Elna Single Needle Lockstitch Machine

Single Needle Lockstitch machine of  Elna, Pfaff and Bernina is developing for garments industries. Lockstitch machine which produces stitches by interlacing of threads is called lock stitch machine. This machine produces durable stitches and is very popular in garment industries. To operate this machine on sewing table one person should have practical knowledge about the plain sewing machine.

Elna Sewing Machine Parts:

Sewing machine parts of single needle machine is given below with a diagram. The diagram shown its different parts.

• Feed dog
• Connection rods
• Pressure foot
• Upright arm shaft
• Upright arm
• Arm shaft
• Needle bar
• Spool pin
• Bobbin
• Loop taker
• Bobbin case
• Paddle
• Side plate
• M/C pulley
• Cone stand
• Horizontal arm
• Head
• Face plate
• Bed shafts

Checklist for needle and metal control:

• Is there a secure location for keeping needles and other tools?
• Is there a trained, authorised person to issue needles or other metal tools?
• Do the authorised people fully understand the procedure?
• Is there a needle record sheet for broken needles?
• Is it correctly and accurately completed?
• Are all broken needles included on the record sheet?
• Do all employees understand the metal control procedure in this area?
• Is there a clear procedure for dealing with missing broken needle pieces?
• Are there any spare needles at the machines or any unused machines with needles in?
• Are there any broken needles on the floor?
• Are there any untied small scissors at machines?
• Are there any other sharp metal items in the work area?
• Are there pins or staples used in this area?

Checklist for needle and metal detection

• Is the metal detector located at the end of the process so all items pass through without being missed?
• Do all products pass directly into a metal free zone after being detected?
• Has the metal detector been serviced in the past 12 months?
• Does the metal detector only detect non-ferrous metal?
• Is the machine operator trained to use the machine?
• If metal is detected, does the conveyor stop and an alarm sound?
• Is there a record sheet for metal pieces found?
• Is the machine restarted by a key?
• Is there an isolation box for items where the metal contamination cannot be found?
• Is the 9 point system used to check the metal detector prior to any product being metal detected?
• Are there record sheets for all system checks?

Function of Single Needle Lockstitch Machine:

For sewing light or heavy fabric i.e. all kinds of plain sewing. It use different types of single needle. It is very easy to install the needles in the machine.

Features of Lock Stitch Machine on Sewing Table:

The features of a lock stitch machine on sewing table is stated here berifly-

• Stiches are produced on sewing table by interlocking of  lockstitch sewing machine
• Bobbin and bobbin case are present on sewing table
• Threads are supplied on sewing table from cone.
• It has one needle and one bobbin.

Specifications of LockStitch Machine:

The specification of a elna lockstitch machine  is specified below-

[label type=”label” title=”Specifications Name“]	[label type=”label” title=”Specifications Value“]
Product Category	Sewing
Machine Category	Lock Stitch Machine
Product Name	Lock Stitch Machine
Product Model	According to Manufacturer
Product Class	New
Origin	China/India/Others
Brand/ Manufacturer	Name of Manufacturer
Agent in Bangladesh	No/Yes
Power	380v
Temperature	Normal
Certification	SGS/Others
Production Capacity	NA
Group	Lock stitch (Interlacement)
Stitch per minute	1500
Needle size	9,11,14,16,18,20,21
Thread per inch	2.5”
No of needle	One needles
Seam class	300
Description	Should be error free.

Adjusting Stitch Length of Elna Single Needle Machine:

Stitch length of Elna Single Needle can be adjusted variably in range from 1.6mm – 4.2mm, or 6-16 stitch per inch.

1. Keep pressing the push button A with the left hand then run the hand-wheel with the right hand until you feel the push button lock in for single needle lockstitch machine.
2. Keep turning the hand-wheel for a inquired stitch length. Turn the pulley and align the inquired scale with mark B and then stop pressing the button
3. Rotate the hand wheel clockwise to increase the stitch length and counter clockwise to decrease for single needle lockstitch machine
4. Adjusting the stitch length will change the differential feed ratio, therefore after adjusting the stitch length, please adjust the differential feed ratio

S.O.P of Sewing: 

To maintain the best quality of Auto garment Group. Any garment of every order & every style when we confirm from buyer for trail or bulk production, at first we (qa. Manager, production manager, maintenance manager, qc supervisor, sewing supervisor, line qc) discuss, all points of the order with p.p. Sample, trim card, order sheet, spec, pattern, buyer comments at pre production meeting then we make a lay out & start making the garments, our line qc/qc supervisor check & measurement every process properly & note on style check file. After complete the garments we (qc supervisor, qa supervisor, qa manager) properly check style one pcs  garments with order sheet, p.p. Sample, trim card, spec. Buyer comments & keep record properly. Our qa team complete ipc inspection & keep record properly.

In the production time we maintain * traffic light system * in-line inspection * random measurement * measurement every size every colour every day * wash test * end of the 100% inspection, we keep all record properly.

Purpose: Identification and control of the needles which are broken in the sewing lines during production to ensure product safety.

Scope: All needles broken at the production floor of Auto Garments Limited.

Responsibility: QC Manager and Production Manager is responsible for ensuring that the procedure is properly followed and Executed.

Store Officer (sub store) is responsible for ensuring proper collection of all broken parts of a needle when a replacement needle is being provided.

Line Supervisor, Quality Control In-charge and Production Manager are responsible for taking immediate action when broken parts of a needle has been reported as lost by the operator.

Procedure:Each and every needle breakage shall be recorded in Broken Needle Register (No. F/ST/29) mentioning date, operator name, card no., process, Line no., Buyer’s name, Needle size, Quantity, Change needle no., sign. of operator, issued by, sign of supervisor, sign of Manager, remarks.

When a needle is reported as broken the line supervisor/Operator must bring and submit all the broken parts of the needle in order to receive a replacement.The store officer will issue a replacement needle and preserve the broken parts in the Broken Needle Register (No. F/ST/29). The Issue will be recorded in the same register.

If all the parts of the needle cannot be located, report shall be made to the QC In-charge and Production Manager and the specific garment and all other garment/garment component located near the single needle lockstitch machine shall be segregated and put in a bin with identification board writing “BROKEN NEEDLE/DO NOT TOUCH”

Each and every garment put in the bin shall be separately inspected using a Metal detector by the Operator and QC In-charge.The single needle lockstitch machine shall be checked using a metal detector by the QC In-charge / QC Inspector.

If the broken part cannot be found, Production Manager and QC In-charge shall make decision and authorize the issue of a replacement needle by signing on the broken needle register after verification of the previous activities performed by the QC In-charge, line supervisor and operator.

Garments segregated in step 5.4 shall be thoroughly checked and confirmed that those are free from any broken needle parts before issuing them to production floor.

Conclusion:

It can also be called plain stitch machine. Here different sizes of needle can be used as per requirements. Single needle lockstitch machine mostly used in the garments industries.

[1] Md. Ferdus Alam, B.Sc. in Textile Engineering, Southeast University, Cell # 1723300700,  Email: ferdus.j@gmail.com