Most single-jersey fabric is produced on circular machines whose latch needle cylinder and sinker ring revolve through the stationary knitting cam systems that, together with their yarn feeders, are situated at regular intervals around the circumference of the cylinder. The yarns is supplied from cones, placed either on an integral overhead bobbin stand or on a free-standing creel, through tensioners, stop motionsand guide eyes down to the yarn feeder guides.
Different types of Sinkers
The sinker is the second primary knitting element (the needle being the first).It is a thin metal plate with an individual or a collective action operating approximately at right angles from the hook side of the needle bed, between adjacent needles.
Different types of Knitting needles
Primary knitting elements:Three primary knitting elements:
Needle: Latch needle, Spring bearded needle & Compound needle.
Cam: Knit cam, Tuck Cam, Missed cam
Sinker: Holding down sinker, Knocking over and loop forming sinker
Main parts and their functions of latch needle
The hook: Grasping a new yarn in the process of knitting i.e. the hook which draws and retain the new loop.
The latch: Freely rotating around the axle and tightly closing the hook owing to the spoon located at the end of the latch.
Knitting Terms and Definition
Knitting is a technique to turn thread or yarn into a piece of cloth. Knitted fabric consists of horizontal parallel courses of yarn which is different from woven cloth. The courses of threads or yarn are joined to each other by interlocking loops in which a short loop of one course of yarn or thread is wrapped over the another course.
Methods of Evenness Testing
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.