Large Circular Knitting Machine Purchase Guide
Weft knitting circular knitting machines are precision machines, and the coordination of each system is crucial. The shortcomings of each system will become the performance ceiling of the machine. So why is it that there are few brands that can do well in the seemingly simple circular machine production on the market?
Many customers fall into a misunderstanding when purchasing circular machines, focusing only on those visible brand configurations such as yarn storage devices and knitting needles, and often ignore the most important parts of the machine itself. So sometimes the purchased machine is like a small shrimp with a crab's big claws, which looks luxurious, but the spent claws (money) are useless.
So today we disassemble the support mechanism, weaving system, cleaning system, transmission mechanism, lubrication system, yarn feeding system, pulling mechanism and other aspects to explain in detail what kind of balanced and stable machine is.
The support mechanism is the frame part, which is equivalent to the human skeleton. People with osteoporosis must have poor athletic ability. Some machine castings are full of pores and have a loose texture. The stability of this kind of casting for machine support will be much worse. When the machine is running at high speed, slight vibrations will be transmitted to the final fabric effect. When it comes to castings, we have to talk about natural aging:
Natural aging is to place the castings outdoors, and after being exposed to wind, sun, rain, and temperature changes in four seasons, the components release residual stress to obtain stable accuracy.
This process does not have a high technical content, but it requires time to settle, inventory capital occupation and storage management costs, so seemingly simple things have screened out most guerrilla manufacturers. Many small factories purchase goods and produce immediately when they are needed, and the castings are even installed on the machine while they are still hot.
The residual stress of the components that have not been effective is not released. There is no problem at the moment of installation, but after a period of time, the components undergo slight deformation or contraction. This deformation is often invisible to the naked eye, but it is already fatal to precision machinery.
For example, the plate in the above picture has a slight deformation (loss of flatness), which will cause the position of the mountain corner seat to change, and the position of the needle closing point of the knitting needle will also change. This will cause the height of the produced coils to be inconsistent.
The high coil has good light transmittance and looks brighter, while the short coil has poor light transmittance and looks darker. This leads to the unexplained yin-yang version.
In order to save costs, some manufacturers make the large plate too thin and the thorn too small, which may cause the deformation of the machine after running for a period of time.
If the same problem occurs on the large plate or the large tripod gear, it will cause the gear meshing clearance to change.
In severe cases, it will cause the upper and lower plate needles to collide with each other, causing serious losses.
The knitting system is also the looping system, including the heart and the needle cylinder. The material of the heart, the equal division, and the matching clearance accuracy are all very important. Today we mainly talk about the needle cylinder, which is the container of the needle and has repeated movement and friction with the needle for many years. In addition to the guarantee of lubrication, the material of the needle cylinder itself is very critical.
The needle cylinder with poor material will be worn by the needle after running for a period of time, and the worn metal powder will be mixed with the needle oil, and the needle will be brought to the yarn by the needle to produce oil needles, and the position of the needle in the worn needle cylinder will change, thus forming coils of inconsistent sizes, resulting in unsolvable vertical stripes.
Fast-cutting alloy steel and quenched needle barrels
Therefore, choose needle barrels of good materials, such as fast-cutting alloy steel and heat-treated needle barrels. These are often overlooked by customers.
The lubrication system is directly related to the service life of the sinker and knitting needles in the later stage, which also means the replacement frequency and use cost.
The lubrication system of the sinker must ensure that the sinker shoulder, heel and body are fully lubricated. The position of the oil spray nozzle is very critical. In terms of the lubrication of knitting needles, everyone is concerned about the lubrication inside the needle heel, and the position of the needle hook and needle tongue is easily overlooked.
A pipeline for oil-gas mixed spray is very important. It mixes air and needle oil to form an atomized oil-gas mixture, which is sprayed on the position of the needle tongue and needle hook, thereby ensuring the cleanliness of the needle hook and the flexible closure of the needle tongue. Achieve the effect of extending the service life of the knitting needle.
The cleaning system can extend the cleaning time, reduce the maintenance work of the machine and reduce the downtime, thereby improving production efficiency.
Whether the position of the air blowing cleaning is reasonable, both inside and outside. The best choice for the fan is the reverse slow dust removal design, that is, the fan and the syringe are selected in opposite directions, and the rotation speed is slower than the syringe. This design can ensure that the fan stays at the dust removal point evenly and for a longer time, thereby achieving a better dust removal effect.
In terms of the yarn feeding system, everyone will pay attention to the yarn storage device, which is not much to say. What is easily overlooked is the yarn frame, thickened square steel and solid bracket, which can make the entire yarn feeding system more stable. Avoid the yarn frame from shaking when the machine is running at high speed, thereby affecting the fabric effect.
In terms of the transmission system, the motor and inverter should choose stable and reliable brands, which I believe everyone will pay attention to. In terms of the transmission belt, the synchronous belt has a more stable transmission ratio. The bearing is installed in an invisible place. It exists in all systems and is often the most easily overlooked by customers. It is best to carefully ask the manufacturer what brand of bearings to use.
In addition to the number of sections, uniform speed and cloth roller of the cloth winding machine, shock absorption is very important in the pulling system. A good shock absorption system can extend the service life of the cloth winding machine gearbox and reduce the wear on the large plate gear.
Visit and ask the manufacturer about the installation accuracy of the machine, and observe whether it is assembled strictly in accordance with the installation accuracy requirements. This is very important. Accuracy means the grade of material selection and the level of installation. Of course, the above are just the basic requirements for making a good machine.
The above aspects represent the basis of machine accuracy and quality. Another crucial point in choosing a manufacturer is R&D capabilities, especially when your customers have special organization and fabric requirements.
Because under the premise of ensuring machine accuracy, R&D capabilities determine the maximum performance of the machine. Take the sweater machine as an example: the upper and lower plate mountain angle curves, the depth of the sinker throat, and the coordination of time position, needle pressing depth, tension, etc. How to develop the comprehensive performance of the machine (in terms of ease of cloth placement, compatibility of different raw materials, silk covering effect, etc.) to the strongest is the embodiment of R&D capabilities.
Many people think that circular knitting machine manufacturing is simple, but we always remain in awe and learn endlessly. Many people think that ordinary machines have little technical content, but we think that the more ordinary the machine model, the more difficult it is to make it well, and the simpler the fabric, the more difficult it is to achieve the ultimate.