Inprocess Inspection - Sewing

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Inspection procedures in Sewing Room

Transcript of Inprocess Inspection - Sewing

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Inspection procedures in Sewing Room

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Introduction • In process inspection in the sewing involves the

inspection of work from each operator, with a quality standard established to limit the amount of bad work permitted and a provision for operators to re inspect and repair entire bundles should this limit be exceeded.

• The decision on where to place the inspection stations will be influenced by various factors, such as the importance of operations, and controlling troublesome or key operations

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• The inspections can often be performed for two or more operations at the same time.

• In process inspection can be established at various inspection points in sewing operations, as opposed to the inspector literally selecting work at each operator’s work station.

• First, a complete manufacturing process chart should be made, clearly identifying the production or manufacturing steps for each type of garment made.

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What to Inspect during Sewing?

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Manufacturing process flow chart for men’s dress shirts

1. Marker lay made according to cutting ticket. Marker lay checked 100%

2. Marker and material delivered to spreading operation. Material spread.

3. Machine knife cut4. Die cutting small parts5. Cut parts delivered to plant

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6. Collar department: Fuse stays, run collar tops, trim points. Turn and press (shape), top stitch, trim tops. Hem bands, stich lining to bands. Band collar. Turn band ends. Top stitch bands. Trim and baste. Quarter-mark band. Button hole. Button sew.

7. Cuff department: Hem cuff, run cuff. Shape cuff top stitch. Button hole. Button Sew.

8. Under fronts: Baste neck. Crease Front. Hem button stay. Button Sew. Set Pocket. Set flap.

9. Upper Fronts: Baste neck. Crease Front. Centre Pleat. Buttonhole. Set Pocket. Set Flap.

10.Sleeves: Piece binding. Bind Sleeve. Tack binding.

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11.Backs: Pleat. Backs12.Yokes: Label. Sew.13.Attach yoke backs. 14.Assemble completed bundles of parts, any size,

section, ply number, and /or shade.15.Join shoulder seam16.Join collar to shirt17.Set sleeve, join side and underarm seams (Side

fell)18.Cuff attach, hem shirt, trim threads.19.Button shirt, run collar, press, and fold.20.Pack

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What to inspect during What to inspect during sewing ?sewing ?

• The inspection points or stations should be carefully selected so that the operations to be checked are neither covered by later operations, nor necessitate ripping good work to repair a defect.

• Inspection stations should provide a uniform work load for each inspector and should minimize the elapsed time between the completion of an operation and its inspection.

• Each operator should be told what standard of work is acceptable and what is not. There should be a written quality specification for each job in the manufacturing process

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• Wherever possible sketches of the garment parts should be included, illustrating how they are supposed to appear after completion.

• Dimensions and tolerances for critical points must be included.

• Knowledge of the factors that create problems in a particular operation helps to determine the specific dimension or characteristic to be maintained.

• Each inspector should be clearly told what to look for while inspecting various operations.

• Most inspections in the in process check points can be performed rapidly without sacrificing the accuracy, and quite large units of inspection should be expected of inspectors each day.

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• The inspectors must be allowed with enough time to inspect in greater detail when necessary and to carefully explain the quality problems to the supervisors.

• As with all the inspection activities, the thoroughness of inspection is more important than the quantity inspected.

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Sewing Defects

• Needle damage are evidenced by holes, picked threads, ruptured threads or other damage to the fabric; caused by wrong size or type of the needle, blunt needle, needle heat, or machine feeding difficulty.

• Feed damage, particularly on thicker sheer fabrics, or when machining over transverse seams, from incorrect type of teeth, excessive pressure by foot, improper alignment of feed and foot, damaged throat plate, excessive machine speed.

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Sewing DefectsSewing Defects

• Skipped Stitches, from the hook irregularly failing to pick up the loop of thread from a needle’s eye owing to a number of causes.

• Thread breaks, arising from too thick a thread for needle, too thin a thread, needle heat, operator working un rhythmically, or too tight tensions.

 • Broken stitches, arising from the wrong stitch

type, too tight tensions, a badly formed joint in the seam where the second line of the stitch runs over the first and cracks it, sharp feeds, and too great a pressure.

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Sewing DefectsSewing Defects• Seam grin, arising from too loose a tension or too

large a stitch, or use of the wrong stitch type.

• Seam pucker, because of incorrect handling by the operator, misaligned notches, or tight tensions.

 • Pleated seams, an extreme form of seam pucker,

where operator failed to ease fullness evenly • Wrong stitch density. Too many give rise to

jamming and rapture of fabric threads; too few to grinning or weak seams

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Sewing DefectsSewing Defects• Uneven stitch density. Operator causes machine

to snatch and does not allow machine to control fabric.

 • Staggered stitch, from faulty feed motion, incorrect

needle, and other machine parts. • Improperly formed stitches, caused by bad

tension, incorrectly adjusted timing, ill fitting machine components.

 • Oil spots or stains.

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Seaming Defects

Seaming defects are usually caused by the errors arising from the interaction of the operator and the machine in the handling of the garment. •Incorrect or uneven width of inlay, arising from bad handling by operator, incorrectly set guide, incorrectly adjusted folder. In extreme cases, the seams burst open, raw edges show, slippage of weave threads occur, or notches are exposed.  •Irregular or incorrect shape of the sewing line (sometimes called run-offs) in top stitching, arising from lack of or badly set guide, not following a mark, or incorrect handling.

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Seaming Defects• Insecure back stitching, because subsequent rows

do not cover the first row of stitching.  • Twisted seam leading to irregular puckering or the

garment parts not hanging correctly when worn; caused by improper alignment of fabric parts, mismatched notches, and allowing one ply to creep against another.

 • Mismatched check or stripes • Mismatched seam, where transverse seams do not

match (e.g., inside leg seams at the fork of the trousers)

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Seaming DefectsSeaming Defects• Extraneous part caught in seam, an unrelated piece

showing through the seam.

• Reversed garment part, where part is sewn with the face side opposite from specification, perhaps when the part cut for one side of the garment is sewn in the other, or when the whole garment is assembled inside out.

 • Blind stitching showing on the face side, or not

securely caught on inside, arising from improperly adjusted bender.

 • Wrong seam or stitch type used.  • Wrong shade of thread used.

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Assembly DefectsAssembly DefectsAssembly defects are perhaps caused by errors arising in marking and cutting, as well as sewing operations in the sewing room, or a combination of these. •Finished components not correct to size or shape or not symmetrical

•Finished garment not to size, arising from incorrect patterns, inaccurate marking or cutting, shrinking or stretching fabric, incorrect seam widths.  •Parts, components, closures, fixtures omitted, caused by bad work flow, wrongly printed work tickets, parts omitted in cutting, careless operator.

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Assembly DefectsAssembly Defects• Components or features wrongly positioned

or misaligned arising from incorrect marking, or sewing not following the mark. (e.g., pockets, bar tacks, top stitching, button holes, buttons, hooks and bars, hooks and eyes, zips).

• Interlining incorrectly positioned, twisted, too full, too tight, cockling.

 • Lining too full, too tight, showing below the

bottom of the garment, twisted, incorrectly pleated and so on.

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Assembly DefectsAssembly Defects• Garment parts cockling, pleated, twisted,

showing bubbles and fullness; for example, collar in relation to the under collar or the neck, sleeve in relation to the armhole, pockets, tapes, zips, pads in relation to the shoulder.

• Garment parts shaded owing to being mixed after cutting

• Parts in one- way fabrics in wrong direction, usually only small parts, such as pockets.

• Mismatched trimming

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Glossary of Sewing Glossary of Sewing room defectsroom defects

Sewing room defectsScissors or Knife Cut Self-explanatory Tear Usually the result of excessive strain or

snagging on the manufacturing machinery.Needle Chew Caused by use of wrong or blunt needle or

machine feeding difficultyIncorrect Material Shading

Where components do not match exactly as to shade

Spots or Stains Normally the result of a defective machine or a dirty work area.

Loose Threads Can be caused either by malformed stitching or poor trimming techniques

Puckered Seams An irregular seam surface usually caused by a) Inherent fabric characteristic, b) Needle puncture, c) Machine feed slippage or d) incorrect machine application

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Pleated Seams Caused by incorrect machine attachments. Machine sewing parts too large or small for fabric or seam desired irregularly cut patterns or fabric irregularities and operator feeding fabric faster than normal feeding action of the machine.

Thread Breaks Wrong thread application, sewing machine malfunction, defective thread.

Insecure Backstitching Original stitch row not covered with second seam.

Wrong Shade of Thread

Either caused by basic purchasing error, manufacturing defect by thread supplier or operator selecting wrong color from thread bin.

Irregular Gauge of Stitching

Not using correct sewing machine or using single needle machine where a multiple needle machine is required

Open Seams Incorrect folder or poor operator technique. Sometime results from poor selection of type of seam for fabric used or purpose of seam in garment.

Run Off Operator not following marking or not using mechanical aids such as edge guides to assure uniform stitching.

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Wrong Seam or Stitch Type

Management error in selection-or operating personnel failing to follow specifications

Loose Thread Tension Tensions not adjusted correctly by operator

Tight Thread Tension Tensions not adjusted correctly by operator

Wrong Stitches per Inch

Normally caused by operators who lengthen stitch to increase machine speed

Skipped Stitch Caused by machine malfunction or excessive needle heat due to friction.

Broken Stitches Often times the fault of wrong type of stitch for specific seam construction. Could be caused by excessive tightness in machine tensions

Closures Omitted Normally an oversight by operators or failure by inspectors

Closures Misplaced. Inattention or inexperience by operating personnel or improper alignment with gauges.

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Finished Components Not measuring to Tolerances

Could be caused by faulty pattern, cutting, previous operations in stitching or by indifferent operator attention to the specified tolerance

Dimensions out of Tolerance

Could be caused by faulty pattern, cutting, previous operations in stitching or by indifferent operator attention to the specified tolerance

Notches Exposed Poor operator technique and execution in not covering notch with seam.

Omission of Any Part of Garment

Poor work flow, inattentive operator. wrong worktickets or poor inspection

Twisted Seam Caused by improper alignment of fabric pieces. uneven tension or pull on plies being stitched

Pieces Not Aligned Pieces sewn together not matched to each other

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Reversed pieces Where piece is sewn with face side opposite from specification; where part cut for one side of garment sewn in other.

Excessive Fullness Caused where piece surface not smoothed prior to stitching.

Uneven Edge Where stitching not straight or improperly formed in creasing machine

Ragged Edges Usually occurs where knives on automatic button-hole machines do not dip smoothly.

Uncut Buttonhole Where knife failed to cut button-hole

United Stitch Where tying stitches on automatic machines fail to secure.

Hole Damage caused by faulty machine or related equipment

Faulty Gauging Where operator has not sewn seam to specifiedMargin

Misaligned Closure Closure components do not line up

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Misplaced Component

Where part not positioned according to specifications

Misaligned Seam Where seams .do not line up or cross specified point

Mislocated Reinforcement

Where bar tack or brad not in proper location

Uneven Stitch Caused by operator speeding up machine too rapidly or by holding back or pushing fabric through machine in variance with correct machine feed

Needle Pick Failure of operator to replace a dull needle

Caught Place Where a component of part of a garment been caught in an unrelated operation.