23. Winder line (distance between the wales opened or closed)
DESCRIPTION & ROOT CAUSES OF KNITTING FAULTS
1. Drop stitches: – It is a small aperture formed as a result of an inadvertently cast-off loop and where the yarn is not broken. General (All m/c’s)
Root cause
Checks
Action
Feeder/s not down properly. (After lifting feeder to remove fluff)
Check for feeder/s that are not pressed down properly.
Press feeder/s down completely.
Extremely weak yarn supply tension. Uneven yarn supply tension ( too high & too low )
Check if yarn path is correct– i.e. yarn guides, potholes, and feeders. See yarn threading diagram. Check if yarn-feeding unit (Iro) is turning freely.Check if yarn tension is to specification. (Refer to Knitting tension specs)
If not correct rethread according to yarn threading diagram If not turning freely, replace with spare one Adjust according to yarn tension specs.
Needles are damaged or bent in cases of drop stitches in a vertical line.
Trace the faulty needles.
Replace with new needles
Position of feeders too far from needles.
Use color yarn to identify the feeder/s causing the problem. (See procedure for tracing problem feeders)
Set feeder/s according to Feeder setting specs
Loose feeder/s or loose feeder block/s.
Check for loose feeder/s and feeder blocks.
Tighten feeder/s and set according to Feeder setting specs. If feeder block threads are damaged, replace with new ones.
2. Needle & Sinker line: – Vertical lines going down the wale of the fabric different in configuration/appearance from the adjacent wales. General (All m/c’s)
Root cause
Checks
Action
Comments
Needles and sinkers are floating due to lint build up in tracks.
Check for needles and sinkers that are floating due to lint build up in tricks
Take out needles and sinkers in the affected areas and clean up the lint & re-fit needles and sinkers.
If needle and sinker lines are all around the fabric tube, a Strip & Clean might be necessary. Check Rev chart for Strip & Clean.
Needles and sinkers are damaged or bent.
Check for damaged/bent needles and sinkers.
Replace needles and sinkers in the affected areas.
Wrong needles and sinkers for the machine gauge.
Check for wrong needles and sinkers for the machine gauge.
Replace the wrong needles and sinkers with the right ones. See needle check-????
Insufficient oil supply to needles and sinkers
Check if the oil level is not too low. If 1 is ok, check if solenoid is working. If 2 is ok, check if there is compressed air and pressure is set according to specs.If 3 is ok, check if oil drop rate is set according to specs.If 4 is ok, check visually if oil mist are moving through the oiler pipes.If 5 is ok, check if the nozzles in the cam boxes are not blocked.
If too low, fill up to the maximum level with the correct oil. (See refill procedure)If not working, fix or replace solenoid.If not to specs, set air pressure according to specs.If not to specs, set oil drop rate according to spec.If not moving, unblock oiler nozzles.If blocked, clean and unblock nozzle
Tight or damaged tracks
Check for tight needle and or needle movement.
If tricks are tight, loosen and polish with trick file where necessary.
3. Holes: – Small aperture in the fabric. General (All m/c’s)
Root cause
Checks
Action
Weak yarn.
Check for weak yarn.
Replace faulty yarn.
Incorrect threading.
Check if yarn path is correct– i.e. yarn guides, potholes, and feeders. See yarn threading diagram.
If not correct rethread according to yarn threading diagram
Excessive yarn supply tension.
Check if yarn tension is to specification. (Refer to Knitting tension specs)
Adjust according to yarn tension specs.
Fluff – Poor house keeping
Check for fluff/house keeping.Check if flutter blower is operating.Check if all fans are turn on and turning.
Clean where necessary.If not operating, fix.If not on, switch on. If not, call electrician.
Thick and thin yarn & slubs.
Check for faulty yarn.
Replace faulty yarn.
Hand tied knots too big.
Knitters to use splicer where possible and do proper hand knots where necessary. ( See Hand knot procedure)
On Double jersey machines, wrong timing might be a problem.
1. Check machine timing according to timing specs.
Adjust timing to the Timing specs.
On Double jersey machines, wrong gating might be a problem.
1. Check machine gating according to Gating specs.
Adjust gating to the Gating specs.
4. Ladders: – A vertical line of unformed stitches caused by a broken needle hook or a needle with a closed latch. General (All m/c’s)
Root cause
Checks
Action
A longitudinal line caused by one or more broken needle hooks.
Check for one or more broken needles.
Replace the damaged needles.
A needle with a closed latch(maybe a stiff latch)
Check for a needle with a closed latch. ( or a stiff latch)
Replace the affected needle.
Needles are floating due to lint build up in tricks, touching the feeders. Thus damaging the needles.
Check whether needles are not floating due to fluff and dirt behind the needles.
Take out needles in the affected areas and clean up the lint & re-fit needles.
Feeder too close to the needles. Thus damaging the needles.
Check if feeder setting is correct. (See Feeder stetting specs)
If not correct, set feeder/s according to Feeder setting specs
Thick slubs in the yarn causing the needle hooks to break.
Check whether knot catchers are not missing. Check yarn for excessive thick slubs.
If missing, fit appropriate knot catchers. (See Knot catcher table)If there are excessive thick slubs, report to manager.
Fluff – Poor house keeping
Check for fluff/house keeping.Check if flutter blower is operating.Check if all fans are turn on and turning.
Clean where necessary.If not operating, fix.If not on, switch on. If not, call electrician.
5. Tuck flaw or crow feet: – A fault with a loop that has been held on the previous course. General (All m/c’s)
Root cause
Checks
Action
A needle with a bent latch causes them.
Check for a needle with a bent latch.
Trace the affected needle and replace.
A needle with an open hook.
Check for a needle with an open hook.
Trace the affected needle and replace.
Not enough takedown or not enough pressure on takedown roller.
Check if takedown is not slipping. Check if takedown is enough.(See Takedown specs)
Check and adjust according to specs.Increase takedown according to Takedown specs.
Chipped needle and/or sinker butt.
Check for chipped needle and /or sinker butt.
Open all cam boxes and look for butt piece/s.Blow all the cam boxes.Replace damaged needle.Close and tighten all the cam boxes.
Bad gating on double jersey.
Check if gating is correct. (See Gating specs)
If not correct, set according to Gating specs.
Feeders not properly adjusted, causing bent latches.
Check if feeder setting is correct. (See Feeder stetting specs)
If not correct, set feeder/s according to Feeder setting specs
6. Oil marks: – Deposited oils that has been absorbed on the fabric and has caused discoloration on the fabric. General (All m/c’s)
Root cause
Checks
Action
Overflowing oil from the machine bed.
Check if drainpipe is blocked. Check if there are no oil spills on the takedown rollers.
Unblock drainpipe. Clean bottom of machine bed. Clean takedown rollers.
Too much oil from the oiler, produces light oil stripes
Check if oil drip rate is not too much. (See Oil drip rate specs). Slightly reduce the quantity.
Adjust according to specs.
Knitter not blowing the machine after manual flushing.
Check machine for fluff accumulation between the sinker cap ring and the cylinder cams.
Knitter must blow after each and every manual flushing.
Insufficient oil leads to dark longitudinal stripes, caused by abrasion of the needles
Check the setting of the oil is correct.The oiler is not blocked.
Increase the lubrication quantity.Flush manually with oil at intervals
7. Yarn line: – A horizontal line that goes around the fabric tube for more than one revolution. General(All m/c’s)
Root cause
Checks
Action
Thin yarn – thinner Tex than required.
Check if yarnTex are different.
Trace wrong yarn & replace with correct one.
Thick yarn – thicker Tex than required.
Check if yarnTex are different.
Trace wrong yarn & replace with correct one.
Wrong yarn –Mixed type
Check if yarn type is mixed.
If mixed, replace with correct yarn type.
8. Iro lines: – A horizontal line that goes around the fabric tube continuously. The stitches are smaller on that course than the others. General
(All m/c’s)
Root cause
Checks
Action
Unlock IRO or out of tape/belt.
Check it Iro is unlocked.Check if belt is in the right position.
Lock IRO into positionPut tape/belt in the right position.
Empty Iro – one or two wraps around the spool only.
Check if there are enough wraps around the spool. See Iro Drawing)
Fill according to Iro drawings.
9. Stopping lines: – A horizontal line that goes around the fabric tube for one revolution. The stitches are smaller on that course than the others. General (All m/c’s)
Root cause
Checks
Action
Positive belts slipping – tension on belts not enough.
Check if belt tension is to specs.
Tighten tension of belts according to Specs.
Positive belts slipping – too many Iros running on one belt.
Check if there are too many Iros one belt.
Re-arrange Iros so that load is split on two belts.
10. Foreign Contamination/fibre: – Color specks/fibre in the fabric. General (All m/c’s)
Root cause
Checks
Action
Foreign fibre i.e. non-cotton fibres spun in the yarn.
Check if the contamination is visible on the cones.
Very difficult to trace offending yarn cones. Report to supervisor/manager
11. Barre: – A horizontal stripe lighter or darker than the rest of the fabric. Width of the stripe might vary. General (All m/c’s)
Root cause
Checks
Action
Mixed merges and/or batches are knitted together.
Check yarn on the creel for mixed merges, batches and/or week no.
If mixed merges/batches/week no. are found, replace with correct yarn.If merges/batches/week no. are ok, send a meter piece of fabric for dyeing in the washing machine & a meter piece to the dyehouse for dyeing.If no barre after above procedure, continue knitting. If barre, report to manager and planning.
Wax barre – Yarn with different wax level on the yarn. ( Yarn merges/batches are not mixed)
Check yarn on the creel for mixed merges, batches and/or week no.
Send a meter piece of fabric for dyeing in the washing machine & a meter piece to the dyehouse for dyeing. If no barre after above procedure, continue knitting. If barre, report to manager and planning.
12. Abrasion marks: – An area of localized wear characterized by the presence of excessive surface hairiness or denuded fibre. It is a surface fault on the fabric.
Root cause
Checks
Action
Severe physical contact or pressure with a rough surface causes this fault.
Check whether spreader height is not too low, thus rubbing onto the takedown rollers.Check whether spreader wheels on the Inspection machine are turning freely.
Raise and set spreader at specified height.(See specs) Clean and ensure that turning freely.
13. Slubs: – A thickened place in the fabric of different length where the yarn knitted in that area is at least 50 % thicker than the normal diameter of the yarn used. General (All m/c’s)
Root cause
Checks
Action
Bad yarn clearing from the yarn supplier.
Check whether problem started with a new week no. Or merge.If 1 is no, trace the bad yarn/s if possible.
If yes, creel with a fresh week no. or merge. If no improvement, report to manager.If bad cones are found, replace with fresh cones. If no improvement, report to manager.
14. Snags:- Yarns or filament in the form of long loops that are protruding from the surface of the fabric. General (All
Root cause
Checks
Action
Sharp or protruding objects pulling on the fabric surface.
Trace back the fabric route and check for sharp or protruding corners and ends.
Polish where necessary
15. Press-off: – Partial or complete breakdown of the fabric structure. General (All m/c’s)
Root cause
Checks
Action
Fluff in the feeders.
Check knitting machine for cleanliness.
Clean the knitting machine.
Yarn tension too high.
Check if yarn tension is to specification. (Refer to Knitting tension specs)
Adjust according to yarn tension specs.
Weak yarn.
Check for weak yarn.
Replace faulty yarn.
Cuts or nicks in the feeder hole.
Check for damaged feeders.
Replace the damaged feeder/s and re-set according to Feeder setting specs.
Too little yarn wraps around the spool.
Check if there are enough wraps around the spool. (See Iro Drawing)
Fill according to Iro drawings and procedure. Half -way full
16. Pulled threads/loops: – An area on the loop/piles side of the fabric where the loop/pile has been pulled. S/Jersey m/c’s
Root cause
Checks
Action
Sharp or protruding objects pulling the loop/pile on the fabric surface.
Trace back the fabric route and check for sharp or protruding corners and ends.
Polish where necessary
17. Missed loops: – An area on the loop/pile side of the fabric where the loop has not been tucked in. Single Jersey m/c’s
Root cause
Checks
Action
Feeder setting not correct.
Check feeders according to Feeder set-up specs.
Check feeders according to Feeder set-up specs.
18. Lycra misplaiting: – Little horizontal indentations of various lengths on the surface of the fabric. General (All m/c’s)
Root cause
Checks
Action
Wrong feeder setting.
1. Check feeders according to Feeder set-up specs.
1. Check feeders according to Feeder set-up specs.
Lycra feed wheel/rollers dirty & not turning.
Check if Lycra wheels are turning freely.
Clean the lycra wheels.
Lycra wrapped at the end of the feeder.
Check yarn path from the elastane spool to the feeder. (See threading diagram)
Correct threading according to threading diagram if necessary.
19. Lycra breaks: – A horizontal fault of various lengths where the lycra has been broken. General (All m/c’s)
Root cause
Checks
Action
Comments
Bad winding – Lycra breaking constantly.
Check whether it is the same spool breaking all the time.
If same spool breaking all the time, replace the faulty spool.
Tension too high.
Check if yarn tension is to specification. (Refer to Knitting tension specs)
Adjust according to yarn tension specs.
20 Needle breaks
Root cause
Checks
Action
Comments
Size of yarn carrier correct
Size of slub catcher correct
Fluff dropping from the roof
Fans not working, positioned correctly…build up of fluff.
Air flutters not working, build up of fluff
21 Winder line – Distance between the wales closed, or wales opened too much
Root cause
Checks
Action
Comments
Fluff between the needles
Check if any fluff evident, especially the airlines (usually 1 or 2), blowing through the cylinder
Remove fluff
Fabric wound too tight on roll
Check tension of fabric by hand, compare to other machines
Reduce tension, until line disappears
Too less tension will cause problems with winding the roll
Edge of expander damaged
Check for sharp points, damage to the frame
Call engineers for repairs
Edge line of fabric not between segments of take down roller
Check if the edge of the fabric is approx 1cm over the end of the segment
Simply Defined, Viscosity is a measure of flow. Practically defined , Viscosity is a measureable property of how thick or thin the color paste is.
The thickness or thinness is measured with a viscometer and given a number. As a relative example a color paste with a viscosity number of 5000 cps is thin (weak resistance to flow), Whereas a color paste viscosity of 25000 cps is thick (strong resistance of flow )
Keeping this in mind , most screen printers like to work with print paste viscosities in the broad range of 10,000 – 20,000 for pigments . But more specifically they find 12000-15000 quite acceptable .
Why do screen printers prefer this range ? Through many years of experience , this viscosity range has proven to be the best for color paste “behaviour “ in the screen printing equipment . By behaviour we mean the physical way the color paste arts inside the screen as printing take place.
For example, when the print machine stops temporarily, The color paste remains in place . The resistance to flow is strong enough to prevent it from pooling and leaking out the sides of the screens. But most importantly , the color paste will flow effectively inside the screen during printing to allow a continuous , even transfer through the screen mesh to the fabric surface.
There are some situation where a lower than normal or higher than normal viscosity will be preferred .
Low Viscosity – Less than 10000 , Provides better performace for printing on fabrics with uneven surfaces . eg towel, rugs, blankets
High Viscosity – Greater than 20000 – Provides better control for fine line printing
Do we know why in swimming pools we use lot chlorine ?
Many people keep their eyes closed or wear goggles when they go swimming at the pool, in an attempt to prevent the burning and itching often blamed on chlorine. However, the truth about the cause of those stinging sensations is a real eye-opener — and not in a particularly pleasant way. While chlorine is used to kill germs, the source of the eye pain is something known as chloramines, which are created when the chlorine binds with sweat, urine and other bodily fluids that end up in the pool.
The chloramines form in the water, but they also rise into the air thanks to air circulation and people splashing around. So if the pool is located in an enclosed space with limited ventilation, the irritation can get worse, affecting not only the eyes and skin, but also breathing. Ideally, pool operators should take steps to limit the amount of chloramines that can build up by ensuring that plenty of fresh air is pumped into the pool area.
As for the swimmers, they can help by wearing bathing caps, taking a shower before jumping in, and –needless to say — not turning the water around them yellow.
Swimming Pool
Chlorination for swimming pools
Chlorine is a chemical that disinfects the water and helps to remove debris. You should use a chlorine stabiliser to extend the chlorine’s half-life. Generally, the longer your filtration cycle, the less chlorine you will need. Similarly, the more chlorine you use, the shorter your required filtration cycle.
Remember that your chlorine requirements will be affected by a range of factors, including your pump and filter system, water temperature, water level, amount of debris and the number of swimmers in your pool.
What is the disinfection of garments .What is the need of disinfection of the garments. This is the primary question now days in every body mind after these Covid-19 crises. Just to explain the need , we will wash our hands, many times a day, that is a given – even the smallest child knows that we should wash hands for 20 seconds but what about the clothes?
It is always better to be careful and do everything you can. Today’s world situation is due to little carelessness only.
As we all know we may be getting infected by the Covid-19 Virus through many media. It may be through garments also. The assumed life of the Virus on the Garments is 7-10 hours based on humid conditions and temperature. With this it is well understood the need to disinfects our garments.
The next things comes in mind that it means whatever garments we will purchase from any shop may be infected , So how to insure it is disinfected . It is very important for the entire retails counter, Multi Brand Store, Single Brand Store selling the garments.
As retail counter Supplier, faces two types of challenges.Each consumer touches the garments to get the feel of the fabric before purchasing the garment. To feel you need to remove your hand gloves.
Each consumer likes to do fit test before purchasing by wearing the garments, which will touch the Body.
Wearer Trial before taking final decision to purchase
And after these trials it is not sure that consumer will purchase the garments. By this the retail counter are under high risk of infection.Hence it is responsibility of User and retail counter owner both to insure that no one is getting infected due to any virus.
Above we talked about the Concern. Next thing comes in mind should we stop the purchasing garments? This is not a purpose of describing concern. We need to provide solution for every concern raised by any idea.
The solution is to disinfect the garments.There are so many methods to disinfect the garments
Chemical method
With steam and temp (By ironing)
By the Ultra Violet Light.
Chemical Disinfection
Disinfectants are chemical agents designed to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores. It is less effective than sterilization, which is an extreme physical or chemical process that kills all types of life.As we understand that Chemical method disinfection is not possible in retails counter,
Steam and Heat Disinfection
Steam and temp disinfection is not of that speed and need boiler at each retail counter to generate steam. This is also not a very practical solution. A steaming process, likewise, which heats things to between 248°F and 302°F can also disinfect.
Ultra Violet Light Disinfection
Ultraviolet germicidal irradiation (UVGI) is a disinfection method that uses short- wavelength ultra violet light to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular functions.
UV light is electromagnetic radiation with wavelengths shorter than visible light but longer than X – Rays. UV is categorised into several wavelength ranges, with short-wavelength UV (UVC) considered “germicidal UV”. Wavelengths between about 200 nm and 300 nm are strongly absorbed by nucleic acids. The absorbed energy can result in defects including pyrimidine dimers. These dimers can prevent replication or can prevent the expression of necessary proteins, resulting in the death or inactivation of the organism.This process is similar to the effect of longer wavelengths (UVB) producing sunburn in humans. Microorganisms have less protection against UV and cannot survive prolonged exposure to it
Effectiveness
The effectiveness of germicidal UV depends on the length of time a microorganism is exposed to UV, the intensity and wavelength of the UV radiation, the presence of particles that can protect the microorganisms from UV, and a microorganism’s ability to withstand UV during its exposure.In many systems, redundancy in exposing microorganisms to UV is achieved by circulating the air or water repeatedly. This ensures multiple passes so that the UV is effective against the highest number of microorganisms and will irradiate resistant microorganisms more than once to break them down.The effectiveness of this form of disinfection depends on line of sight exposure of the microorganisms to the UV lightDust and films coating the bulb lower UV output. Therefore, bulbs require periodic cleaning and replacement to ensure effectiveness. The lifetime of germicidal UV bulbs varies depending on design. Also, the material that the bulb is made of can absorb some of the germicidal rays.Lamp cooling under airflow can also lower UV output; thus, care should be taken to shield lamps from direct airflow, or to add additional lamps to compensate for the cooling effect.
Measurements of Effectiveness.
One way to compare disinfectants is to compare how well they do against a known disinfectant and rate them accordingly. Phenol is the standard, and the corresponding rating system is called the “Phenol coefficient”. The disinfectant to be tested is compared with phenol on a standard microbe. Disinfectants that are more effective than phenol have a coefficient > 1. Those that are less effective have a coefficient < 1.
The standard European approach for disinfectant validation consists of a basic suspension test, a quantitative suspension test (with low and high levels of organic material added to act as ‘interfering substances’) and a two part simulated-use surface test.
A less specific measurement of effectiveness is the United States Environmental Protection
(EPA) classification into either high, intermediate or low levels of disinfection. “High-level disinfection kills all organisms, except high levels of bacterial spores” and is done with a chemical germicide marketed as a sterilant by the U.S. Food and Drug Administration (FDA). “Intermediate-level disinfection kills mycobacteria, most viruses, and bacteria with a chemical germicide registered as a ‘tuberculocide’ by the Environmental Protection Agency. Low-level disinfection kills some viruses and bacteria with a chemical germicide registered as a hospital disinfectant by the EPA. An alternative assessment is to measure the Minimum inhibitory concentrations (MICs) of disinfectants against selected (and representative) microbial species, such as through the use of micro broth dilution testing. However, those methods are obtained at standard inoculum levels without considering the inoculum effect. More informative methods are nowadays in demand to determine the minimum disinfectant dose as a function of the density of the target microbial species.
Dangerous Of UV Light Exposure to Body
Most skin cancers are a result of exposure to the UV rays in sunlight. Both basal cell and squamous cell cancers (the most common types of skin cancer) tend to be found on sun-exposed parts of the body, and their occurrence is typically related to lifetime sun exposure.
The risk of melanoma, a more serious but less common type of skin cancer, is also related to sun exposure, although perhaps not as strongly. Skin cancer has also been linked to exposure to some man-made sources of UV rays.
And UV light is harmful for the eyes also if one is exposed in the only UV light room for longer period, so please do not allow any person to stand in the UV room, or UV light box.
How to Do It
Now question comes how to do it. So we need to design one simple machine for that. It is very simple as like below figure, Fit the three UV Tube lights of full width, and keep 45 sec to 60 sec any garment in open condition in this machine.
When to Do.
Whenever one touches it, prior to touch and after touch at both stage.
Knitted finished fabric may have different type of defects , it may be due to yarn, Knitting, Processing. Here we will discuss about knitting related defects
List of Knitting Faults and their route causes
Drop stitches
Needle & Sinker line
Holes
Ladders
Tuck flaw or crow feet
Oil marks
Yarn lines
Iro lines
Stopping lines
Foreign contamination/fibre
Barre
Abrasion marks
Slubs
Snags
Press/off
Pulled threads/loop
Missed loops
Lycra misplating
Lycra breaks
Oil line
Fleper tension
Wrong creeling of yarn
23. Winder line (distance between the wales opened or closed)
1. Drop stitches: – It is a small aperture formed as a result of an inadvertently cast-off loop and where the yarn is not broken. General (All m/c’s)
Root cause
Checks
Action
Feeder/s not down properly. (After lifting feeder to remove fluff)
Check for feeder/s that are not pressed down properly.
Press feeder/s down completely.
Extremely weak yarn supply tension. Uneven yarn supply tension ( too high & too low )
Check if yarn path is correct– i.e. yarn guides, potholes, and feeders. See yarn threading diagram. Check if yarn-feeding unit (Iro) is turning freely.Check if yarn tension is to specification. (Refer to Knitting tension specs)
If not correct rethread according to yarn threading diagram If not turning freely, replace with spare one Adjust according to yarn tension specs.
Needles are damaged or bent in cases of drop stitches in a vertical line.
Trace the faulty needles.
Replace with new needles
Position of feeders too far from needles.
Use color yarn to identify the feeder/s causing the problem. (See procedure for tracing problem feeders)
Set feeder/s according to Feeder setting specs
Loose feeder/s or loose feeder block/s.
Check for loose feeder/s and feeder blocks.
Tighten feeder/s and set according to Feeder setting specs. If feeder block threads are damaged, replace with new ones.
2. Needle & Sinker line: – Vertical lines going down the wale of the fabric different in configuration/appearance from the adjacent wales. General (All m/c’s)
Root cause
Checks
Action
Comments
Needles and sinkers are floating due to lint build up in tracks.
Check for needles and sinkers that are floating due to lint build up in tricks
Take out needles and sinkers in the affected areas and clean up the lint & re-fit needles and sinkers.
If needle and sinker lines are all around the fabric tube, a Strip & Clean might be necessary. Check Rev chart for Strip & Clean.
Needles and sinkers are damaged or bent.
Check for damaged/bent needles and sinkers.
Replace needles and sinkers in the affected areas.
Wrong needles and sinkers for the machine gauge.
Check for wrong needles and sinkers for the machine gauge.
Replace the wrong needles and sinkers with the right ones. See needle check-????
Insufficient oil supply to needles and sinkers
Check if the oil level is not too low. If 1 is ok, check if solenoid is working. If 2 is ok, check if there is compressed air and pressure is set according to specs.If 3 is ok, check if oil drop rate is set according to specs.If 4 is ok, check visually if oil mist are moving through the oiler pipes.If 5 is ok, check if the nozzles in the cam boxes are not blocked.
If too low, fill up to the maximum level with the correct oil. (See refill procedure)If not working, fix or replace solenoid.If not to specs, set air pressure according to specs.If not to specs, set oil drop rate according to spec.If not moving, unblock oiler nozzles.If blocked, clean and unblock nozzle
Tight or damaged tracks
Check for tight needle and or needle movement.
If tricks are tight, loosen and polish with trick file where necessary.
3. Holes: – Small aperture in the fabric. General (All m/c’s)
Root cause
Checks
Action
Weak yarn.
Check for weak yarn.
Replace faulty yarn.
Incorrect threading.
Check if yarn path is correct– i.e. yarn guides, potholes, and feeders. See yarn threading diagram.
If not correct rethread according to yarn threading diagram
Excessive yarn supply tension.
Check if yarn tension is to specification. (Refer to Knitting tension specs)
Adjust according to yarn tension specs.
Fluff – Poor house keeping
Check for fluff/house keeping.Check if flutter blower is operating.Check if all fans are turn on and turning.
Clean where necessary.If not operating, fix.If not on, switch on. If not, call electrician.
Thick and thin yarn & slubs.
Check for faulty yarn.
Replace faulty yarn.
Hand tied knots too big.
Knitters to use splicer where possible and do proper hand knots where necessary. ( See Hand knot procedure)
On Double jersey machines, wrong timing might be a problem.
1. Check machine timing according to timing specs.
Adjust timing to the Timing specs.
On Double jersey machines, wrong gating might be a problem.
1. Check machine gating according to Gating specs.
Adjust gating to the Gating specs.
4. Ladders: – A vertical line of unformed stitches caused by a broken needle hook or a needle with a closed latch. General (All m/c’s)
Root cause
Checks
Action
A longitudinal line caused by one or more broken needle hooks.
Check for one or more broken needles.
Replace the damaged needles.
A needle with a closed latch(maybe a stiff latch)
Check for a needle with a closed latch. ( or a stiff latch)
Replace the affected needle.
Needles are floating due to lint build up in tricks, touching the feeders. Thus damaging the needles.
Check whether needles are not floating due to fluff and dirt behind the needles.
Take out needles in the affected areas and clean up the lint & re-fit needles.
Feeder too close to the needles. Thus damaging the needles.
Check if feeder setting is correct. (See Feeder stetting specs)
If not correct, set feeder/s according to Feeder setting specs
Thick slubs in the yarn causing the needle hooks to break.
Check whether knot catchers are not missing. Check yarn for excessive thick slubs.
If missing, fit appropriate knot catchers. (See Knot catcher table)If there are excessive thick slubs, report to manager.
Fluff – Poor house keeping
Check for fluff/house keeping.Check if flutter blower is operating.Check if all fans are turn on and turning.
Clean where necessary.If not operating, fix.If not on, switch on. If not, call electrician.
5. Tuck flaw or crow feet: – A fault with a loop that has been held on the previous course. General (All m/c’s)
Root cause
Checks
Action
A needle with a bent latch causes them.
Check for a needle with a bent latch.
Trace the affected needle and replace.
A needle with an open hook.
Check for a needle with an open hook.
Trace the affected needle and replace.
Not enough takedown or not enough pressure on takedown roller.
Check if takedown is not slipping. Check if takedown is enough.(See Takedown specs)
Check and adjust according to specs.Increase takedown according to Takedown specs.
Chipped needle and/or sinker butt.
Check for chipped needle and /or sinker butt.
Open all cam boxes and look for butt piece/s.Blow all the cam boxes.Replace damaged needle.Close and tighten all the cam boxes.
Bad gating on double jersey.
Check if gating is correct. (See Gating specs)
If not correct, set according to Gating specs.
Feeders not properly adjusted, causing bent latches.
Check if feeder setting is correct. (See Feeder stetting specs)
If not correct, set feeder/s according to Feeder setting specs
6. Oil marks: – Deposited oils that has been absorbed on the fabric and has caused discoloration on the fabric. General (All m/c’s)
Root cause
Checks
Action
Overflowing oil from the machine bed.
Check if drainpipe is blocked. Check if there are no oil spills on the takedown rollers.
Unblock drainpipe. Clean bottom of machine bed. Clean takedown rollers.
Too much oil from the oiler, produces light oil stripes
Check if oil drip rate is not too much. (See Oil drip rate specs). Slightly reduce the quantity.
Adjust according to specs.
Knitter not blowing the machine after manual flushing.
Check machine for fluff accumulation between the sinker cap ring and the cylinder cams.
Knitter must blow after each and every manual flushing.
Insufficient oil leads to dark longitudinal stripes, caused by abrasion of the needles
Check the setting of the oil is correct.The oiler is not blocked.
Increase the lubrication quantity.Flush manually with oil at intervals
7. Yarn line: – A horizontal line that goes around the fabric tube for more than one revolution. General(All m/c’s)
Root cause
Checks
Action
Thin yarn – thinner Tex than required.
Check if yarnTex are different.
Trace wrong yarn & replace with correct one.
Thick yarn – thicker Tex than required.
Check if yarnTex are different.
Trace wrong yarn & replace with correct one.
Wrong yarn –Mixed type
Check if yarn type is mixed.
If mixed, replace with correct yarn type.
8. Iro lines: – A horizontal line that goes around the fabric tube continuously. The stitches are smaller on that course than the others. General
(All m/c’s)
Root cause
Checks
Action
Unlock IRO or out of tape/belt.
Check it Iro is unlocked.Check if belt is in the right position.
Lock IRO into positionPut tape/belt in the right position.
Empty Iro – one or two wraps around the spool only.
Check if there are enough wraps around the spool. See Iro Drawing)
Fill according to Iro drawings.
9. Stopping lines: – A horizontal line that goes around the fabric tube for one revolution. The stitches are smaller on that course than the others. General (All m/c’s)
Root cause
Checks
Action
Positive belts slipping – tension on belts not enough.
Check if belt tension is to specs.
Tighten tension of belts according to Specs.
Positive belts slipping – too many Iros running on one belt.
Check if there are too many Iros one belt.
Re-arrange Iros so that load is split on two belts.
10. Foreign Contamination/fibre: – Color specks/fibre in the fabric. General (All m/c’s)
Root cause
Checks
Action
Foreign fibre i.e. non-cotton fibres spun in the yarn.
Check if the contamination is visible on the cones.
Very difficult to trace offending yarn cones. Report to supervisor/manager
11. Barre: – A horizontal stripe lighter or darker than the rest of the fabric. Width of the stripe might vary. General (All m/c’s)
Root cause
Checks
Action
Mixed merges and/or batches are knitted together.
Check yarn on the creel for mixed merges, batches and/or week no.
If mixed merges/batches/week no. are found, replace with correct yarn.If merges/batches/week no. are ok, send a meter piece of fabric for dyeing in the washing machine & a meter piece to the dyehouse for dyeing.If no barre after above procedure, continue knitting. If barre, report to manager and planning.
Wax barre – Yarn with different wax level on the yarn. ( Yarn merges/batches are not mixed)
Check yarn on the creel for mixed merges, batches and/or week no.
Send a meter piece of fabric for dyeing in the washing machine & a meter piece to the dyehouse for dyeing. If no barre after above procedure, continue knitting. If barre, report to manager and planning.
12. Abrasion marks: – An area of localized wear characterized by the presence of excessive surface hairiness or denuded fibre. It is a surface fault on the fabric.
Root cause
Checks
Action
Severe physical contact or pressure with a rough surface causes this fault.
Check whether spreader height is not too low, thus rubbing onto the takedown rollers.Check whether spreader wheels on the Inspection machine are turning freely.
Raise and set spreader at specified height.(See specs) Clean and ensure that turning freely.
13. Slubs: – A thickened place in the fabric of different length where the yarn knitted in that area is at least 50 % thicker than the normal diameter of the yarn used. General (All m/c’s)
Root cause
Checks
Action
Bad yarn clearing from the yarn supplier.
Check whether problem started with a new week no. Or merge.If 1 is no, trace the bad yarn/s if possible.
If yes, creel with a fresh week no. or merge. If no improvement, report to manager.If bad cones are found, replace with fresh cones. If no improvement, report to manager.
14. Snags:- Yarns or filament in the form of long loops that are protruding from the surface of the fabric. General (All
Root cause
Checks
Action
Sharp or protruding objects pulling on the fabric surface.
Trace back the fabric route and check for sharp or protruding corners and ends.
Polish where necessary
15. Press-off: – Partial or complete breakdown of the fabric structure. General (All m/c’s)
Root cause
Checks
Action
Fluff in the feeders.
Check knitting machine for cleanliness.
Clean the knitting machine.
Yarn tension too high.
Check if yarn tension is to specification. (Refer to Knitting tension specs)
Adjust according to yarn tension specs.
Weak yarn.
Check for weak yarn.
Replace faulty yarn.
Cuts or nicks in the feeder hole.
Check for damaged feeders.
Replace the damaged feeder/s and re-set according to Feeder setting specs.
Too little yarn wraps around the spool.
Check if there are enough wraps around the spool. (See Iro Drawing)
Fill according to Iro drawings and procedure. Half -way full
16. Pulled threads/loops: – An area on the loop/piles side of the fabric where the loop/pile has been pulled. S/Jersey m/c’s
Root cause
Checks
Action
Sharp or protruding objects pulling the loop/pile on the fabric surface.
Trace back the fabric route and check for sharp or protruding corners and ends.
Polish where necessary
17. Missed loops: – An area on the loop/pile side of the fabric where the loop has not been tucked in. Single Jersey m/c’s
Root cause
Checks
Action
Feeder setting not correct.
Check feeders according to Feeder set-up specs.
Check feeders according to Feeder set-up specs.
18. Lycra misplaiting: – Little horizontal indentations of various lengths on the surface of the fabric. General (All m/c’s)
Root cause
Checks
Action
Wrong feeder setting.
1. Check feeders according to Feeder set-up specs.
1. Check feeders according to Feeder set-up specs.
Lycra feed wheel/rollers dirty & not turning.
Check if Lycra wheels are turning freely.
Clean the lycra wheels.
Lycra wrapped at the end of the feeder.
Check yarn path from the elastane spool to the feeder. (See threading diagram)
Correct threading according to threading diagram if necessary.
19. Lycra breaks: – A horizontal fault of various lengths where the lycra has been broken. General (All m/c’s)
Root cause
Checks
Action
Comments
Bad winding – Lycra breaking constantly.
Check whether it is the same spool breaking all the time.
If same spool breaking all the time, replace the faulty spool.
Tension too high.
Check if yarn tension is to specification. (Refer to Knitting tension specs)
Adjust according to yarn tension specs.
20 Needle breaks
Root cause
Checks
Action
Comments
Size of yarn carrier correct
Size of slub catcher correct
Fluff dropping from the roof
Fans not working, positioned correctly…build up of fluff.
Air flutters not working, build up of fluff
21 Winder line – Distance between the wales closed, or wales opened too much
Root cause
Checks
Action
Comments
Fluff between the needles
Check if any fluff evident, especially the airlines (usually 1 or 2), blowing through the cylinder
Remove fluff
Fabric wound too tight on roll
Check tension of fabric by hand, compare to other machines
Reduce tension, until line disappears
Too less tension will cause problems with winding the roll
Edge of expander damaged
Check for sharp points, damage to the frame
Call engineers for repairs
Edge line of fabric not between segments of take down roller
Check if the edge of the fabric is approx 1cm over the end of the segment
Pigment dyeing is an electrical process whereby the goods to be dyed are given an electrical charge opposite that of the pigment. When the pigment is added to the bath, the opposite electrical charges attract each other , Here garment is beeing charged with Cations which helps to attract the Pigment. As it surface reaction only, hence there are lot of challenges of repeatability of the shade. Even in the same batch garment to garment shade variation is common problem.
Pigment Dyeing – Problems and their probable causes
▪ Uneven/Patchy Dyeing – Probable causes of uneven dyeing could be:
1) Poorly pre-treated garments.
2) Garments are not allowed to wet-out sufficiently before pretreatment
3) Very low liquor ratio during dyeing.
4) High rate of rising of dye bath temperature.
5) Water hardness is high .
6) Bath temperature is higher than room temperature at the beginning of dyeing.
7) Acetic acid added earlier than the dyes exhaustion in dye bath. Generally, dye should be 70-80% exhausted and then acetic acid should be added .
▪ Poor Dye yield – Poor dye yield could be because of:
Face Masks are classified into civilian masks and medical(Surgical) masks. A civilian mask is used for the purpose of filter air into the mouth and nose to prevent harmful gases, odors, and droplets from entering and leaving the wearer’s mouth and nose. Civilian(Non Surgical) masks mainly divided into cotton mask, non-woven mask, polymer material mask, activated carbon powder filter mask, activated carbon fiber felt pad mask. Medical masks can prevent most of the bacteria, viruses and other pathogens, and WHO recommends that medical personnel use protective masks (N-95 masks) against particles to prevent virus infection in the hospital air. Medical masks mainly divided into medical protective masks, medical surgical masks, general medical masks.
There are three commonly used masks on the market: cotton masks, medical surgical masks and medical protective masks (N-95 masks), among which medical surgical masks can block 70% of bacteria, N-95 masks can block 95% of bacteria, and cotton masks can block only 36% of bacteria.
Take dimensions, and report actual finding. Values in cm.
Compare to client specifications and perfect sample if applicable.
Inner packing barcode scan
Scan barcode
Compare result with actual printed number and specification from client if applicable.
Inner packing sticker
Check inner packing stickers
Confoms to specifications
Instruction manual
Check instruction manuals
Compare to client specification if applicable.
Inner packing polybag
Look at a polybag details
Report actual findings and tick the boxes below. Findings must conform to client specifications.
Inner packing information
Look at a carton details.
Report actual findings and tick the boxes below. Findings must conform to client specifications.
Appearance & workmanship
Report actual finding and take detailed photos.
Confoms to specifications
Dimension
Take dimensions
Report actual finding and compare to client specification if applicable. Values in cm.
Weight
Take weight
Report actual finding and compare to client specification if applicable. Values in g.
Certification
Check with factory for applicable certifications.
Report actual findings
Color check
Check unit colors according to client’s file
Confoms to specifications
Material check
Check product material according to client’s file
Confoms to specifications
Smell check
Open the master carton, inner box, and product.
No strong or irritative smell should be found
Printing check
Printing on masks is correct, good quality
Confoms to specifications
Fabric straps
Fabric straps are fixed on the mask, not loose. Strap ends are neatly trimmed.
Confoms to specifications
Function test
Check the function of the product, it should work as claimed
Confoms to specifications
Fitting test
Put product on a dummy or a live model.
Product should look good (no obvious fitting problem)
Waterproof test
Drop water on the product surface.
It should be waterproof
Fatigue test
Push/press/use adjustable parts 50 times.
The products should be as remain the same as new.
Color fastness to rubbing test
Rub the markings and the logo 20 times, with a soft cloth dipped in alcohol (if no alcohol is available, use oxygen water and mention it in the findings).
Yarn Twist , means the direction of twisting the fibre during spinning proccess. It isveryimportant in the knitted fabric. In general practise we use “Z ” Type Twist yarn, But we can use the “S ” Type twist also .
Twist is the spiral arrangement of the fibres around the axis of the yarn. The twist binds the fibres together and also contributes to the strength of the yarn. The amount of twist inserted in a yarn defines the appearance and the strength of the yarn. The number of twists is referred to as turns per inch.
Yarn twist direction
Twist direction: The direction of the twist at each stage of manufacture is indicated by the use of letters S or Z in accordance with the following convention:
A single yarn has S twist if, when it is held in the vertical position, the fibres inclined to the axis of the yarn conform in the direction of the slope to the central portion of the letter S. Similarly the yarn has Z twist if the fibres inclined to the axis of yarn conform in the direction of slope to the central portion of the letter Z.
WPI: WPI can be calculated from this equation of width. No of needles=no of wales, and width is expressed in inch. So, No of wales per inch=Total no of wales or no of needles/Width of the fabric in inches. t is to be mentioned that actual WPI can be less than the WPI found from this equation if any needles are inactive.
Course Per Inch (CPI):
A knitted fabric is a combination of courses in horizontal direction with continuous yarn. A wale is formed having courses as shown in figure 5. A loop contains a tail yarn of previous loop and a head yarn of next loop [From figure 5], so effective height of every course is (d1-2dy) mm.
So, Course height is (d1 – 2dy) mm or { (d1 – 2dy)*39.36/1000 } inch Let, n=no of courses required for 1 inch of fabric or CPI
This equation can be used to have idea of CPI or to determine required no of feeder/course.
Fabric width is formed by courses that are laying crosswise (loops in horizontal direction). So, Width=loop Dia* no of loops Width=loop Dia* no of course Width=loop Dia* no of needles
According to this equation the width calculation should be easy and loop should stay like the image cited below: But every circle share part of circle of both sides. Fabric width from this equation will be less than actual width because the loop circles placed consecutively shares both sides with preceding and successive loops (Figure 3).
Now let’s make relation between values from this equation & actual values and see how much closer they stay.
Table 1 shows that the actual width and the width from the equation always maintain approximately same ratio among themselves.If this ratio can be considered as a constant actual width of the fabric can easily be derived.
So the equations can be written as considering R as a constant as it shows in the Table 1.
The value of R for Single jersey is 1.25-1.30 and for 1*1Rib is about 1.00 and for others fabric type’s value of R can be calculated.
Variation of R is related withtype of fabric construction, needles number, yarn types and composition, machine tension, speed, and tightness factor.
GSM means the weight in gram per square meter of fabric. Fabric area density can be calculated by the following formula,
Here, T = Tex, S = Stitch density, l= Stitchlength GSM is one of the primary parameters for determining fabric quality and GSM depends on WPI, CPI, yarn count (Ne) and stitch length.The GSM cutter isvery popular and easy usable GSM testing instrument used in most of the knittingfactories.The construction of this cutter is very simple. It is circular disk of 100 square cm area with sharp blade attached to its edge. So 100 square cm of fabric can easily cut by it and weighted at the electric balance to get GSM Reading. Technical formula used for GSM calculation,
The equation for GSM can be formulated by using equation of WPI & CPI formulated here. The general formula for calculating GSM is
Figure 6 shows the variation of Actual GSM and GSM from derived equation for single jersey grey fabrics made of 100% cotton at standard condition.
Figure 7 shows a relative presentation of actual and calculated GSM when required GSM is 130.The analyzed data shows that the error percentage for calculated GSM is below 5% in most of the time. And this variation of GSM is related with so many factors like: color, yarn count, tightness factor, relaxation state, andprocessesoccurred onthe fabric.
The equationof GSM contains the constant ‘R’ &statistical analysis for the values of R for 100% cotton single jersey fabric foundfrom analyzed data shows 1.46% standard deviation when mean value is 1.273 at table 4.
In the knitted industry there are two types of dyeing techniques .
1- Exhaution Based Dyeing
2- Cold Pad batch Based Dyeing .
Exhaustion based dyeing is done in the Winch, Soft Flow, Air Flow type of machine. As now We are proceeding for the low liquor ratio dyeing techniques , So the salt formation during exhaust dyeing increases .
If a salt is formed during dyeing process , it will be deposited on the textilefabric and gives the White patches, In general these salts are of Calcium and Magnesium . Hence it is due to hardness of the fabric or the water or the Chemicals used in the dyeing , may be Dyes, Salt, Soda, etc.
Hence a strong demineralising agent is needed in the dye bath, But the concentration of the Demin agent should be very minimal . Other wise it will effect dyeing process.
By this we can avoid the white patches in the fabric, It is geerally visualise in the black, navy shades.
