Finally… I’ve managed to put something together to post online for you people to go through. Although I’ve been telling in class time and again which pages from which book need to be referred to, here’s a more elaborate description of what needs to be studied.
We’ve already seen in class stress strain curves, and scrutinized them as never done before leaving several mouths agape, some in awe while others yawning, this post will help clarify concepts further.
During the course we realized that we need to spend more time understanding the mechanical properties of textile fibres. These properties were studied using a variety of methods. We started off with an introduction to terms such as strength, elongation and toughness.
A very good introduction to mechanical properties is available on the PSLC. This should be first read to understand basic concepts of mechanical properties such as what tensile strength is, what other types of strengths a fibre can have, what the term toughness corresponds with and what does it mean if a fibre is labelled as tough. These properties have been studied in greater detail from other sources through a facilitated learning quiz where the students were encouraged to look into key issues related to previous concepts. In these notes I will be referring to specific pages from chapter five in PP Saville’s book Physical Testing of Textiles.
Once you’ve gone through the PSLC you should start reading PSCL from page 115 onwards. A separate section is dedicated to each of the properties we discussed in class namely section 5.2 and 5.3.
Breaking strength, tensile strength
Stress
Specific (mass) stress
Tenacity
Breaking length
Elongation
Strain
Extension percentage
Guage length
Yield point
Modulus
Work of rupture
Time dependence
Elastic recovery
These points are discussed in appropriate depth for this course. The sections on different ways to measure moduli and yield point from pages 119 – 126 are meant to help you understand the complexities that may arise in taking such measurements .
Section 5.5 on fibre strength and 5.10 should also be read to further concepts on tenacity, tensile strength and stretching properties of textile fibres. The rest of the chapter, section 5.4, 5.6, 5.7, 5.8, 5.9 and 5.11, are part of the recommended reading for this course.
sir me and some other students would really appreciate if you would give us the class presentationz you made. it would help us atleast remember what we have to study !!
thanxx :p
Comment by waqas — April 16, 2008 @ 3:00 pm
sir i am trying my level best to study your subject from morning but my main problem is WHAT TO STUDY .. abhi tak yehi samaj he nahe aya ke kia parhana hai .. :p
sorry that was another of my SLIP OF TONGUE !
Comment by X — April 16, 2008 @ 3:04 pm
sir i want to ask about what is regenarated cellulose. i know that it is cellulose 2 and anti parallel arrangements are persent but waht i wanted to know is how it is formed whether it is originally produce in this form or we convert cellulose 1 into 2 byy altering chemical compostion plz ans me
Comment by ovais siddique — April 19, 2008 @ 7:54 am
secondly sir please allowed us to bring our notes in the exam so we can mark the important things and write some important thing in it
Comment by ovais siddique — April 19, 2008 @ 7:56 am
Salaam…
I would like you to please clarify that would we be tested in exams on the following sections of BP Saville book …
Section 5.4, 5.6, 5.7, 5.8, 5.9 and 5.11
Comment by Furqan — April 19, 2008 @ 8:31 am
Ovais you are correct, both cellulose 1 and 2 have the same chemical composition. The difference lies in the way the chains are arranged.
Consider the chains in Cotton. Even if the fibre is shred into very small pieces, the cellulose chains in cotton would have the arrangement of cellulose 1. But if these fibres are dissolved in a solution, as they are to make rayon and then extruded in the form of regenerated cellulose fibres, the chains would have a different, anti parallel arrangement from the original. This new form is Cellulose 2.
Alternately when cotton is mercerised, one can say that the crystallites in the fibres rotate and open up. This rearrangement also converts the cellulose 1 to cellulose 2.
I’ll put up some more notes tonight along with reading pages from Physical Properties of Textile Fibres which’ll help you understand this further.
Comment by Aasim Ahmed — April 19, 2008 @ 9:41 pm
No Furqan, I will not be asking you specific questions from the sections you have quoted in your comment. However, I can ask you any other question from any other book if it is suitable according to the course content.
Waqas, I’ll post PDF’s of the lecture notes tonight so that you people can refer to them if required, as discussed in class.
Regarding bringing your own notes, I have no issue with that but this has to be uniform for everyone. Considering that only 10 people read the material I post, most of you will not know of this change and that will cause tremendous confusion. I’ll have to discuss this matter with your class representatives before agreeing to it. If you people really want to bring in the handouts with your handwritten notes then please send a request through your CR’s and I’ll try and sort something out.
Comment by Aasim Ahmed — April 19, 2008 @ 9:51 pm
thankx sirr.. gt the notes .. helped alot
Comment by waqas — April 22, 2008 @ 3:03 pm
Asim
this really is a very interactive way to loop in all the students u teach.
its very fascinating indeed.
great work
Comment by Ali kazmi — August 6, 2009 @ 4:41 am