The spinnability of polyester chips has a critical impact on filament production. Good spinnability of polyester chips results in strong adaptability to the process, a stable production process, and high quality of the processed products.
Characteristics of Spinnability Performance
1.Pressure Increase Rate of Pre-filters or Spinning Packs
The daily pressure increase rate should be less than 10% for high-speed spinning and less than 6% for conventional spinning. Otherwise, issues such as uneven dyeing, fluff, and thread breakage are likely to occur. A high pressure increase rate will also shorten the service life of pre-filters and spinning pack body, leading to other adverse effects.
2.Full Winding Ratio of Bobbins
The full winding ratio of bobbins reflects the frequency of breakage from the melt exiting the spinneret to the winding forming area. This is closely related to the fiber-forming properties of the polyester. Chips with good spinnability result in fewer breakages and a high full winding ratio (greater than 95%).
3.Drawing Breakage Rate and Roller Wrapping Rate
Under drawing tension, internal fiber defects are most easily exposed. For chips with good spinnability, both the breakage rate and roller wrapping rate during drawing are low.
4.False-Twist Texturing Breakage Rate
Most polyester filaments are used after false-twist texturing. Under texturing or draw-texturing tension, chips with poor spinnability exhibit a high breakage rate.
5.Physical Properties of Finished Products
The physical property indices of finished products are all related to spinnability, especially strength, elongation, and unevenness of yarn regularity. When chip spinnability is poor, strength and elongation are low, and the unevenness is high.
Pre-Spinning Judgment of Chip Spinnability
1.Appearance and Packaging of Chips
Chips with a smooth-cut cylindrical shape, moderate size, and low content of broken particles and powder are easy to screen cleanly. They produce less powder during the drying process, ensuring smooth screw feeding and minimal pressure fluctuation, which does not negatively affect spinnability. The chip packaging should prevent easy contamination and accumulation of dust, sediment, etc., during storage and transportation.
2.Color and Luster of Chips
Chips with uniform and bright color and luster generally exhibit good spinnability. If the color and luster are dull, unevenly bright, yellowish, or contain sandwiched carbonized particles, the spinnability is likely poor.
3.Quality Variation Between Batches
When sampling and testing chips within the same batch or between different batches, small differences in quality indices indicate good spinnability. Conversely, large differences suggest poor spinnability and unstable production.
4.Molecular Weight Distribution Index Practice has proven that when the α value, measured by gel permeation chromatography, is less than 2.0, the spinnability is good.
5.Differential Thermal Analysis
Chips exhibiting a high melt crystallization temperature, narrow peak distribution, or extremely sharp peaks generally have poor spinnability. Chips with a low melting temperature and broad, flat peak distribution usually demonstrate good spinnability.
6.Heat Resistance
Thermal degradation products of polyester are related to the heat resistance of the chips. A method for testing heat resistance involves placing two or more samples in an oven at 240°C for 4-7 hours and observing the color change. Significant color change indicates poor spinnability.
The spinnability of polyester chips significantly influences spinning quality. Futai Machinery Co., Ltd. provides Components of Texturizing Machines, Components for Synthetic Fiber Spinning Machine(including candle filter, metal powder, leaf disc filter, spin pack filter, filtration system, spin pack body, spinneret, metering pump), ceramic guide, and related auxiliary equipment. Our products can help customers improve their spinning quality.
Post time: Mar-12-2026