For worsted spinning mills, the quality of the raw material defines the efficiency of production and the hand-feel of the final yarn. While wool is the traditional staple, polyester sliver tops (also known as combed sliver) have become indispensable for creating durable, cost-effective, and functional blended yarns.
What are Polyester Sliver Tops?
Polyester tops are semi-finished textile products consisting of continuous polyester fibers that have been carded and combed. Unlike loose staple fiber which is randomly oriented, the fibers in a sliver are:
- Parallelized: Aligned in a single direction.
- Cleaned: Free from neps (entangled clumps) and short fibers.
- Continuous: Formed into a thick, untwisted rope (sliver) ready for drawing.
Key Terminology
Sliver: The rope-like strand of fibers.
Top: Specifically refers to sliver that has undergone the combing process (worsted system).
Tow: The precursor to tops—a thick bundle of continuous filaments before they are cut or broken into staple lengths.
Sliver vs. Loose Staple Fiber
The main difference lies in the processing stage. Loose staple fiber is sold in bales of randomly oriented fibers and requires opening, carding, and combing by the spinner. Sliver tops have already undergone these steps.
Mills that lack carding/combing capacity (or want to increase throughput) purchase tops directly to feed into their gill boxes and draw frames.
Key Specifications for Buyers
When sourcing polyester tops, four parameters are critical:
| Spec | Typical Range | Impact on Spinning |
|---|---|---|
| Cut Length | 76mm - 110mm | Must match the wool fiber length for even blending. |
| Fiber Fineness | 2.0D - 3.0D | Affects yarn count limit and softness (hand-feel). |
| Luster | Semi-Dull, Bright, Trilobal | Determines the shine of the final fabric. |
| Oil Content | 0.15% - 0.25% | Critical for static control and drafting smoothness. |
Applications in Worsted Spinning
The primary use case is wool blending. Polyester adds strength and wrinkle resistance to wool, while wool provides warmth and breathability. Common blends include:
- 45% Wool / 55% Polyester: The industry standard for corporate uniforms and suiting.
- 30% Wool / 70% Polyester: Cost-effective blend for trousers and skirts.
- 100% Polyester Worsted Yarn: Used for heavy-duty fabrics and sewing threads.
Why Source from Topsliver?
As a specialized brand under Yarnx, Topsliver focuses exclusively on export-grade combed sliver. We ensure:
- Consistency: Low C.V.% (Coefficient of Variation) ensures even yarn.
- Customization: We cut to 88mm or 102mm specifically for your machinery.
- Logistics: Vacuum packing available to maximize container load (8.5 - 9 tons/20GP).
Ready to test our quality?
View our product catalog or contact us for a sample bump.