Enhancing Elasticity Properties through Finishing Processes and Different Wool Fabric Designs ()
1. Introduction
Wool fabric production is crucial in driving innovation within the textile industry. Technological advances have enabled the processing and adaptation of wool fabrics for various applications [1]. As a result, wool fabrics can be utilized in both conventional and innovative textile designs. Due to their inherent elasticity, high thermal insulation, and superior moisture management, wool fabrics provide aesthetic appeal, comfort, and durability, making them indispensable in modern textile applications [2].
Sustainability has become a primary focus in contemporary textile manufacturing, with objectives such as reducing carbon emissions, minimizing water consumption, and utilizing recyclable materials [3] [4]. The renewable nature and reusability of wool contribute significantly to waste reduction in the textile sector. Wool’s sustainability aspects are critical for minimizing environmental impact, optimizing resource efficiency, and extending product lifespan [5]. Additionally, wool fabrics align with circular economy principles by offering a recyclable and biodegradable material option [6]. Given their compostability and recyclability, wool-based textiles support “zero-waste” strategies [7]. Furthermore, within the slow fashion movement, the preference for durable, high-quality textiles has increased the demand for wool fabrics [8].
Wool fabrics are frequently blended with elastane-based fibers to enhance their natural elasticity and mechanical performance [9]. Although wool inherently exhibits a certain degree of flexibility, various finishing treatments are required to enhance its elastic recovery and resistance to permanent deformation during wear.
Several finishing techniques are employed to enhance wool fabrics’ elasticity and mechanical properties. These include elastomeric coatings, resin treatments, and protein modifications, while mechanical approaches such as stretching, steaming, and heat-setting processes are also widely applied [10]. The finishing process plays a critical role in improving elasticity. In wool-Lycra fabrics, thermalization is applied to stabilize elastane fibers, whereas thermal treatment under controlled temperature and humidity conditions is used to modify the elasticity of natural wool fibers. However, these treatments exhibit distinct effects on fabric performance, durability, and comfort properties [11].
This study investigates the comparative performance of wool-Lycra blended fabrics with different woven structures and wool fabrics subjected to natural finishing processes to enhance elasticity. Post-finishing, the fabrics were evaluated for key physical and mechanical properties, including tear strength, tensile strength, seam slippage, elongation and permanent elongation, abrasion resistance, Dimensional Change Against Steam Press A, Dimensional Change Against Steam Press B, and color fastness characteristics. The influence of these finishing treatments on fabric performance was systematically analyzed.
2. Experimental
Materials and Methods
In this study, wool fibers were used for the production of both elastane-containing fabrics and non-elastane fabrics. The properties of the wool fibers utilized in fabric production are presented in Table 1, while the characteristics of the Lycra fibers used as elastane are detailed in Table 2. The tests performed and the corresponding standards applied are listed in Table 3.
Table 1. Fiber properties.
Parameter |
Value |
Fibre Fineness (µ) |
18.3 |
% CV Micron |
18.1 |
Fiber Length (Hauteur) mm |
65.0 |
% CV |
46.8 |
Barbe Bmm (All-Meter) |
79.2 |
% CV Bmm |
35.4 |
Short Fiber % < 30 mm |
14.7 |
Short Fiber % < 40 mm |
23.7 |
Elongation |
16.5 |
Neps (1 - 3 mm) (Pieces/100g) |
6 |
Vegetable Matter (A*1 + B*2 + C*5 + D*17 + E*25) (specks/100g) |
19 |
Oil (%) |
0.45 |
Moisture (%) |
13.9 |
Table 2. Properties of elastane fiber.
Property |
Value |
Fiber, Code, Origin |
Elastane (Lycra) 166L TU UK Lycra Company |
Linear Density |
44 dtex |
Breaking Tenacity |
0.87 cN/dtex |
Elongation at Break |
528% |
Heat Resistance |
180˚C - 220˚C |
Moisture Regain |
1% - 1.5% |
Modulus Value |
0.1 cN/dtex |
Characteristics |
Combined multifilament, 5 filaments, semi-dull, for core spinning and weaving |
Table 3. Fiber tests and standards.
Tests |
Standards |
Fibre Fineness (µ) |
(Microprojection ASTM D 2130) |
% CV Micron |
Fıber Length (Hauteur) Hmm |
AL-METER (IWTO-17-85 E) |
% CV Hmm |
Barbe Bmm (All-Meter) |
% CV Bmm |
|
Short Fiber % < 30 mm |
Short Fiber % < 40 mm |
Neps (1 - 3 mm) (Pieces/100g) |
Vegetable Matter (A*1 + B*2 + C*5 + D*17 + E*25) (specks/100g) Oil (%), Moisture (%) |
ASTM D-1770 |
Figures 1-3 present the production stages and processes of the yarns used in this study. Table 4 provides the properties of the yarns that were produced, while Table 5 lists the tests that were performed and the corresponding standards.
Figure 1. Tops process—machines diagram.
Figure 2. Preparation process—machines diagram.
Figure 3. Spinning and winding process—machines diagram.
Table 4. Yarn properties.
Property |
Plain |
2/1 Twill |
2/2 Twill |
Warp |
Weft |
Warp |
Weft |
Warp |
Weft |
Yarn Count (Nm) |
76 |
96 |
48 |
76 |
48 |
76 |
CV (%) |
2.0 |
1.8 |
1.7 |
1.3 |
2.9 |
2.0 |
Twist (T/m) |
749 |
865 |
842 |
750 |
897 |
750 |
CV (%) |
1.8 |
0.8 |
2.2 |
2.4 |
2.1 |
2.0 |
Strength (cN) |
217 |
171 |
174 |
234 |
161 |
231 |
CV (%) |
12.4 |
13.9 |
12.6 |
12.6 |
16.8 |
17.7 |
Twist Direction |
750 S |
850 S |
900 Z |
750 S |
900 Z |
750 S |
Elongation at Break (%) |
20.4 |
21.8 |
18.6 |
24.0 |
16.6 |
23.0 |
CV (%) |
34.8 |
39.9 |
36.7 |
33.5 |
51.9 |
38.5 |
Unevenness (Uster %) |
11.5 |
12.9 |
12.6 |
11.3 |
12.6 |
12.0 |
Thin Places (−50%) (Per 1000 m) |
33 |
101 |
99 |
29 |
104 |
58 |
Thick Places (+50%) (Per 1000 m) |
7 |
28 |
11 |
9 |
16 |
19 |
Neps (+200%) (Per 1000 m) |
7 |
18 |
27 |
3 |
15 |
16 |
Hairiness (S3-count) |
1011 |
532 |
1073 |
753 |
1425 |
1300 |
Table 5. Yarn tests and standards.
Property |
Method |
Yarn Count |
TS 244 EN ISO 2060 |
Twist |
TS 247 EN ISO 2061 |
Breaking Length |
TS EN ISO 2062 |
Strength (cN) |
TS EN ISO 2062 Method B |
Elongation at Break (%) |
TS EN ISO 2062 Method B |
Unevenness (Uster %) |
TS EN ISO 12947-2 |
Thin Places (−50%) (Per 1000 m) |
TS EN ISO 12947-2 |
Thick Places (+50%) (Per 1000 m) |
TS EN ISO 12947-2 |
Neps (+200%) (Per 1000 m) |
TS EN ISO 12947-2 |
Hairiness (S3-count) |
ASTM D 5647-95 |
In this study, six different fabrics were created with three different weaving structures. The fabric creation process is shown in Figure 4, and the fabric weaving structures are presented in Figure 5. The fabric codes and properties are provided in Table 6, while the tests and corresponding standards applied to the fabrics are listed in Table 7.
Figure 4. Fabric creation processes.
Figure 5. Fabric weaving structures.
Table 6. Fabric properties.
Weave Samples |
Code |
Fabric Weight (g/m2) |
Fabric Blend (%) |
Weft yarn count (Nm) |
Warp yarn count (Nm) |
Thickness (mm) |
Plain Weave |
W/L-P |
153 |
96/4 Wool/Lycra |
Nm96/2 Siro Wool |
Nm76/2 Siro 100% Wool |
0.46 |
Plain Weave |
W-P |
150 |
100% Wool |
Nm48/1 Wool |
Nm76/2 Siro 100% Wool |
0.46 |
2/1 Twill |
W/L-T1 |
182 |
96/4 Wool/Lycra |
Nm96/2 Siro Wool |
Nm76/2 Siro 100% Wool |
0.65 |
2/1 Twill |
W-T1 |
178 |
100% Wool |
Nm48/1 Wool |
Nm76/2 Siro 100% Wool |
0.65 |
2/2 Twill |
W/L-T2 |
196 |
96/4 Wool/Lycra |
Nm96/2 Siro Wool |
Nm76/2 Siro 100% Wool |
0.78 |
2/2 Twill |
W-T2 |
186 |
100% Wool |
Nm48/1 Wool |
Nm76/2 Siro 100% Wool |
0.78 |
Table 7. Fabric tests and standards.
Tests |
Standards |
Tear Strength |
BS 4303 |
Tensile Strength |
BS 2576 |
Abrasion Resistance |
ISO 12947-2 |
Seam Slippage |
BS 3320 |
Dimensional Change Against Steam Press (Hoffman Shrinkage-A) |
DIN 53894 |
Dimensional Change Against Steam Press (Hoffman Shrinkage-B) |
DIN 53894 |
Elongation |
DUPONT TTM079 A |
Permanent Elongation |
DUPONT TTM079 A |
Colorfastness to washing |
ISO 105-C06:2010 |
Colorfastness |
ISO 105-E01:2013 |
Rubbing fastness |
ISO 105-E04:2013 |
Lightfastness |
ISO 105 B02:2014 |
To enhance elasticity, finishing treatments were applied to fabrics with three different weaving structures, including Lycra/Wool blend fabrics and 100% wool fabrics, under varying process conditions. The finishing process applied to the fabrics is provided in Table 8. The performance of the fabrics was evaluated after the treatment.
Table 8. Natural stretch wool fabric design—finishing processes.
Process Steps |
Purpose |
Natural Stretch Process Conditions (Speed, Temperature, Chemical g/l) |
Lycra Process Conditions (Speed, Temperature, Chemical g/l) |
Washing (Open Width) |
Removing spinning oil and warp wax |
70˚C, 20 m/min, Soap 1.5 g/l |
70˚C, 20 m/min, Soap 1.5 g/l |
Crabbing |
Boiling, preventing creases, and balancing internal fabric tensions |
95˚C - 100˚C, 15 m/min |
95˚C - 100˚C, 15 m/min |
Fixation (Ram) |
Pre-stabilization of Lycra |
- |
180˚C, 35 m/min |
Drying (Ram) |
|
130˚C, 20 m/min |
- |
Fabric Dyeing |
|
Yes |
Yes |
Drying (Ram) |
|
130˚C, 25 m/min |
130˚C, 25 m/min |
Gassing Process |
Burning surface fuzz |
90 m/min |
90 m/min |
Washing (Open Width) |
Removing burnt fibers from the surface |
Water only (No chemicals, room temperature) |
Water only (No chemicals, room temperature) |
Drying (Ram) |
|
130˚C, 25 m/min |
130˚C, 40 m/min |
Tweezer Process |
Mechanical repair of weaving defects |
Yes |
Yes |
Shearing |
Cutting surface fuzz |
15 m/min |
15 m/min |
Thermofixation (Ram) |
Lycra stabilization |
- |
190˚C, 20 m/min |
Drying (Ram) |
|
130˚C, 25 m/min - 10 g/l Silicone |
130˚C, 25 m/min - 20 g/l Silicone |
Continuous Decatizing (Decofast) |
Pre-dimensional stabilization, hand feel |
20 m/min, reverse process |
18 m/min, reverse process |
Decatizing (KD-Boiler Decatizing) |
Final dimensional stabilization, gloss, hand feel |
1.2 bar |
1.2 bar |
Calendering |
Polishing & glossy finish |
8 m/min, 0.5 g/l glossy finish, face side |
- |
Drying (Ram) |
|
130˚C, 25 m/min |
- |
Continuous Decatizing (Decofast) |
Pre-dimensional stabilization, hand feel |
20 m/min, reverse process |
- |
Decatizing (KD-Boiler Decatizing) |
Final dimensional stabilization, gloss, hand feel |
1.2 bar |
- |
Drying (Ram) |
|
130˚C, 25 m/min |
130˚C, 40 m/min |
3. Results
The tear strength of the fabrics obtained in this study was evaluated in both the warp and weft directions (See Figure 6), with the highest value associated with the W-T2 fabric. The fabrics with the highest tear strength have a 2/2 Twill weave structure. The 2/2 Twill weave structure is looser, which allows the yarns to slide during tear and better distribute the applied load. The yarns used in the 2/2 Twill weave structure are more twisted and thicker than those used in other weave structures, contributing to an increase in tear strength. After the finishing process, tear strength generally shows greater resistance in the warp direction. The thermofixation process has been particularly effective regarding tear strength in the Twill 2/1 and 2/2 fabrics. Following the finishing process, the 100% wool fabrics exhibited higher tear resistance than the Lycra-blended fabrics.
Figure 6. Tear and tensile strength of fabrics.
The tensile strength of the 2/1 and 2/2 Twill woven fabrics is higher compared to plain woven fabrics. Particularly in the 2/2 Twill weave structure, the tensile strength reached 27.1 kgf in the warp direction and 39.7 kgf in the weft direction. The high yarn strength (161 - 234 cm) and twist (750 - 900 T/m) in the 2/2 Twill woven fabrics contribute to the increased tensile strength of the fabric. The break strength of the 100% wool fabrics, which gained natural elasticity through the influence of temperature and chemicals, increased in relation to the dimensional stability of the wool fabrics. Fabrics, particularly those with a 2/2 Twill weave structure, show high tensile strength values after the finishing process.
Figure 7. Seam slippage of fabrics.
In Figure 7, the fabrics with the W-T2 weave structure (20.4 mm) and the W-T1 weave structure (18.7 mm) exhibit the highest seam slippage. This situation is generally associated with a looser knit construction and lower yarn twist ratio. The W/L-P knit fabric shows the lowest seam slippage in the weft direction (12.2 mm). The tight weave structure and high yarn twist ratio prevent the yarns from slipping along the seam. This characteristic provides the fabric structure with more durable and long-lasting properties. The lowest warp strength may result in higher seam slippage after thermofixation, while Lycra stabilization may increase seam slippage.
The W/L-T2 fabric (16.7 mm) and W-P fabric (15.4 mm), along with the W/L-T1 fabric (14.4 mm), exhibit noticeable seam slippage. The connection points in the fabric’s knit structure are fewer, so under excessive load and tension, deformation may occur compared to the 2/2 Twill structure fabrics. The 2/2 Twill structure has reduced seam slippage; however, due to Lycra, seam slippage may still occur in the weft direction after thermofixation. The W/L-P fabric (12.2 mm) has the lowest seam slippage in the weft direction. The plain, tightly knitted structure and high yarn twist ratio make seam slippage more difficult. It exhibits the highest seam strength and is minimally affected by thermofixation, maintaining its stability.
Figure 8. Elongation and permanent elongation properties of fabrics.
The elongation percentage characteristics of the produced fabrics, as shown in Figure 8, demonstrate that Lycra-based fabrics generally exhibit higher elasticity. These fabrics have an elongation rate of 23% to 23.4%, with permanent elongation rates between 1% and 1.3%, indicating that most of the high elasticity is recoverable. For 100% wool fabrics, the elongation rate ranges from 18.6% to 20%, with a permanent elongation rate of 1%. In this case, wool fabrics have lower elasticity. However, with the Twill knitting structure, elasticity is increased, and the permanent elongation rate reaches 21.7% with a 0.7% permanent elongation. Thus, a balance has been achieved in wool fabrics, allowing for permanent elongation without Lycra. After the finishing processes, the Lycra-blended fabrics exhibited a reduction in permanent elongation and an improvement in recovery. The best balance in permanent elongation was achieved in the Wool-Lycra Twill 2/2 (W/L-T2) fabric.
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Figure 9. Abrasion cycle properties.
As shown in Figure 9, the abrasion cycle properties exhibited higher durability in the Lycra-based fabrics. When the knitted structures underwent finishing processes and were combined with the Twill weave structure, they became both more flexible and more resistant to abrasion. According to the finishing process results, Twill woven fabrics exhibited higher abrasion resistance compared to plain woven fabrics. While Lycra-containing wool fabrics enhanced their elasticity, they showed a reduction in abrasion resistance. The fabric with the best abrasion resistance was the Wool-Twill 1/1 (W-T1) fabric.
Figure 10. Dimensional change against steam press properties of Lycra-containing wool fabrics.
Figure 10 shows that the fabrics L-P, W/L-T1, and W/L-T2 exhibited greater dimensional changes when pressed with steam. Generally, these fabrics demonstrated higher flexibility and dimensional changes, but they maintained dimensional stability, with W/L-P showing the most significant changes. Although the Lycra structure provides elasticity to the fabrics, it also limits their dimensional changes. Wool fabrics without Lycra, such as W/P, W-T1, and W-T2, showed less dimensional change. These fabrics, particularly those with the Twill knit structure, exhibited lower dimensional changes during the steam press process. Wool Twill fabrics, such as W-T2, demonstrated highly stable structures with dimensional change rates of 0.5%. Overall, the finishing process improved dimensional stability across all fabrics, with Lycra-containing fabrics showing higher dimensional changes. These alterations promote fiber reorientation, reduce residual stresses, and stabilize the yarns, particularly in Lycra-blended fabrics. These treatments cause a permanent dimensional set, which is a key feature for the performance of tailored garments, where retaining shape and structure is crucial. Although minimal recoverable shrinkage may be observed after further laundering or re-pressing, the majority of the dimensional changes are irreversible, ensuring that the garments maintain their intended fit and structure over time. The best stability was observed in the Wool-Twill 2/2 (W-T2) fabric. The Twill weave structure, combined with finishing processes, contributed to better dimensional stability.
Fastness Properties
The fastness properties of different fabric types were evaluated based on the factors influencing them after the finishing process. The results of the fastness properties are provided in Table 9.
Table 9. Fastness properties results.
Material |
Washing |
Rubbing Fastness |
Light Fastness |
Color Change |
Staining |
|
CA |
CO |
PA |
PET |
PAN |
WO |
Dry |
Wet |
|
W/L-P |
4 - 5 |
4 |
4 |
4 |
4 |
4 - 5 |
5 |
4 - 5 |
4 - 5 |
4 - 5 |
W-P |
4 |
4 |
4 |
4 |
5 |
4 - 5 |
5 |
4 |
4 |
4 |
W/L-T1 |
4 - 5 |
4 - 5 |
4 - 5 |
4 - 5 |
4 - 5 |
4 - 5 |
4 - 5 |
4 - 5 |
4 - 5 |
4 - 5 |
W-T1 |
4 - 5 |
4 |
4 |
5 |
4 - 5 |
5 |
4 |
4 |
4 - 5 |
4 - 5 |
W/L-T2 |
4 - 5 |
4 - 5 |
5 |
5 |
4 - 5 |
4 - 5 |
5 |
5 |
4 - 5 |
5 |
W-T2 |
4 - 5 |
5 |
5 |
5 |
4 - 5 |
5 |
5 |
5 |
5 |
5 |
Upon evaluating the washing fastness results, all fabric types exhibit high washing fastness, ranging between 4 - 5. The W-T2 and W/L-T2 fabric types stand out as having the highest washing fastness. Rubbing fastness is around 4 - 5 for all fabric types. The wet rubbing fastness of the W-P and W-T1 fabrics is rated 4, showing slight color loss. Light fastness ranges between 4 and 5 for all fabric types, with the W/L-T2 fabric showing an increase in light fastness. For staining tests against different fiber types, the fastness values are in the 4 - 5 range. The W/T2 and W/L-T2 fabrics achieved the best stain fastness, reaching a level of 5 across all fibers.
4. Conclusions
This study analyzed the mechanical and physical properties of different fabric types after the finishing process. Overall:
The highest tensile and tearing strength was observed in the Wool-Twill 2/2 (W-T2) fabric.
The highest abrasion resistance was found in the Wool-Twill 1/1 (W-T1) fabric.
Wool-Twill 2/2 (W-T2) exhibited the best dimensional stability and the least steam press effect.
The Wool-Twill 2/2 (W-T2) fabric was the most resistant to seam slippage.
Regarding elongation, the best values were found in the Wool-Lycra Twill 1/1 (W/L-T1) fabric.
Wool-containing Lycra fabrics (W/L-P, W/L-T1, W/L-T2) performed well in all fastness tests, showing generally high performance.
The W/L-T2 fabric demonstrated the highest performance in nearly all categories, indicating that the elasticity treatment did not negatively affect fastness properties, and in some cases, it even improved them.
The W-P and W-T1 fabrics showed relatively lower wet rubbing fastness, but they generally exhibited acceptable durability.
In conclusion, the Wool-Twill 2/2 (W-T2) fabric demonstrated the best performance in terms of breaking and tearing strength, abrasion resistance, seam slippage, and dimensional stability. Wool/Lycra fabrics stood out for their elastic properties. Finishing treatments, especially on twill structures, positively affected the overall fabric properties.