Fibre Friction WHAT IS FIBRE Fibre is a class of materials that are continuous filaments. Any thing having high length to width ratio. Diameter or width of fibre is negligible which cant be measured. Fibres are made of polymers. Polymers are long chained elements. 1
Friction is the force of two surfaces in contact, or the force of a medium acting on a moving object. μ is the coefficient of friction, Fn is the normal force exerted between the surfaces Ff is the force exerted by friction, or, Friction Friction Force that opposes the relative motion or tendency toward such motion of two surfaces in contact. It is not a fundamental force, as it is made up of electromagnetic forces between atoms. kinetic energy into thermal energy, or heat. 2
FIBRE FRICTION It is the surface property of the fibre when two solid surfaces slide against each other. Friction of fibres is the force that holds together the fibre in a spun yarn and the interlacing threads in a fabric. Fibre Friction It is the surface property of the fibers when two solid surfaces slide against each other. for example if we rub silk fabric with itself or any other type of material static charge and heat energy is produced due to fiber friction. 3
Fiber weight Force applied Rough surface Surface Area Factors Affecting Cross-sectional area Cross-Sectional Shape Cross-sectional shape is a physical property of fibers and this shape is important in luster, body size, texture, and hand. Surface contour describes the outer surface of the fiber and may be smooth, serrated, striated, or rough which produced the friction. Crimp may be found in some fibers and refers to the waves, bends, twists, coils, or curls along the length of a fiber. 4
Cross sectional shape Different fibres have Waves and twist like cotton has twist. In the same way coils and curls are there in different fibres like wool has curls. Cross-Sectional Shapes Of Fibres 5
Impact of cross-section section Cross-sectional shape of two filament in a yarn Two fibers contact each other at a single point Surface area Cross sectional shape provide an area of link between two fiber surfaces, which is directly proportional to the fiber friction Impact of cross-section section Spaces where air and water can trapped Edges produce friction 6
Impact of Cross-Section Edges increased the fiber friction, strength, air permeability, bending resistance, water absorbency and it also affect the interference of light. Due to angular change it provide the places where water and air can easily trapped. In synthetic fiber without chemical change we can change the cross-sectional shape of the fiber by changing the alignment of the polymer chains. Impact of cross-section section and weight If we neglect the weight of the fiber then there is no frictional difference between hollow and solid fibers because friction is depend on the surface structure. Now discuss the weight of the Faber, two fibers with same diameter one is solid and second is hollow the solid fiber having more friction due to high weight. 7
Impact of Surface Visualize Which fibre Has Maximum Friction??? Impact of Surface Friction describes the resistance to being dragged or slid along a surface. The structured surface has more friction as compared to the smooth surface due to the scales or any other crimps on the fiber surface. 8
Impact of Surface coarse wool has more rough scales on the surface than fine wool, which produce the resistance when it rub with other material heat energy and static charge is produced. polyester fiber, it has smooth surface but it also has the friction. Its Static behavior shows this property. Fibre Friction in different fibres WOOL: Wool have greater friction with respect to other fibres. Hair is the best example of wool. 9
Friction in flax fibre Flax is a type of fiber. It has less resistance or friction. Cotton 10
Friction in cotton fibres Cotton has maximum friction due to convolution (natural crimp). A point to be noted that the wool fiber has less friction as compared to the cotton.due to high friction less fibrils produced in cotton yarn as compared to the wool yarn its due to natural crimp which has high friction. Silk Silk is a natural fibre. It has very low fibre friction. Men are not allowed to wear silk in our religion but a person who have allergy can wear silk. 11
IMPORTANCE OF FIBRE FRICTION Friction of fabrics is important from two different viewpoints: (i) Friction of fabrics against skin is an important aspect of comfort and (ii) Fabric friction is important in appearance control of the fabric MEASUREMENT OF FIBRE FRICTION To develop a new method for measurement of fiber-on on-fiber friction in textile manufacturing processes based on the frictional energy dissipated in dynamic loading of a fibre assembly, including (i) To develop a new theoretical model for characterization of inter-fibre friction from frictional energy loss of a fibre bundle subjected to dynamic loading 12
Measurement (ii) To design and build a set of instrument for measurement of fiber- on-fiber friction energy (iii) To determine the effect of various environmental factors such as moisture content, temperature, loading frequency and fibre mechanical properties on friction energy loss of fibrous assembly MEASUREMENT OF FIBRE FRICTION a)description of Frictometer It is made from a single piece of steel, measuring 12 cm x 15 cm x 2.5 cm. 13
Measurement The compound sled that forms the guarded friction meter is shown. The conventional sled, S, is pulled by cord, C, and tension load transducer, T2, which measures the force, Fc,, required to pull the compound sled. S, in turn, pulls the guarded sled, G, via compression load transducer, T1, which measures the force, Fg,, required to pull only the guarded sled. The guarded sled floats freely within the conventional sled, restrained only by T1. MEASUREMENT OF FIBRE FRICTION Test Procedures During a test, the sample is placed on an aluminum block and the back edge is clamped in place The compound sled is placed on a flat surface and the unloaded readings The transducers are read while pulling the sled, Rpull,, and the force, F, required to pull the sled is F=C( R pull Runloaded ) 14
MEASUREMENT OF FIBRE FRICTION Test Materials Several test materials were chosen such that they would not readily deform under the conditions of the test These included a transparency film (3M type CG3300), a solid aluminum plate that acted as the sample support, a 200 g/m2 poly(ethylene terephthalate) ) double knit jersey fabric MEASUREMENT OF FIBRE FRICTION Results and Discussion The friction coefficient for various substrates as measured by both the outer sled and the guarded sled The difference between the friction coefficients determined by the two sleds for a single substrate is not considered significant. Thus, the instrument described in this manuscript is only the first step in improving the measurement of friction of highly deformable substrates 15
The addition of Interfibe cellulose fiber in friction material Is generally accepted as a way to improve many aspects of a friction formulation. In man made fibres we add chemicals to increase friction because without friction it is not possible to spun the fibre. Conclusion Yarn can t be spurn without fiber s surface friction 16