Yaa Friction Inwards Stuff Fibers Together With Its Upshot Inwards Fiber Processing

FRICTIONAL PROPERTIES OF TEXTILE FIBER

Ali Rayhan Sarkar 

B.Sc. inwards Textile Engineering
Daffodil International University
Email: alirayhansarkar3268@diu.edu.bd

Introduction:
Friction is the strength that resists the motion of a surface over some other surface during sliding. When the textile materials are processed, together with then friction is developed betwixt the fibers. The properties which are shown yesteryear a textile stuff during friction is known every bit frictional property. This properties are shown during processing. Too high friction together with also depression friction is non proficient for yarn. Therefore it is an of import belongings when yarn manufacturing together with processing. 

 

There are 2 types of friction.

1. Static friction: The strength that must live overcome inwards gild to start sliding is called static friction.
2. Kinetic friction: The strength that resists continued sliding is known every bit kinetic friction.

Frictional properties depend on:

1. Composition of the stuff
2. State of the surface of the stuff
3. Pressure betwixt the surfaces
4. Temperature
5. Relative humidity %
6. Area of contact
7. Water absorption of fiber

Co-efficient of friction:
Frictional strength is proportional to the normal or perpendicular of a stuff due to its ain weight. 

 

That is, F ∞ due north Or, F = μ due north Or, μ = F/N 

 

Where, F = Frictional force, due north = Normal / perpendicular force. Here, μ is the proportional constant known every bit “co-efficient of friction”. So, co-efficient of friction tin live defined every bit the ratio of frictional strength together with perpendicular force.

Methods of measuring co-efficient of friction:
Capstan method is most commonly used to mensurate co-efficient of fraction. Capstan method tin live classified into 2 classes-

1. Static capstan method
2. Dynamic capstan method

Other methods-

1. Buckle & Pollitt’s method
2. Abboh & Grasberg method
3. Gutheric & Olivers method

Frictional properties influences:
In fiber stage

1. The conduct of fiber during drafting.
2. The frictional strength holds together the fiber inwards yarn, i.e, frictional strength helps to spun the fiber to yarn.

In yarn phase

1. If the frictional strength is also low, yarn strength volition live low.
2. Friction increases the luster together with smoothness of yarn.
3. Friction makes to a greater extent than build clean yarn.
4. Friction increases hairiness.
5. Friction occurs nep formation.

In stuff stage

1. Fabric feelings varied for departure betwixt static together with kinetic friction.
2. Fabric volition live slippery if µs >µk is high. Fabric volition live harsh if µs >µk is low.
   Here, µs= Co- efficient of static friction, µk= Co-efficient of kinetic friction.
3. If the frictional strength is high the receive got properties of stuff character volition live low.
4. High static friction causes high breakage of yarn inwards weaving.

Factors affecting frictional intensity:

1. Load: If charge increases frictional intensity volition also increase.
2. Area of contact or angle of contact: Frictional intensity increases amongst the increasing of angle of contact.
3. Speed of sliding: More speed of sliding causes to a greater extent than frictional intensity.
4. The solid soil of surface: The frictional strength is changed if the surface is lubricated either naturally or artificially or has been contaminated yesteryear dirt or impurities. The frictional strength increases both every bit the oil content is increased together with every bit the viscosity of the oil increases.
5. Effect of absorbed water: The frictional strength commonly increases every bit the regain of the fibre is raised.

Importance of friction inwards Textile Industry:

1. Friction holds the fibre inwards a sliver together with hence stuff does non interruption due to self weight.
2. Friction helps inwards drafting together with drawing process.
3. Uniform tension tin live maintained inwards winding together with warping because of friction.
4. Friction helps inwards twisting during spinning.
5. Friction modifies the luster together with appearance of a cloth.
6. Friction makes to a greater extent than build clean yarn.

Demerits of friction on textile material:

• Friction causes nap formation. 
• High static friction causes high breakage of yarn during weaving.
• If the frictional strength is high, the receive got properties of stuff volition live low.
• Friction generates temperature together with thus static electricity is developed which attracts dust, dirt etc. together with the materials go dirty.
• Sometimes due to over friction materials may live elongated.
• Friction increases yarn hairiness. 
• Friction worn out parts of machine.

Friction inwards textile material

Minimization of friction intensity:

1. By processing amongst lubricates:
Lubricating stuff every bit emulsion is used earlier jute spinning. Sizing is done during weaving grooming process. It also reduces yarn damage. Emulsion, oil, lubricants are applied specially on jute fibre to cut friction.

2. By chemic treatment:
By using acid or alkali. Acid or alkali is done on wool fibre to cut scale sharpness together with thus frictional intensity.

3. By finishing process:

• Mechanical finishing: Ironing of calendaring.
• Chemical finishing: By using resin. Resin is i typed anti-crease agent because it prevents fibre from creasing yesteryear blocking hydroxyl groups.
• By using softener nosotros tin minimize frictional intensity.

Theories of friction inwards textiles:
In this section, the diverse theories proposed for friction inwards textiles are reviewed. Kragelskii divided friction theories into iv groups, every bit follows: friction is a final result of (i) lifting asperities over i some other (ii) overcoming the forces of molecular interaction; (iii) displacing a book of stuff (ploughing); together with (iv) at to the lowest degree 2 components contributing to friction, i.e. composite theories.

The adhesion theory of friction has been the footing of explanation for friction inwards fibrous materials.

Arrows are vectors indicating directions together with magnitudes of forces (Figure 1). W is the strength of weight, due north is the normal force, F is an applied force, together with Ff is the strength of kinetic friction, which is equal to the coefficient of kinetic friction times the normal force. Since the magnitude of the applied strength is greater than the magnitude of the strength of kinetic friction opposing it, the block is accelerating to the left.

Yarn friction

Factors affecting yarn friction Overview:
Yarn friction is related to both surface properties together with mass properties of yarns. There are iv top dog groups of factors: (i) Fibre parameters; (ii) Yarn structural together with mass parameters; (iii) Operational parameters; together with (iv) Finishes. Fibre parameters include fibre structural together with mass parameters. Yarn structural together with mass parameters include yarn twist, spinning method, yarn denier, etc. Operational parameters consist of normal load, frictional speed, humidity, temperature, sliding speed, measuring method, contact geometry, together with the like. The number of finishes depends on the nature, the viscosity, together with the content of lubricant, etc.

Yarn friction has been investigated inwards relation to fibre parameters; yarn structural parameters, operational parameters, together with finishes, including lubricants.

Effects of fibre parameters:
Fibre Surface Roughness: It has been observed that amongst an increment inwards roughness of the fibre surface, finally tension together with hence friction inwards the yarn increases (Table 1).

Table 1: Effect of fibre surface roughness on yarn friction

Continuous filament yarn sample tested	Initial tension (gm)	Final tension (gm)
		Smooth	Rough
Yarn to metallic test	25	60	40
Yarn to yarn test	15	41	31

 
Molecular Orientation:
Gupta together with El Mogahzy investigated the number of molecular orientation on the friction of acrylic yarns. Inter-fibre friction together with molecular orientation at the fibre surface, characterised yesteryear a sonic modulus orientation factor, increased amongst describe ratio. They flora a potent correlation betwixt molecular orientation of the fibre together with inter-fibre friction. More intimate or greater expanse of contact yesteryear smoothing out of the surface for a to a greater extent than highly oriented fibre may live responsible for this finding.

Table 2: Orientation factor together with Coefficient of Friction (µ) of acrylic yarns at dissimilar values of cascade stretch (Xc.s)

Sample no	Xc.s	Orientation factor	µ, Point contact	µ, Line contact
1	2.0	0.6949	0.135	0.186
2	3.0	0.7316	0.136	0.221
3	4.0	0.7556	0.134	0.230
4	5.0	0.7725	0.138	0.235
5	6.0	0.7847	0.138	0.238
6	7.0	0.7918	0.141	0.243

Effects of yarn structural together with mass parameters:
Yarn denier: The fineness (denier) has an increasing number on friction due to an increment inwards the expanse of contact. Kalyanaraman observed that the coefficient of friction of yarn increased amongst increasing yarn linear density, due to the larger contact area, using the SITRA friction measuring device.

Yarn twist: Chattopadhyay together with Banerjee flora that, amongst increasing yarn twist of band together with rotor spun yarns, friction decreased for cotton, viscose rayon, together with polyester yarns. In this study, the stuff together with processing parameters selected were Yarn linear density = 59 tex, Relative Speed = xl m/min., Input Tension = xi cN. together with Number of wraps = 2. Higher twist decreases compressibility, resulting inwards a smaller expanse of contact together with thus lower frictional force. Higher twist showed greater friction for cotton fiber band spun yarns. Subramaniam together with Natarajan flora that the coefficient of friction of siro spun yarns increased amongst increasing strand spacing together with twist. This final result was attributed to the nature of the yarn surfaces.

Spinning method: Chattopadhyay together with Banerjee studied the effects of spinning method on yarn-to-yarn together with yarn-to-guide friction, using ring, rotor together with friction spun yarns for cotton, polyester together with viscose rayon. The effects of spinning method on yarn to-guide friction depend on the frictional speed together with stuff type. Yarn surface structural characteristics, eg, belt fibres of rotor yarns, together with compressibility were considered every bit of import factors affecting yarn friction.

From the results, it may live observed that. For both cotton fiber together with viscose fibres, band spun yarn shows the maximum frictional strength together with tension ratio, followed yesteryear rotor together with friction spun yarns, which are closed to each other. The results are thus just the contrary of what was observed for friction betwixt yarns. The gild inwards which the magnitude of the friction changes for cotton fiber together with viscose fibre is thus dissimilar inwards 2 cases together with shown below:

Between yarns: friction-spun > rotor-spun > ring-spun
Between yarn together with guide: ring-spun > rotor-spun > friction-spun

 
In inwards a higher house study, the stuff together with processing parameters selected were Yarn linear density = 98.4 tex. Input Tension = 12 cN. In illustration of polyester fibre, friction spun yarn shows the highest value, followed yesteryear rotor- together with ring-spun yarns. The gild inwards which the friction changes is thus just the contrary of what is observed for cotton fiber together with viscose fibres.

Yarn surface roughness: Yarn roughness was increased yesteryear insertion of twist inwards a multifilament yarn together with yesteryear incorporation of titanium dioxide. The yarn friction decreased amongst increased roughness of the yarn surface. However, for a rattling crude oil yarn surface, the yarn friction tended to increment owing to the Coulomb component.

Unevenness: Unevenness of yarn tends to influence the frictional forces. As yarn unevenness increases, frictional strength becomes greater.

 
Effects of operational parameters:
Pretension: An increment inwards pretension results inwards an increment inwards friction. This may live because the increment inwards push clit per unit of measurement area amongst pretension causes an increment inwards the expanse of contact together with thus an increment inwards friction. 

 
The coefficient of friction betwixt silk filaments together with steel is reduced from 0.44 to 0.27 (along the fibre) together with 0.34 together with 0.23 (across the fibre) amongst increasing yarn tension from v to twenty cN at a specified angle of wrap. 

 
Sliding Speed: The increment inwards the friction of spun yarns amongst increasing speed may live attributed to the fact that, at high-speeds, the hairs may curvature downward owing to the trace of the yarn, leading to an increment inwards the contact area.

With increment inwards speed, the friction coefficient of cotton, rayon, together with silk yarns increases when measured yesteryear the capstan method.

The friction of ring, rotor together with friction spun yarn decreases amongst increasing frictional speed from xl to 200 m/min. In this study, the stuff together with processing parameters selected were Yarn linear density = 98.4 tex. Input Tension = xi cN. Number of wraps = 2.

Temperature: The effects of temperature on yarn friction convey been related to the thermal electrical conductivity of guide materials.

The number of guide temperature on friction should live considered along amongst speed. Thermally stable lubricants are required to foreclose melting of fibres at the fibre-to-metal surface, due to high temperature. For the number of temperature, the initial decrease inwards friction amongst increasing temperature may live attributed to the decrease inwards lubricant viscosity, together with subsequent increment inwards friction to volatilisation and/or thermal decomposition of lubricant causing softening of the polymer surface.

Humidity: The effects of relative humidity together with wet content of yarns on friction acquit upon yarn breakage rates together with the character of products. The coefficient of friction of yarn was reported to increment amongst increment inwards humidity together with sharply increment inwards a higher house 80% relative humidity.

Effects of Finishes:

General: In this section, the effects of finishes including lubricants together with softeners, together with finishing such every bit mercerization, plasma etching together with Light Amplification by Stimulated Emission of Radiation irradiation are discussed.

Lubricants: The activeness of a lubricant is to (a) cut the abrasion of fibres, yarns together with machine parts, (b) cut static electrification during textile processing, together with (c) ensure adequate strength of spun yarns together with their finally products. Influenza A virus subtype H5N1 lubricant has been flora to convey a pronounced number on both yarn-to-metal together with yarn-to-yarn friction. Under boundary lubrication, friction is governed yesteryear the chemic nature of lubricants together with the sliding surfaces, the shear strength of the lubricants, the rigidity of the substrates, together with the push clit per unit of measurement area at the areas of contact.

Lubricants reduced friction of spun yarns yesteryear reduction inwards friction index a. The index n remained constant either amongst the type or concentration of lubricants. Lubrication of the yarn gradually reduced the coefficient of friction. This tendency was to a greater extent than pronounced when the lubricant or the surface active agent was deposited at the interface, every bit inwards dry out handling studies, rather than when it was acquaint inwards solution, every bit inwards the illustration of submerged experiments.

Softeners: Sebastian, et al reported that handling amongst cationic softening agents reduced inter-yarn sliding friction.

Mercerization: The effects of slack mercerization, using zinc chloride, on yarn properties of band together with open-end spun cotton fiber yarns convey been investigated. The coefficient of friction of yarns increased after mercerization.

Plasma etching: The number of plasma etching on frictional properties of polyester filaments has been investigated. Plasma handling increased the roughness of fibre surface together with caused an increment inwards inter-fibre friction together with fibre cohesion.

Laser Irradiation: By Light Amplification by Stimulated Emission of Radiation irradiation of polyester yarn surfaces during a continuous winding process, the friction betwixt the yarns together with the guiding elements was reduced. 

 
Lubrication of yarns:
Purpose: Lubrication of yarn is critical to knitting yarns together with sewing threads for their processing performance-to render depression levels of friction (Table 7), together with for protection from oestrus generated yesteryear the needle. Fabric together with garment manufacturing require proficient yarn lubrication.

Lubricants tin modify both the surface together with the mass of yarn. For yarn, depending on its molecular size together with charge, the lubricating agent may deposit itself on the yarn surface, or penetrate the yarn together with deposit on the surface of the private fibre.

Applications:
Friction is an of import factor inwards many applied scientific discipline disciplines. 

 
Transportation:

1. Rail adhesion refers to the travelling steal wheels of a develop convey on the rails, meet Frictional contact mechanics.
2. Road slipperiness is an of import pattern together with security factor for automobiles
3. Split friction is a peculiarly unsafe status arising due to varying friction on either side of a car.
4. Road texture affects the interaction of tires together with the driving surface.

Laws of friction:

1. The frictional strength is independent of the expanse of contact betwixt 2 surfaces.
2. The frictional strength “F” is proportional to the normal reaction “RN”.
3. This constabulary is known every bit Coulomb’s constabulary together with friction’s tertiary law. Kinetic strength is independent of the speed of sliding.

Measurement of friction:
Methods of friction touchstone tin live divided into 2 classes. They are – 

 
1. Frictional at solely i call for of contact.

• Between 2 dissimilar fibres.
• Between 2 dissimilar fibres.
• Between a fibre together with non-fibre materials such every bit metal, plastic together with ceramic.

2. Average friction at a groovy number of contacts.

Conclusions :
Friction is the resistance to motion of i torso over body. The intelligence comes to us from the Latin verb fricare, which way to rub. The bodies inwards inquiry may live a gas together with a company (aerodynamic friction), or a liquid together with a company (liquid friction); or the friction may live due to internal liberate energy dissipation processes within i torso (internal friction). In this article, the give-and-take volition live express to the effects of company friction. Two of the most pregnant inventions of early on human being are friction-related: He learned to usage frictional heating to start his cooking fires, together with he discovered that rolling friction is much less than sliding friction (that is, it is easier to displace heavy objects if are on rollers than it is to drag them along). This instant regain would eventually Pb to the innovation of the wheel. 

 

Friction plays an of import usage inwards a pregnant number of our daily activities together with inwards most industrial processes. It aids inwards starting the motion of a body, changing its direction, together with after stopping it. Without friction, nosotros could non readily displace about, travelling steal objects, low-cal a match, or perform a multitude of other mutual daily tasks. Without friction, most threaded joints would non hold, rolling mills could non operate, together with friction welding would plainly non exist. Without friction, nosotros would listen neither the vocal of the violin nor the squeal of the brake. In moving machinery, friction is responsible for dissipation together with loss of much energy. It has been estimated, for example, that 10% of oil consumption inwards the US of America is used just to overcome friction. The liberate energy lost to friction is an liberate energy input that must continually live provided inwards gild to hold the sliding motion. This liberate energy is dissipated inwards the system, primarily every bit heat—which may convey to live removed yesteryear cooling to avoid harm together with may boundary the weather condition nether which the mechanism tin live operated. Some of the liberate energy is dissipated inwards diverse deformation processes, which final result inwards vesture of the sliding surfaces together with their eventual degradation to the call for where replacement of whole components becomes necessary.

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