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Saturday, December 3, 2016

Textile Testing Process in a Third Party Lab

Textile Testing is an Important Part for a Textile Company as they need a quality certificate to export their Textile or Garment Products. It’s a Buyer requirement that the products they buy from different Garment Companies should meet their product criteria and quality. So here the question arises, where and how the products should be tested. Is it in the In-house lab of Manufacturing Company or in a Third party lab.


Tests can be done in the In-house lab of a Manufacturing Company or in a buyer approved Textile Testing Company. In the development stage, most of the tests are done in the in-house labs to develop the products quality. But it is necessary to send the products to a Third Party lab for testing to get the products testing certificate. The tests can be done in the Development stage or in the Production stage or in the both stage according to the Buyers requirement.

Some In-house labs and Tests are accredited by some Buyers. So the accredited tests are no longer need to be tested in the Third Party Testing Labs. After verifying, some European Buyers give accreditation to the in-house labs of the Manufacturing Companies and a very few Manufacturing Companies get accreditation from American Buyers.

Now we will learn how Textile Testing is done in the Third party Testing Labs –
There is so far difference between an In-house lab and a Third party lab. In a Third party lab, there are many departments. The departments are as follows –
  • Customer Service
  • Login
  • Test Assign
  • Big Cut and Break Down
  • Soft lines
  • Analytical or RSL
  • Reporting
Customer Service
It is the very first department where the Testing samples are received for testing. The Merchandisers contact with the customer service to give their products with a Test Request form for testing. Then the customer service passes the products with Test Request Form to the Login department.

Login
In the login department, the samples are sorted according to the Test Request Form, Sample Category and services like Regular, Express, Emergency, Shuttle and logged in. They give a login number in the Test Request Form by mentioning service. Generally the regular service is given by 5 days, Express by 3 days, Emergency by 2 days and Shuttle by 24 hrs. Data Entry service is also given by the Login Department. Then the samples are passed to the Test Assignment department.

Test Assign
Test Assignment is the most important department where the tests are assigned for a product. The tests are assigned according to the product category and Buyers Program manual or Protocols. Not a single extra test should be assigned or not a single test should be missed. The test Assignment is also done by department wise like Physical, Chemical, Colorfastness, FIbre etc. Washing instructions, testing methods etc. are also defined by this department. Then the samples are passed to the Big cut and Breakdown Department.

Big Cut and Breakdown
According to the Test Assignment, Big Cut prepare the samples for different technical departments like physical, Dimension, Fibre, Colorfastness, and Breakdown etc. and the samples are passed to the technical departments and also to Breakdown. The Breakdown department prepares the samples for Analytical or RSL tests and Also for PH and Formaldehyde tests.

Soft lines
There are many departments relate to Soft line. The departments are Physical, Wet and Dimension Lab, Colorfastness Lab, Flammability Lab, Fiber Lab.

Physical Lab
In the physical lab most of the Physical tests are done. Tensile and Tear strength of fabrics, Operability of zipper, strength and torque test for zipper, Pocket reinforcement, seam strength, attachment strength of garments etc. are done in the physical lab.

Flammability Lab
In Flammability lab Flammability of clothing textile, Children Sleepwear flammability etc. tests are done.

Colorfastness Lab
In colorfastness lab, Colorfastness to Light, Water, Sea water, Pool water, Chlorine Bleach, Dry Clean, Non-Chlorine Bleach, Perspiration, Saliva, Phenolic Yellowing, Dye transfer, Rubbing/Crocking etc. tests are done.

Fibre Lab
In fibre Lab, Fiber analysis, Exclusive of Decoration, Labeling review of fibre etc. tests are done.

Wet and Dimension Lab
In wet and Dimension Lab, Dimensional Changes, Appearance, Actual Laundering, Colorfastness to Commercial Dry Cleaning, Side seam Twisting, Durability after repeated Home Laundering, Iron Ability etc. are done in the Wet and Dimension lab.

Analytical or RSL (Restricted Substrates List)
In the RSL department, many tests like, Ph, Formaldehyde, Azo Dye Determination, Phthalates, California Proposition 65, CPSIA and Total Lead in Surface Coating and Substrates, Cadmium Content, Nickel Spot and Nickel Release test, Chromium 6, Soluble Heavy Metals Content etc. tests are done.

Reporting
Reporting is the last and most important department in a 3rd party Textile Testing lab. There is a due date for every Test Request form and on that due date all the data for a specific Test Request Form come to the reporting department. The reporters work Buyer wise. They analyze the data and give Pass and Fail according to the Buyer requirements. They make the Report against a TRF release the report.

Saturday, October 8, 2016

Buyers Approved Textile Testing Laboratories

Most of the Garments and Textile industries around the world are 100% export oriented. They export their textile and garments products to other countries. While trendy designs and incomparable colors may preliminary sell a garment, it’s final the quality and safety that will confirm customer loyalty, generate repeat business, and maintain a brands value. That is why like other products, before exporting Textile Manufacturing Companies should have their testing reports to make sure of their qualities. So the manufacturers have to send their products sample to the third party laboratories to get their products certificate for exportation. These third party labs should be Buyers Approved. There are many third party labs around the world which are buyer approved. Such as Bureau Veritas, SGS, ITS etc.


Textile Testing Labs

The Following Labs Deliver Various Types of services like Auditing, Certification, Classification, Consulting, Inspection, Outsourcing, Quality Assurance and Quality Control, Testing and Analysis, Training, Constructions and Engineering, Food and Health Care, Transportation, Agriculture, Chemicals etc. but I’ll just discuss the Labs summary and TextileTesting
  • SGS
  • Bureau Veritas (BV)
  • Intertek Testing Service (ITS)
  • Modern Testing Services (MTS)
  • TÜV Rheinland.
  • TÜV SÜD
  • UL
  • Consumer Testing Laboratories (CTL)
SGS
SGS is the world’s leading Inspection, Verification, Testing and Certification Company. It’s headquartered in Geneva, Switzerland.  Now has more than 85,000 employees and operates over 1,800 offices and laboratories worldwide. Its total revenue in 2015 was 5.412 billion Swiss Franc.

It provides services like Audit, Certification, Consultancy, Inspection, Outsourcing, Testing, Training, and Verification. It provides services to Agriculture & Food, Automotive, Aviation, Chemical, Construction, Consumer Goods & Retail, Energy, Finance, Industrial Manufacturing, Life Sciences, Logistics, Mining, Oil & Gas sectors.

SGS provides a wide range of services to the Textile and Apparel sector of the Softline and Accessories Industry. SGS services in the Textiles and Apparel sector include:
  • Audits and certification
  • CPSIA
  • Eco-design
  • Inspection
  • REACH
  • Testing                                
Bureau Veritas Consumer Product Service Ltd.
Bureau Veritas was founded in 1828 and is called the world leader in Certification, Inspection and Testing services. It’s headquarter is in Neuilly-sur-Seine, Paris, France. At the end of 2016, the group has more than 67,000 employees in more than 1,400 offices and laboratories located in 141 countries. The total revenue of this company was near about 4.6 billion Euros in 2015.

It provides the services like Auditing, Certification, Classification, Consulting, Inspection, Outsourcing, Quality Assurance and Quality Control, Testing, Analysis and training. The Large or small organizations like Aerospace, Agriculture and Food, Automotive, Chemicals and Petrochemicals, Construction and Real Estate, Government and Public, Industrial and Manufacturing, Marine, Mining, Oil and Gas, Power generation, Retail and Consumer Goods, Transport and Infrastructure can rely on Bureau Veritas to support them in protecting their respective brands, assets and business.

Bureau Veritas provides all types of Textile and Apparel testing services like Physical, RSL, Colorfastness, Dimension, Appearance, Flammability, Fibre and all relevant tests on items ranging from fabric samples to finished products for all age grades like Active wear, Swimwear, Beachwear, Exercise wear, Outerwear, Casual and Formal dresses, Trims and Accessories, Care labeling etc.

Intertek Testing Service
Intertek is the trusted provider of quality and safety solutions for many of the world’s leading brands and companies. It’s headquarter is in London, United Kingdom. It was founded in 1888 and now it has more than 40,000 employees in 1,000 locations in over 100 countries. In 2015 its total revenue was 2.167 billion Euros.

It provides services like Inspection, Product Testing and Certification. It provides services to Chemicals, Constructions and Engineering, Energy and Commodities, Food and Healthcare, Government and Trade, Products and Retail, Transportation sectors.

Intertek’s tailored solutions help brands, retailers and manufacturers of Textile, Apparel and Home Textile by ensuring the products performance, safety and quality. Intertek’s services in the field of Textile and Apparel are listed below:
  • Accessory Testing
  • Active wear Testing
  • Apparel Testing
  • Auditing and Systems Certification
  • Care Labeling
  • Chemical Smart Screening
  • Children’s Textile and Apparel Testing
  • CPSIA Testing
  • Footwear Testing
  • GB 18401 Testing
  • Softlines Testing
  • Trim Qualification Programme
Modern Testing Services
Modern Testing Services is a global and strategic partner for rapid, exact and cost effective quality assurance execution in the consumer products industry. MTS Headquarters, Eden Prairie, Minnesota U.S.A. MTS provides the services like Hazardous Chemical Management, Hardlines Testing, Softlines Testing, Toys, Arts and Craft Testing, Factory Compliance Audit and Inspection.

MTS has mass capabilities to cover such the areas like bulk fabric, preproduction garments, and children’s sleepwear testing. MTS also provides testing service for Home Textiles, Curtains, Bedding, Upholstery and many more. In addition with physical, RSL and Colorfastness it also provides testing services for performance and special claims. The most common testing criteria for Textile and Clothing are listed below:
  • Fibre Labeling
  • Care labeling and Care Label development
  • Performance abrasion and pilling
  • Seam strength tests
  • Colorfastness evaluations
  • Dimensional stability, Skewness, Stretch and Recovery
  • Fabric constructions, Fibre ID and Fabric weight
  • Flammability
  • Specials claims like Waterproof, Wind proof, Antibacterial, Antimicrobial
TÜV SÜD
TÜV SÜD is one of the world's leading technical service organizations was founded in 1866 and Headquartered in Munich, Germany. Today it has more than 24,000 employees across more than 800 locations in the world. It has earned 2.2 billion Euros in 2015.
TÜV SÜD is a third party service corporation focusing on consulting, testing, certification and training. The most common testing features for Textile and Clothing are listed below:
  • California Proposition 65
  • Chemical Testing
  • CPSIA
  • Flammability
  • GB Testing
  • REACH Testing
  • RSL
TÜV Rheinland
TUV Rheinland was founded in 1872 and has grown from a local testing organization into one of the world’s leading testing service providers. Now days the company conducts with own companies globally. It is working for the quality and safety with new technologies in new sectors. The company has a workforce of 19,300 people in 69 countries all around the world. It has earned 1.88 billion Euros in 2015.

It provides services in the field of Construction and Real Estate, Consulting, Information Security, Education and Personnel, Management system, Materials Testing and Inspection, Occupational Safety and Health, Plants and Machinery, Product Testing, Vehicles and Traffic.

Today, near about 7,000 chemicals are used in textile and apparel, including dyeing agents, anti-creasing agent, or even to protect against mold during transport. It ensures the quality of products with their lab testing services. They have also an accredited auditing body which inspect and certify textiles for harmful substance content and any physical, qualitative characteristics.

UL
UL is the first global exclusive safety science company that has gained progress for more than 120 years. It has more than 11,000 employees are trained by the UL mission to promote safe working and living environments for all people. Its core services are certification, testing, inspection, advisory and education.

UL quality assurance specialists are partner with textile and Clothing companies to address product regulatory requirements, performance and quality through textile testing and analysis. The most common testing features for Textile and Clothing are listed below:
  • Performance and Special Claim related tests
  • Physical and Mechanical testing
  • Chemical Analysis
  • Flammability
  • Home Textiles
  • Accessories
  • China GB testing
  • Fibre Analysis
  • Colorfastness
  • CPSC requirements for lead and Phthalates
  • California proposition 65
  • Dimensional Stability and Durability
  • EU – REACH SVHC
Consumer Testing Laboratories
Consumer Product Laboratories was established in 1952 and is independent and privately owned Company. It is conducting all of its testing and relevant services from its own facilities.

CTL offers a wide range of testing services for any types of men's, women's and children's clothing and accessories such as casual, outerwear, swimwear, socks, handbags and gloves. CTL offers the following Textile and Apparel testing services:
  • Colorfastness
  • Dimensional Stability and Appearance Testing
  • Flammability
  • Fibre Composition
  • Fabric Construction
  • Physical
  • Total Lead
  • Phthalates
  • Formaldehyde
  • Nickel
  • PH
  • Toxics in Packaging

Saturday, June 18, 2016

Garment Washing Symbols and Meanings

When we buy a garment it looks nice and ok but when we use it, it becomes dirty day by day and becomes unfit to wear. So to wear it again, we’ve to clean it. Then the questions come in our mind that how we will clean it and iron it so that the dresses become ready to wear. Then we search for garments care instructions. The care instructions are given by the care symbols attached with the garment.

Clothing Care Label

Garment Care Label is a label by which we can take care of a garment. In a garment care label we can see many care instructions. When we want to clean a garment we should follow the care instructions. It defines the machine wash should be warm, normal cycle or the garment should be tumble dry low or just tumble dry etc.

The apparel manufacturers attach the care symbols in care label which suits the best for a garment. Before attaching a care label the apparel is tested under different tests for care instructions like Dimensional stability, Appearance after laundering or dry cleaning, Colorfastness to Actual Laundering or Dry Cleaning, Colorfastness to laundering: Accelerated, Colorfastness to crocking, Bleaching and Ironing. When the garment passes under these tests, the care instructions are fixed for the garment.

Now I’ll describe the Garment Washing Symbols and Meanings in AATCC methods as below Images –

Washing Care Symbols and their meanings –

Apparel Washing Care Symbols

Bleaching Care Symbols and their meanings –

Garment Bleaching Care Symbols

Drying Care Symbols and their meanings –

Garment Drying Care symbols

Ironing Care Symbols and their meanings –

Garment Ironing Care Symbols

Dry Cleaning Care Symbols and their meanings –

Garment Dry Cleaning Care Symbols

Friday, June 10, 2016

Different types of Textile Testing methods

Most of the people among us have heard the different types of Textiles and Garments Brand and Buyer name like CK, Dockers, Kohl’s, Kmart, H&M, C&A, Levi’s, Gymboree, American Eagle, Gap, Walmart etc. I would like to inform you that Walmart, Inditex, Gap, Levi’s, American Eagle, PVH, H&M, Esprit, S. Oliver, Mothercare, C&A, George etc. are the top Garments Buyer in the world. These Buyers produce their products with their own brands name and also with other brands name. Such as, H&M produces their products with their own brand name H&M. PVH produces their products with their own brand name PVH, CK and also different brands name like JC penny, Kohl’s, GH Bass etc.

Different Textile Testing Methods

Different buyers use different Textile testing methods. Most of the American Buyers like JC Penny, Target, Walmart USA, Carter’s, Kohl’s, Bass Pro Shop, Marks Work Wear House, LF USA, SHGS, Shopko Lands End etc. use AATCC methods and rest others like Levi’s, Gap, Gymboree, American Eagle etc. use both AATCC and ISO methods. The European Buyers like Mothercare, Koton, George, Esprit, Siplec, s. Oliver, Tom Tailor etc. use BS/ISO methods. Some Buyers like H&M, C&A, M&S use their own methods. Some buyers like Best and Less uses Australian methods, Walmart Canada uses Canadian methods.

Details about different types of Textile Testing methods

There are different types of Textile and Garments Testing methods such as –
  • American Society of Testing &Materials (ASTM)
  • American Association of Textile Chemists and Colorists (AATCC)
  • International Organization for Standardization (ISO)
  • European Norms (EN)
  • British Standards (BS)
  • British Standards for European Nations (BS EN) 
  • Deutsches Institut fur Normung (DIN) 
  • Bureau of Indian Standards (BIS)
  • Japanese Industrial Standards (JIS) 
  • TAPPI
Now I’ll describe some of the above methods as below table for example and for your clarification –

Test Methods
Brief Description
AATCC 20
Fibre analysis. This method is used to identify the fibres used in Textile products. In this method chemical, physical and microscopical techniques are used.
AATCC 8
Colorfastness to crocking. This method is used to identify the amount of color transferred from dyed textile surface to another surface due to abrasion.  
ASTM D1683
Seam Strength. This test method is used to determine the seam strength in woven garments by applying a force perpendicular to the sewn seams.
ASTM D2594
Stretch Properties. This test method is used to determine the stretch and growth of knitted fabrics composed of Lycra.
ISO 3071: 2006
pH value of Textile. This test method is used to determine the pH value in the Textile materials.
ISO 14184-1 : 2011
Formaldehyde content in Textile. This method is applied to test Textiles in any form to determine the total amount of free formaldehyde in Textiles.
EN 14689
Leather. This method is applied to leather products for physical and mechanical tests to determine bagginess, creep and relaxation.
BS 3424-5:1982
Coated fabrics test method. Methods are 7A, 7B and 7C. This method is used to determine the tear strength of coated fabrics.
BS 4098:1975
This test method is used to determine the comparison, thickness and recovery characteristics of floor coverings made of Textiles.
BS EN 13542:2001
This test method is used to determine the compressibility of quilted Textiles.
BS EN 13895:2003
Monofilament Textiles. This test method is used to determine the tensile properties of Textiles made of monofilament yarns.
BS EN ISO 9073-4:1997
Non-woven Textiles. This test method is used to determine the tear resistance of Non-Woven Textiles.
BS EN ISO 105-E01:2013
Colorfastness to water. This test method is used to define the amount of color transferred from dyed textiles in presence of water.
JIS L 1041:2011
Formaldehyde content in Textiles. This test method is used to determine the amount of formaldehyde content in Textiles.

Saturday, October 31, 2015

What is Textile Testing | Definition and Meaning

Testing
Before putting something into widespread use, production or practice, the quality, performance, reliability etc. are checked. It finds out how well something works.
Testing can be defined as the process of determining the properties of different kinds of substances.

Textile Testing lab

There are mainly two types of testing, one is routine process testing and another is quality record testing. The result of routine process testing can be got quickly in the working field. The result of quality record testing is to be recorded for different objects to finish the work.

Textile Testing
Textile Testing is an important part for textile production, distribution, and consumption. We can also define Textile Testing as the process of determining the properties of different kinds of Textile substances.
 
Objectives of Textile Testing
The objectives of Textile Testing are as follows –
  • In case of research, the results of testing will help the scientist to decide which route should be followed.
  • It helps to select the proper raw materials. Raw material is a relative term. As for example, fibre is the raw material of spinner, yarn is the raw material of weaver etc.
  • Textile Testing helps to control the different processes. Such as Spinning, Weaving, Dyeing, Finishing etc. End breakage is controlled by controlling weight per lap length, sliver length and roving length. Weaving process is controlled by controlling the excessive breakage of warp and weft yarn. Dyeing process is controlled by M : L, temperature and pressure.
  • In case of product control, it helps to ensure the fulfillment of the desired quality of the end product. Such as the end product of spinning is yarn.
  • In case of process development, it helps to improve the quality of end product by avoiding unnecessary waste of time and money.
  • In case of product development, it helps in continual search for new knowledge and to develop new products.
Factors affecting Test result
  • Atmospheric conditions
  • Test methods
  • Testing instruments
  • Technician’s efficiency etc.
Different types of Textile Testing
Fibre Tests
Fibre tests include identification of fibres, grading, fibre length, strength and elongation, fineness, maturity etc.
Yarn Tests
Yarns tests include yarn count, twist per unit length, strength, appearance, evenness and regularity, hairiness etc.
Fabric Tests
Fabric tests include strength and elongation, width, thickness, number of ends and picks per unit length, the count of yarn used, fabric weight per unit length, design and construction of the cloth, air permeability, thermal properties, stiffness, handle, drape, crease resistance and recovery, abrasion, pilling, shrinkage etc.

Wednesday, August 19, 2015

Different Tests for Textile Quality Control

Quality Control section is the most important section in Textile and Garment industries. Most of the Textile and garment industries in Bangladesh are 100% export oriented. The buyers who deal with the manufacturers in Bangladesh always want quality. So to maintain quality, quality control section is necessary.

Textile Quality Control

Quality control is defined as the set of procedures intended to ensure that an end product adheres to a defined set of quality criteria or meets the demand of the customers.

The principal aim of QC is to ensure that organization is achieving the standards. Though QC is strictly followed in every factory, it is not possible to achieve perfection. For example, sometimes shade variation occurs in wet processing. In QC section, quality controller tries to make different swatches of same shade but little variation occurs among the swatches and it is as usual.  The closest shade that matches with the sample is accepted by the buyers.

Tests for Quality Control
There are two types of tests are done in QC department. They are –
  • Physical Tests
  • Chemical Tests
Physical Tests
  • Yarn Grade
  • GSM
  • Shrinkage
  • Spirality
  • Tensile Strength
  • Abrasion Resistance
  • Pilling Resistance
  • Button Strength testing
  • Lycra% determination
  • Crease Resistance
  • Finished Dia
  • Shade Check
  • Width
Chemical Tests
Now I’ll describe them in brief:
 
Yarn grade
Here, yarns grades are checked. This is checked on the basis of fineness or coarseness of the yarn. Super fine, fine, light, medium, bulky, super bulky etc. are the different grades of yarn.
GSM
GSM stands for gram per square meter. This is a metric system. GSM of woven or knitted fabrics are tested.
Shrinkage
Shrinkage is defined as the process in which a fabric dimension becomes less than its original size. It is a fabric fault. So, it should be checked.
Spirality
Generally, spirality occurs in knitted fabric and the woven fabric made by twill weaves. Spirality is revealed after washing. As for example, a T-Shirts side seam comes at front. It is also a fabric fault. So, it is also tested.
Tensile Strength
The tensile strength of a material is defined as the maximum amount of tensile stress that it can take before failure, for example breaking. Tensile strength of yarn, fabric etc. are tested.
Abrasion Resistance
There are two different methods are commonly used to test abrasion resistance. One is Wyzenbeek and another is Martindale.
Pilling resistance
The resistance of pill formation on fabric surface or other changes due to abrasion is called pilling resistance. It should be tested for better quality of fabric.
Button Strength testing
Button strength is also an important factor because buttons always face more obstacles. It is also tested in the QC lab.
Lycra% determination
Lycra is used to produce blended fabrics. It is used to make sportswear, socks, pantyhose, sweaters etc. So we have to determine the Lycra%.
Crease Resistance
It is defined as the capability of a textile material to resist creases. It is also tested for better quality of the end product.
Finished Dia
Finished dia of the garment is tested.
Shade check
Sometimes shade variation occurs in a dyed fabric. So, it is checked to match the accurate shade.
Width
The width of a fabric is tested for proper dimension.
Light Fastness
The resistance to the loss of color of any dyed or printed material to light is preferred to as its light fastness. It is a very important test.
Wash Fastness
The resistance to the loss of color of any dyed or printed material to washing is preferred to as its wash fastness. Like light fastness test, it is also important.
Rubbing Fastness
The resistance to the loss of color of any dyed or printed material to rub is preferred to as its rubbing fastness. It is an important test too.
Perspiration Fastness
The garments which come into the contact with the body reference where perspiration is heavy (like neck, underarm, etc.) may suffer from serious local discoloration fastness to perspiration is the resistance to color of textile against the discoloration effect of acidic or alkaline perspiration. It is also an important test.
Heat fastness
The resistance to the loss of color of any dyed or printed material to heat is preferred to as its heat fastness. Heat fastness is done for thermal clothing.

Monday, July 6, 2015

How to Identify Rayon and Acetate Fibre

Recognition and identification of fibre content in fabrics has become extremely difficult even for knowledgeable and experienced merchants because of the growing variety of types of fibres, the blending techniques in yarn and fabric construction, and the finishes that affect the appearance and hand of the fabrics. Therefore, certain laboratory tests are used for identification and verification.
Now I’ll discuss how to identify Rayon and Acetate fibre:
Burning Test
Rayons
Like cotton, the rayons ignite quickly unless they either are fire-retardant types or re given a fire-retardant finish. They burn with a bright yellow flame, sometimes more rapidly than cotton because rayons are essentially purified cellulose. The odor of burning viscose and high wet-modulus rayons is like that of burning paper, also a cellulose product. The ash disintegrates unless the fibre has been chemically dulled.

Rayon fibre Identification

Acetate
It blazes as it burns. The edge of the fabric puckers and curls as the material fuses and melts into a hard mass. It sputters and drips like tar. The ash of acetate is hard and brittle, and is difficult to crush between the fingers. Because of the acetic acid used in the manufacture of acetate, the ash has an acid odor similar to that of vinegar.

Acetate fibre Identification

Microscope Test
Rayons
Basically, these fibres have a glasslike luster under the microscope and appear to have a uniform diameter when viewed longitudinally. The appearance of fine paper like particles on a cross-sectional view is an indication that the rayon has been delustered.

Rayon fibre Microscopic test

Viscose rayon has a cross-sectional view under the microscope that is very irregular. These irregularities or wrinkles run the length of the fibre and appear as striations or fine lines in the longitudinal view on an otherwise glossy surface. The rayon filaments differ in appearance according to the process used in their manufacture. Some may have a cross section that is somewhat flat and irregular or on the other hand, have a dough nut like cross section.
Acetate
The cross-section view of acetate fibre is less irregular than viscose rayon; it has a bulbous or multilobal appearance with indentations. These indentations appear as occasional markings or striations in the longitudinal view. The cross-section can be regulated during the manufacturing process to produce various shapes to affect the appearance and hand of the fibre.

Acetate fibre microscope test
 
Chemical Test
A solution containing equal parts of concentrated sulfuric acid and iodine may be used to distinguish each of the different fibres. When samples are immersed in this solution, a dark-blue coloration indicates viscose; a yellow coloration indicates acetate. Another test to distinguish acetate from rayon, when both types are known to be used in a fabric, is to immerse the sample in a 50% solution of acetic acid. The acetate dissolves; the rayons are not affected. All rayons will dissolve in a 60% solution of sulfuric acid or a concentrated solution of hydrochloric acid.