Good maintenance of the machine will not only prolong the life of the machine, but also increase the production efficiency. The so-called maintenance includes cleaning, checking and repairing; lubrication and adjustment aimed at keep the machine in its perfect working condition and mechanical property.
The maintenance of the knitting machine will be summed up as the following five items.
(A)Surface cleaning of the machine:
1、 Clear off the fabric hair on the surface of the machine and adhered on the creels.
2、Clean the machine, segment, dial, shaft, control panel, shields and all parts of the machine to keep them clean.
3、 Clear off the flocking adhered on the cylinder, parts between the segment and the dial cam, batching rollers and driving parts while the machine is out of running.
(B)Maintenance and adjustment of the major parts of the machine:
1、 Cleaning the needle grooves to keep from dirt coming into the fabric with the needle. To do the cleaning: first replace the bobbin yarn on the machine with low-graded one or waste yarn and run the machine, inject a great of needle oil into the cylinder, adding the oil while running the machine until the dirty oil fully flowing out of the groove.
2、 Check if the needle in the cylinder are damaged, if so, replace them right away. If the fabric quality knitted is inferior, complete replacement for new needles may be taken into consideration.
3、 Check the groove insert of the cylinder to see if the width of the needle groove is the same (or there are any straight stripes on the knitting fabric), and the groove wall damaged or not, if any, repair it or replace a new one right away.
4、 Check the wearing status of the cam, make sure the installation position is right and the retaining screws are firm.
5、Check and calibrate the installation positions of each yarn rod, if a worn-out one is found, replace it right away.
6、Calibrate installation positions of each stitch cam to make the length of each yarn ring is uniform.
(C) Maintenance and adjustment of knitting accessories:
1、Checking auto-stop motion:
Check the red light of auto-stop motion in top and middle, and bottom indicators of feeler detectors, if damaged, repair or replace them.
Check the hairsprings of auto-stop motion in top and middle, arm rod of top stop motion, and the feelers of feeler detectors. Check their sensitivity, if malfunctioned, replace them right away.
Check the ceramic eyes of guide yarn of auto-stop motion in top and middle, if worn out or damaged, replace them right away.
Adjust the tension of each arm rod spring of top and middle auto-stop motion to make uniform reaction when down due to increased yarn tension.
2、Checking tension device:
Check if the numbers on the tension-meter scale are the same.
Check ceramic eyes of guide yarn of the tension-meter to see if worn out or dropped.
Calibrate each tension-meter to make each yarn tension through the tension-meter is the same.
3、Checking positive feed device:
Check the belt of positive feed, press it by hand to see if the tension is proper.
Check positive feed wheel, iron wheel, and tripod to see if they are flexible while running.
4、Check fabric winder:
Check springs and screws in each part to see if they are loose.
Check if the bevel gear of the chassis and the driving shaft are loose, the eccentric size of the eccentric block and the both directions are the same to avoid unbalanced rolling fabric.
(D)Lubrication of knitting parts:
1、 Varieties of lubrication:
NEEDLE OIL: Low impurities, used to lubricate precise running parts such as medium 30# spindle oil or NUR FITEX22# needle oil of ETROFINA (U.K.) LTD's FINA to put into oil tank of injector or into the cylinder directly.
MEDIUM MACHINE OIL: Used for lubrication of axle and other parts, such as medium 65# gear oil.
HEAVY GEAR LUBRICANT: Used to lubricate driving gears ( or reduction box). SAE20# to SAE40# gear oils can be used.
CUP GREASE: Used in oil nozzles. Check once every half a year. If consumed, add with grease gun.
SPECIAL GEAR BOX OIL: Special for reduction box. Medium oil 140#-160# oils can be used.
The oil in the oil injector can be added according to the following brands and specifications:
a.Brand: FINA b.Specifications: ETROFINA (UK ) LTD.
c.Designation: NURFINTEX22
2、Lubrication of the knitting parts:
Use SAF20#-SAE40# oil for all mechanical parts, gears, spindle driving gear, driving gear of roller etc which run the whole clay. Add high viscosity lubricant once half a year.
 Add special gear oil for driving gear in the main plate. If any deposits, replace new oil right away.
3、Lubrication operation:
a、Shift chief's checking operation:
Pay attention momentarily to the oil amount in oil tank of auto-oil-supply system to keep the oil in a certain level frequently.
Check the oil outlet of auto oil injection system to see if the vitta is broken, nozzle dropped off, proper oil out flow. Control the oil amount by adjusting screw. If the screw is loose, replace it right away.
Check if the oil in cylinder is too much, if so, try to pump out to keep from tainting the fabric.
b、Maintenance administrator's checking operation: 
Be sure of lubrication time and oil varieties of each part of the all machine so as to ensure lubrication at the set time with set variety and amount.
(E) Maintenance of motor and electrical system:
Motor and electrical system is the power source of the machine. Periodical maintenance should be carried out seriously to prevent unnecessary troubles. The following are the main points of the operation:
1、Check if any leakage of electricity.
2、Check if the fuse and the carbon brush of motor are damaged (no carbon brush in V.S motor and inverter motor).
3、 Check if switch buttons are malfunctioned.
4、 Check if electrical line is frayed or cut off.
5、 Check the motors, connect circuits to clean each part and lubricate the bearings.