One. Test Material: White Knit Cutting Clips

• Source: Cutting room scraps from garment manufacturing

• Type: 100% cotton knit fabric pieces, a typical pre-industrial textile waste

• Representativeness: This type of waste is found in garment factories and textile mills worldwide – nearlevery spinning or weaving plant generates similar edge trims and offcuts

• Test Objective: Answer the most practical question – what quality level can a waste cotton cleaning line restore this waste to?

Two. What Are the Core Indicators of Recycled Fiber Quality?

In textile recycling, fiber quality is ultimately determined by several core metrics. If you're marketing reclaimed fiber to any spinning mill, they will ask these questions:

1.Are the fibers long enough? (Mean Length L(n))

Fiber length determines yarn strength and spinnability. Longer fibers produce stronger yarns with fewer breakages and higher spinning efficiency. For recycled fiber, the industry-recognized threshold is: if mean length reaches 20mm or above, the fiber qualifies for blending in rotor or ring spinning.

2.How much short fiber content? (Short Fiber Content – SFC)

SFC is the percentage of fibers shorter than 12.7mm. Short fibers tend to break during spinning, create fly and hairiness, and reduce yarn quality. The industry generally considers an SFC of around 15% as a desirable target for recycled cotton.

3. Are there hard contaminants? (Yarn/Fabric Fragment Count)

This is where recycled fibers most often fail. If the equipment doesn't open thoroughly, residual yarn pieces or fabric fragments entering the spinning process can cause yarn breakage, fabric defects, and even damage machinery. Fewer hard contaminants is always better.

4. How uniform is the fiber length? (Uniformity Index – UI)

The more uniform the fiber length distribution, the less waste generated during spinning, the higher the production efficiency, and the more consistent the yarn quality.

Three. What Did We Measure? – Comparative Analysis of Three Sample Sets

Fiber Length Parameters

Yarn/Fabric Fragment Removal Data

1. Mean Length – From 20.33mm to 22.07mm

Raw material after just 2 openers showed a mean fiber length of 20.33mm. This is a decent starting point, indicating the raw material itself is of reasonable quality. But after 5 cleaning stages, Sample 20's mean length increased to 22.07mm – an 8.6% improvement.

Why does cleaning make fibers "longer"? The cleaning process removes micro-dust and impurities adhering to fiber surfaces, allowing previously "entangled" fibers to fully extend, thus measuring at their true length. At the same time, well-designed cleaning equipment doesn't over-damage fibers, avoiding fiber breakage from mechanical impact.

2. Short Fiber Content – From 17.19% to 13.93%

This is one of the most impressive results from this test. 17.19% SFC is mid-to-high for recycled fiber, while 13.93% reaches the industry's "good" range.

The direct benefit of reduced SFC: when spinning this reclaimed cotton, breakage rates are lower, yarn hairiness is reduced, and yarn strength is higher. For spinning mills planning to blend 30%-50% recycled fiber into their cotton mix, this SFC level means they won't need to significantly adjust their process parameters.

3. Yarn Fragment Count – From 531 to 125

This data shows the largest improvement – a 76% reduction. The raw material (Sample 19) contained 531 unopened yarn fragments, accounting for 27.94% of the sample. This means over a quarter of the material in each gram was unopened yarn pieces rather than individual fibers.

After 5 cleaning stages, Sample 20 contained only 125 yarn fragments, down to 7.97%. By final output (Sample 21), only 15 remained – just 0.60%.

This demonstrates that the cleaning line's opening and impurity removal mechanisms effectively decompose fabric scraps into individual fibers, and the sorting mechanism removes residual hard contaminants.

4. Uniformity Index – From 77.64% to 79.46%

The Uniformity Index improved from 77.64% to 79.46%. Though the increase may appear modest, it's highly significant for spinning – more uniform fiber length distribution means fibers align more consistently during carding and drawing, drafting is more stable, and yarn evenness is improved.

Four. Why Are Sample 21's Fiber Indicators Slightly Lower Than Sample 20?

Readers examining the data may notice that final output (Sample 21) shows lower mean length (19.69mm) and higher SFC (18.65%) than the mid-stage sample (Sample 20).

This is not equipment "underperforming" – it's because Sample 20 and Sample 21 measure different materials:

• Sample 20: Material sampled before sorting – contains opened fibers + yarn fragments + fabric pieces. The unopened yarn fragments, being longer, pull the average length upward.

• Sample 21: Final output after sorting – all unopened hard contaminants have been removed, leaving only clean opened fibers.

Sample 21's slightly lower fiber length actually proves the system's sorting mechanism is working effectively – it removes those longer, unopened yarn fragments as "waste" rather than letting them pass through into the finished product.

This is actually a positive quality control signal: the final output contains no "undeserved" hard contaminants – every fiber is genuinely opened and qualified for re-spinning.

From Sample 19 to Sample 20, fiber quality showed quantifiable improvements across four dimensions:

Five. From Data to Business – What This Means for Recyclers

If you're a textile recycling company evaluating investment in waste cotton cleaning equipment, or marketing reclaimed fiber to spinning mills – these three business conclusions may be more useful than technical specifications:

1. Quality Determines Price: Every 1mm increase in fiber length translates to a measurable uplift in reclaimed cotton market value. The 0.91mm fiber length improvement in this test directly translates to a product grade upgrade.

2. GRS Certification Requires Data Support: More and more international brands require suppliers to hold GRS (Global Recycled Standard) certification, and GRS certification hinges on "traceability of recycled materials" and "quality stability." AFIS test data provides the hard evidence to support these certification requirements.

3.The Core Question Spinning Mills Ask: "Can We Run It As-Is?" With SFC at 13.93% and only 125 yarn fragments, this reclaimed fiber can be fed into production at blend ratios without major process modifications – for spinning mills, that means "less hassle" and "cost savings."

A properly designed waste cotton cleaning line quantifiably improves reclaimed fiber quality across multiple dimensions – transforming textile waste that was once landfilled or downcycled into material qualified to re-enter the spinning room. Not based on feel. Not based on claims. Based on numbers.