Starting stage: laying the foundation for weaving
The starting stage plays a crucial starting role in the entire weaving process. At the beginning of weaving, the pre-selected three-system flying shoe upper computer flat knitting machine needs to weave a row of starting coils first to prevent the bottom edge of the subsequent knitted garment pieces from coming apart and to facilitate the subsequent pulling operation. This row is professionally called the starting row. Usually, the starting row is woven in the form of 1 + 1 ribbing.
When the starting weaving is ready to start, the head of the pre-selected three-system flying shoe upper computer flat knitting machine will drive the yarn guide converter to guide the yarn guide with the starting yarn to operate. The yarn guide accurately inserts the yarn into the gap of the needle bed. After the insertion is completed, the yarn head will be wound and fixed. This winding and fixing operation is by no means random. Factors such as the tightness of the winding and the fixed position will affect the stability of subsequent weaving. If the loop is loose, the yarn is prone to displacement in the subsequent knitting, resulting in an uneven start; if the fixed position is improper, the start of knitting may deviate from the preset trajectory. After the fixation is completed, the operator pushes the machine head to officially start the knitting process of the start row. The moving speed of the machine head during the knitting process is not constant. In the start stage, the speed is usually relatively slow, so as to better control the feeding of the yarn and the movement of the knitting needles to ensure the knitting quality of the start row. When the machine head successfully completes the knitting of the start row, it will stop on the left. At this time, the sensor inside the machine will detect the position of the machine head. After confirming that it is in place, the various systems of the pre-selected three-system flying knitting upper computer flat knitting machine begin to adjust parameters to prepare for the upcoming formal knitting stage.
Normal knitting stage: construction of complex patterns and structures
After the start row is successfully completed, the pre-selected three-system flying knitting upper computer flat knitting machine enters the normal knitting stage. This stage is the critical period for the flying knitting upper to gradually build complex patterns and structures from a simple start basis.
First, the control system plays a core command role. It precisely controls the movement speed, direction and various actions of the machine head and the knitting needles according to the pre-set pattern files and the carefully compiled knitting programs. For example, when the designed upper pattern contains fast-changing complex geometric figures, the control system of the pre-selected three-system flying knitting upper computer flat knitting machine will quickly adjust the movement speed of the machine head to make it shuttle quickly and smoothly on the needle bed, and at the same time accurately control the knitting needles to complete a series of actions such as rising, falling, and moving left and right in a very short time to achieve accurate knitting of the figure.
The needle selection system is responsible for selecting the working needles at this stage. According to the pattern requirements, the needle selection system of the pre-selected three-system flying knitting upper computer flat knitting machine can quickly and accurately identify and select specific needles to participate in knitting. Taking the knitting of a complex logo with brand characteristics as an example, the needle selection system will carefully identify the needles corresponding to the logo pattern part, and only allow these needles to participate in the knitting action, while the needles in other irrelevant areas remain stationary. In this process, the response speed and accuracy of the needle selection system directly determine the clarity and accuracy of the logo knitting. If there is a deviation in needle selection, even if there is only one wrong needle selection, it may cause the logo pattern to deform or blur, seriously affecting the design effect of the upper.
The yarn delivery system is also indispensable. It strictly follows the program settings to deliver yarns of different colors and materials to the working needle position in an orderly and accurate manner. When actually producing flying knitted uppers with a variety of color and material combinations, the yarn delivery system of the pre-selected three-system flying knitting upper computer flat knitting machine needs to complete the yarn switching operation in a very short time. For example, in the same row of knitting, the first half needs to use polyester fiber yarn with good breathability, and the second half needs to be switched to functional yarn with antibacterial function. The yarn delivery system can complete this switch quickly and smoothly according to the instructions, ensuring the continuity of the knitting process and providing strong support for designers to realize rich and diverse design concepts.
The knitting action execution system converts the control system's instructions into actual knitting needle movements through key devices such as the triangle structure, needle track and press plate in the machine head. The triangle device is like a precise choreographer, flexibly adjusting the movement trajectory of the knitting needle according to different instructions issued by the control system. When knitting loops, the triangular device will carefully plan the rising and falling trajectories of the needles to ensure that the yarns smoothly form tight and uniform coils, which are the key units that constitute the basic structure of the fabric. When knitting tucked loops, the triangular device will cleverly change the movement path of the needles so that some needles only perform tucks, thereby creating eyelets, bumps and other structures with unique visual and functional effects on the surface of the fabric. The needle track is like a carefully laid track, ensuring that the needles maintain a stable trajectory during movement without external interference. The role of the pressure plate should not be underestimated. It applies appropriate pressure to the yarn when the needles are knitting, ensuring that the yarn is in a stable position during the process of looping, tucks, etc., and avoiding problems such as yarn slack or entanglement.
In the entire normal knitting process, the coordination between different systems is crucial. Any failure or mismatch in any system may cause defects in the knitted upper. For example, if there is a time difference in the coordination between the yarn delivery system and the knitting action execution system, the yarn may be fed before the needles are ready, resulting in incomplete coils or yarn knots. In order to ensure the smooth coordination of the pre-selected three-system flying knitting upper computer flat knitting machine, the parameters of each system need to be repeatedly debugged and optimized before the machine is run, and the operating status of each system is monitored in real time through sensors during the knitting process. Once an abnormality is found, it is adjusted immediately.
As the machine head moves back and forth on the needle bed, layer after layer of coils are woven in an orderly manner. In this process, the weaving of each layer of coils strictly follows the design requirements, and through the clever combination of different tissue structures, a flying knitting upper with a complex structure and exquisite design is gradually constructed. For example, the designer may use the looping tissue as the main basic structure of the upper to provide basic strength and stability for the upper; in the sweat-prone area of the upper, the collection tissue is interspersed to form dense breathable holes to improve the breathability of the upper; in the parts that need key support, the transfer tissue is used to form a unique thickening or reinforcement pattern to enhance the support effect of the upper.
Pulling and winding stage: ensuring weaving quality and continuity
While the normal weaving stage continues to advance, the pulling and winding stages play an important role simultaneously. The two work closely together to ensure the smooth progress of the weaving process and the stability of the fabric quality.
The main responsibility of the pulling mechanism of the pre-selected three-system flying knitting upper computer flat knitting machine is to apply continuous and appropriate tension to the fabric being woven, so that the fabric always maintains a certain tension during the weaving process. This process is crucial to ensure the flatness of the fabric and the smooth progress of subsequent weaving operations. Common pulling mechanisms mostly use heavy hammer type or other automatic adjustment methods. The heavy hammer pulling mechanism uses gravity to generate tension on the fabric by hanging a heavy hammer of a certain weight. In actual applications, the weight of the heavy hammer is not determined arbitrarily, but needs to be accurately calculated and adjusted according to the material, thickness and weaving process requirements of the fabric. If the heavy hammer is too light, it cannot provide enough tension for the fabric, which may cause the fabric to sag, wrinkle and other problems during the weaving process, affecting the weaving quality; if the heavy hammer is too heavy, it may cause excessive pulling on the fabric, resulting in yarn breakage or fabric deformation. The automatic adjustment pulling mechanism is more intelligent. It monitors the tension changes of the fabric in real time through sensors and automatically adjusts the pulling force according to the preset tension range. For example, when the sensor detects that the fabric tension decreases due to changes in weaving speed or fluctuations in yarn characteristics, the automatic adjustment mechanism will respond quickly, increasing the pulling force on the fabric by increasing the operating speed of the pulling device or adjusting the pulling angle, so that the tension returns to the normal range.
During the pulling process, the fixed width comb bar plays a key auxiliary role. The fixed width comb bar is installed under the fabric, and its comb teeth are evenly distributed. During the pulling process of the fabric, the comb teeth will be embedded between the coils of the fabric to prevent the fabric from shrinking or deforming in the width direction, ensuring that the width of the fabric remains stable at all times. The comb tooth density and material selection of the fixed width comb bar also need to be adapted according to the type of fabric and weaving requirements. For finer fabrics, it is necessary to select a fixed width combing bar with a larger comb tooth density to better control the width of the fabric; for fabrics with harder materials or special textures, it is necessary to select a fixed width combing bar with wear-resistant materials and special comb tooth shapes to avoid damage to the fabric during the combing process.
When a certain length of weaving is completed, the winding mechanism begins to play a role. The main task of the winding mechanism of the pre-selected three-system flying knitting upper computer flat knitting machine is to automatically wind the woven fabric on the cloth winding roller. The winding process is not a simple winding, but requires precise control of the winding speed to perfectly match it with the weaving speed. If the winding speed is too fast, the fabric will be overstretched during the winding process, which may cause the fabric to deform or the yarn to break; if the winding speed is too slow, the fabric will accumulate under the machine, affecting the continuity of the weaving, and may even cause the fabric to wrinkle due to uneven force. In order to achieve accurate speed matching, the winding mechanism is usually equipped with a high-precision speed adjustment device and sensor. The sensor monitors the changes in weaving speed in real time and transmits the data to the speed regulating device. The speed regulating device quickly adjusts the operating speed of the winding mechanism according to these data to ensure a smooth and smooth winding process.
During the entire pulling and winding stage, it is also necessary to pay close attention to the flatness and tightness of the fabric during the winding process. If the fabric is uneven or the tightness is different during the winding process, it may cause problems in the subsequent processing or wearing of the upper. To solve this problem, some advanced pre-selected three-system flying knitting upper computer flat knitting machines are equipped with pressure sensors and deviation correction devices on the cloth roller. The pressure sensor monitors the pressure on the fabric during the winding process in real time to ensure that the pressure is evenly distributed; the deviation correction device detects the position of the edge of the fabric. When the fabric is found to be offset, it adjusts the position or angle of the cloth roller in time to keep the fabric in the correct winding position at all times, thereby ensuring the winding quality.
