An Overview of Quality and Quality Control in Textile Industry

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An Overview of Quality & Quality Control in Textile Industry
Akter Hossain
Department of Textile Engineering
Daffodil International University





Introduction:
Quality means customer needs is to be satisfied. Failure to maintain an adequate quality standard can therefore be unsuccessful. But maintaining an adequate standard of quality also costs effort. From the first investigation to find out what the potential customer for a new product really wants, through the processes of design, specification, controlled manufacture and sale.

There are a number of factors on which quality fitness of garment industry is based such as - performance, reliability, durability, visual and perceived quality of the garment. Quality needs to be defined in terms of a particular framework of cost.

Quality Control:
Quality is of prime importance in any aspect of business. Customers demand and expect value for money. As producers of apparel there must be a constant endeavor to produce work of good quality.

"The systems required for programming and coordinating the efforts of the various groups in an organization to maintain the requisite quality". As such Quality Control is seen as the agent of Quality Assurance or Total Quality Control.

In the garment industry quality control is practiced right from the initial stage of sourcing raw materials to the stage of final finished garment. For textile and apparel industry product quality is calculated in terms of quality and standard of fibres, yarns, fabric construction, colour fastness, surface designs and the final finished garment products. However quality expectations for export are related to the type of customer segments and the retail outlets.

Quality control and standards are one of the most important aspects of the content of any job and therefore a major factor in training.

Total Quality Control:
"To ensure that the requisite quality of product is achieved". This ensures customer satisfaction, but it leaves quality control as a necessary but expensive evil.

To ensure, at minimum practicable cost, that the requisite quality of product is being achieved at every stage of manufacture from raw materials to boxed stock

Objectives:
  • To maximize the production of goods within the specified tolerances correctly the first time.
  • To achieve a satisfactory design of the fabric or garment in relation to the level of choice in design, styles, colours, suitability of components and fitness of product for the market.
Textile Quality Control Experts:
Quality Control: AQM performs quality control and inspection services for different customers from all over the world. Using international standards such as ISO 2859, our Quality Controllers (QC) method consists to check different control points:

Conformity: The QC checks the conformity of the product (design, colors, raw material…) with the Pre-Production Sample (PPS) and other technical files.

Quality: Our QC checks for defects (fabric defects, colors defects, accessories and label defects, manufacturing defects) and classifies them accordingly.

Measurement: Following the measurement chart, our QC checks the measures for each size of the product.

Packaging: Our QC checks the quantity of cartons, size of cartons, their weight, shipping marks, etc.

Concept of Quality:
Simply, quality refers to one or more desirable characteristics that a product should possess. Quality is inversely proportional to (unwanted) variability.
Quality curve
Quality Characteristics:
Every product possesses a number of properties that jointly describe what the user or consumer thinks of as quality. These properties are known as quality characteristics. For example, fiber length is known to be one of the important quality characteristics of a fiber.

Quality Cost :
Preventing, detecting and dealing with defects cause costs that are called quality costs or costs of quality. Quality costs can be broken down into four broad groups.

(1). Prevention Costs:
  • Product/process design.
  • Process control.
  • Burn-in.
  • Training.
  • Quality data acquisition and analysis
(2). Appraisal Costs:
  • Inspection and test of incoming material.
  • Product inspection and test.
  • Material and services consumed.
  • Maintaining accuracy of test equipment.
(3). Internal failure Costs:
  • Scrap
  • Rework
  • Retest
  • Failure analysis
  • Downtime
  • Yield losses
  • Downgrading/ off-spacing
(4). External failure costs:
  • Complaint adjustment
  • Returned product/material
  • Liability costs
  • External costs
Quality control in Garment Manufacturing Process:
Quality is a relative term. It means customer needs is to be satisfied. Quality is of prime importance in any aspect of business. Customers demand and expect value for money. As producers of apparel there must be a constant endeavor to produce work of good quality. In previous article, I discuss about quality control system in garment industry. Now I will give a short description of Quality Control in Garment Manufacturing Process.
Quality inspection
Quality inspection and control in RMG industry:
The various Steps of Garments manufacturing where in-process inspection and quality control are done are mentioned below-
  1. In Sample making section
  2. In- Marker making section
  3. Inspection in fabric spreading section
  4. Inspection in fabric cutting section
  5. Inspection in fabric sewn section
  6. Inspection in pressing & Finishing section
Quality Control in Sample Section:
  • Maintaining buyer Specification standard
  • Checking the sample and its different issues
  • Measurements checking
  • Fabric color, gsm, Fastness etc properties required checking
  • Spi and other parameter checking
Quality Control in Marker Making:
  • To check notch or drill mark
  • Fabric width must be higher than marker width
  • Fabric length must be higher than marker length
  • Matching of green line
  • Check pattern size and dimension
  • Matching of check and stripe taking into consideration
  • Considering garments production plan
  • Cutting table length consideration
  • Pattern direction consideration
Quality Control in Fabric Spreading:
  • Fabric spreading according to correct alignment with marker length and width
  • Maintain requirements of spreading
  • Matching of check and stripe
  • Lay contains correct number of fabric ply
  • Correct Ply direction
  • To control the fabric splicing
  • Tension control
Quality Control in Fabric Cutting:
  • The dimension of the pattern and the cut piece should be same and accurate
  • Cut edge should be smooth and clean
  • Notch should be cut finely
  • Drill hole should made at proper place
  • No yarn fraying should occur at cut edge
  • Avoid blade deflection
  • Maintain cutting angle
  • More skilled operator using
Quality Control in Sewing Section:
  • Input material checking
  • Cut panel and accessories checking
  • Machine is in well condition
  • Thread count check
  • Special work like embroidery, printing panel check
  • Needle size checking
  • Stitching fault should be checked
  • Garments measurement check
  • Seam fault check
  • Size mistake check
  • Mismatching matching of trimming
  • Shade variation within the cloth
  • Wrong placement of interlining
  • Creased or wrinkle appearance control
Quality Control in Finishing Section:
  • Proper inspection of the garments including measurement, spot, dirt, impurities
  • Water spot
  • Shading variation check
  • Smooth and unfold in pocket
  • In secured or broken chain or button
  • Wrong fold
  • Proper shape in garments
  • Properly dried in after pressing
  • Wanted wrinkle or fold in lining
  • Get up checking
  • Collar closing
  • Side seam
  • Sleeve placket attach
  • Cuff attach
  • Bottom hem
  • Back yoke
  • Every parts of a body
Quality Control of Sewing Thread:
A slender, strong strand or cord, especially one designed for sewing or other needlework. Most threads are made by plying and twisting yarns. A wide variety of thread types are in use today, e.g., spun cotton and spun polyester, core-spun cotton with a polyester filament core, polyester or nylon filaments (often bonded), and mono filament threads.
Sewing thread
Following Features of Sewing Thread are Considered:

1. Thread Construction/Ticket number
  • Thread count
  • Thread Ply
  • Number of twist
  • Thread balance
  • Thread Tenacity
  • Thread Elongation
2. Sew ability
3. Imperfection
4. Thread finish
5. Thread color
6. Package Density
7. Winding
8. Yardage

Quality Control in Zipper:
A zipper, zip, or zip fastener, is a commonly used device for temporarily joining two edges of fabric. It is used in clothing (e.g., jackets and jeans), luggage and other bags, sporting goods, camping gear (e.g. tents and sleeping bags), and other items.
Zipper
Following Factors are Considered in Zipper:
  1. Proper dimension of zipper
  2. The top and bottom end should correctly sewn
  3. The tape and color of zipper should be uniform
  4. Slider has to be locked properly
  5. The slider should move properly
Quality Control System:
  1. On- line quality control system
  2. Off line quality control system
On Line Quality Control System:
This type of quality control is carried out without stopping the production process. During the running of production process a set up is automatically performs and detect the fault and also takes corrective action. Online quality control comprises with the raw material quality control and the process control.

Raw Material Control :
As the quality product depends on the raw material quality so we must be provided with the best quality raw material with an economical consideration. The fabric must be without fault, with proper absorbency, whiteness as per requirement of the subsequent process. The Grey inspection report gives the condition of the raw fabric.

Process Control :
The method chosen for the process must be provided with the necessary accurate parameters. Here the specific gravity, water level, residual hydrogen per oxide etc. at each stage is checked.

Laboratory :
Lab is the head of the textile industries. Higher precision lab can aid easily to achieve the goal of the organization. Before bulk production a sample for the approval from industry is sent to the buyer. As per the requirement of the buyer the shade is prepared in a lab considering the economical aspects.

Lab Line:
  1. Standard sample: The buyer to the industry gives the standard sample. The sample is measured by the CCM to get the recipe.
  2. Lab trial: Getting the recipe the lab officer produce lab trial and match with standard according to buyer requirement. Lab trial is made by the AHIBA dyeing machine.There are some programs for dyeing.
Off Line Quality Control System:
Performed in the laboratory and other production area by stopping the production process consisting of fabric inspection and laboratory and other test. Correction steps are taken according to the test result.

Off-Line Tests: All the Off-Line tests for finished fabrics can be grouped as follows:

A. Physical tests
B. Chemical tests

A. Physical Tests:
  1. GSM test
  2. Shrinkage test
  3. Spirality test
  4. Tensile strength
  5. Abrasion resistance
  6. Pilling resistance
  7. Button Strength Testing
  8. Crease resistance
  9. Dimentional stability
  10. Brusting strength test
B. Chemical Tests:
  1. Color Fastness to washing.
  2. Color Fastness to lighting.
  3. Color Fastness to heat.
  4. Color Fastness to Chlorinated water.
  5. Color Fastness to water spotting.
  6. Color Fastness to perspiration.
  7. Color Fastness to Seawater.
  8. Fibre analysis.
  9. PH test.
  10. Repellency.
Quality of Fabric:
Quality is very important for all types of fabric and textiles. There are some important topics given blow about quality of fabric..........

Quality Parameters of Woven, Knitted and Non-woven Fabrics:
Generally to test the quality parameters of woven,knitted and non-woven fabric, the fabric must be conditioning at 24 hours in the standard testing atmosphere. It is very important for all types of fabric.

Quality Parameters of Woven Fabrics:

There are some quality parameters of woven fabric.....................

1. Dimensional characteristics:
  • Length
  • Width
  • Thickness.
2. Weight of fabric:
  • Weight per unit area.
  • Weight per unit length.
3. Fabric strength and extensibility:
  • Tensile strength.
  • Tearing strength.
4. Threads per inch of fabric:
  • Ends per inch.
  • Picks per inch.
5. Yarn count:
  • Warp count
  • Weft count.
6. Crimp:
  • Warp crimp
  • Weft crimp.
7. Handle:.
  • Stiffness
  • Drape.
8. Crease resistance and crease recovery.
9. Air permeability.
10. Abrasion resistance.
11. Water resistance.
12. Shrinkages.
13.Different fastness properties:
  • Fastness to light.
  • Fastness to wash.
  • Fastness to perspiration.
  • Fastness to Rubbing.
Quality Parameters of Knitted Fabrics:
There are some quality parameters of knitted fabric...............
  1. Strength and extensibility.
  2. Course density.
  3. Wales density.
  4. Lop length.
  5. Elasticity.
  6. Deformation.
  7. Grams per square meter (G.S.M)
  8. Yarn count.
  9. Design.
Quality Parameters of Non-woven Fabrics:
There are some quality parameters of non-woven fabric..................
  1. Strength and extensibility of fabric.
  2. Weight.
  3. Thickness.
  4. Air permeability.
  5. Crease resistance.
  6. Stability of washing.
  7. Stability of dry cleaning.
  8. Dimensional stability.
  9. Elasticity.
Apparel Quality Control System:
Some main quality aspects for export basis:
Below are some of the main quality aspects that are taken into consideration for garment manufacturing for export basis:
  1. Overall look of the garment
  2. Right formation of the garment
  3. Feel and fall of the garment
  4. Physical properties
  5. Color fastness of the garment
Quality is a multi-dimensional aspect:
There are many aspects of quality based on which the garment exporters are supposed to work.
  1. Quality of production
  2. Quality of design of the garment
  3. Purchasing functions – quality should be maintained
  4. Quality of final inspection should be superior
  5. Quality of the sales also has to be maintained
  6. Quality of marketing of the final product is also important as the
  7. Quality of the garment itself
To ensure quality:
  • To insure quality some factors are considered:
  • Recognize who the customer is
  • Build processes that anticipate and prevent defects
  • Make a plan to achieve the desired quality level
  • Set up ways to measure progress
  • Work as a team to achieve goal
In this context, customer is the entity receiving a service or product from our work. For example, we can take a short production line.

Receiving → Cutting → Sewing → Inspecting → Finishing

Quality problem in cutting may lead to problems in sewing,inspecting and finishing. It’s like “garbage in garbage out”. In other words, one needs to have good quality materials to produce good quality goods. So this has to be applied to every process in the system to have a total quality control.

A good plan requires:
  • A clearly defined objective
  • Goals or expected results
  • The activities needed to achieve the desired results
  • Defined roles and responsibilities for the activities
  • Dates for beginning and completion of each activity
  • An analysis of potential problems
Measurements are a vital part of any quality improvement program. Anything that is not measured does not improve. We need to establish these standard measures and measure the progress periodically.

Team work is also an essential element for the success of the program. Remember “ONE of us is NOT better than an All of US”. The whole effort needs to have a direction that a team leader will provide.

Way of control quality:
  1. Have the proper approach toward operators.
  2. Train the operator to sew with good quality from the beginning.
  3. Know quality specifications and tolerance. Be sure you understand what constitutes good and poor quality. Be consistent in your decisions toward quality.
  4. Comment on both good and bad quality. We all have a tendency to be silent during good times and vocal during the bad.
  5. Be sure to check each operators work daily.
  6. Use a check list. Do not rely on memory of specifications.
  7. Do not rely on inspectors to tell you the quality level of your operators, instead find out yourself.
  8. Do not have a compromising attitude towards problem related to quality.
Basic quality inspection procedure in cutting area:
  1. Marker is checked for all parts and for any variation against pattern.
  2. Spreading has to be inspected
  3. During cutting:
  4. The marker line had to be followed
  5. All notches should be located correctly with even depth say 1/8 in. (± 1/16). When cutting, care should be taken not to shift the stack of parts to a side or cut with the blade at an angle.
  6. In bundling and shade marking, care should be taken to ensure that the numbering is correct. For the final audit process, the quality inspector will determine how many bundles to check from every size depending on the sample size.
Basic quality control procedure in sewing line:
(a) 100% inline parts checking
The operations which are difficult to re-process after assembling is checked 100% to avoid damages and waste of time.

(b) Inline inspection
During the production of garments the operator’s finished work is audited in an inline inspection. A quality inspector moves from one operator to another at random inspecting a pre-determined number of parts from a finished bundle. This helps to control quality at needle point.

(c) 100% end-line inspection
At the end of a line or section there should be a checker to inspect all the parts before they leave the section. The inspections should be effective in identifying all defects in a garment. The checkers should have their forms filled correctly. A good source of information to determine the quality performance of the section is the point of 100% inspection. The section supervisor should check the quality level at the point of 100% inspection periodically. With this information, the supervisor should address the problems, correct the possible causes and make plans to prevent them.

(d) Pre-final audit
A pre-final audit should be performed on packed items on a daily basis to ensure that the good packed items are meeting the quality standards. Any problem seen can be arrested at the early stage. If pre-final audits are done properly, the final audit of the buyer should also be carried out without any issues.

Quality Training:
The purpose of the training program is to train operators to attain high speed and production together with good quality work. Good quality comes from the consistent use of correct methods

The steps to be taken to achieve good quality are as follows:

1. Initial instruction
Point out the key points of method and quality to the trainee and be sure that she understands them.

2. Trainee practice
When the trainee first practices an exercise, the instructor should watch her methods very closely and correct any incorrect methods immediately. The trainee should not be timed or be permitted to start timing until she is doing the exercise correctly. Even after starting her timing, the instructor should keep a close watch on her methods and quality.

3. Quality checking
Whenever the instructor finds any faulty work, or whenever defects are found by other inspectors or operators, the instructor should:
Look at the faulty work or record to determine what mistakes the trainee is making.
Tell the trainee not just what she is doing wrong, but what she must do to perform the work correctly.

4. Methods checking
The best way for an instructor to ensure good quality is by watching the trainee while he is working, by inspecting some of his work and by correcting any faults immediately. It is much easier and more effective to correct a fault when it happens, than to try to change the method after he has turned out a quantity of bad work. In order to become skilled at this part of training, the instructor should take every opportunity to stand and watch each trainee at work, in order to detect and stop any defects in method, immediately.

Statistical Quality Control (S.Q.C) :
It is the application of statistical tools in the manufacturing process for the purpose of quality control. In SQC technique attempt is made to seek out systematic causes of variation as soon as they occur so that the actual variation may be supposed to be due to the guranted random causes.

Statistical quality control refers to the use of statistical methods in the monitoring and maintaining of the quality of products and services.

Basic Categories of Statistical Quality Control (S.Q.C):
All the tools of SQC are helpful in evaluating the quality of services. SQC uses different tools to analyze quality problem.
  1. Descriptive Statistics
  2. Statistical Process Control (SPC)
  3. Acceptance Sampling
1. Descriptive Statistics:
Descriptive Statistics involves describing quality characteristics and relationships.

2. Statistical process control (SPC):
The application of statistical techniques to determine whether a process is functioning as desired

3. Acceptance Sampling:
The application of statistical techniques to determine whether a population of items should be accepted or rejected based on inspection of a sample of those items.

Variations of Statistical Quality Control (S.Q.C):
  1. Allowable or cause variation
  2. Assignable or preventable variation
Function of Statistical Quality Control (S.Q.C):
  1. Evaluation of quality standards of incomeing material, product process and finished goods.
  2. Judging the conformity of the process to establish standards taking suitable action , when deviation are noted.
  3. Evaluation of optimum quality, obtainable under given condition.
  4. Improvement of quality and productivity by process control and experimentation.
Main Purpose of Statistical Quality Control (S.Q.C):
The main purpose of Statistical Quality Control(S.Q.C) is to divide statistical method for separating allowable variation from preventable variation.

The Significance of Statistical Quality Control (S.Q.C) in the Textile Industry:
  1. The expected quality of product can be produced and hence customers satisfaction can be achieved which brings higher profit.
  2. It is very easy to separate allowable variation from the preventable variation by this.
  3. It ensures an early detection of faults in process and hence minimum wastage.
  4. With its help one can easily defect the impact of chance in production process in the change in quality.
  5. It ensures overall co-ordination.
  6. It can be use in the interpretation control chart.
Some test for quality control textile finishing:
  1. Shrinkage Test
  2. GSM Test
  3. Tensile Test
  4. Tearing Test
  5. Color Fastness Test
  6. Rubbing fastness Test
  7. PH Test
  8. Shade Matching Test
  9. Fabric Width Test
Conclusion:
There are many quality parameters in different types of fabric. And there are also many different faults in different types of fabric, which are effect in quality of fabric. If we control those faults and effects ,we can get the good quality of fabric. So quality control is very important for all types of fabric and textiles.


Published by:
S. M. Hossen Uzzal
B.Sc. in Textile Technology
Monno Fabrics Ltd. Manikgonj
 

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