Circularity in Knitting: The Potential of Re-Using Natural Yarns After Unraveling

Figures & data

Figure 1. Photos of yarn used in research: (a) cotton; (b) wool.

Figure 2. Half Milano rib structure: a – graphical representation; b − 3D model.

Figure 3. Photos of fabrics used in research: (a) cotton; (b) wool.

Table 1. Structural characteristics of knitted fabric.

Characteristics		Yarn type
		74 tex cotton	72 tex wool
Stitch density, loops per sq.cm	front	60 ± 2.5	50 ± 2.1
	back	32 ± 1.1	27 ± 0.8
Stitch lengh, mm	rib	5.77 ± 0.05	5.16 ± 0.08
	plain	5.65 ± 0.06	5.56 ± 0.05
Basis weight, gram per sq. m		234.3 ± 5.7	188.5 ± 6.4
Thickness, mm		1.43 ± 0.08	1.40 ± 0.05

Figure 4. Normal distribution of breaking force values (F_o): a − 74 tex cotton yarn; b − 72 tex wool yarn.

Table 2. Strength properties of yarn (before knitting).

Characteristics	Yarn type
	74 tex cotton	72 tex wool
Breaking force F0, N	4.72	7.29
Variance S^2	0.016	0.022
Standard deviation σ	0.13	0.15
Coefficient of variation as ratio CV	0.03	0.02
Coefficient of variation CV, %	2.7	2.1
Breaking tenacity T, cN/tex	6.4	10.1
Breaking elongation ε, %	3.9	5.2
Variance S^2	0.02	0.03
Standard deviation σ	0.13	0.17
Coefficient of variation as ratio CV	0.03	0.03
Coefficient of variation CV, %	3.4	3.3
Time to break t, s	13.5	18.8

Table 3. Strength properties of cotton yarn after unraveling.

Condition	Type of stitch	F, N			T, cN/tex	ε, %			t, s
		mean	σ	CV %		mean	σ	CV %
DR	Plain	4.63	0.07	1.5	6.2	4.10	0.14	3.4	13.9
	1x1 rib	4.80	0.09	1.8	6.4	4.18	0.16	3.9	14.0
	Average	4.71			6.3	4.14			13.9
IR1	Plain	4.25	0.17	4.1	5.7	3.94	0.09	2.3	13.5
	1x1 rib	4.35	0.14	3.2	5.9	4.00	0.05	1.2	13.7
	Average	4.30			5.8	3.97			13.6
IR5	Plain	3.90	0.21	5.5	5.3	3.96	0.09	2.3	10.8
	1x1 rib	4.09	0.29	7.2	5.5	4.01	0.12	2.9	10.9
	Average	3.99			5.4	3.99			10.8
W1	Plain	4.47	0.17	3.8	6.0	4.01	0.11	2.8	13.5
	1x1 rib	4.56	0.11	2.3	6.2	4.07	0.12	3.0	13.2
	Average	4.51			6.1	4.04			13.3
W2	Plain	4.46	0.08	1.8	6.0	4.00	0.16	3.9	13.5
	1x1 rib	4.55	0.18	3.9	6.2	4.10	0.15	3.7	13.2
	Average	4.51			6.1	4.05			13.4
W3	Plain	4.46	0.13	2.9	6.0	4.00	0.17	4.3	13.5
	1x1 rib	4.55	0.20	4.3	6.1	4.10	0.20	4.9	13.2
	Average	4.50			6.1	4.05			13.4
W4	Plain	4.43	0.16	3.5	6.0	4.10	0.17	4.2	13.4
	1x1 rib	4.53	0.18	3.9	6.1	4.10	0.19	3.9	13.2
	Average	4.48			6.1	4.10			13.3
W5	Plain	4.44	0.15	3.5	6.0	4.10	0.17	4.2	13.5
	1x1 rib	4.54	0.20	4.4	6.1	4.10	0.18	4.5	13.2
	Average	4.49			6.1	4.10			13.4
W6	Plain	4.42	0.17	3.9	6.0	4.10	0.17	4.3	13.4
	1x1 rib	4.53	0.18	4.0	6.1	4.10	0.18	4.4	13.3
	Average	4.48			6.0	4.10			13.4
W7	Plain	4.42	0.14	3.1	6.0	4.10	0.17	4.1	13.4
	1x1 rib	4.53	0.22	4.8	6.1	4.10	0.19	4.8	13.3
	Average	4.47			6.0	4.10			13.4
W8	Plain	4.44	0.15	3.3	6.0	4.10	0.18	4.3	13.5
	1x1 rib	4.54	0.21	4.6	6.1	4.10	0.22	5.3	13.2
	Average	4.49			6.1	4.10			13.4
W9	Plain	4.42	0.14	3.1	6.0	4.10	0.18	4.3	13.4
	1x1 rib	4.53	0.22	4.8	6.1	4.10	0.19	4.8	13.3
	Average	4.47			6.0	4.10			13.4
W10	Plain	4.42	0.15	3.3	6.0	4.05	0.14	3.5	13.4
	1x1 rib	4.53	0.13	2.8	6.1	4.09	0.15	3.6	13.3
	Average	4.47			6.05	4.07			13.3

Figure 5. Knittability KA of 74 tex cotton yarn.

Table 4. Strength properties of wool yarn after unraveling.

Condition	Type of stitch	F, N			T, cN/tex	ε, %			t, s
		mean	σ	CV %		mean	σ	CV %
DR	Plain	7.36	0.55	7.4	10.2	3.94	0.29	7.4	17.5
	1×1 rib	6.64	0.37	5.5	9.0	3.45	0.30	8.6	15.8
	Average	7.00			9.6	3.70			16.7
IR1	Plain	7.05	0.35	5.0	9.8	3.48	0.27	7.9	16.2
	1×1 rib	6.75	0.30	4.5	9.4	3.73	0.32	8.7	16.6
	Average	6.90			9.6	3.61			16.4
IR5	Plain	7.34	0.37	4.9	10.2	4.12	0.36	8.8	18.0
	1×1 rib	6.73	0.36	5.3	9.4	3.78	0.50	13.2	16.6
	Average	7.03			9.8	3.95			17.3
W1	Plain	6.63	0.40	6.0	9.2	5.23	0.52	10.0	18.6
	1×1 rib	6.36	0.30	4.7	8.8	4.50	0.53	11.8	16.8
	Average	6.50			9.0	4.86			17.7
W2	Plain	6.70	0.35	5.2	9.3	5.26	0.46	8.8	18.6
	1×1 rib	6.63	0.40	6.0	9.2	4.45	0.30	6.7	16.5
	Average	6.66			9.3	4.85			17.5
W3	Plain	6.79	0.30	4.4	9.4	5.43	0.47	8.6	18.6
	1×1 rib	6.26	0.15	2.5	8.7	4.56	0.28	6.1	16.8
	Average	6.52			9.1	4.99			17.7
W4	Plain	6.88	0.33	4.8	9.6	5.68	0.78	13.7	18.3
	1×1 rib	6.40	0.35	5.5	8.9	5.57	0.34	6.1	19.2
	Average	6.64			9.2	5.62			18.8
W5	Plain	6.77	0.44	6.5	9.4	5.26	0.62	11.8	18.3
	1×1 rib	6.45	0.50	7.7	9.0	4.09	0.57	13.9	16.6
	Average	6.61			9.2	4.68			17.5
W6	Plain	6.52	0.39	6.0	9.0	5.59	0.59	10.6	18.9
	1×1 rib	5.24	0.30	5.7	7.3	3.47	0.27	7.9	15.9
	Average	5.88			8.2	4.53			17.4
W7	Plain	5.76	0.56	9.8	8.0	5.21	0.45	8.6	15.5
	1×1 rib	4.84	0.40	8.3	6.7	3.27	0.29	8.8	15.3
	Average	5.30			7.4	4.24			15.4
W8	Plain	5.74	0.58	10.0	8.0	5.36	0.48	8.9	15.2
	1×1 rib	4.27	0.57	13.4	5.9	3.16	0.28	8.9	15.1
	Average	5.01			7.0	4.26			15.2
W9	Plain	4.60	0.47	10.2	6.4	4.45	0.48	10.7	15.2
	1×1 rib	3.46	0.40	11.6	4.8	2.67	0.46	17.4	15.2
	Average	4.03			5.6	3.56			15.2
W10	Plain	4.43	0.48	10.9	6.2	4.39	0.45	10.3	15.1
	1×1 rib	3.27	0.44	13.6	4.5	2.56	0.48	18.8	15.1
	Average	3.85			5.4	3.47			15.1

Figure 6. Knittability KA of 72 tex wool yarn.