![Material ↓ Yield strength (MPa) ↓ Ultimate strength
(MPa) ↓
Density (g/cm³)
↓
first carbon nanotube ropes ? 3,600 1.3
Steel, high strength alloy ASTM
A514
690 760 7.8
High density polyethylene
(HDPE)
26-33 37 0.95
Polypropylene 12-43 19.7-80 0.91
E-Glass N/A 3,450 2.57
S-Glass N/A 4,710 2.48
Basalt fiber N/A 4,840 2.7
Marble N/A 15
Concrete N/A 3
Carbon Fiber N/A 5,650 1.75
Human hair 380
Spider silk 1,000
UHMWPE fibers[4][5]
(Dyneema or Spectra)
2,300-3,500 0.97
Vectran 2,850-3,340
Polybenzoxazole (Zylon) 5,800
Nylon, type 6/6 45 75 1.15
Rubber - 15
Boron N/A 3,100 2.46
Silicon, monocrystalline (m-Si) N/A 7,000 2.33
Silicon carbide (SiC) N/A 3,440
Sapphire (Al2O3) N/A 1,900 3.9-4.1
Carbon nanotube N/A 62,000 1.34](https://image.slidesharecdn.com/1-240827174916-979be2a6/85/1-Properties_of_Textile_Fibres-Also-known-as-the-modulus-of-elasticity-elastic-modulus-or-tensile-modulus-pdf-21-320.jpg)
1. Properties_of_Textile_Fibres , Also known as the modulus of elasticity, elastic modulus or tensile modulus.pdf
- 1. Properties of Textile Fibres 1
- 2. Different types of Fibre Properties • Classification – Physical properties – Mechanical properties – Electrical properties – Thermal properties – Chemical properties – Biological properties – Optical properties – Acoustic properties – Radiological properties – Environmental properties
- 3. Physical Properties • A physical property is any aspect of an object or substance that can be measured or perceived without changing its identity • Examples – Diameter – Linear density – Length – Cross-section – Colour – Crimp – Density – Moisture regain – Coefficient of friction – Lustre, etc.
- 4. Linear density • Linear density: Linear density is the measure of fiber's mass per unit length or length per unit mass. Commonly seen units of linear density include denier (D), decitex (dtex), cotton count (cc or Ne), and metric count (Nm). • Denier – Weight in grams of 9000 meters of material • Tex – Weight in grams of 1000 meters of material • dtex – Weight in grams of 10,000 meters of material
- 9. Mechanical Properties • The properties that describe a material's ability to compress, stretch, bend, scratch, dent, or break. Mainly mechanical properties focus on fibre which are given below: • Young's modulus / Stiffness • Tenacity • Specific modulus • Tensile strength • Compressive strength • Shear strength • Yield strength • Elasticity , etc.
- 10. Young's modulus (E) • A measure of the stiffness of fibers. • Also known as the modulus of elasticity, elastic modulus or tensile modulus • It is defined as the ratio of the uniaxial stress over the uniaxial strain in the range of stress in which Hooke's Law holds. • This can be experimentally determined from the slope of a stress-strain curve created during tensile tests conducted on a sample of the material
- 11. yield stress - max stress before permanent deformation ultimate tensile stress - max stress before catastrophic failure rupture stress - max stress at catastrophic failure •Stress = (force) / (unit of area) at any given point inside an object •Pressue = (force) / (unit of area) applied to the outside surface of an object •Pressure is an external load. Stress is an internal condition resulting from external loads of forces and pressures. Strain = (change in length) / (original length)
- 12. Types of Load Compression/Tension: Compression is squeezing together. Tension is pulling apart. Compression can be considered negative tension. Shear: a force moving apart on each side of the element similar to the action of a pair of scissors or shears. Bending Moment: a twisting action
- 13. Stiffness • The stiffness, k, of a body is a measure of the resistance offered by an elastic body to deformation (bending, stretching or compression) where P is a steady force applied on the body δ is the displacement produced by the force
- 14. Hardness • Hardness refers to various properties of matter in the solid phase that give it high resistance to various kinds of shape change when force is applied – Scratch hardness: Resistance to fracture or plastic (permanent) deformation due to friction from a sharp object – Indentation hardness: Resistance to plastic (permanent) deformation due to a constant load from a sharp object – Rebound hardness: Height of the bounce of an object dropped on the material, related to elasticity.
- 15. Toughness • The ability of a metal to deform plastically and to absorb energy in the process before fracture is termed toughness.
- 16. Specific modulus • Specific modulus is the elastic modulus per mass density of a material. • It is also known as the stiffness to weight ratio or specific stiffness. • High specific modulus materials find wide application in aerospace applications where minimum structural weight is required. • The utility of specific modulus is to find materials which will produce structures with minimum weight, when the primary design limitation is deflection or physical deformation, rather than load at breaking--this is also known as a "stiffness-driven" structure. Many common structures are commonly stiffness-driven for example airplane wings, bridges, bicycle frames.
- 17. Units of Young’s modulus • Young's modulus is the ratio of stress, which has units of pressure, to strain, which is dimensionless; therefore Young's modulus itself has units of pressure. • The SI unit of modulus of elasticity (E, or less commonly Y) is the pascal (Pa or N/m²); the practical units are megapascals (MPa or N/mm²) or gigapascals (GPa or kN/mm²). In United States customary units, it is expressed as pounds (force) per square inch (psi). 1 pascal (Pa) = 1 N/m2 = 1 kg/(m·s2)
- 18. Tensile Strength • Yield strength – The stress at which material strain changes from elastic deformation to plastic deformation, causing it to deform permanently. • Ultimate strength – The maximum stress a material can withstand when subjected to tension, compression or shearing. It is the maximum stress on the stress-strain curve. • Breaking strength – The stress coordinate on the stress-strain curve at the point of rupture.
- 19. Units of Tensile Strength • Tensile strength is measured in units of force per unit area. • In the SI system, the units are newtons per square metre (N/m²) or pascals (Pa), with prefixes as appropriate. • The non-metric units are pounds-force per square inch (lbf/in² or PSI). • Engineers in North America usually use units of ksi which is a thousand psi. • One megapascal is 145.037738 pounds-force per square inch.
- 20. Tenacity • Tenacity is the customary measure of strength of a fiber or yarn. • In the U.S. it is usually defined as the ultimate (breaking) strength of the fiber (in gram-force units) divided by the denier. • Units – g/denier; cN/tex; N/tex
- 21. Material ↓ Yield strength (MPa) ↓ Ultimate strength (MPa) ↓ Density (g/cm³) ↓ first carbon nanotube ropes ? 3,600 1.3 Steel, high strength alloy ASTM A514 690 760 7.8 High density polyethylene (HDPE) 26-33 37 0.95 Polypropylene 12-43 19.7-80 0.91 E-Glass N/A 3,450 2.57 S-Glass N/A 4,710 2.48 Basalt fiber N/A 4,840 2.7 Marble N/A 15 Concrete N/A 3 Carbon Fiber N/A 5,650 1.75 Human hair 380 Spider silk 1,000 UHMWPE fibers[4][5] (Dyneema or Spectra) 2,300-3,500 0.97 Vectran 2,850-3,340 Polybenzoxazole (Zylon) 5,800 Nylon, type 6/6 45 75 1.15 Rubber - 15 Boron N/A 3,100 2.46 Silicon, monocrystalline (m-Si) N/A 7,000 2.33 Silicon carbide (SiC) N/A 3,440 Sapphire (Al2O3) N/A 1,900 3.9-4.1 Carbon nanotube N/A 62,000 1.34
- 22. Specific Strength • The specific strength is a material's strength (force per unit area at failure) divided by its density. • It is also known as the strength-to-weight ratio or strength/weight ratio. • Materials with high specific strengths are widely used in aerospace applications where weight savings are worth the higher material cost. • In fiber or textile applications, tenacity is the usual measure of specific strength.
- 23. Material ↓ Specific Strength (kN·m/kg) Polypropylene 88.88 Nylon 69.0 Glass fiber 1,307 Vectran 2,071 Carbon fiber (AS4) 2,457 Kevlar 2,514 Spectra fiber 3,619 Carbon nanotube 46,268 Colossal carbon tube 59,483 Specific Strength
- 24. Elastic deformation • This type of deformation is reversible. Once the forces are no longer applied, the object returns to its original shape. • The elastic range ends when the material reaches its yield strength. At this point plastic deformation begins
- 27. From point ‘E’ onward, the strain hardening phenomena becomes predominant and the strength of the material increases thereby requiring more stress for deformation, until point ‘E’ is reached. Point ‘E’ is called the ultimate point and the stress corresponding to this point is called the ultimate stress. It is the maximum stress to which the material can be subjected in a simple tensile test. At the point ‘E’ the necking of the material begins and the cross- sectional area starts decreasing at a rapid rate. Due to this local necking, the stress in the material goes on decreasing in spite of the fact that actual stress intensity goes on increasing. Ultimately the specimen breaks at point ‘F’ known as the breaking point, and the corresponding stress is called the normal breaking stress bared up to original area of cross-section.
- 28. Strength: It is the property of a material which sustain the load. Elasticity: It is the property of material by virtue of which it can regains its original size and shape after deformation on removing load causing deformation. Plasticity: It is the property of material by virtue of which it can’t regains its original size and shape after deformation on removing load causing deformation. Ductility: It is a property of material by virtue of which it can under goes considerable deformation under tension before its failure. Brittleness: It is a property of material by virtue of which it can’t under goes considerable deformation under tension before its failure. Toughness (Impact strength): It is a property of material by virtue of which it can absorb suddenly applied load without its failure. Hardness: It is property of material by virtue of which it can resist wear, abrasion and scratching. Hardenability: It is the ability of a material to attain the hardness by heat treatment processing
- 29. Effects of Fiber length, fineness, strength and moisture on Yarn strength 1. Fiber length: If length of fiber is longer, then sufficient strength of yarn will be obtained even at low twist. If length of fiber is shorter, then breakage of yarn will be increased. In that cases needs more twist to achieve sufficient strength. 2. Fibre Strength If fiber strength is more the resultant yarn strength will also be more. For example immature cotton fiber has less strength than mature cotton. Hence, yarn made from immature cotton fibers will be less strength than that of mature cotton fibers. Effects of Fiber Properties on Yarn Properties
- 30. Effects of Fiber length, fineness, strength and moisture on Yarn strength 3. Fiber fineness: In case of finer fibers, there will be more number of fibers in a given cross-sectional area of yarn. So, there will be more frictional forces. As a result, strength of yarn will be more. In case of coarser fibers, there will be less number of fibers in a given cross-sectional area of yarn. Hence, strength of yarn will be less. 4. Fibre Moisture In case of Vegetable fibers such as cotton and flax, if fiber moisture content is higher, then strength of the yarn will be higher. Except vegetable fibers, other fibers strength will be decreased when moisture absorbed by the fibers. Hence strength of the yarn will be less. Effects of Fiber Properties on Yarn Properties