bUtton Attachment SOP

January 22, 2018 | Author: ratno wijaya | Category: Textile Arts, Sewing, Clothing, Fashion & Beauty, Textiles
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Button attachment SOP...

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Lockstitch Buttoning Machines Operating & Control Procedures

TABLE OF CONTENTS PAGE I.

PURPOSE OF GUIDE

II.

FACTORIES PRODUCT SAFETY TASK FORCE COORDINATOR GUIDE & PROCEDURES

LS - 1

LOCKSTITCH BUTTONING MACHINES OPERATING & CONTROL PROCEDURES

III.

1.

Button Attachment Control Procedures and Maintenance Program

LS - 2 ~ 4

2.

Cause and Corrective Action For Buttoning Problems

LS – 5 ~ 6

3.

Lockstitch Button Sewing Machine Suppliers

LS – 7 ~ 9

4.

Button Attachment Statistical Process Control Procedure

LS - 10

FORMS (to be completed by Field QA & Product Safety Officers) : 1.

2.

3.

Buttons Attachment Strength Test (Pre-production Control)

LS – 11 ~ 12

a) b)

LS – 12a LS – 12b

Blank Form Sample

Lockstitch Button Attachment Capacity and SOP Check

LS - 13

a) b)

LS – 13a LS – 13b

Blank Form Sample

Check Record of Even Attachment Tension for Bobbin Thread

LS - 14

a) b)

LS – 14a LS – 14b

Blank Form Sample

PRODUCT SAFETY HANDBOOK

1999

Lockstitch Buttoning Machines Operating & Control Procedures

I. Purpose of Guide

The purpose of the Lockstitch Buttoning Machines Operating & Control Procedures is to ensure that sewn-on buttons on each garment will last a life time. It completely provide guides to ensure all the buttons are securely attached on the garments and avoid buttons falling off. It does provide control measure in helping the factory understand the proper maintenance program. The Guide also consists of the following sections : a) Button Attachment Control Procedures & Maintenance Program b) Cause & Corrective Action for Buttoning Problems c) Lockstitch Button Sewing Machine Suppliers d) Button Attachment Statistical Process Control Charts

PRODUCT SAFETY HANDBOOK

1999 LS - 1

Lockstitch Buttoning Machines Operating & Control Procedures

II.

FACTORIES PRODUCT SAFETY TASK FORCE COORDINATOR GUIDE & PROCEDURE

LOCKSTITCH BUTTONING CONTROL PROCEDURES

MACHINES

OPERATING

&

1. Button Attachment Control Procedures and Maintenance Program Buttons All buttons must meet the following minimum performance requirements:

Ligne Size Minimum Thickness Center/Breaking Strength

Two Hole 22 2.0mm/0.0750in.

7.7 kg / 17lbs.

7.7kg / 17 lbs.

10 kg / 22 lbs.

Machine Vendor must clean button attachment machines on a daily basis to avoid any fluff, which could snag the thread and cause missing stitches/passes.

Bobbin Vendor must clean bobbin area on machine to remove fluff and dirt twice a day (4 hourly) : • During lunch break • Before a shift change or before a worker finishes work for the day

Needle Size The correct needle size must be used. Needle size prefer #11 to #16 is the best for button attachment. Needle size selection is also a key point to note and in recommending a particular needle size to be used, the vendor need to take into consideration the garment construction, fabrication, and number of ply being used to apply to the garment.

PRODUCT SAFETY HANDBOOK

1999 LS - 2

Lockstitch Buttoning Machines Operating & Control Procedures

Condition of Needle A faulty needle is one of the primary causes of button attachment defects. A faulty needle must be replaced before production can be allowed to continue. Examples of faulty needles are: a) No bent needle b) No tipped needle Operator need to change the buttoning needle at least twice a day, to Ensure the needle is in good condition.

Faulty Needle Check An operator can check whether a needle is bent or tipped by rolling it on an even smooth surface. If a needle will not roll smoothly on the surface, it is defective and must be changed immediately before production continues.

Thread Tension Thread tension must be adjusted in a right position. a) not too loosen b) not too tighten Thread tension must be properly adjusted as it may cause missing stitches (i.e. 2 holes instead of 4 holes). Note : Always adjust bobbin thread tension first. No sewing operator is allowed to do any adjusting on the machine. All adjustment must be made by the mechanic or technician.

Button Attachment • • • • • • •

All buttons must be attached using a lockstitch buttoning machine. Button must in a complete stitch pattern. 100% check of complete stitch pattern for baby and kids. Only polyester or polyester/cotton wrap threads are to be used. 100% cotton thread should be used for current dye programs only, when buttons are attached prior to dyeing. All buttons must withstand a direct pull force of 17 lbs. for 10 seconds. Lockstitch buttoning characterized by 2 “Rabbit Ears” and Knot on back side, prefer 1/4” thread length and must not be trimmed off. Button attachment must be attached with a minimum of 16 passes.

PRODUCT SAFETY HANDBOOK

1999 LS - 3

Lockstitch Buttoning Machines Operating & Control Procedures

Missing Stitches/ Security & Tension Check On the machine, the thread remaining on the needle must not be too short, the minimum length being at least 3” long. This will prevent the thread from slipping out of the needle eyelet at the start of sewing or sewing from the middle of the predetermined stitches. Note : The above reason is the cause for missing or skipped stitches on one side of a button. To overcome the problem of skipped or missed stitches and evenness of thread tension, this simple procedure must adopted by every operator: •

When a bobbin case is refilled with thread, perform the first (1st) button attachment on a piece of interlining before going into actual production.



When the bobbin thread in the bobbin case is depleted, the last button sewn from the depleted bobbin must always be removed from the garment.



Record of P.O #, Style #, date and time of procedure must be clearly recorded and kept as part of standard operating procedures.

PRODUCT SAFETY HANDBOOK

1999 LS - 4

Lockstitch Buttoning Machines Operating & Control Procedures

2. Cause and Corrective Action For Buttoning Problems Problem

Cause

Corrective action

needle thread 1. The needle thread A) The remaining on the needle slips out of the is too short. needle eyelet at the start of sewing. B) The material used flaps. 2. The machine starts sewing from the C) The wiper does not catch the thread. middle of the predetermined stitches for sewing a button.



Decrease the tension of the thread tension controller.



Adjust the timing to release the tension disc of the thread tension controller.



Apply the needle hole guide with a higher boss.



Apply the button clamp jaw levers with a thinner plate.



Correct the spring of the wiper properly.

3. The needle often A) The needle hits against • breaks the button in the area around the holes.

Adjust the position of the button clamp jaw levers so that the needle enters the center of the holes in the button.

B) The tip/point/ball of the • needle hole guide comes in contact with the recess of the feed plate.

Adjust the position of the feed plate to prevent it from coming in contact with the boss of the needle hole guide. If the sewing size specified is too large, use the feed plate for medium-sized buttons or that for large buttons.

C) The needle used is too thin. •

D) The knotting mechanism • comes in contact with the needle.

needle thread • 4. The finished state A) The remaining on the needle of the stitches sewn is too long. on the underside of the material is B) The wiper clamps the • extremely poor. thread with an excessive clamping force.

Change the needle of another count according to the sewing product to be sewn or the holes in button to be attached. Adjust the timing of the knot-tying mechanism or its stroke so that the knottying plate does not come in contact with the needle. Increase the tension of controller (thread discs).

the

tension

Adjust the timing to release the tension disc of the tension controller.

C) The bobbin thread • tension is too loose.

Decrease the pressure of the spring of the wiper.

D) When using buttons • with round sole, tangled stitches may result on the wrong side of the material.

Use the exclusive bobbin case (provide With an idling prevention spring)

PRODUCT SAFETY HANDBOOK

1999 LS - 5

Lockstitch Buttoning Machines Operating & Control Procedures

2. Cause and Corrective Action For Buttoning Problems (cont) Problem 2.

3.

Cause

Corrective action

The knot-tying A) The timing of knot-tying • mechanism is not mechanism fails to correct, or its stroke is secure the end of not proper. the thread with consistency. B) The needle hits against • the button in the area around the holes.

Adjust the timing of the knot-tying mechanism or its stroke so that knot-tying plate does not come in contact with the needle. Adjust The position of the button clamp jaw levers so that the needle enters the center of the holes in the button.

C) The tension of the • tension controller is too high.

Decrease the controllers.

D) At the time of stop- • motion, the tension disc is not released.

Adjust so that the tension disc is released at the time of stop-motion.

E) The needle is caught in • the reinforcement interlining.

Use a thinner needle.

tension

of

the

tension

The button clamp jaw • levers do not securely clamp the button.

Adjust so that the button clamp jaw levers securely clamp the button.

The pressure of the leaf • spring of the button clamp jaw levers is excessive.

Correct the leaf spring of the button clamp jaw levers so that the spring pressure is decreased.

C) When using a button with • round sole, the thread enters the section between the sole of the button and the surface of the boss of the needle hole guide. As a result, the button fails to be smoothly moved during sewing.

Replace the button clamp jaw levers with those with a thicker plate.

The button is not A) attached on the predetermined position on the B) garments.

PRODUCT SAFETY HANDBOOK

1999 LS - 6

Lockstitch Buttoning Machines Operating & Control Procedures

3. Lockstitch Button Sewing Machine Suppliers 1) BROTHER a) Model # LK3 - B438E - B438 with a ‘E’, is an electronic lockstitch button sewer machine. - No button feeder is available for model # LK3 - B438E. - It can be used for attaching buttons with 2, 3 or 4 holes, and has 22 different types of built in programs available. - For different types of buttons, the desired program can be selected by using a switch on the control panel. - Backtack sewing method help to prevents the thread from pulling out at the sewing start and unraveling at the sewing end. * Please take note for model without an ‘E’ behind the number, is a Mechanism lockstitch button sewer machine (model # LK3-B438). b) Model # LK - B448E/BA-16 – B448E with a ‘E/BA-16’, is an electronic lockstitch button sewer with auto button feeder machine. – It can be used for attaching buttons with 2, 3 and 4 holes, and has 22 different types of built in programs available. – The adoption of Brother’s unique back tack sewing method ensures that the thread will not unravel. – A double-check function for button feeding prevents sewing operations from continuing when no button has been set.

2) JUKI a) Model # LK-1903SS - 1903SS, is an electronic lockstitch button sewer machine. - It prevents thread fray from the end of sewing. - The machine provided as standard with 33 kinds of patterns and the pattern can be changed over by one-touch simple operation. b) Model # LK - 1903SS / BR-25 - 1903SS with a / BR-25, is an electronic lockstitch button sewer with button feeder.

PRODUCT SAFETY HANDBOOK

1999 LS - 7

Lockstitch Buttoning Machines Operating & Control Procedures

3. Addresses and contact numbers Juki Corporation Japan Juki Corporation International Sales Division 8-2-1, Kokuryo-Cho, Chofu-Shi Tokyo 182, Japan Tel: 03(3430) 4001-5 Fax: 03(3430) 4909-4914-4984 Hong Kong Juki (Hong Kong) Ltd. Units 1901 & 1911 - 12 Level 19, Metroplaza Tower II 223 Hing Fong Road Kwai Fong, N.T., Hong Kong Tel: (852) 24237888, 24238608, 24237906 (Parts) Fax: 24237121, 24237151 (Parts) Singapore Juki (Singapore) Pte Ltd. 159 Sin Ming Road #07-02 Amtech Building, Singapore 575625 Tel: 5534388 Fax: 5525565

PRODUCT SAFETY HANDBOOK

1999 LS - 8

Lockstitch Buttoning Machines Operating & Control Procedures

Brother’s Lockstitch Button Sewing Machine Supplier Japan Brother International Corporation 15-1, Naeshiro-cho, Mizuho-ku, Nagoya 467-8561 Telephone: 81-52-824-3393 Facsimile: 81-52-824-3390 Hong Kong Brother Corporation (Asia) Ltd Suite 1103, Chinachem Golden Plaza 77 Mody Road, Tsimahatsui East, Kowloon, Hong Kong Telephone: 852-2723-4198 Facsimile: 852-2723-1776 Singapore Brother International Singapore Pte Ltd No. 1 Phillip Street #06-00 Lippo Centre, Singapore 048692 Telephone: 65-538-0311 Facsimile: 65-538-7003, 1020

PRODUCT SAFETY HANDBOOK

1999 LS - 9

Lockstitch Buttoning Machines Operating & Control Procedures

4. Button Attachment Statistical Process Control Procedure a) Pre-production Control = Button Attachment Strength Test * Before wash mock seam - Apply 5 buttons sewn to a mock seam (before wash) - Button attachment strength must withstand a direct pull force of 20 Lbs. for 10 seconds. * After wash mock seam - Apply 5 buttons sewn to a mock seam (after wash) - Button attachment strength must withstand a direct pull force of 17 Lbs. for 10 seconds.

PRODUCT SAFETY HANDBOOK

1999 LS - 10

Lockstitch Buttoning Machines Operating & Control Procedures

III. FORMS (to be completed by Field QA & Product Safety Officers) : 1) Lockstitch Button Attachment Strength Test (Pre-production Control) - refer to form LS – 12a

Generated by Factory authorized staff e.g. Task Force Coordinator When Every new order sewed with sewn on button. Why The purpose is to ensure the fabric; sewing thread and the button are secured and can withstand a direct pull force of 20 lbs. for 10 seconds (before wash) and 17lbs. for 10 seconds (after wash).

PRODUCT SAFETY HANDBOOK

1999 LS - 11

Lockstitch Buttoning Machines Operating & Control Procedures

1) Lockstitch Button Attachment Strength Test (Pre-production Control) - refer to form LS – 12a (cont.)

Procedure • Please refer to the button attachment statistical process control procedure for more details. Production Control Attachment)

=

Checked

Appearance

(Button

Construction review: Appearance and security of button stitching • A 100% check must be conducted on buttons sewn-on garments. • The total quantity of production done at every 2-hour interval must be collected, serial number of machine recorded and quantity noted before 100% inspection begins. • Three criteria must be noted during the audit : • Buttons are sewn with a complete stitch pattern; • The “Rabbit Ears” and knot are clearly visible on the back side; • The first and last button tension check which is characterized by missing or skipped stitches on one side of a button..

Note: All button attachment defects are considered criteria defect. If one is found during the audit, a 100% re-audit of the whole production is required. Line supervisor must trained by appropriate button machine supplier annually.

PRODUCT SAFETY HANDBOOK

1999 LS - 12

Lockstitch Buttoning Machines Operating & Control Procedures

2) Lockstitch Button Attachment Capacity and SOP Check – refer to form LS – 13a

Generated by Factory authorized staff e.g. factory QC. When Apply 100% check every two hours per day per order. Why The purpose is to ensure all the buttons are security attached on the garments and avoided button falling off. Additional it is a control measure in helping the factory management to track the production. Procedure • Please refer to the button attachment statistical process control procedure for more details.

PRODUCT SAFETY HANDBOOK

1999 LS - 13

Lockstitch Buttoning Machines Operating & Control Procedures

3) Check Record of Even Attachment Tension for Bobbin Thread - refer to form LS – 14a

Generated by Factory authorized staff e.g. button sewing operator When The initial refilled and the ending of each bobbin thread. Why The purposes are to ensure all the buttons are security attached on the garments, as to avoid missing stitch and caused button falling off. Additional it is a control measure in helping the factory management to track running production. Procedure • Please refer to the button attachment statistical process control procedure for more details.

PRODUCT SAFETY HANDBOOK

1999 LS - 14

Product Safety Button Attachment Strength Test - (Pre-production Control) Vendor:

Factory:

Garment description

Machine model / Number

Gap Style Number / Division

Operator

Button Description / Size

Type/Size of Thread & Stitch Pattern

No. of Buttons on garments

Stitch Density (no. of stitches)/ needle size

Location on garment

Fabric Thickness ( no. of plies )

Name of Task Force Coordinator

Date

PRE-PRODUCTION SETTING - apply 10 buttons per style to a mock / faux seam which is same construction as the production Maintain 20 lbs. for 10 seconds before washed

Sample

Pass

PS5

Fail

Maintain 17 lbs. for 10 seconds after washed

Sample

Type of Failure

Pass

1

1

2

2

3

3

4

4

5

5

LS - 12a

Fail

Remarks

Type of Failure

1999

Product Safety Button Attachment Strength Test - (Pre-production Control) Vendor:

Ponie Garment

Factory : Intravest - Malaysia

Garment description BabyGap Girl Ctn Jsy Embroidery Collar Slip Dress (GW)

Machine model / Number LK-1851 / 00189 (Juki)

Gap Style Number / Division

Operator 322103 (BGK)

Mei Type/Size of Thread & Stitch Pattern Polyester / #180 / 'X' Completed Stitch Pattern Stitch Density (no. of stitches)/ needle size 16 Stitches / # 12 Fabric Thickness ( no. of plies ) 2 Fabric + 1 Interlining Date 7/23/1998

Button Description / Size Polyester / 18L No. of Buttons on garments 3 Location on garment Half Front Placket Name of Task Force Coordinator Anna Loh

PRE-PRODUCTION SETTING - apply 10 buttons per style to a mock / faux seam which is same construction as the production Maintain 20 lbs. for 10 seconds before washed

Sample

Pass

Sample

Type of Failure

Pass

1

X

1

X

2

X

2

X

3

X

3

4

X

4

X

5

X

5

PS5

Fail

Maintain 17 lbs. for 10 seconds after washed

X

Button fell off

Fail

X

LS - 12b

Remarks

Type of Failure

Button fell off

Button attached on uneven surface

Stitches incomplete, no lockstitch

1999

Product Safety Lockstitch Button Attachment Capacity And SOP Check Vendor :

Factory:

Model No. / Machine No. :

Operator :

Task Force Coordinator:

Date :

Style No. :

Stitch Density (Nos. of stitches) :

Production Control - apply 100 % check every two hour. The initial refilled and the ending of each bobbin thread, button must sewn on Interlining.

Time

Complete 2 "Rabbit Ear" Output

PS6

TTL Defective

Complete Stitch Pattern (Cross or Parallel stitches)

Action Taken

LS - 13a

Output

TTL Defective

Action Taken

The initial refilled & ending of bobbin thread record Nos. Of Button

1999

Product Safety Lockstitch Button Attachment Capacity And SOP Check Vendor :

Ponie Garment

Factory:

Intravest -Malaysia

Model No. / Machine No. :

LK-1851 / 00189 (Juki)

Operator :

Mei

Task Force Coordinator:

Anna Loh

Date :

23 July 98

Style No. :

322103

Stitch Density (Nos. of stitches) :

16

Production Control - apply 100 % check every two hour. The initial refilled and the ending of each bobbin thread, button must sewn on Interlining.

Time

Complete 2 "Rabbit Ear" Output

10.30 AM

200

TTL Defective

Complete Stitch Pattern (Cross or Parallel stitches)

Action Taken

1- Knot on backside too Adjust bobbin thread

Output 200

TTL Defective

1-Missing stitches, due Check bobbin case

heavy stitches and 1.00 PM

200

stitches is too loose Nil

tension Nil

200

Action Taken

The initial refilled & ending of bobbin thread record Nos. Of Button

to bobbin depleted 1- Thread breakage

tension and bobbin

2

thread Adjust needle thread or

2

bobbin thread tension and it depends on the type of fabric construction and the nos. of ply is being used

PS6

LS - 13b

1999

Product Safety Check Record Of Even Attachment Tension For Bobbin Thread Vendor :

Factory:

Model No. :

Machine No.:

Operator :

Date :

Style No. :

Stitch Density (Nos. of Stitches) :

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

2

1

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

9

Button attached for initial refilled of each bobbin Time:

4

3

6

5

PS7

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

8

7

Button attached for initial refilled of each bobbin Time:

10

LS - 14a

Button attached for initial refilled of each bobbin Time:

11

12

1999

Product Safety Check Record Of Even Attachment Tension For Bobbin Thread Vendor :

Ponie Garment

Factory:

Intravest - Malaysia

Model No. :

LK-1851 (Juki)

Machine No.:

00189

Operator :

Mei

Date :

23-Jul-98

Style No. :

Stitch Density (Nos. of Stitches) : 16 322103

Button attached for initial refilled of each bobbin Time: 10:30 AM

Button attached for initial refilled of each bobbin Time: 1:00 PM

2

1

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

9

Button attached for initial refilled of each bobbin Time:

4

3

6

5

PS7

Button attached for initial refilled of each bobbin Time:

Button attached for initial refilled of each bobbin Time:

8

7

Button attached for initial refilled of each bobbin Time:

10

LS - 14b

Button attached for initial refilled of each bobbin Time:

11

12

1999

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