Drop needle is a rib with needles taken out to make vertical lines, and almost all of it in our records has elastane. Here is the route for each fibre, from greige fabric to the cutting table.
At a glance
72Parts in our records
230Median required GSM
41%Within GSM tolerance
9%Viscose drop needle median length shrinkage
Drop needle fabric is knitted with some needles left out of action, so a wale is missing at regular intervals and the fabric shows vertical lines or channels. Most of it is a Lycra rib (drop needle rib); some is built on interlock. It is used for fitted ladies’ tops, where the lines and the stretch are the point of the fabric.
| Type in our records | Parts |
|---|---|
| L/Drop Needle Rib | 36 |
| Ly Drop Needle Rib | 4 |
| L/Drop Needle Design Rib | 4 |
| Drop Needle Interlock | 4 |
| Drop Needle Rib | 3 |
| Yd L/Drop Needle Rib | 3 |
| 4X4 Ly Drop Needle Rib | 3 |
| Ly Drop Needle Design Rib | 2 |
By fibre: what our records show
| Fibre or blend | Parts | Median required GSM | Within ±5% GSM | More than 5% light | Median length shrinkage | Median width shrinkage | Heat set |
|---|---|---|---|---|---|---|---|
| Polyester-viscose | 26 | 260 | 80% | 20% | 2% | 2% | 92% |
| Viscose | 15 | 220 | 7% | 80% | 9% | 2% | 87% |
| Cotton-elastane | 14 | 225 | 29% | 71% | 4% | 10% | 100% |
| CVC / PC | 6 | 240 | 60% | 40% | 3% | 2% | 100% |
Polyester-viscose with elastane is the largest group, 26 parts, and 80% of it finishes within GSM tolerance. Viscose drop needle is the hard one: median length shrinkage 9%, and only 7% within GSM tolerance.
Our records hold fewer parts of this fabric than of the common knits, so read the figures as a guide, not a rule.
What makes drop needle different
The vertical lines are the design. Dyeing and finishing must keep them straight and clear, control the width, and avoid crease marks.
Lycra drop needle is not always heat set. It is heat set when the elastane or the dimensional stability requires it, open width at 180–190°C.
Viscose drop needle has higher relaxation and wet shrinkage than polyester-viscose, so its GSM changes more after finishing. It is controlled through stitch length and Lycra feed in knitting, then relaxation, dryer overfeed, width and compaction in finishing. Viscose also gets a mild scour at 70–80°C, a hot wash of 80°C at most, and no enzyme.
The sequence before the dyeing machine
Every chart below follows the same sequence before dyeing. Steps a fabric does not need simply drop out; they are drawn dashed.
- Greige inspection, then batching. A fabric that stays a tube is turned inside out here.
- If it needs heat setting, singeing or mercerising: slitting first. None of these is ever done on a tube.
- If it needs heat setting: heat setting in open width.
- If it needs singeing: singeing in open width, after checking the flame cannot damage the fabric.
- If it is mercerised: mercerising, then drying.
- If the fabric was opened: back sewing, to make it a tube again with the face side inside (the loop side, for terry).
- Loading into the dyeing machine, then scouring, bleaching and dyeing, single part or double part as the fibre needs.
Flowcharts by fibre
- Polyester-viscose drop needle rib
- Viscose drop needle rib
- Cotton-elastane drop needle rib
- CVC / PC drop needle rib
Polyester-viscose drop needle rib
In our records: 26 parts, 80% within GSM tolerance, median length shrinkage 2%, heat set 92%. Full process: Polyester-viscose dyeing process.
Dyeing and finishing: Polyester-viscose drop needle rib
Viscose drop needle rib
In our records: 15 parts, 7% within GSM tolerance, median length shrinkage 9%, heat set 87%. Full process: Viscose dyeing process.
Dyeing and finishing: Viscose drop needle rib
Cotton-elastane drop needle rib
In our records: 14 parts, 29% within GSM tolerance, median length shrinkage 4%, heat set 100%. Full process: Cotton-elastane dyeing process.
Dyeing and finishing: Cotton-elastane drop needle rib
CVC / PC drop needle rib
In our records: 6 parts, 60% within GSM tolerance, median length shrinkage 3%, heat set 100%. Full process: CVC / PC dyeing process.
Dyeing and finishing: CVC / PC drop needle rib
Common faults and buyer complaints
Lines distorted. Control tension and feed through finishing so the lines stay straight.
GSM variation. Control stitch length and Lycra feed in knitting, and width and overfeed in finishing.
Width and shrinkage. Optimise dryer overfeed and compaction.
Crease marks. Gentle handling and full relaxation.
Spirality. Balance knitting and finishing tension.
Needle and drop faults. A knitting fault: check the needles, sinkers and feeders before the fabric reaches dyeing.
Textile engineer with 14+ years in dyeing and fabric development. He writes every guide on Dyeing Solution from real production work. Full profile