Wet spinning is the oldest of the five processes. This process is used for polymers that need to be dissolved in a solvent to be spun. The spinneret is submerged in a chemical bath that causes the fiber to precipitate, and then solidify, as it emerges. The process gets its name from this "wet" bath.
Method for measuring or investigation of fiber structureShawan Roy
Method for measuring or investigation of fiber structure (details about optical and X-ray diffraction & electron microscopy and electron diffraction method)
The contents are written in a way that the student understands the basics tests that are done to evaluate the textile fibers. In specific the properties namely length, strength, maturity and elongation.
An experimental sample about tear strength testing of a fabric by Elmendorf's Tear Tester. This will helpful for the Textile Engineering student to know the measuring process of tear strength of a fabric.
Method for measuring or investigation of fiber structureShawan Roy
Method for measuring or investigation of fiber structure (details about optical and X-ray diffraction & electron microscopy and electron diffraction method)
The contents are written in a way that the student understands the basics tests that are done to evaluate the textile fibers. In specific the properties namely length, strength, maturity and elongation.
An experimental sample about tear strength testing of a fabric by Elmendorf's Tear Tester. This will helpful for the Textile Engineering student to know the measuring process of tear strength of a fabric.
As we know polyester is a synthetic fiber and has
more crystalline structure than natural fibers. In continuous
dyeing of polyester by pad-Thermosol process, there are many
advantages such as bulk production, low-cost, good efficiency etc.
But during dyeing process there is a severe problem occurs that
is dye migration .in order to control the dye migration different
migration inhibitors are used in this project. Both natural and
synthetic migration inhibitors are applied on the 100% polyester
fabric in order to compare that which migration inhibitor hives
better results on the pad-Thermosol process.
After comparing the different properties of the both migration
inhibitors the synthetic inhibitors found more efficient then the
natural one. The following tests were conducted during project:
Migration test, tensile strength, color strength, bending length,
light fatness.
Synthetic migration inhibitors gives better results for the tests
which were conducted .but there is a problem that the synthetic
migration inhibitors are not environmental friendly and they are
costly then natural migration inhibitors.
Nano technology based bio degradable plasticsprasad reddy
nanotechnology is emerging science having a lots of applications in various feilds including food and agriculture " the small things can make big difference "
Diffusion Studies of Nanofibril Reinforced Unsaturated Polyester NanocompositesIRJESJOURNAL
ABSTRACT: This work deals with the water sorption characteristics of isorananofibril reinforced polyester composites with special reference to filler loading as well as temperature. It was found that, the neat polyester resin shows high water absorption at room temperature. The reduction of water absorption of INF filled composites is due to the improved inter-facial adhesion, which prevents the easy penetration of water molecules in the nanofibril composite. The formation of fibrous network of cellulose nanofibrils with the polyester matrix also prevents the swelling of the composite and thus reduces the water penetration. At 90 ˚C, after the initial capillary uptake of water, as the INF loading increases the water uptake also increases. This is due to the hydrophilic character of INF. At higher temperature, the composite lost all its hydrogen bonding interactions and the neat polyester shows lower water uptake. The mechanism of diffusion was analysed and the effect of INF on the sorption kinetics was studied. Parameters like diffusion, sorption and permeability coefficients of the composites were determined.
Spinning process
What is gel spinning
Gel spinning process
what are the factors affecting gel spinning
Gel spinning process polyethylene
Structure and Properties of Gel spun fiber
Applications
Natural dye(Madder,Cochineal,Lac and Fustic dye)BerihunGashu
It is easy to extract the natural color from plants, fruits, or flowers. Many natural dyes also have antimicrobial properties, making them safer for kids in particular. Additionally, natural dyes neither contain harmful chemicals nor carcinogenic components, common to artificial or synthetic dyes
Moisture management and soil release finishBerihunGashu
Soiling is the major problem of cloth in textile during use. soil release finish for easy removal of soil. Moisture management for wicking of sweat from our body to outer garment surface.
The application of technical textile to building and construction is due to some specific properties of textile fibers like, tenacity, strength, light weight, comparatively low cost, can and resistance to chemical plus to that ability of resisting the UV light. Basically technical textiles are applicable in different areas for different purpose.
GOTS and Okeo-Tex are most widely used certified standards for quality product and processing of production to finished products of textiles.
The principle is production of textile products with in green environment and use of natural raw material as input and reduce environmental pollution.
Transfer printing is the term used to describe textile and related printing processes in which the design is first printed on to a flexible non-textile substrate and later transferred by a separate process to a textile.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
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.
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.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
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/
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
1. 1
BAHIR DAR UNIVERSITY
Ethiopian Institute of Textile and Fashion Technology
“Manmade fiber Technology”
Title: Wet spinning of Acrylic fiber
Prepared By:-Berihun Gashu (MSc in TC)
Submitted to:- Mr. Adane H. (Assoc. Prof.)
June 2021 G.C.
2. Contents
2
o Introduction
o Theoretical background
o Wet spinning of Acrylic fiber
o Working principle
o Parameters of wet spinning of acrylic fiber
o summery
o References
3. 3
Introduction
Oldest spinning mothed from other processes.
Non- volatile solvent for preparation,
Non-solvents for coagulation,
Submerged in a coagulation bath
Acrylic, rayon, aramid, modacrylic, and spandex.
Acrylonitrile
4. 4
Conti…
volatile solvent
non-volatile solvent
Coagulation medium.
Warm Air
Spinneret in
coagulation bath
Wet spinning Dry spinning
Comparison of Solution Spinning
No phase separation
No non-solvent
No coagulation
No voids
Existence of voids
non-solvent involves
Phase separation
5. 5
Theoretical background of acrylic fiber
Nylon, polyester, PP, and polyacrylonitrile.
Stability in the molten stage,
Polyacrylonitrile would not melt without decomposition, degradation of polymer,
Low cost , plastics and rubber nature intensive research to find a solvent for polyacrylonitrile
was initiated by a number of American and German companies in the 1940s.
extrusion
Organic solvents Wet and dry-spinning
melt-spinning technology
8. 20 000–100 000 holes with diameters of 0.05–0.25 mm.
T°C spinning dope & coagulation bath,25–125°C and 0–50°C, respectively.
The spinneret is immersed in the coagulation bath =solidified
8
Conti….
The solidification speed is affected by :-
o The concentration of the spinning dope,
o The ratio of solvent/non-solvent and
o The temperature of the coagulation bath.
Easy flow of fluid vs Cohesiveness
10. 10
solid polymer dissolved
1
solution heated in the heat exchanger
2
solution is passed/extruded to spinneret
3
The filament wound on the bobbin
5
Wended filament is then drawn
6
washed & dried wound on a suitable package
7
Delivery
8
filament of solid form
4
Spinning process
12. 12
B. Coagulation
Spinning dope form gel fibers due to phase separation of the dope in solvent/water mixture.
The initial fiber formation performed at exits the spinnerets capillaries.
Counter-diffusion of the solvent from the dope and counter-diffusion of the non-solvent from
the coagulation bath,
But it may occur at different rates, which depend on
20,000 to 100,000 capillaries
Mass transfer
The coagulation bath composition and temperature
protofibers
13. 13
The Effect of Coagulation Variables
on Initial Fiber Structure
1. The effect of dope composition,
2. The effect of coagulation bath composition,
3. The effect of coagulant temperature, and
4. The Effect of Jet stretch
14. 14
1. The Effect of Dope Solids
Raising dope solids, improves the homogeneity of the fiber structure by reducing voids.
No simultaneous change in the cross-sectional shape of the fiber occurs, and
Solvent/polymer
15. 15
2. Effect of spin bath composition
Effect of spin bath composition on protofibre structure at 55°C bath temperature
16. 16
3. The Effect of coagulation temperature
Dwell time
Retardation
Solidification speed
17. 17
4. The Effect of Jet stretch
It is the ratio of taken out of the coagulation bath to dope is pumped
through the spinneret holes.
At a given set of bath conditions, increasing jet stretch is accompanied
by decreasing density, decreasing surface area, and decrease the
number of voids.
18. 18
C. Diffusion
Spinning solution contact with a coagulation bath diffusional interchange occurs.
Due to concentration differences extruded dope and coagulation proceeds at the exit of the
capillary.
Solvent leaves, while non-solvent enters,
After a sufficient length of time no more exchange takes place,
Mass Transfer
mixture of solvent and non-solvent
state of equilibrium
polymer phase
19. 19
Conti…
Diffusion process influenced by,
o Spin rate,
o Dope concentration and
o Temperature of dope.
increase in temperature increases
the diffusion of solvent and nonsolvent
Increased polymer concentrations less solvent,
high rate of diffusion due to increase solvent out
20. 20
D. Phase Separation
Polymer solution to a solid phase or porous gel
network.
A polymer rich phase and solvent/non-solvent
phase.
The voids are due to solvent/non-solvent phase
separation and diffusion processes.
21. 21
E. Structure
It is result of the counter-diffusion of solvent and non-solvent and the phase separation.
Gel network of interconnected polymer fibrils separated by void.
The void size is determined by the rate of diffusion and phase separation.
Fiber cross section can be altered by changing the coagulation conditions.
The void size increases as the rates of diffusion and phase separation increase.
size and number of voids dry, collapse, and relax
VS
23. 23
1. Washing
Fiber washing with the help of temperature and wash liquid concentration.
Water use a wash temperature limited to the boiling point of the water.
Conducted mainly preceding, or concurrent with, stretching.
A small amount of residual solvent is usually purposefully left in fiber to optimize
processing behavior.
The fibrillar network remains a porous structure at this point in the process and gel state.
24. 24
Fibers oriented the molecular chains, which resulted in an improvement in tenacity.
Diameter of fibers decreased, and their surfaces became smoother
The porosity decreased and became more compact,
The crystalline orientation of PAN fibers increased with increasing draw ratio.
2. Drawing
due to the draw ratio increases
improvement in the mechanical properties
25. 25
3. Finish
A chemical treatment is applied to the fiber.
The chemical or "finish" is normally an aqueous solution or
emulsion and
It has both lubricants and antistatic components that facilitate
fiber processing in the subsequent collapse/drying steps and
transforming the fiber into yarns and fabrics.
26. 26
4. Drying, Collapsing, Relaxing
A drying/collapsing process passing the fiber over heated zones and/or hot rolls.
While drying the fiber, collapsing is also occurring as the water is driven from the internal
fibrillar network.
The fiber collapse is the closure of the oriented open pore structure,
The relaxation process is the final step in changing fiber morphology and significantly alters
the fiber stress-strain behavior.
A hot, wet environment; both batch and continuous relaxation systems are utilized.
External and internal fiber water
27. The conversion of polyacrylonitrile to fiber was more difficult as the polymer would not melt
without decomposition wet spinning technology for such fiber production.
Wet spinning basically used for polymers that need to be dissolved in a solvent to be spun.
The spinneret is submerged in a chemical bath that causes the fiber to precipitate, and then
solidify, as it emerges.
The only different from other spinning solidification due to coagulation bath that makes
precipitated filament.
27
Summery
28. Reference
Dong, R., Zhao, J., Zhang, Y. and Pan, D., 2009. Morphology control of polyacrylonitrile (PAN) fibers by phase separation technique. Journal of Polymer Science
Part B: Polymer Physics, 47(3), pp.261-275.
Han, C. D., & Segal, L. (1970). A study of fiber extrusion in wet spinning. II. Effects of spinning conditions on fiber formation. Journal of Applied Polymer Science,
14(12), 2999–3019.
Knudsen, J.P., 1963. The influence of coagulation variables on the structure and physical properties of an acrylic fiber. Textile Research Journal, 33(1), pp.13-20.
Paul, D.R., 1968. Diffusion during the coagulation step of wet‐spinning. Journal of Applied Polymer Science, 12(3), pp.383-402.
Masson, J. ed., 1995. Acrylic fiber technology and applications. CRC Press.
Paul, D.R., 1968. A study of spinnability in the wet‐spinning of acrylic fibers. Journal of Applied Polymer Science, 12(10), pp.2273-2298.
Zhou, P., Lu, C., Shi, J., Li, K., He, F., Zhang, S. and Li, Y., 2011. Effect of bath concentration on coagulation kinetics at the early stage during wet spinning of PAN
copolymer nascent fibers. Journal of Macromolecular Science, Part B, 50(6), pp.1215-1225.
Peng, G.Q., Wen, Y.F., Yang, Y.G., Liu, L. and Wang, W., 2009. Effect of dope extrusion rate on the formation and characterization of polyacrylonitrile nascent fibers
during wet-spinning. Polymer bulletin, 62(5), pp.657-666.
Arbab, S., Noorpanah, P., Mohammadi, N. and Zeinolebadi, A., 2011. Exploring the effects of non-solvent concentration, jet-stretching and hot-drawing on
microstructure formation of poly (acrylonitrile) fibers during wet-spinning. Journal of Polymer Research, 18(6), pp.1343-1351.
Han, C.D. and Segal, L., 1970. A study of fiber extrusion in wet spinning. II. Effects of spinning conditions on fiber formation. Journal of Applied Polymer Science,
14(12), pp.2999-3019.
Knudsen, J.P., 1963. The influence of coagulation variables on the structure and physical properties of an acrylic fiber. Textile Research Journal, 33(1), pp.13-20.
Wang, Y.-X., Wang, C.-G., Bai, Y.-J., & Bo, Z. (2007). Effect of the drawing process on the wet spinning of polyacrylonitrile fibers in a system of dimethyl sulfoxide
and water. Journal of Applied Polymer Science, 104(2), 1026–1037.