中文简体
عربىThe Basic Principle of Weft Knitting Technology
As an important branch of knitting technology, weft knitting is based on feeding yarn in the weft direction, allowing the working needles to bend the yarn into loops in sequence and interlace them to form a knitted fabric. Each yarn forms one or more loops in a horizontal row, and these loops are tightly interlaced in the longitudinal direction to form the basic structure of weft knitted fabrics. Compared with warp knitting, weft knitting gives fabrics better lateral extensibility and elasticity, which makes weft knitted fabrics excellent in fitting the curves of the human body and adapting to body movements. Whether it is close-fitting underwear or sportswear with high activity, it can be perfectly adapted.
Key components of knitting weft knitting machines
Circle forming mechanism
The circle forming mechanism is the core of the knitting weft knitting machine, just like the heart to the human body. This mechanism is mainly composed of key parts such as knitting needles, sinkers, triangle devices and yarn guide devices. Under the precise control of the triangle device, the knitting needle moves up and down along a specific trajectory to complete a series of fine movements such as piercing the yarn and bending the yarn into loops. The sinker works in harmony to pull and hold the yarn in time to ensure a smooth looping process. The yarn guide device accurately guides the yarn so that it reaches the knitting needle accurately, providing a guarantee for knitting uniform and tight coils. The cooperation between the various parts is like a precise dance, and every movement is accurate and correct, playing the beautiful movement of looping together.
Color mechanism
In the field of weft knitting, the color mechanism is also called the needle selection mechanism. It is like a creative "palette" that adds rich and diverse colors and patterns to knitted products. With the help of advanced computer control systems and sensitive needle selection devices, the color mechanism can accurately select and control the knitting needles according to the preset patterns. Whether it is a simple geometric figure, or a colorful floral and animal pattern, or a modern abstract art design, it can be perfectly presented on the fabric through the color mechanism. The existence of this mechanism has greatly expanded the design space of knitted products and met consumers' strong demand for personalized and fashionable textiles.
Yarn feeding mechanism: a stable "energy supply station"
The yarn feeding mechanism is responsible for the continuous and stable supply of yarn for the weaving process, just like a "supply station" that injects a steady stream of energy into the machine. Its design needs to ensure that the yarn can be delivered to the weaving area with uniform tension and stable speed. To achieve this goal, the yarn feeding mechanism is usually equipped with components such as yarn storage, tension adjustment device and yarn feeding device. The yarn storage can store a certain amount of yarn to buffer the fluctuations in the yarn supply process; the tension adjustment device can finely adjust the tension of the yarn according to the requirements of the weaving process to avoid fabric defects caused by excessive or insufficient tension; the yarn feeding device feeds the yarn into the looping area with a precise rhythm, and closely cooperates with the operation of the looping mechanism to ensure the efficient and continuous weaving work.
Pulling and winding mechanism
As the weaving process continues to advance, the knitted fabric needs to be pulled out of the weaving area in time and wound into a specific package in an orderly manner. This key task is undertaken by the pulling and winding mechanism. The mechanism mainly includes important parts such as the fabric expansion frame (fabric support frame), transmission arm (wall panel), and adjustment gear box. The fabric expansion frame is like a pair of gentle and powerful hands, slowly stretching the fabric horizontally, effectively preventing it from wrinkling or deforming during the pulling process, and always keeping it flat. The transmission arm and the adjustment gear box are like precise speed and force controllers, which cleverly control the speed and tension of pulling and winding, so that the fabric can be evenly and tightly wound on the cloth roller. At the bottom of the large plate, an induction switch is generally installed. When the transmission arm equipped with cylindrical nails passes by, the induction switch will keenly send out signals. These signals are used to accurately measure the cloth rolling data and the number of revolutions of the large circular machine, so as to achieve accurate control of the uniformity of the weight of the lower cloth (drop cloth). Reasonable and accurate adjustment of the various parameters of the pulling and winding mechanism plays a decisive role in ensuring the quality and appearance of the fabric, and lays a solid foundation for the subsequent finishing process.
Operation process of needle weft knitting machine
Starting preparation
Before starting the needle weft knitting machine for knitting operation, a series of meticulous preparations need to be carefully completed. First of all, it is necessary to carefully select the appropriate yarn according to the specific requirements and intended use of the product. This process involves comprehensive consideration of many factors such as yarn material, color, count, etc. Yarns of different materials, such as natural cotton and wool, chemically synthesized polyester, nylon, and their blended yarns, each have unique performance characteristics, which will give the fabric a completely different feel, gloss, breathability and durability. After selecting the yarn, it is immediately necessary to pre-treat it, among which the winding process is particularly critical. The winding process can rewind the yarn into a bobbin that meets the yarn supply standards of the needle weft knitting machine, ensuring that the yarn can be unwound smoothly and stably supplied during the subsequent knitting process. At the same time, the needle weft knitting machine needs to be fully and deeply debugged and inspected, covering various aspects such as the mechanical state of each component of the machine and the parameter setting of the electronic control system. Only when all components are confirmed to be in good working condition and the knitting process parameters such as needle cylinder speed, yarn feeding amount, and triangle position are accurately adjusted, can we be fully prepared for knitting high-quality products, and truly achieve everything is ready, only the east wind is missing.
Knitting process
When all preparations are ready, the knitting process officially begins. Taking the widely used circular knitting machine as an example, the yarn is slowly unwound from the creel, and passes through the yarn storage device, yarn feeding nozzle and other components in turn. Under the coordinated guidance of these components, it is accurately and accurately delivered to the knitting area. In the knitting area, the needle cylinder is like a high-speed rotating "stage", rotating with the knitting needle at a very high speed. Under the precise control of the triangle, the knitting needle rises and falls in an orderly manner in strict accordance with the preset program. In this process, the knitting needle bends the yarn into circles one by one, and cleverly makes them intertwine with each other, gradually outlining the prototype of the knitted fabric. In a single-sided circular knitting machine, the sinker will closely cooperate with the movement of the knitting needle to pull and hold the yarn, ensuring the smooth progress of the looping process. In a double-sided circular knitting machine, the upper needle cylinder (needle disc) and the lower needle cylinder are set perpendicular to each other, and the knitting needles carefully weave a double-sided structure knitted fabric under the synergistic effect of the upper and lower needle cylinders. During the entire knitting process, the computer control system is like an all-knowing commander, always monitoring the operating status of the machine and various knitting parameters in real time. Once any abnormal situation is detected, the computer control system will respond quickly, make adjustments in time and issue an alarm to ensure the stability and continuity of the knitting process, so that the yarn can achieve a gorgeous transformation in this precise mechanical operation and gradually transform into a beautiful knitted fabric.
Pulling and winding
As the knitting work continues to deepen, the pulling and winding mechanism begins to play a key role. It is like a skilled master of gathering, with just the right strength and speed, to smoothly pull the gradually formed knitted fabric out of the knitting area and wind it on the cloth roller in an orderly manner. The fabric expansion frame takes the lead in stretching the fabric horizontally, gently and firmly, effectively avoiding wrinkles or deformation of the fabric during the pulling process, and always maintaining its smooth appearance. The transmission arm and the adjustment gear box work closely together to accurately control the speed and tension of pulling and winding according to the requirements of the weaving process. Through the fine control of these parameters, it is ensured that the fabric can be evenly and tightly wound on the cloth roller to form a neat and tight cloth roll. The induction switch installed at the bottom of the large plate is like a pair of sharp eyes, always paying attention to the movement of the transmission arm. When the transmission arm equipped with cylindrical nails passes by, the induction switch will immediately send out a signal, which is accurately used to measure the cloth rolling data and the number of revolutions of the large circular machine, thereby realizing the precise control of the uniformity of the weight of the lower cloth (drop cloth). Reasonable adjustment of the various parameters of the pulling and winding mechanism can not only significantly improve the quality and appearance of the fabric, but also provide a good foundation for the subsequent finishing process, just like carefully framing a beautiful painting to make it more perfect.
