When the cylinder is inlaid, the cylinder rack cannot effectively puncture, open and comb the cotton whiskers. It will also rub and cut the spinnable fibers, which will increase the effective fiber content in the combed waste and reduce the quality of the waste. A large number of production tests have shown that: poor condition of the cylinder and top comb, damage to the teeth, and intarsia will increase production costs and reduce yarn quality.
So, what are the causes of cylinder inlay?
Impact of raw materials
1) When processing raw cotton with high sugar content (such as PIMA with sugar content above 2.7), the sugar will liquefy due to heat and moisture absorption, and the precipitated viscous substance will adhere to the gaps between the cylinder teeth to form inlays.
2) Long-staple cotton has long fiber length, fineness, and large friction coefficient between fibers. It wears the cylinder needle teeth quickly and easily causes cylinder inlays.
The influence of process on machine
1) The configuration of the preparation process is unreasonable (for example, the variable-speed carding and combing machine adopts the backward cotton feeding process), the small volume is too heavy, the transverse uniformity of the small volume is not good, the fiber straightness in the small volume is poor, and the workshop is relatively Higher humidity will cause greater stress on the first row of cylinder pins, making them prone to wear and broken teeth, resulting in the first row of cylinder teeth being inlaid.
2) Some companies make the cylinder carding spacing very small, which aggravates the damage to the cylinder card clothing and leads to intarsia.
3) The depth of the brush penetrating into the cylinder, the gap between the brush and the triangular airflow plate, the linear speed ratio between the brush and the cylinder, etc. do not meet the process requirements, which affects the cleaning effect of the brush on the cylinder teeth.
4) The elasticity and fineness of the brown bristles of the brush are improperly selected, which affects the cleaning effect of the brush on the cylinder teeth.
The sharpness and wear resistance of the needle teeth, the surface roughness of the needle and the tooth density arrangement
1) Affected by the theory of “sparse in the front and dense in the back, progressive combing”, the density of cylinder teeth is usually too thin in the two groups of rack needles in the front half area, resulting in too weak combing ability in the front half, and the combing load is too concentrated on the middle and back combing. area, resulting in the first row of needle intarsia in each group.
This phenomenon is particularly obvious on variable speed carding and combing machines. If the density of adjacent two sets of cylinder racks is very different and the tooth density transition is unreasonable, it is easy to cause the first row of needles in the transition area to have crooked teeth, broken teeth, and inlays.
2) The choice of the brand of combed cylinder and the configuration of the speed are very important. The material and heat treatment process of cylinder card clothing are not ideal, and the hardness of the tooth tip is low, which can easily cause fatigue fracture of the tooth tip, low sharpness of the card clothing and short impaction. Velvet and impurities. In particular, in order to increase the total number of combing points in the cylinder, some combing and carding element manufacturers have designed increasingly thinner teeth, which reduce the strength of the teeth and make it difficult to adapt to high-speed, heavy-weight process requirements, especially when producing long-staple cotton. The first row of gears in the first three sets of racks will quickly wear, break, and become embedded.
3) The surface roughness of the needle is not good, the combing channel is astringent, and it is easy to cause mosaic.
Irregular operating methods
1) The method of correcting the cylinder combing gap is not standardized. For example, when the nipper plate opening is large and the combing gap is corrected, the corrected combing gap value will be larger than the normal value (the upper and lower nipper lips are not completely closed). When it is necessary to increase the combing noil gauge, it is easy to reduce the carding gauge or the clamping lip of the nip plate to the cylinder to connect with the needle.
2) Some companies only correct the carding spacing of the two sets of racks at the entrance and exit, but do not correct the spacing at the tightest spacing point (39-40 degrees), resulting in a smaller spacing at the tightest point of the cylinder and poor quality on the clamping plate. The pliers lip connects the needle with the cylinder.
3) If the upper pliers lip is not completely cleaned, correct the cylinder combing gap. Once the debris embedded in the upper and lower pliers lips falls, the cylinder combing gap will shrink sharply, and even the upper pliers lip and the cylinder will contact the needle.
4) The oil nozzle is clogged, the oil nozzle is missing, and the oil is not refueled in place, resulting in dry grinding of the machine parts, wear of the cylinder shaft and the upper and lower bearings of the front swing arm of the lower nip plate, and the sinking of the nip plate, causing the upper nip plate clamp lip to contact the cylinder. Needle.
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