The optical method measures the variations in diameter of a yarn and not in its mass. The instrument an infra-red transmitter and two identical receivers. The yarn passes at speed through one of the beams, blocking a portion of the light to the measuring receiver. The intensity of this beam is compared with that measured by the reference receiver and from the difference in intensities a measure of yarn diameter is obtained.
Speed Frame Production Calculation
Math 1: Calculate the TPI (twist per inch) produced on a simplex with diameter of front roller 28 mm and its rpm be 30. The rpm of flyer is 1000.
Twisting and Amounts of Twist for Different Materials – why is the amount of twist in a yarn important
The roving coming out of the front delivery roller is threaded through the top of the flyer, passes through its hollow leg around the presser arm on to the bobbin. The purpose of providing twist in roving is to give the strand sufficient strength to withstand the strain during unwinding in the creel of the ring frame. The insertion of twist is achieved by the rotation of the flyer.
Shaded Twill Weave and Stepped Twill Weave
Shaded twill is formed shade effect on the surface of the fabric. The shade effect is created by the combination some thick to thin twills and thin to thick twills. Stepped twill is formed by steeping a continuous twill and keeping the direction of twill line same or opposite.
Elongated Twill Weave and Combined Twill Weave
Elongated twill is constructed by advancing the points of intersection two or more threads in one direction and one thread in the other direction.On the other hand combined twill is formed by combination two regular twill and arranging them alternately with each others.
Drafting system of roving frame I Draft Distribution of Speed or roving Frame |The simplex/roving frame is a necessary evil
The drafting section of the roving frame may be 3 over 3 or 4 over 4 with or without apron roller arrangement. Only the 3-over-3 or 4 over 4 roller with double apron drafting system are still to be found in modern machines offered by manufacturers. In general 3/3 drafting system is used, but for higher draft applications 4/4 drafting system is used.
Yarn Numbering System
Yarn number is a measure of the fineness or size of a yarn expressed either as mass per unit length or length per unit. Yarn Count and Yarn Size are synonymous with Yarn Number.There are two systems of expressing yarn number or yarn count.
❶ Direct yarn numbering system (mass/unit length)
❷ Indirect yarn numbering system (length/unit mass)
Man-Made Fibers & Classification of Man-Made Fibers
In a very general way, a fiber is defined as any product capable of being woven or otherwise made into a fabric. It may be thought of as the smallest visible unit of textile production. Fibers may be agricultural products (such as cotton or wool) or units (such as nylon or polyester) manufactured in a chemical plant. Fibers than serve as the raw material in the next stage of textile manufacturing.
Speed Frame Machine Components
Top rollers are held strictly parallel to and in perfect alignment with bottom rollers.//The bottom rollers of speed frame exercise immense influence on the quality of roving.//The flyer is a special component of the roving frame that helps to insert twist in the roving. The flyer speeds employed normally range from about 1000 to 1400 rpm. The flyers’ special shape offers less air resistance, preventing roving breakages.
Plain Weave Definition and Plain Weave Classification
A weave in which there are 2 ends and 2 picks in a repeat is called a plain weave. It has the smallest repeat 2 x2. Classification of plain weave: Approximately square cloth, Warp face cloth, Weft face twill, Balanced cloth, Unbalanced cloth.