Animation- Weaving Principles and Fabric Structure

1. Relationship between Draft, Peg Plan, Denting Plan and Design- Click Here

2. Weave and Color Combination - Click Here

3. Principle of Double Cloth Formation- Click Here

4. Principle of Tubular Fabric - Click Here

5. Double Cloth based on Exchange Principle- Click Here

6. Principle of Terry Towel Weaving- Click Here

7. Principle of Weaving Leno Fabric- Click Here

8. Principle of Weaving  Velvets and Corduroys- Click Here

9. Principle of Jacquard- Click Here

Now that you've finished reading this post, what are you going do? You should go join the Forum.

A Few Notes About Fiber Chemistry

1. All fibers are formed from polymers, are not the only products containing polymers

2. Polymer means many units. Each individual molecule is known as monomer and the process of joining all the monomers together to form long chain molecules (polymers) is known as polymerisation.

3. The degree of polymerisation is the number of monomers units in the polymer. These may be of same type ( a homopolymer ) or two different randomly arranged monomers ( a copolymer)

4. There are two types of polymerisation: addition polymerisation, where all the atoms present in the monomers are also present in the polymer and condensation polymerisation where some small molecules are eliminated during polymerisation.

5. Polypropylene and acrylic polymers are produced by addition polymerisation.

6. Polyester, polyamide, wool, silk, cotton, flax, jute and viscose polymers are produced by condensation polymerisation.

7 There are three types of intermolecular forces. In decending order of strength: they are hydrogen bonds, polar bonds and Van der Waal's forces.

8. The properties of polymers for good fiber formation are: high degree of polymerisation, good intermolecular forces, linear and regular arrangement of monomers, high orientation of molecules and an inflexible repeat unit.

9. Crystalline regions are highly ordered areas within the fibers. They give the fiber its tensile and rigidity properties.

10. Amorphous regions are where the molecules are not closely packed within the fibers. They give the fiber its flexibility, extensibility and elasticity.

11. In natural fibers, crystalline regions develop as the fiber grows. In MMF, the ratio of crystalline to amorphous regions can be altered by drawing and heat setting.

Now that you've finished reading this post, what are you going do? You should go join the Forum.

Cloth setting and Fabric Geometry Theories

1. Fractional Cover is defined as d/p where d is the diameter of the yarn and p is the thread spacing.

2. There are various theories for calculation of yarn diameter. According to Law yarn diameter d is equal to 1/ sqrt (Fn) where F is 500 for worsted yarn, 800 for cotton yarns, 530 for woolen n being worsted and cotton and Yorkshire count respectively. According to Ashenhurst yarn diameter d = 1/(F sqrt(N)), where F is .95, .9,.84 for cotton, worsted and woolen yarns respectively and n= yds/lb. According to Pierce, yarn diameter is 1/(28 sqrt(N) where N is the English count.

3. Ashenhurst Diameter  intersection theory says that when the count of warp and weft are the same, it is assumed that an intersection takes up as much space as a thread. Then Threads/inch (T) can be determined as equal to D x W/ (W+I) where D is the diameter per inch of yarn, W is the threads in one repeat of weave and I are the intersection in one repeat of weave. For plain weave W =2, I=2 for 2/1 twill weave, W=3 and I = 2.

4. Curvature theory says that T = D x W/ ( W +.732 I), the notations being the same as in point 3.

5. Armitage Maximum Setting Theory says that cloths which are similarly built are equally firm. For regular twill weaves Threads per inch (T) = Sqrt (6 x C(F+4)) where C are the counts of worsted yarn and F is the average float of weave. For other weaves, Armitage gave the following “setting ratio” instead of (F +4). For plain weave it is 4.75, for 2/2 hopsack it is 6.25, for 4 end satin it is 6.5 for 5 end, 6 end and 8 end satin it is 7.5, 7.75 and 9.0 respectively.

6. Laws Maximum Setting suggests that T = ((D x F)/ (F+1) )+ various percentages where F is the average float and D is the diameter per inch. For common weaves like plain weave T = ( D X 1)/(F+I), for twill weave T= ((DF)/(F+1))+ 5% for each float exceeding two, for satin weave T = ((DF)/(F+1))+5.5% for each float, for hopsack weaves T= ((DxF)/(F+1))+ 4.5% for 2 floats and 9.5% for floats exceeding two.

7. Brierjey’s Maximum Setting suggests that square settings vary according to the formula T= sqrt (KC x (F)^m) where C is the average count of yarn, F is the average float, K is a constant varying according to kind of yarn and numbering system: it is 134 for worsted yarn, 200 for cotton yarn and 60 for york shire yarn. m is a constant varying according to the type of weave: For twill weaves it is 0.39, for Satin weaves it is 0.42 and for plain and hopsack weaves it is 0.45.

An amazing treatment on fabric geometry is done in this presentation.

Now that you've finished reading this post, what are you going do? You should go join the Forum.

Why Wool Feels Warm

Image via Wikipedia

Why Wool is Warm to Wear- Heat of Sorption

When a fiber absorbs water, heat is evolved. It results from the attractive forces between the fiber and water molecules. The phenomenon occurs due to the fact that when moisture vapour is absorbed into fiber’s internal structure, it transforms from gas to liquid and the phase change produces the rise in temperature.

It is calculated by heat of wetting. It is the heat evolved when a specimen of the material at a given regain, whose dry mass is one gram is completed is completed wetted.

It is expressed in joules per gram ( of dry material)

The heat of wetting is greatest for the more highly absorbing fibers and is very small in the non-hygroscopic fibers. Thus it is 113 J/g for wool, 106 for viscose, 69 for silk, 55 for flax, 46 for cotton , 73 for mercerized cotton and only 34, 31,5 and 7 respectively for Acetate, Nylon, Polyester and Acrylic.

As we can see from the figures above, wool has the highest heat of sorption. And this heat raises the temperature of the wearer which makes the wool feel warmer. In fact “the heat of sorption from a kg of Merino can be equivalent to the output from an electric blanket over eight hours” (Source ).

You can also find some discussion on Heat of Sorption here.

Now that you've finished reading this post, what are you going do? You should go join the Forum.