Knitting Machine

Loom is a mechanical device on circular knitting machine which can insert warp yarn and weft yarn to produce woven fabric. In weaving technology, loom is the principle mechanical device on circular knitting machine for weaving. Various types of loom are used for weaving. Changing the setting of loom can produce different types of designed fabrics.

Loom is a mechanical device interweaving yarn to fabric for dress or industrial uses.

Classification of loom: Fabric is produced by the means of loom. Loom has a long history. In the early of the fabric manufacturing history, man used hand loom to produce fabrics. With the development of loom, weaving mechanism is also changed. Nowadays, the loom which is used for fabric manufacturing has high production capacity as well as complex design production capacity.

Loom is classified into three types:

Conventional Loom:
1. Hand Loom
2. Plain Loom
3. Twill Loom
4. Dobby Loom
5. Jacquard Loom

Automatic Loom:
1. Modern Loom
2. Missile Loom or Projectile Loom
3. Rapier Loom
4. Water Jet Loom
5. Air Jet Loom

Special loom can be classified into shuttle loom and shuttle less loom further:

Shuttle loom: Shuttle loom is the loom that inserts weft yarn through the warp yarn. Conventional loom and automatic loom can also be considered as the shuttle loom. Other special types of shuttle loom include short loom, broad loom, pile loom, gauge loom and tri-axial loom etc.

Shuttle less loom: Shuttle less loom inserts weft yarn through warp yarn. The entire shuttle less loom is called as modern loom. The production capacity of shuttle less loom is higher than shuttle loom.

Weave structures is the design by which fabric is produced. The yarns are used in various ways to produce different weave effects. Different simple and complex fabric design is produced by the weave structures. The loom is set according to the fabric structure. Specific loom is used for producing special types of design. We can say jacquard and dobby which two are used for making special design on the fabric.

Basic Weave Structures for Fabric manufacturing
There are three basic weave structures for fabric manufacturing.

They are:
Plain Weave
Twill Weave
Satin Weave or Sateen Weave

On the other hand, there are lots of derivatives of the above basic weave. Followings are the most important weave structures.
Cut Pile
Uncut Pile
Leno
Jacquard
Dobby
Basket Weave
Rib Weave
Herringbone Weave
Oxford Weave
Double Knit

Now, I like to give a short idea about above weave design.

Plain weave is produced when each weft yarn passes over and under each warp yarn with each row alternatives. It is the simplest form of weave structure.

Twill weave is similar to plain weave, in this the warp yarn skip at regular predetermined intervals creating a diagonal rib in the fabric surface. Twill weave is more flexible than plain weave.Satin weave is so called when fabric is manufactured by filament yarn like silk or nylon.

Flexible fabric is produced by this weave structure. In the other hand, when fabric design is produced by short staple yarns like cotton that is called sateen weave. In satin structure, the face of the fabric consists only the warp on the weft threads giving the fabric a smooth and lustrous surface.

Cut pile is specially used for a carpet fabric where the face of the fabric is composed of cut ends of pile yarn.

Uncut pile is a pile of carpet consisting of loops.

Leno weaves, in this the warp yarns are arranged in pairs. One yarn being twisted the other between picks of the filling yarn.

Jacquard weave is used for producing complex patterns on the fabric. Jacquard loom is used for creating jacquard weave.

Dobby weave is a decorative weave, which is characterized by small design or geometric figures being woven in the fabric structure.

Basket weave is one of the variations of plain weave where fabric has a loose constructions and flat look. It is strong and flexible than basic plain weave.

Rib weave is a basic weave in which rib cord is produced on the fabric. Abrasion and tearing strength of the rib weave is high.

If you want to produce a fine, soft and light weight fabric then you have to consider oxford weave which is a modification of plain weave. It is generally used for apparels.

Double knit is a knit fabric which is produced in circular knitting machine. Double knit fabric has loops on both sides.So, there are a lots of weave design. The weave design is one of the arts in textile manufacturing. So, try to create new design.

Circular knitting into a loop system (enterprise called into yarn ones, referred to as large ones) and more, high speed, high yield, flower-shaped changing fast, good quality fabric, less process, strong product adaptation, it has developed rapidly. According to its processing fabric (called academic positions inside the plant commonly known as gray) species to specific division, has the following categories: 1, single-sided series circular knitting; 2, double circular knitting class.

1. the process requirements
· Circular knitting yarn is woven into a tubular cotton, equipment often requires emergency stop.
· Require a flexible jog run function, work process requires the motor to run smoothly.
· Require high starting torque.
· Operating ambient temperature is too high.

2. the system components
(A) electrical control system parameters can be set for the completion of the operation, simple button operation, fault indication stops.

2.1, a microcomputer control panel, and highly integrated control circuit, convenient parameter setting and reliable operation of the button, to display visual information.

2.2, the drive is an important part of the motor (motor) AC control system can achieve the purpose of changing the motor speed by controlling the output frequency. You can adjust the speed of a wide range of start, stop, slow performance set by the parameters that can be done quickly and smoothly to avoid shocks.

2.3, the electrical control box lines clear and orderly, the entire cabinet in scraps inside, effective ventilation to prevent dust. Electrical wiring in the shelter, taking into account the aesthetics and safety.

(B) the transmission is controlled by a frequency converter stepless variable speed motor. Motor with V-belt or belt (toothed belt) driven by the drive shaft gears, gear while passing to the market, thus boosting syringe needles carrying the running, knitting. Drive shaft extends above the knitting machine, driven by the amount of yarn feed tray conveyor yarn. Requires transmission smooth operation, no noise.

3. the advantages of high-performance vector inverter system
Arfa low frequency torque converter output steady, starting torque of 180%.
Smooth soft start function · inverter device to reduce the impact on the grid, superior protection features greatly improved the process equipment, improve the quality of the product.

· Good thermal design, fully meet the long-term work in high-temperature device environment.

4. the technical requirements
Knitting machine industry requirements for the control of the inverter is more concise, general access terminal control start and stop, given the frequency of the analog multi-speed or use a given frequency. Knitting machine work load is heavy, requiring low speed to jog or fast, so mechanical and electrical drive control performance, low torque requirements have a greater ability to control the drive motor at low frequencies. General application in the knitting machine, the drive to the vector control without speed sensor (also called open-loop vector) mode, assure accuracy and low-frequency electromechanical steady speed high torque output.

In knitting machine operation, and must not allow the motor to reverse rotation phenomenon, otherwise the needle bed needle is bent or broken pins. Some knitting machine access-way bearing, can not be considered. If the system is entirely dependent on reversing reversing motor control, you need to set reasonable parameters, on the one hand to be set to prohibit reverse function, on the other hand need DC braking function. Also note that the phenomenon does not appear stall to avoid breakage and other damage. The program uses the analog input at a given frequency. Simple circuit (omitted) knitting machine requires faster response when starting, low frequency and large torque output; shutdown to be smooth, softer, in order to protect the needle bed. Therefore reasonable to set the table parameters are fully guaranteed round machine performance, the principle is through the mediation of P0.19, P9.00 parameters to get the best low torque output capability and reduce vibrational circular machine high-speed operation, control by starting mediation (P1 group) as well as the acceleration and deceleration time parameters (P0 group) to get frequency adjustment smoothness.

5. the use of effects
Alpha Series low frequency inverter output side jog more straightforward and low torque converter insufficient to overcome most shortcomings, both to protect the electrical equipment, and bring significant economic benefits.

Smooth soft start function · inverter device to reduce the impact on the grid, superior protection features greatly improved the process equipment, improve the quality of the product.

· Good thermal design, fully meet the long-term work in high-temperature device environment.
· PLC increased the degree of automation equipment system control.

In the field of knitting machinery, especially in the field of circular knitting machine, a growing emphasis on versatility of the device, namely, a machine capable of weaving a variety of products, without the need for major changes to the machine without taking up more the conversion time and more spare parts. In this regard because of knitted product variety and more frequent changes, manufacturers must continually adapt to market changes in a timely manner to produce a market need, but do not need to put more equipment and funds; on the other hand, new increasingly high price knitting machine with a machine only produces a product is difficult to give full play to investment returns.

Versatile knitting machine mainly through standardization of parts, universal, so after a quick change into a variety of basic models of similar models:

1. single/double knitting machine interchangeable
Single jersey machines often require assistance needles sinker loop and stitch back into the ring, while the traditional single-sided double jersey knitting machine for the product, because there is no normal sinker device is difficult to weave. Now generally taken two approaches to solve this problem, one is the most circular machines are equipped with double-sided anti-channeling triangle, that when the next knitting needle, the needle can elongation of some outward and return before lapping go Thus, the elongation can be used as a grip on the needle sinker increase the pressure in the needle back loop of the old loop, the old loop to prevent the rise along with the needle; another more effective method is two-sided with a sinker round machine, it is also in the double-sided circular machine sinker device installed, to assist the needles into the ring. Thus, one can in the double-sided knitted fabric, no cloth hanging, automatic start, there is easily restored when knitting cloth, or larger holes out; the other hand, in the fabric can be woven like a single-sided machine as the use of sinker machine needles help ring and stitch back into the ring, so as to achieve the purpose of single-sided machine interchangeable.

2. the structure of single jersey machine swap
According to the weaving of different products, single latch needle knitting machines can be divided into single jersey circular knitting machines, single-sided three-wire and single-sided terry velvet weaving machines machines. Now due to the rack, triangle and other basic parts to achieve the standardization and universal, among the manufacturers of these models by simply replacing the triangle and some parts of the transition from one model to another model . Just an engineering technician with 2 ~ 3h to complete their interchangeable.

3.Interchange between double knit machine
Sided knitting machine, rib style is usually divided into two categories and cotton, in each category, but also produce some changes or changes in rib cotton, rib composite tissue or cotton composite tissue by transforming triangle triangular structure, depending on the location such as Milano rib, polyester cotton cover, honeycomb mesh and so on. Sided versatile knitting machine, in addition to be interchanged between the rib and cotton, but also can be easily interchanged between the various organizations that species change very convenient.

To accommodate this change, multi-sided circular machine types in addition to the traditional triangle into a circle, tuck and float, but also increased the anti-channeling triangle, you can have a synchronous or lag in the triangle into a circle to circle. Channeling triangle weaving course for single-sided, on the syringe into a circle with a triangle can be separately lag and synchronization into a circle and a triangle to a wide rib knit interlock class organization.

4. the number and the cylinder diameter knitting machine replacement
In order to adapt to different seasons can be used on the same machine with different thicknesses woven products, the replacement machine number has practical significance for manufacturers. In order to meet this demand manufacturers, machinery manufacturers are now many will replace the cylinder and dial work greatly simplified, as the previous “X”-shaped rack into a “V”-shaped frame, so that the past can only replace the syringe from the top, from the side to be replaced now, without disassembly of the machine as big. As can be interchanged from the machine interlock between E18 ~ E28, and without the need to replace the yarn guide triangle.

1. structural analysis of circular knitting machine Transmission

To solve this problem, we must first understand the current transmission methods and principles of several commonly used on the market, analyze their strengths and weaknesses.

1.1 wear-plate structure
Wear-plate structure, also known as the slider type, shown in Figure 1.

This configuration process is simple, low cost, its disadvantage is that a large load. On the one hand, sliding friction and wear piece crankset between will have a greater load; the other hand, due to the small gap with the broader market ended the mouth and tooth plate, when the machine is running friction between the tape and dental plate generates heat , resulting in expansion of the outer tooth plate, resulting in increased load, if the gap is enlarged, will affect the radial positioning accuracy. Further, the friction between the parts subject to wear of parts, especially at the outlet of the wear stop, directly reduces the radial positioning accuracy, it is extremely difficult to repair. Although the wear plate and ended the mouth using a range of new wear-resistant materials such as Teflon, especially, greatly reducing the wear and tear, but the load is unavoidable, especially during cold start-up. In addition, because crankset rely on the market since the weight of the performance of its poor resistance to axial impact.

1.2 Modular structure of steel track
This structure is similar to the structure of the wear plate, and the steel balls instead of just using the wear plate, the sliding friction to rolling friction variation, shown in Figure 2.

And wear plate structure, as this structure is also relying crankset on the market since the weight, so the poor performance of its anti-axial impact. There is a saying that: Due to the structure of the load is too light, high-speed operation when the machine will produce buoyancy crankset rise, while another theory is that this phenomenon does not exist, when the rotating cranks level, will produce buoyancy However, this depends on the size and direction of the buoyancy of the shape and speed crankset to crankset now the situation knitting machine, but also unable to produce so crankset overcome its own weight increase buoyancy. Further, this structure requires high machining accuracy, the manufacturing cost is high.

1.3 Hanging wire runway structure
This structure is different from the first two shown in Figure 3.

This structure not only run a small load, but a strong performance anti-axial and radial shocks. After the machine long run, due to the wear of the wire and the ball leaving the running accuracy crankset reduced (ie, in the case of poor stability issues raised), then you can resume running accuracy Withdrawal gasket dental plate. By this structure requires high manufacturing precision machining techniques to ensure its manufacturing cost is also high.

2. circular knitting machine FAQ

Understanding the structure of these three kinds of work we can easily find that operating performance steel structure to be far better than the runway wear-plate structure.

In actual operation, the part of the track structure using steel machine running accuracy indeed exist decline (ie, poor stability) situation. The reason is due to higher steel track structure requires precision machining and assembly technology, the machine can not be reached in many parts manufacturing or assembling precision due, not structural problems. Currently on the market, most of the Japanese production of circular machines use more runway stacking steel structures, European countries (such as Germany) production of circular machines use more runway hanging wire structure, reduced accuracy problems were not there. Fundamentally speaking, the use of structural steel circular runway appeared precision machine design drop phenomenon is not part of the problem, but the processing, manufacturing, material selection and other aspects of the problem.

Choose what kind of structure, and machine manufacturers design, manufacturing ability. From the practical effects look, wear plate structure compared to the original, stacking steel track structure design is reasonable, and hanging wire track structure is most reasonable, but also three kinds of structures in the most advanced.

Thus, to ensure the stability of the machine precision, the need to understand the quality of each brand and market reaction at the time of purchase the machine, do not blindly freeloaders or believe in advertising, marketing. In addition, with energy prices rising, the cost of electricity in weaving the proportion is growing, low-power performance advantages of steel structures on the runway more obvious. Therefore, the use of steel circular knitting runway transmission structure is the inevitable trend of future development.