Common failures and cause analysis of NEUMAG Crimper

Abstract: Introduced the working principle, main structure and common failures of the NRUMAG heavy-duty crimper for polyester staple fiber. Analyze the causes of failures based on actual production experience and propose methods to deal with common failures. Some factors affecting the crimper effect of tow are proposed.

Keywords: Crimper crimping roller stuffer box Crimping blade/knife Unibest/ TXMC

I. Overview

In the Staple Fiber Finishing line (Drawing line), the Staple Fiber Crimper is one of the important machine. The Fiber spinnability, feel, and wearability will be greatly enhanced after crimping by the Crimper,. NEUMAG Crimper is mainly composed of crimping head, stuffer box and crimping knife. The crimping head is a rigid torque casting structure, consisting of a pair of crimping rollers, a stuffer box and two Swing arms. When replacing the Crimper roller, the two Swing arms can rotate 180° at the same time to meet the needs of convenient disassembly. The crimping roller has high surface hardness and is equipped with a temperature control system to adjust its required surface temperature. The upper Crimper roller is mounted on the Swing arm hinged with the crimper head, and the contact with the down roller can be realized through the action of the connecting rod and the air cylinder. The stuffer box is made of phosphor bronze or stainless steel, and the width of the crimped stuffer box is gradually increased from 260-560mm to 20mm to meet the needs of production. The function of the crimping knife is to shovel the tow from the crimping roller. The tow is shoveled from the crimping roller. The surface of the crimping knife and the crimping roller must maintain a tiny gap so that both are not worn. This requires a thinner blade. At the same time, the strength should be high. The diameter and width of the crimping roller of the NEUMAG Crimper are relatively large, and the probability of failure of the Crimper is also greater. In actual production, the crimping blade and the crimping roller are often damaged due to various reasons.

2. Working principle of NEUMAG Crimper

The crimping method of the crimper can generally be divided into groove roll crimping and stuffer box crimping. At present, the crimping method adopted by the Staple fiber device is stuffer box crimping. The principle can be expressed as: the crimped tow is fed into the crimping head through a feed hopper that can be finely adjusted according to the thickness of the tow, the tow is held by the crimping roller, and pushed into the stuffer box at the operating speed, and the upper crimping roller The thrust to feed the tow into the stuffer box comes from the pressure of the lower crimping roller against the upper crimping roller, and the upper plate of the stuffer box squeezes the tow to produce a blocking force in the stuffing box. This blocking force makes the tow form in the stuffing box With a “plug”, the continuously input tow and the “plug” are squeezed against wrinkles to produce a crimper effect.

3. Main composition structure and characteristics

1. Crimper roller

The crimping roller is made of chromium molybdenum stainless steel alloy, and the surface requires high strength. The shaft of the lower crimping roller is located on the fixed frame, and the upper crimping roller is mounted on the Swing arm hinged with the crimping head, and the contact with the lower crimping roller can be realized through the action of the connecting rod and the air cylinder. The upper and lower crimping rollers clamp the tow by the pressure of the pressure mechanism. When the crimping roller rotates, the tow enters the stuffer box under the action of friction caused by the positive pressure. Warm water can be passed through the hole of the crimping roller for circulating cooling to prevent the surface temperature of the crimping roller from rising, and to prevent the tow from sticking to the surface of the crimping roller or bonding with each other, affecting the crimping effect.

2. Stuffed box

The stuffer box is mainly composed of an upper knife assembled on the second Swing arm, a lower knife connected to the lower part of the crimping head, two large side plates and side plates on both sides of the crimping roller. The stuffer box is the main space for tow crimping, and its size adjustment directly affects the crimping quality. The adjustment of the stuffer box includes the adjustment of the height of the box and the height of the outlet. The side plate is fixed during the crimping process. The stuffer box is sealed by a hydraulic push plate in the crimping roller area. There are small holes on the bottom of the stuffer box. The saturated steam is directly sprayed on the crimped tow through the small holes, which greatly improves In order to achieve the crimper effect, the steam discharge hole can discharge the steam in the stuffer box.

3. Crimper knife

The function of the crimping knife is to shovel the tow on the rotating crimping roller from the crimping roller. There must be a very small gap between the crimping knife and the surface of the crimping roller to prevent the crimping roller and the cutter head from being worn during operation. The blade is required to be thinner and strong. In order to improve the strength of the cutter head, it is generally necessary to heat the cutter head.

The crimper of the NEUMAG crimper adopts a split design, which is divided into two parts, the head and the body, which are connected by bolts. In the process of use, the cutter head is always affected by friction, so the damage rate of the cutter head is relatively high. In the overall design, if the cutter head is damaged, it must be replaced as a whole. After adopting the split design, replace the crimper knife At this time, only the cutter head can be replaced while the cutter body is retained, which also saves a lot of money. However, this design has strict requirements on the matching accuracy of the two parts. In addition, when processing the cutter body, the cutter head is slightly smaller than the cutter body, so that there is no gap between the side plate and the cutter head when the side plate is installed. , To prevent tow clamping.

4. Analysis of common failure causes of NEUMAG Crimper

1. The surface of the Crimper roller is severely worn.

The reasons for this failure are: (1) The crimping roller jumps due to the hard crimping tow. (2) The crimping knife is not fixed firmly, causing the crimping roller to directly contact with the crimping knife, causing scratches to the crimping roller. (3) The gap between the crimping knife and the crimping roller is too large, which leads to the failure of the crimping knife. The tow cannot be peeled from the crimping roller in operation, which causes the winding of the tow and increases the surface wear of the crimping roller. (4) The effect of tow stacking is poor. The thickness of the tow entering the Crimper is uneven or there is a slurry block in the tow, which causes the crimping roller to vibrate, resulting in uneven wear on the surface of the crimping roller.

2. The surface of the Crimper roller is cracked

The reasons for this failure are: (1) The temperature of the tow entering the Crimper is too low, resulting in an excessive difference between the surface temperature of the crimping roller and the temperature of the crimping tow, resulting in an excessively large temperature difference between the relative surface of the crimping roller in operation, and hardening treatment Residual stress is generated on the surface of the crimping roller, and it is easy to cause cracks on the surface of the crimping roller after a certain period of operation. (2) The warm water circulating cooling system of the crimping roller fails, which makes the cooling effect of the crimping roller in operation poor, and forces the temperature of the crimping roller to be greatly increased by the temperature of the crimping tow. After a certain period of continuous operation, the crimping roller is cracked.

3. Damaged roller bearing

The reasons for this failure are: (1) Long-term non-lubrication or deterioration of lubricating oil in the bearing of the crimping roller has aggravated the damage of the bearing. (2) Due to the hard tow, pulp block, etc., frequent roll skipping of the crimper occurs. Each runout will cause the bearing and the shaft to collide, which will cause great damage to the bearing. (3) The gap between the crimping roller shaft and the bearing becomes larger, so the shaft and the bearing will inevitably be impacted during operation, which will cause the bearing to aggravate and damage.

4. The crimper knife has a chipped edge

The reasons for this failure are: (1) The tow entering the Crimper contains lumps, hard filaments, and foreign matter. When the crimper is running at a high speed, the blade will have a gap when it impacts and damage the blade. (2) The crimper knife itself has insufficient heat treatment process requirements. The crimper knife edge should be relatively thin, and the strength must be high, and it must undergo a certain heat treatment. If it does not meet the technological requirements, the blade will become soft when the cutter head is used for a long time to scrape the tow, and the fast passing tow will damage the blade.

5. The Crimper roller frequently jumps

The reasons for this failure are: (1) The tow entering the crimper contains hard filaments. (2) The stacking machine does not stack the filaments uniformly, resulting in inconsistent thickness of the tow entering the crimper, and it is also easy to cause the crimping roller to jump frequently. (3) The width and position of the tow before crimping are not standard. (4) In addition, factors such as tow clamping, back pressure, and the temperature of the preheating box that cannot meet the technological requirements in the crimping can easily cause the crimping roller to jump frequently.

5. Factors affecting crimper effect

In order to obtain the best crimping performance, the pressure between the crimping rollers and the pressure of the upper plate of the stuffer box can be adjusted, and the saturated steam of the fiber material can be supplied through the fine holes. When the linear pressure between the crimping rollers is not affected by the back pressure of the stuffer box, a very uniform crimping effect can be obtained. The special hinged design of the back pressure cylinder on the upper plate of the stuffer box of the heavy-duty Crimper prevents the pivot shaft of the upper plate of the stuffer box from being generated. The reaction force, so as to achieve the purpose that the back pressure of the stuffer box does not affect the main pressure of the crimping roller. In addition, the diameter and width of the crimping roller will affect the crimp and the number of crimps to a certain extent. From the actual production experience, generally when the diameter of the crimping roller is small, the crimping ripples are finer, and the size of the crimping roller diameter mainly affects the primary crimping of the tow.

6. Conclusion

In summary, through the analysis of common failure causes of NEUMAG crimper, we can have a more in-depth understanding of the performance of the crimper. Some common failures can often be prevented to minimize the loss, which requires us to strengthen the crimper. Routine maintenance, regular inspection of equipment, regular monitoring of equipment temperature, vibration, abnormal noise and other problems, and timely handling of problems found. In addition, it is necessary to ensure a good equipment lubrication system to lay the foundation for long-term continuous operation of the equipment.

Complete Polyester Staple Fiber (PSF) Production Line Manufacturer-TXMC  
Zhangjiagang Tengxiang Machinery Co., Ltd.


www.txmc.com.cn

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