Spirality (skew) is the deviation of wales/courses from the vertical axis after washing, and its root cause is residual yarn torque in single jersey knitting; edge curling is the torque of an unbalanced single-faced (single jersey) structure. Both "originate" at the knitting stage but are largely controlled at the finishing stage: through compacting, heat-setting and controlled relaxation, the accumulated tension in the yarn is released and the structure is balanced. At a single coordinator like KARCEM — knitting in-house and steering dyeing and finishing through a vetted contract network under one point of contact — these parameters are adjusted at the source. A typical buyer specification requires ≤5% spirality after washing.
What exactly is spirality and why does it occur?
Spirality is when the wale and course lines in a knit fabric take on an angled position instead of remaining perpendicular to each other. It usually stays hidden in the greige fabric and is revealed when the tension in the yarn is released by the first wash/relaxation. The actual mechanism is as follows: in a single jersey structure the loops form in one direction, and when the residual torque accumulated during yarn twisting is released, it rotates the loops. For this reason spirality is not a "surface defect" but essentially a yarn and structural balance problem. Our dimensional stability and spirality page, where we address the subject in a broader framework, lets you evaluate it together with shrinkage/relaxation behavior.
Which drivers increase spirality, and which reduce it?
The severity of spirality is the resultant of yarn properties and knitting parameters. Long loop length and a loose (low tightness factor) structure increase skew, while fine count yarn, balanced/plied (ply) yarn and the addition of elastane reduce it. The table below summarizes the main drivers along with their direction of effect.
| Driver | Direction of effect | Reason |
|---|---|---|
| Long loop length | Increases | Loose structure, loops follow the torque more freely |
| Low tightness factor (loose structure) | Increases | Structural resistance restraining the yarn's rotation is reduced |
| High single-yarn twist | Increases | Residual torque accumulated in the yarn rises |
| Fine count yarn | Reduces | Smaller loops/tighter structure limit the skew |
| Balanced / plied (ply) yarn | Reduces | Opposing twist neutralizes the residual torque |
| Addition of elastane (lycra) | Reduces | Recovery force keeps the structure in balance |
In practice, decisions on the yarn side (twist, count, plying) are made at the design stage; knitting tightness is fixed on the machine. We address the behavior of elastane qualities on the lycra/elastane knitting page, and the weight-tightness relationship on the weight/GSM guide page.
Why does edge curling occur and which structures are affected?
Edge curling is when the cut fabric edge rolls onto itself like a roll, and it results from the torque created by an unbalanced single-faced structure. Single-faced single jersey tends to curl at the edges: the top and bottom edges curl to the back, the side edges to the face. By contrast, double-faced and symmetric structures lie flat — interlock and rib structures, being balanced, keep their edges horizontal. For this reason edge curling is as much a structure-selection issue as it is a quality issue. You can see the differences between the structures comparatively on the single jersey vs interlock and 2x2 rib/rib differences pages; for the general family of knit fabrics, the knit fabric guide is the starting point.
How does finishing control these defects?
Although spirality and edge curling originate in the yarn/knitting, the place where they are controlled in a measurable way is the finishing line. KARCEM's finishing capacity uses the following levers:
- Compacting: Relaxes the fabric in a controlled way and removes mechanical tension; it improves dimensional stability while lowering the tendency to skew.
- Heat-setting: Especially in elastane and synthetic-content qualities, it fixes the structure under heat and permanently calms the residual torque.
- Controlled relaxation: Releases the fabric's tension until it reaches its natural balance; this way the defect is revealed and corrected on the line, not in the field.
- Balanced width + weight fixing: While setting the fabric to the target width and weight, a symmetric placement is achieved so that skew is minimized.
The sequential and correct combination of these steps provides a balance that cannot be achieved through yarn selection alone. You can find the details of the finishing steps, primarily compacting and sanforizing, on the finishing: sanforizing and compacting page, and the planning of finishing together with dyeing in the dyeing/printing guide. Coordinating in-house knitting with the contracted dyeing and finishing under one point of contact allows the parameters to be harmonized in one pass rather than round by round — the technical equivalent of this is on the coordinated contract network advantage page.
How is spirality measured and what limit is accepted?
Spirality is measured as angle/percentage shift after washing. The common standards are ISO 16322 (determination of skew after washing) and AATCC 179 (skew after automatic drying). The test is calculated from the deviation of reference lines marked on the fabric after specified wash cycles. A typical B2B buyer specification accepts ≤5% spirality after washing; stricter programs may require a lower threshold. For test methods in general, see the textile test standards page; you can find the controls on the fastness and color side on the color fastness and Delta E page (KARCEM's color control target is Delta E < 1).
| Topic | Standard / target | Note |
|---|---|---|
| Spirality (skew after washing) | ISO 16322 | Angular/percentage deviation of reference lines |
| Spirality (skew after drying) | AATCC 179 | Automatic drying-based method |
| Typical acceptance limit | ≤5% | May be stricter depending on the buyer |
How do you reduce spirality risk before sourcing?
The most effective approach is to prevent the defect at the design and sample stage rather than catching it at shipment: preferring balanced/plied yarn, selecting the tightness factor to suit the target weight, planning heat-setting for elastane qualities, and measuring skew after washing from the outset on an approved lab-dip/sample. This discipline reduces the risk of surprise returns when the batch grows. For control points on the sourcing side, you can refer to the quality and testing guide and the fastness testing (ISO/AATCC) pages. For definitions of terms, the Glossary page is helpful.