Sewing machine consists with production or sewing lines and the packing or finishing section. Garment manufacturing process start with the pre-production meeting, basically this meeting held before start cutting.
Pre-Production meeting
Pre production meeting will link the merchandising & development with the production, which guide and provide customers requirement to production to follow.
The main purpose of this Pre-Production meeting is to share information and difficulties faced during the development stage with all concern people.
Auto Textile PP meeting will be arranged by the central planning department and meeting minutes will be taken by the planner.
During the meeting discuss the delivery and production plan, sample comments and approval sample will be present to the meeting by sample room, trim card will be approved during the meeting by quality responsible by reviewing the buyer approvals. Further sample room will present approval sample and technical package to the production during this meeting. Technical people will give the instruction to production people how to do the production. Quality manager will explain the critical quality points should maintain during the production.
Production supervisor will be attending to the meeting with the supervisor sample and quality department comment sheet and this will be review in the meeting when discussing quality points.
Line feeding & Mock-up system
During the feeding technician will test the machine setting and teach the operator how to stitch. At this movement in line QI will make sure SPI & appearance of the sewing. Once the operators comes to the desired level of the quality, technician and in line QI will put one good piece as mock-up sample which operators should follow rest of the order and this will be applied mainly on the critical operations. Once the sample select technician, QI, supervisor, mechanic has to sign on the mock up card and assure all aspect of the operation being achieved, after that operator has to sign on the mock-up sheet accepting the requirement of the operation. QI and technician are responsible for mention any critical points on the mock-up sheet which should follow by operator. After that mock-up and the sheet will be hang in front of the machine for the ease of operator view. Once this is process finished only technician can feed the next operation. Putting mock-up will be applicable only for the Critical operations and depend on the complexity of the style quality manager will decides the number of points mock-up should be.
First Production Meeting
First Production meeting is another technique that Auto Textile used to control the quality of the product. After line feeding finish, first out put will be reviewed by the production, technical & quality teams against the customer specifications and sample to assure quality standard. If there are any deviation will be address immediately by the team and then only continue the production.
At this stage first in line QI will measure & check the out put and make a report, with this report and garments this meeting will be held. First production meeting minute will be taken by the Quality officer of the section.
Sewing quality control
During the production continue will use different systems to assure the quality of the product. Auto Textile has in line quality controller who will closely monitor and control the measurement & quality each & every process.
Trim card
Each and every line provided the approved trim card and approved/ similar sample. During production input supervisor will check each and every input raw material randomly against the trim card before release to operators. If any raw material not matches with trim card he/she will stop and informed to quality and production officer, if the case is serious will informed to quality manager for corrective action. If the items are rejected will return to the stores or cutting. In line QI will do random check the out put with trim card & sample minimum twice a day.
Traffic light system
Each production line has one in line Quality Inspector and responsible to maintain traffic light system.
In-line QI must conduct the random inspection all the work station hourly or once in two hours, the frequency of the inspection based on the operation difficulty & damage level but minimum 4 time a day each operation should audit.
Traffic Light Process
Base of the traffic light system is seven-zero audit that is randomly select seven pieces from the bundle and inspect if one or more defects found bundle will reject and depend on the result red, green or yellow card will hand on the work station. Each work station consists with the hourly audit sheet and QI is responsible for the marking the result of the audit in this.
First inspection fails Quality inspector will informed to the supervisor and technician. Supervisor and technician are responsible for the corrective action and the duration of fixing the matter will be recorded. If third time inspection fail in the same operation Quality Inspector must stop the machine & informed to quality and production manager. So production & quality manager has to provide solution with senior technician immediately.
Measurement procedure
In Line Quality Controller is responsible for maintain measurement of the garments. Minimum twice a day he has to measure the finish garment covering the 2pieces per size which produce in the particular day.
If the measurements are out of tolerance QC will made additional 10 measurements in the same point to verify the deviation. If this proves measurements are out of tolerance has to informed QA manager and he suppose to guide the corrective action.
End Table Inspection
100% end line inspection will be conduct by each and every end line table by the Quality Inspector. The main object of this inspection is to pass 100% reject free garments to Finishing. QI are trained to follow the cycle of checking to avoid missing any operation checking and take 100% Bottom Band measurement to make assure there is no garment size mixed-up. QC will responsible to mark all the findings in the end table report & line supervisor and officer has to monitor this report and take necessary corrective actions.
Audit at Sewing Section
Every 4 sewing line have one Q.C Auditor. Auto Textile uses 2.5 AQL systems to audit complete garments of each line and for check workmanship & measurement. In this stage Auditor should considering approval standard, Buyer Comments, PO sheet, and Swatch card. The main purpose of this inspection is to identify any major mistake in very beginning.
In-line Inspection Packing
When we start poly in packing section we do in-line inspection. The main purpose of this inspection to check & confirm the folding method, hungering (If Need) ,Price ticket placement, Hang tag placement, poly etc. this stage we are using as per reference by buyers requirements.
Assortment Check
When we start assortment we do random assortment check. The main purpose of this inspection is to check & confirm the assortment. In this Stage we also check Shipping mark of Carton & item qty in a carton. To do this job we maintain the below format.
Packing audit random
Finishing Table Inspection
Here inspection is done randomly after Attached packing material & before send to carton. In this stage we take random under bust & Cup measurement for the all kind’s bra and waist, side seam & leg opening measurement for under wear.
Shipment Sample Inspection
In every style buyer require shipment sample from bulk production. The shipment sample is very important for any order because after getting this sample buyer check this sample properly & confirm us to ship the goods. One quality inspector is confirming the workmanship & measurement of shipment sample.
Pre-Final Inspection
When finish 80% carton packing, conduct in house Pre-Final Inspection as per 2.5 AQL systems. The main object of this inspection is to check & confirm garments workmanship, Measurement, packing accessories & packing method before complete full boxing.
Note: For all types of random audits use 2.5 AQL system for major defects and 3 minor defects will consider as 1 major where unless specified.
General Guidelines
All measurement must meet specifications assigned by the Q.A Department (Auto Textile Limited) or specific buyer’s requirements. Auto has tolerances for all measurements. Measurements outside of tolerances are unacceptable.
Garments should be measured on a clean, flat, smooth surface, never on other fabric, carpet or other surface that may distort the garments.
No
Document
Section
Responsibility
Supervision
1
Daily Quality Audit sheet
Sewing
In Line Quality Inspector
Quality Officer
2
Hourly corrective Action report
Sewing
In-Line Quality Inspector
Technician & Production Officer
3
Measurement Report Sheet
Sewing
In-Line Quality Inspector
Quality Officer
4
Traffic Light Highest 3 defects report
Sewing
In-Line Quality Inspector
Quality Officer
5
Mock-up Sheet
Sewing
In-Line Quality Inspector
Quality Officer
6
End Line Inspection Report
Sewing
Quality Inspector
Quality Officer
7
Hourly End Line AQL Report
Sewing
AQL Auditor
Quality Officer
8
AQL Measurement Audit report
Sewing
AQL Auditor
Quality Officer
9
Top 3 Offender Report
Sewing
Quality Officer
Quality Manager
10
Daily Quality Meeting Report
Sewing
Quality Officer
Quality Manager
11
First Out Put Analysis Report
Sewing
Quality Officer
Quality Manager
12
Finishing Quality Audit Report
Finishing
Quality Inspector
Quality Officer
13
Packing Inspection Report
Finishing
Quality Inspector
Quality Officer
14
Pre-final inspection Report how a sewing machine works
A hi-speed lockstitch sewing machine is the best common mechanical system stitch made by the sewing machine. The term of single needle stitching often found on dress shirt labels, referering to lockstitch machine. The height of needle from its lowest position of upward stroke when the hook point reach at the center line of needle.
Feature of Lockstitch Machine
Most common machine for woven garments
More secured sewing
No of needle:1 or 2
SPM:1500-5500
Stitch Density is variable, max. stitch length 5mm
Different types of feed mechanism (Puller Feed, Top AND bottom Feed etc.)
Automatic bobbin winder and thread trimmer present in some of the versions.
Needle Replacement: Check whether the needle of hi-speed lockstitch sewing machine is bent or blunt or not. If it is bent or blunt change the needle and install it under the supervision of maintenance personnel.
Rotary hook: Clean the tail of thread of hi-speed lockstitch sewing machine dust and lint in the rotary hook and bobbin case.
Lubrication:Lubricate the lockstitch sewing machine parts where necessary.
Time required: 10 minutes.
Cleaning the bobbin case and other possible parts: Clean the lint, loose thread and other dirt from the shuttle of bobbin and bobbin case. Besides the table and other parts which cannot effect the setting must be cleaned.
Required time: 5 minutes.
Lockstitch Machine Weekly Maintenance:
Done by : Maintenance Personnel
Supervised by: Maintenance Manager
Criteria:
Needle – Hook point timing: Check whether the needle of lockstitch – hook point timing is correct or not. If there lies miss-timing then adjust it.
The check points are
Needle – hook point clearance
At the same time the distance between the hook point and the top end of the needle eye.
Required time: 10 minute.
The clearance between bobbin case holder and bobbin case holder bracket: Check the clearance between the bobbin case and bobbin case holder bracket (1-1.5mm). Make sure that the hook will not touch bobbin case holder bracket of lockstitch mc.
Required time:5 minutes.
Presser foot pressure: Check whether the pressure of presser foot of lockstitch is proper or not. If not adjust it by adjusting the distance between the bottom washer and top of pressure bar guide bracket. And the bottom of work clamp must be kept parallel to the top of the work.
Required time: 5 minutes
Thread take-up amount: Check the amount of the thread take-up stroke, clearance between needle thread and thread take-up lever guide (.5-1 mm). Make sure that it is not more than necessary.
Required time: 5 minutes
Needle & bobbin thread tension adjustment: Check whether the standard operating range of thread take-up spring of lockstitch mc is accurate or not (6-8 mm). The tension at appropriate operating range must be checked.
Required time: 5minute.
Needle installation: It must be remembered during needle installation of lockstitch mc that the long groove of the needle is on the left and tightened with the needle clamping screw. Adjust the needle clearance and lift amount.
Required time: 2 or 3 minute.
Stitch Length: Check whether the lockstitch length is appropriate or not. If not , push the reverse feed lever halfway down, turn the dial until desired number align the pin at top and release the reverse feed lever. It is remembered that the number, the longer the stitch length will be and the reverse sewing device is the automatic-resetting type.
Required time: 2 or 3 minute.
Needle Bar height: It is remembered that when the needle bar is in its lowest position the reference line on the must be at the lower end of the containing the needle bar. If it is not so, remove the needle plate, loosen the needle bar connecting stud clamping screw and adjust by raising or lowering the needle bar.
Required time: 10 minute.
Adjstment of Pressure on the material (fabric): The pressure on the material during sewing must be as weak as possible, but strong enough so that the material does not slip. Adjust the pressure through loosing the adjustment nut.
Required time: 5 minute.
Feed Dog Height: The standard height of the feed dog for sewing thin material is 0.8 mm, and for medium material is 1.00 mm and for thick material is 1.2 mm (when the stitch length is set to the maximum).
Adjust the feed dog height by loosening the screw when the feed dog is above the needle plate surface and move the feed lifting arm up and down.
Required time: 5 minute.
Feed dog angle: in order to prevent puckering, material from slipping the feed dog is to be raised or lowered downward at standard angle.
When the feed dog angle has been adjusted, check to confirm that the height of feed dog has not changed.
Required time: 5 minute.
Presser foot height: The standard height of the presser foot is 6 mm when the presser foot is raised with presser foot lifter lever. To adjust the presser foot height, loosen the nut of the adjustment screw and then the presser foot adjustment screw so that no pressure will be applied to the presser foot, then loosen the set screw and adjust the presser foot height by raising or lowering the presser bar.
Required time: 5 minute.
Lockstitch Machine Monthly Maintenance
Oil replacement and other interrelated checks:
Check lubricant or oil whether that is to replace.
Check bush leakage, oil seal leakage or age, vibration of oil and the flow of oil pump more or less than setting.
Check rubber cushion seats, four corners of machine tool groove on which oil pan stands.
Required time: 10 minute.
Rotary hook of plain sewing machine: Check rotary hook wear whether it is need to replace.
Required time: 10 minute.
Presser foot canal: check hi-speed lockstitch sewing machine canal wear. If necessary replace it.
Interlock machine is a stretch stich sewing machine generally used in garments factory. We need to adjust different variable of a stretch stitch sewing machine like adjusting tension, adjusting needle and thread, adjusting spreader thread, adjusting stitch length, adjusting differential feed ratio, adjusting presser foot, adjusting presser foot pressure etc. We need to manage light near the sewing machine. Cleaning the sewing machine and oiling the sewing machine is very necessary.
How to Adjust Tension on Sewing Machine:
The tension of the thread should be adjusted according to:
The material type
The thickness of the fabric sewed,
The thread,
The stitch length,
If you turn the thread tension knob clockwise, thread will be tighter. If you turn it counter –clockwise, will be looser.
Adjusting Needle and Thread of Interlock Machine:
When turning the pulley and make the needle bar in the lowest position, the top edge of the needle and thread take-up (1) should remain horizontal. To adjust the position of take up if necessary, loosen the screw (4). Loosen screw (2) to adjust the length between point A and B to be about 81.5mm, then fasten it tightly. To loosen the needle and thread turns the needle and thread take up (3) toward the left. To tighten the needle take up (3) toward the right. Do not move the spreader thread take up (5)
Adjusting Needle
Adjusting Spreader Thread Take Up:
When the spreader thread take up (1) is adjusted to the top, the small hole A to the other spreader thread take up (2) must be at the same level with the long grove of the spreader thread take up (1). For necessary adjustment loosen screw (3) and (4) first, move the spreader take up (2) up and down, and then fasten the screws again.
Spreader Thread Take Up
How to Adjust Stitch Length:
Stitch length can be adjusted variably in range from 1.6mm-4.2mm or 6-16 stitch per inch. Keep pressing the push button A with the left hand, then turn the hand –wheel with the right hand until you feel the push button lick in.
Keep turning the hand –wheel for a inquired stitch length. Turn the pulley and align the inquired the button. Rotate the hand-wheel clockwise to increase the stich length and counter clockwise to decrease.
Adjusting the stitch length will change the differential feed ratio, therefore after adjusting the stitch length, please adjust the differential feed ratio.
Adjusting Differential Feed Ratio:
The differential feed ratio of this machine is adjustable from 1:0.5 to 1:1.3. To adjust the ratio loosen the nut (2), move the indicator (1) up or down. To stretch the cloth moves the indicator (1) upward. To gather the cloth moves the indicator (1) downward.
Differential Feed Ratio
Do not adjust screws freely (3)(4) to prevent the feed teeth colliding with the needle plate when the stitch length is the longest and the differential ratio is the biggest. If it is necessary to adjust, please shorten the stitch length.
Adjusting Presser Foot:
Loosen screw (1) and adjust presser foot (2) left and right to a proper position to let the needle may get into the center of presser foots eyelet.
Presser Foot
How to Adjust Presser Foot Pressure:
If the fabric is fed smoothly and has perfect sewing the pressure foot could be adjusted to be lightened.Loosen the unit A and turn the screw B clockwise to increase the pressure turn it counterclockwise to decrease the pressure
Lightening of the Operation Environment:
Provide a warning that an industrial sewing unit or sewing system must always be unplugged form the local lightening of the sewing area before relamping, the marking of maximum rated input of a lamp shall be easily discernible while the lamp I being replaced.
Clean Sewing Machine:
Raise the pressure foot.
Remove the two screws (1) and then remove the needle plate (2)
Use a soft brush to clean dust and lints on the feed dog teeth (3)
Install the needle plate (2) after doing the above cleaning.
Lubrication of Sewing Machine by Sewing Machine Oil:
Please use a Mobil #10 or sewing machine oil or its equivalent lubricant. The sewing machine oil has been drained from the machine before delivery. Therefore before using the new machine remove the oil until the oil level is between the high /low indicate lines of oil level gauge.
Before sure to check the sewing machine oil level every day and refill l the sewing machine oil if oil level is lower than the lower indicate line of sewing machine oil level gauge. When the machine starts functioning check the lubrication system to see if it is well functioned before operating the machine.
Standard Opereating Procedure of Sewing Needle:
To make sure that all metal equipment such as needles, hand sewing needles, kimball guns, scissors, snips, pins, etc. is held under control during the manufacturing processes and that all products manufactured for Auto do not contain any hazardous metal materials that could harm the customers.This procedure is applicable to all our ready-to-wear suppliers.
Responsıble Partıes:
Suppliers: The suppliers are bound to comply with all the conditions stated in this memorandum and take necessary precautions in the light of warnings provided.
Auto Auditors: Auto auditors will pay random visits to the suppliers to make sure that the suppliers comply with all the conditions stated in this procedure.
General Requırements:
The equipment that has been given to the operators by the Department Supervisors should be attached to work benches to stop accidental loss.
The supervisors must check equipment periodically and withdraw any equipment found not fit for purpose.
Only the supervisors or nominated personnel can issue replacement needles, or equipment. Spare needles, kimball guns, scissors are not allowed at the work station.
The supervisors should keep the metal equipment in secured and locked cabinets. The cabinets are always locked and keys are kept only by the supervisors or a nominated employee.
Metal Contamınatıon:
Mechanics/operators should pay extra attention to ensure that tools or instruments do not get lost in garments.
Staples must not be used in any operation or in the sewing room.
Pins must not be used in the packaging of any product.
Razors must not be used as cutters. If cutting of this type is needed, a modeling knife/scalpel with a secure blade must be used.
Scissors and clippers should be tied to the workplace to prevent potential loss within a product. If it is not possible to tie them, then they should be logged in/out at the beginning/end of each shift.
Personal items such as keys, hairgrips, jewellery, etc. cannot be placed on/near machines or/and tables.
If a product is found to be contaminated with metal fragments and the metal cannot be found after thorough inspection, then the product must be placed in a sealed locked container labeled Contaminated Stock by the Department Supervisors, and recorded in the Metal Detected Stock Sheet.
Applıcatıon Of The Broken Needle Polıcy:
All needles must be accounted for in all operations of the manufacturing process. This is ensured with the implementation of the Needle Change Report.
Whenever a needle break occurs, every effort must be made to recover all of the broken pieces before the manufacturing starts again and the products move onto the next process. Needle parts need to be checked against a profile or new complete needle to ensure that all parts are found.
If a needle breaks during a manufacturing process, machine operator should stop working and inform the Department Supervisor. The incident should be recorded with all relevant information on the Broken Needle Report and all parts of the broken needle should be collected immediately and affixed on the report with a large, transparent adhesive tape.
If all parts of a broken needle are not found, then the products on which the operator is working, and any others in close proximity to the machine and workspace must be checked. If all parts are still not found, all products must be removed and packed into a polybag and passed through the metal detector in order to isolate any products containing metal fragments. These products must be thoroughly examined in a quarantined area until the missing needle parts are found. This must be recorded in the Metal Detected Stock Sheet. If, for any reason, all parts of the needle cannot be found, the products need to be put into a sealed locked container labeled Contaminated Stock and must be recorded in the Metal Detected Stock Sheet accordingly.
New needle can only be attached to the machine when the broken needle is found and accounted for. Then the machine operator can continue working.
Broken Needle Reports must be kept for a minimum of three years, and there after disposed off in sealed containers. Auto Auditors will check these reports randomly.
