The slide contains advances (recent developments) in textile pretreatment called desizing, scouring, and bleaching. Different advances such as an enzyme, ozone, and plasma treatments are included for each pretreatment process.
Studies on textile printing on cotton fabric with Various ThickenerVijay Prakash
Printing is a process for reproducing text and images using a master form or template. The earliest examples include Cylinder seals and other objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The earliest known form of woodblock printing came from China dating to before 220 A.D. Later developments in printing include the movable type, first developed by Bi Sheng in China. The printing press, a more efficient printing process for western languages with their more limited alphabets, was developed by Johannes Gutenberg in the fifteenth century.
Modern printing is done typically with ink on paper using a printing press. It is also frequently done on metals, plastics, cloth and composite materials. On paper it is often carried out as a large-scale industrial process and is an essential part of publishing and transaction printing.
Printing spread early to Korea and Japan, which also used Chinese logograms, but the technique was also used in Turpan and Vietnam using a number of other scripts. This technique then spread to Persia and Russia. This technique was transmitted to Europe from China, via the Islamic world, and by around 1400 was being used on paper for old master prints and playing cards. However, Arabs never used this to print the Quran because of the limit of Islam doctrine.
It has great effect of hot brand reactive dye on cotton fabric with exhaustion method. Migration method is more acceptable for proper color fixation in a dyeing process. Another way when we followed ISO method has create a lot of problem such as wash fastness variation rubbing fastness variation, uneven dyeing etc. If we want to get perfect dyeing than we must maintain migration method.
The slide contains advances (recent developments) in textile pretreatment called desizing, scouring, and bleaching. Different advances such as an enzyme, ozone, and plasma treatments are included for each pretreatment process.
Studies on textile printing on cotton fabric with Various ThickenerVijay Prakash
Printing is a process for reproducing text and images using a master form or template. The earliest examples include Cylinder seals and other objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The earliest known form of woodblock printing came from China dating to before 220 A.D. Later developments in printing include the movable type, first developed by Bi Sheng in China. The printing press, a more efficient printing process for western languages with their more limited alphabets, was developed by Johannes Gutenberg in the fifteenth century.
Modern printing is done typically with ink on paper using a printing press. It is also frequently done on metals, plastics, cloth and composite materials. On paper it is often carried out as a large-scale industrial process and is an essential part of publishing and transaction printing.
Printing spread early to Korea and Japan, which also used Chinese logograms, but the technique was also used in Turpan and Vietnam using a number of other scripts. This technique then spread to Persia and Russia. This technique was transmitted to Europe from China, via the Islamic world, and by around 1400 was being used on paper for old master prints and playing cards. However, Arabs never used this to print the Quran because of the limit of Islam doctrine.
It has great effect of hot brand reactive dye on cotton fabric with exhaustion method. Migration method is more acceptable for proper color fixation in a dyeing process. Another way when we followed ISO method has create a lot of problem such as wash fastness variation rubbing fastness variation, uneven dyeing etc. If we want to get perfect dyeing than we must maintain migration method.
Lab dip is a process by which buyers supplied swatch is matched with the varying dyes percentage in the laboratory with or without help of “DATA COLOR”
Lab dip plays an important role in shade matching & and detaching the characteristics of the dyes and chemicals are to be used in the large scale of production. So this is an important task before bulk production.
Softener is an finishing agent that when applied to textile material improves its handle giving pleasing touch. As a general rule, the softening agents applied are lubricating agents, which facilitate the fiber sliding within the fabric structure, thus granting easier deformation and creasing of the fabric.
Basic knowledge about blend dyeing
Dyeing of Blended Fibres & Fabrics
Blends:
Blends are any textile material from fiber through yarn to fabric which are deliberate combination of chemically or physically different fibrous polymer. Cotton and Polyester blend is an example of chemically different blend and Cotton and Viscose is physically different blend because both are cellulosic.
Reason for blending:
1.Economy: The dilution of an expensive fibre by blending with a cheaper substitute.
2.Durability: The incorporation of a more durable component to extend the useful life of a relatively fragile fibre.
3.Physical properties: A compromise to take advantage of desirable performance charactristics contribuition by both fibre components.
4.Color: The development of new fabric design for garments incorporating multicolor effect.
5.Appearance: The attainment of attractive appearance & perceptible qualities using combinations of yarns of different lusture, crimp or denier which still differ in appearance even when dyed with same color.
6.Other reasons-
Blending develops fibre properties.
Colorant modification is possible by blending.
Finishing process modification.
Improved moisture absorption, antistatic characteristics, reduced pilling, improved abrasion resistance.
Dyeing Possibilities with Blends:
1.Union Dyeing:
• This is suitable for fabrics containing two fibres to dye them in a single uniform colour, each dye suitable for one kind of fibre in the blend.
• Union dyeing is same as cross dyeing except that instead of multi-colour effects. One solid colour is produced. The dyer accomplishes this by using two or more classes of dye, each of the same colours.
• Different fibres may require different dyes to obtain the same colour; this may be done by putting the appropriate colour dye that is specific to each type of fibre in to one dye bath.
• For eg: a fabric composed of rayon and acetate can be dyed with a solid colour green by using a direct dye for the rayon, and a disperse dye of the same colour for the acetate.
2.Resist/Reserve dyeing:
• In resist dyeing at least one (but not all) of the components of the blend remains essentially undyed i.e almost white.
3.Cross dyeing:
• Cross dyeing produces fibres of contrasting color
• This is two types-
a)Shadow effect/Tone-in-Tone dyeing:
Two fibres are dyed in same hue & brightness but the depth is different. It is called tone-in-tone or shadow effect.
b)Contrast effect:
Two fibres are dyed with strong difference in hue, brightness & depth.This is called contrast effect. Pleasing final appearance is important here.
Dye effluents impose hazardous effects on human beings as well as on environment. The present powerpoint deals with some of the decolourization techniques that can be adopted for treating wastewater containing toxic dyes and chemicals
Lab dip is a process by which buyers supplied swatch is matched with the varying dyes percentage in the laboratory with or without help of “DATA COLOR”
Lab dip plays an important role in shade matching & and detaching the characteristics of the dyes and chemicals are to be used in the large scale of production. So this is an important task before bulk production.
Softener is an finishing agent that when applied to textile material improves its handle giving pleasing touch. As a general rule, the softening agents applied are lubricating agents, which facilitate the fiber sliding within the fabric structure, thus granting easier deformation and creasing of the fabric.
Basic knowledge about blend dyeing
Dyeing of Blended Fibres & Fabrics
Blends:
Blends are any textile material from fiber through yarn to fabric which are deliberate combination of chemically or physically different fibrous polymer. Cotton and Polyester blend is an example of chemically different blend and Cotton and Viscose is physically different blend because both are cellulosic.
Reason for blending:
1.Economy: The dilution of an expensive fibre by blending with a cheaper substitute.
2.Durability: The incorporation of a more durable component to extend the useful life of a relatively fragile fibre.
3.Physical properties: A compromise to take advantage of desirable performance charactristics contribuition by both fibre components.
4.Color: The development of new fabric design for garments incorporating multicolor effect.
5.Appearance: The attainment of attractive appearance & perceptible qualities using combinations of yarns of different lusture, crimp or denier which still differ in appearance even when dyed with same color.
6.Other reasons-
Blending develops fibre properties.
Colorant modification is possible by blending.
Finishing process modification.
Improved moisture absorption, antistatic characteristics, reduced pilling, improved abrasion resistance.
Dyeing Possibilities with Blends:
1.Union Dyeing:
• This is suitable for fabrics containing two fibres to dye them in a single uniform colour, each dye suitable for one kind of fibre in the blend.
• Union dyeing is same as cross dyeing except that instead of multi-colour effects. One solid colour is produced. The dyer accomplishes this by using two or more classes of dye, each of the same colours.
• Different fibres may require different dyes to obtain the same colour; this may be done by putting the appropriate colour dye that is specific to each type of fibre in to one dye bath.
• For eg: a fabric composed of rayon and acetate can be dyed with a solid colour green by using a direct dye for the rayon, and a disperse dye of the same colour for the acetate.
2.Resist/Reserve dyeing:
• In resist dyeing at least one (but not all) of the components of the blend remains essentially undyed i.e almost white.
3.Cross dyeing:
• Cross dyeing produces fibres of contrasting color
• This is two types-
a)Shadow effect/Tone-in-Tone dyeing:
Two fibres are dyed in same hue & brightness but the depth is different. It is called tone-in-tone or shadow effect.
b)Contrast effect:
Two fibres are dyed with strong difference in hue, brightness & depth.This is called contrast effect. Pleasing final appearance is important here.
Dye effluents impose hazardous effects on human beings as well as on environment. The present powerpoint deals with some of the decolourization techniques that can be adopted for treating wastewater containing toxic dyes and chemicals
Scope of Dyeing Polyester Cotton (PC) Blended Fabric in Single Bath Process f...iosrjce
Dyeing of fabric blends such as Polyester/Cotton (P/C) is presently done with two
chemically different classes of dyes namely disperse for polyester and reactive for cotton, in
two bath process. Experimental work was carried out on finding the possibility of dyeing the
P/C blends in one bath process without drain the liquor after polyester part dyeing. All the
existing chemical and conventional temperature range were applied in this study. The result
indicates that, the using of one bath method in the polyester cotton dyeing can slightly change
the fastness properties than the conventional method. The one bath dyeing method showed
level dyeing having good fastness properties and offers the option of cost effective and ecofriendly
dyeing process.
Each colour of disperse dyes requires different raw materials. Because the range of colours is very large each colour has its own manufacturing process. The difference in the processes is primarily in the reaction period.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
3. Cotton fiber is contaminated with coloring matters.
Causes for discoloration:
Related to the pigment of the cotton flower
Growth conditions can cause various degrees of yellowness
Tips of leaves coming in contact with the moist boll
Contamination from processing machines
INTRODUCTION
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5. The discoloration is undesirable
Reduces visual aesthetics & impair successful coloration
The process for removal of unwanted color
from textile substrates and brightening them
is known as BLEACHING.
WHITENESS
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6. TYPES OF BLEACHING
Chemical bleaching
Physical bleaching
Chemical bleaching involves use of oxidizing and reducing
agents for breakdown of the coloring matters easing their removal.
Physical bleaching is the process of enhancement of brightness of
textiles by introduction of optical brighteners without
involvement of any chemical breakdown .
Destruction of double bonds in conjugated system
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6
9. 9
PEROXIDE BLEACHING
Peroxide bleaching is carried out using hydrogen
peroxide [H2O2] as the oxidizing agent.
The active bleaching specie is obtained from
ionization of hydrogen peroxide.
PERHYDROXYL ION [HOO-]
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10. Rapid decomposition of H2O2 in bleaching
baths causes fiber damage
Peroxide decomposition is Catalyzed by metal impurities
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Metals increase peroxide decomposition
11. The Strength of Commercial Hydrogen Peroxide is expressed in
terms of the volume of Oxygen liberated by a Unit of Volume of
H2O2 Solution.
Thus a 10-volume Peroxide Solution: Means 1Ml of H2O2 is
capable of liberating 10 Ml of Oxygen.
Hydrogen Peroxide is Generally Available 10, 20, 100 and 130
Volume Strength or it can expressed in %.
11
% H2O2 Concentration/strength
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12. Factors Affecting Peroxide Bleaching
Effect of pH: Perhydroxyl ion is desired bleaching specie, adding
caustic soda neutralizes proton and shifts the reaction to the right.
pH Active species Effect
10 Hydrogen peroxide No bleaching
10.2 – 10.7 Perhydroxyl ion Optimum bleaching
> 11 Perhyroxyl ion & oxygen gas Out of control
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13. Effect of temperature/time:
Stabilized hydrogen peroxide does not decompose at high temperature, so
Bleaching is carried out at high temperature [90 – 100 C].
Bleaching time depends on temperature used in bleaching.
% H2O2 Concentration
Chemicals used Concentration (%)
Hydrogen peroxide (35%) 3 - 5
Caustic soda 0.3 - 0.8
Sodium carbonate 0.6 - 0.1
Sodium silicate 2 - 3
Magnesium sulphate 0.5
Wetting agent + Sequestering agent (EDTA) 0.1 - 0.5
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Typical recipe for batch process
14. RECIPE FOR CONTINUOUS PROCESSING
A typical recipe for a wet on wet bleaching using
Hydrogen Peroxide 35% 30-40 ml/l
Sodium Silicate or 10 g/l
Organic Stabilizer 10 g/l
Sodium Hydroxide 3 g/l
Wetting Agent 1-2 g/1
Liquor Pick-up 100%
Sequence: Pad-steam for 1 hr at about 95°C. (J-Box)
In Case of Roller Steamer , Steaming is Carried Out For 30-50 Min. at 102
Deg C
Concentration of the reactants and the time of treatment may vary according to the
degree of impurities and quality of whiteness required.
In semi-continuous pad-roll process, the time of steaming is usually 1 to 2 hours.
Wet on wet treatment means wet fabric (after squeezing to remove excess water) from
previous is used.
14
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15. 15
Effect of stabilizers:
Peroxide bleaching of cotton is carried out at high
temperature in the presence of alkali.
To control the rate of decomposition of hydrogen
peroxide in the bleach bath stabilizers are added.
Provide buffering action to control the pH /alkalinity
Complex with trace metals which catalyze peroxide decomposition
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16. 16
INORGANIC STABILIZER (SODIUM SILICATE)
Sodium silicate forms complex compound with perhydroxyl ions
which are liberated slowly at higher temperature during bleaching
process.
Stabilization by silicates is enhanced by the presence of
magnesium ions.
Sodium silicate and magnesium ions form colloids, which act as
buffers.
Silicate deposition on equipment and on substrate
Abrasion and harsh feel
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17. 17
Organic stabilizers:
Operate as sequesterants to complex with
polyvalent metal ions which catalyze peroxide
decomposition and disturb bleach bath stability.
Example: Ethylene Diamine Tetra Acetic Acid [ EDTA]
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18. HYPOCHLORITE BLEACHING [NaOCl]
Reactions in bleaching solutions with NaOCl
Hypochlorous acid (HOCl) is active bleaching specie.
Factors that affect hypochlorite bleaching:
Bleach bath pH
Temperature/time
Concentration (available chlorine)
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19. pH Active species Effect
>11 OCl- with minimal HOCl No bleaching
5- 8.5 HOCl Rapid bleaching and fiber degradation
< 5 Chlorine gas No bleaching
9 - 11 Optimum HOCl Optimal bleaching without fiber degradation
Generally bleaching of cotton is carried out with 1-3g/1 available
chlorine at a pH of 9 –10 at about 400C for 1 h.
Fabrics bleached with hypochlorite will develop a distinctive chlorine odor
(removed with an aftertreatment [ANTICHLOR]): Treatment in a bath
containing sodium bisulfite and acetic acid.
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19
20. CHLORITE BLEACHING [NaClO2]
Reactions in bleaching solutions with NaClO2
HClO2 (chlorous acid) --- active bleaching species in
chlorite bleaching with NaClO2
Similar factors in hypochlorite bleaching affect chlorite bleaching process.
Bleach bath pH
Temperature/time
Concentration (available chlorine)
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21. pH Active species Effect
Below 3 HClO2 at maximum Damage to cotton fiber (hydrolysis)
3 – 5 HClO2 at optimum Optimum for bleaching [3.5 – 4.5]
> 5 ClO2
- No bleaching (no active bleaching specie)
Little or no bleaching takes place at temperatures below 50
0C,however the bleaching rate increases considerably up to
90 0C.
Generally bleaching of cotton is carried out with
2.5-5g/1 available chlorine at 80 – 900C for 1/2 h.
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21
22. PROBLEM WITH OXIDATIVE BLEACHING
FORMATION OF OXYCELLULOSE RESULTING FIBER DAMAGE
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23. Hydrogen peroxide is the most widely used bleaching agent from
the point of view of obtaining high degree of whiteness.
Problem with regard to fiber damage particularly in the presence
of metal ions.
There is a limited use of chlorine based bleaches nowadays mainly
due to formation of high toxic chlorinated compounds.
Reductive bleaching using reducing agents [SO2 and
hydrosulphite]
No permanent white when fabric is exposed to oxygen in the air.
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24. PHYSICAL BLEACHING
After chemical bleaching textiles do not appear perfectly
white.
Trial to increase degree of whiteness by chemical bleaching can
result over-bleaching and fiber degradation.
Certain organic compounds in their presence in textiles
increase brightness of textiles without chemical degradation of
impurities.
Compensating the yellow coloration of the textile materials;
increasing the total amount of light reflected from the textile
surface.
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25. BRIGHTENING MECHANISM
Absorption of light in shorter wave lengths (300 -
400nm) (UV range) & re-emission in longer visible
wavelengths (400 - 500nm) (bluer range).
FLUORESCENCE
The ultimate effect is increasing total amount of light reflected &
increase the brightness/degree of whiteness.
OPTICAL/FLUORESCENT BRIGHTENING AGENTS
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26. 26
Most widely used OBA’s:
Stilbene derivatives [diaminostilbenedisulphonic acid]
Like dyes their affinity for different fibers is different
Anionic type optical brighteners are used in brightening of
cotton.
Exhaustion is controlled by adjustment of proper temperature,
pH and addition of electrolytes (NaCl).
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PH = Neutral
Temperature = 40 -60°C
Time = 1hr
OBA concentration = 0.1-1%
Salt concentration = 1%
27. TEST FOR BLEACHING
DEGREE OF WHITENESS
Yellow impurities adsorb blue light
Measurement of the amount of blue light reflected by the goods,
against a white standard
The standard ceramic tile is measured and set to equal
100.
The other specimen are rated against this standard.
CERAMIC TILE
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28. FLUIDITY MEASUREMENT
Damaged cellulose has low molecular weight than undamaged
cellulose.
Solutions from undamaged fibers are less fluid than from damaged
fibers.
Fluidity is measured by dissolving cotton in cupriethylene
diamine hydroxide and determining the solution's viscosity.
High fluidity results low viscosity and indicates the extent of
bleaching.
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