How to solve rubber cot winding problems in cotton spinning

How to solve rubber cot winding problems in cotton spinning

The process of cot winding on the rubber cots first involves a single fiber that is free on the surface of the yarn being adsorbed onto the surface of the rubber cots. Exerting adhesive tape on other fibers on the surface of the yarn, causing more and more fibers to adhere to the surface of the rubber cots, resulting in the phenomenon of winding fibers on the rubber cots. The causes of rubber cots entanglement include internal factors such as the performance, grinding process, and maintenance of the rubber cot itself,  as well as external factors such as raw material properties, environmental temperature and humidity, and yarn breakage.  Specific analysis is needed to determine which one or several reasons are causing the rubber cot winding phenomenon, and corresponding solutions should be formulated based on the analyzed reasons.

cotton spinning

Internal cause analysis

1.1 Self reasons to solve rubber cot winding problem

In the spinning process of fine yarn rubber cots, in order to ensure the quality of yarn and improve the performance of rubbers. Rubber tube manufacturers have added different amounts of anti-static, anti-aging and other additives to the production materials according to the purpose of the rubber cots.

Therefore, different manufacturers, types and even batches of rubber cots have different adaptability to the production workshop environment, resulting in different degrees of entanglement of the rubber cots.

• The hardness and elasticity of rubber rollers. Soft elastic rubber rollers with low hardness and elasticity, under the pressure of the rocking frame, form a curved channel with the roller clamp. The fibers pass through the curved channel and move forward along the inertia of the curved surface. The fibers tend to rotate around the rubber roller, which easily leads to the phenomenon.
• Friction factor (roughness) of rubber cot Rubber cots with rough, sticky surface and high friction coefficient are prone to sticking short fibers, resulting in entanglement. Generally, under the same grinding conditions, the surface roughness of soft elastic rubber cot is higher than that of high hardness low elastic rubber rollers.
• The conductivity of rubber rollers. The conductivity of rubber cot is the main factor affecting their resistance to “dry winding”. When the static electricity dissipation of rubber cot is poor and static electricity accumulates to a certain extent, it will adsorb fibers.
• The moisture absorption and release performance of rubber rollers. The moisture absorption and release performance of the rubber cot is the main factor affecting its resistance to “wet wrapping”. When moisture accumulates on the surface of the rubber cot in the air or fibers, it weakens the control fiber performance of the rubber cot and is more prone to the phenomenon of rubber roller entanglement.
• The anti fouling performance of rubber cot The anti fouling performance of rubber cot is one of the factors affecting their anti winding performance. The wax accumulated on the surface of cotton cots will stick to the fibers, and the oil and grease from synthetic fibers will also stick to the surface of rubber cots under the combined force of chemical bonds.
• Wear resistance. The wear resistance of rubber cots is an important factor affecting their lifespan. After using the rubber roller for a period of time, it is prone to wear and dents at the yarn guide stroke, resulting in a decrease in the gripping force of the jaws. At the same time, the roughness of the rubber roller wear area increases, making it easy to wrap around.
• The aging resistance. The rubber cot begins to decline from the moment it is made and used, with a gradual increase in hardness and a decrease in elasticity. The control over fibers weakens, and in severe cases, the surface of the rubber roller may crack, leading to fiber adhesion.

Rubber cot

1.2 Reasons for the production and maintenance of rubber cots.

1.2.1 The grinding process on the surface roughness of rubber rollers. The surface roughness of rubber rollers is an important reason for the entanglement of rubber cots. Using different grinding processes for the same type of rubber roller can obtain different surface roughness values, thereby changing the performance of the rubber roller.

• The influence of grinding wheel types on the surface roughness of rubber cots. Rubber cot is a polymer material mainly composed of nitrile rubber, with extremely poor thermal conductivity. As the grinding time increases, the temperature of the rubber cot rises and the temperature of the grinding wheel also gradually increases. However, excessively high temperatures can cause the anti-static agent contained in the rubber roller to overflow, resulting in a decrease in the anti winding performance of the rubber cot and causing the phenomenon.
• The influence of the number of grinding cycles on the surface roughness of rubber cots. The number of times the rubber cot is sharpened is closely related to the surface roughness, but the more times the rubber cot is sharpened, the better. The squeezing friction between the cot and the grinding wheel causes the rubber cot and the grinding wheel to heat up, and the rubber cot expands due to heat. As the number of grinding cycles increases, the grinding amount decreases, and the rubber roller gradually cools down and retreats. At this time, increasing the grinding cycle puts the rubber cot and the grinding wheel in a quasi contact and non-contact state, causing damage to the surface roughness of the rubber cot, resulting in an increase in roughness unevenness and an increase in the phenomenon of rubber cot entanglement.
• The influence of grinding feed on the surface roughness of rubber cot The amount of grinding feed of the rubber cotdirectly affects the surface roughness Ra value of the rubber cot, and has an impact on the uniformity of the surface roughness of the cot. Excessive grinding feed can increase the compression friction between the rubber cot and the grinding wheel, causing the surface temperature of the rubber cot to reach around 200 ℃, which can cause burns to the surface of the rubber roller and seriously affect its surface roughness.

External factor analysis

2.1 The influence of spinning equipment on the entanglement of cots wrapping with fibers.

• The breakage of fine yarn has a direct impact on the entanglement of rubber cots, and there are many reasons for yarn breakage, including stretching process, tension winding, and steel ring and ring traveller selection. However, all fine yarn breakage has a common feature, which is to greatly increase the probability of rubber cot entanglement
• A good blowing and suction cleaning device can timely blow away flying flowers and short fibers adhered to the surface of the rubber cot, keeping it in a clean working state and effectively reducing the occurrence of entanglement of the cot.
• When the position between the flute tube and the top roller is too large or there is a blockage of the cotton eye, the flute tube cannot timely suck up the broken fibers, which will cause fibers winding on the rubber.
• The improper installation position of the ring frame hanger resulted in the coarse yarn strip touching the support foot of the yarn guide rod; The spinning frame guide rod has burrs, damaged horn mouth and other scratches on the surface of the coarse yarn, causing the surface of the coarse yarn to become fuzzy and increasing the chance of the rubber roller wrapping fibers.
• The use of the top cleaner roller in spinning frame can timely remove free fibers stuck on the rubber cot, and reduce the interference of free fibers on other fibers in the yarn strip, greatly reducing the phenomenon of rubber cot entanglement.

2.2  The influence of spinning process reasons on the wrapping fibers of rubber cot.

• In the process of opening and cleaning cotton(blow room machines), excessive opening strength and severe fiber damaged. The bending rigidity, fracture strength, elongation and other performance indicators of the fibers change, which can easily lead to short fibers in the subsequent processing, resulting in the phenomenon of winding rubber.

The opening points configured in the cotton cleaning process are too few, the opening degree is not enough, and the effect of removing impurities and short fibers is poor, which increases the combing load of the carding process, affects the combing quality of the carding machine, and easily causes too many short fibers, cotton knots, and impurities in the raw strips. In the later processing process, it is also easy to produce entanglement of the rubber cots.

• The twist of the roving yarn is too small, resulting in poor grip and force between the fibers of the roving. The surface fibers of the roving are fluffy, which exacerbates the phenomenon of entanglement on the rubber
• When the speed of the spinning machine is high, it is easy to carry away the free fibers in the loose yarn strip passing through the stretching front area and attach them to the surface of the rubber cots. As the fibers accumulate on the surface of the rubber cot,
• The smaller the diameter of the rubber roller, the higher the surface linear velocity of the rubber cotat the same roller speed, and the higher the chance.
• The small spacing between the top roller of the spinning machine, the large thickness of the bottom ring, and the low tension of the tension frame result in a small distance between the lower ring and the top roller. The fibers adhered to the rubber ring are prone to accumulate, causing the rubber roller to become tangled

Conclusion

Rubber cots are crucial spinning equipment on ring frame machines, closely related to yarn quality, production efficiency, and other factors. There are many factors that affect the occurrence of rubber cot entanglement. When rubber cot entanglement occurs, it is necessary to carefully analyze and identify the cause, and take targeted measures to effectively control the occurrence of cot entanglement and improve the quality level of fine yarn production.