Use of nylon/cotton blend yarn in military uniform is common and due to advantages in its fabric in comparison to 100% cotton fabrics, capabilities of military uniforms have been improved. In this study the effects of navel type on properties of (50%-50%) nylon/cotton blend yarn and wrapper formation were investigated and compared with similar ring spun yarn. Rotor spun yarn was produced on a single head laboratory rotor spinning machine with four navels (smooth, spiral, 3 grooved, and 4 grooved) and ring yarn was produced on a zinser 319 ring spinning machine. Test result showed that navel type has a significant effect on yarn strength and strength of smooth navel yarn was maximum. Elongation of a 100% cotton rotor spun yarn is more than similar ring yarn, but it was not observed in cotton/nylon blend. Yarn irregularity and imperfections varied significantly with navel type and for rotor yarns were more than the ring yarn. Navel type had significant effect on yarn hairiness but it didnot have an effect on yarn abrasion significantly.
The use of blended yarn has increased significantly these days. Blending is used as a means of substituting a less expensive fiber for a highly priced one and to produce yarns with qualities that cannot be obtained by using one type of material alone.
El-sheikh [
Navels differ in their material, forms, number of grooves, existence of fluted inserts, length of ceramic parts, and grooves [
The work reported here is concerned about the evaluation of the quality and mechanical properties of five different nylon/cotton blends of yarn that are particularly used in military uniforms, apparel and textile industry.
Nylon66 and Cotton have been used in the present investigation (Table
Properties of fibers.
No | Fiber | Blend ratio | Length (mm) | Linear density (fineness) |
---|---|---|---|---|
1 | Cotton | 50% | Effective 28 | 0.15 tex (3.8 micronaire) |
2 | Nylon66 | 50% | Cutting 38 | 0.17 tex (1.5 den) |
Spindle speed, nominal count, and twist were 6700 rpm, 20 Ne, and 637 T.P.M, respectively. Also the speed of rotor, opening roller, take-up roller, and feed roller was 49300 rpm, 9200 rpm, 71.3 m/min, and 0.48 m/min, respectively.
The codings of the four different rotor spun yarns and ring spun yarn (witness yarn) are listed in Table
Navel types.
Navel type | Yarn code | Properties | Processed material | Spinning system | Navel design |
---|---|---|---|---|---|
— | R1 | — | — | Ring | — |
KN | O1 | Ceramic, Smooth | Cotton and blend | Rotor |
|
KS | O2 | Ceramic, Spiral | Cotton and blend | Rotor |
|
K3KK | O3 | Ceramic, 3 grooved, short | Cotton and blend | Rotor |
|
K4KK | O4 | Ceramic, 4 grooved, short | Cotton and blend | Rotor |
|
All the samples were tested for the following: tensile strength, evenness, hairiness, and abrasion resistance.
Yarn tensile properties (tenacity, breaking elongation, and work of rupture) were determined on a SDL tensile tester with a jaw speed of 1 m/min and a test length of 50 mm, and 30 tests were conducted for each yarn.
The irregularity and yarn imperfection (thick, thin, nep, and CV%) were measured by using a Keisokki uster over a length of 1000 m of yarn speed at 25 m/min and 5 tests were conducted for each yarn. The degree of sensitivity of the thinness, thickness, and neps was −50%, +50% and +280% respectively.
A SDL hair tester was used to determine the hairiness with a testing speed of 20 m/min and a test length of 30 m for 5 samples (totally 150 m); only hairs with a length greater than or equal to 3 mm were measured. The yarn abrasion resistance was measured by using a SDL yarn abrasion tester. A abradant (P1200) was used and 30 tests were conducted for each yarn sample. All tests were conducted under the standard laboratory conditions (
Wrapper formation of the samples was observed by scanning electron microscopy (VEGA TESCAN, Czech Republic). Samples were fixed in SEM holders and coated with a thin layer of gold prior to SEM investigation.
The data was analyzed statistically by using CRD (complete random design) method for the interpretation of data. Analysis of variance (ANOVA) and Duncan test were provided at
Table
Test result for yarn quality properties.
Yarn type | Tensile strength | Evenness | Hairiness |
Abrasion | |||||
---|---|---|---|---|---|---|---|---|---|
Tenacity (cN/tex) | Breaking elongation (%) | Work of rupture (N |
CV% | Thin (−50%) |
Thick (+50) |
Nep (+280) | |||
R1 | 13/65 | 21/80 | 0/27 | 13/94 | 0 | 18 | 8 | 6 | 6/87 |
O1 | 9/68 | 21/05 | 0/18 | 16/13 | 8 | 34 | 2 | 1/9 | 8/53 |
O2 | 8/62 | 20/16 | 0/16 | 14/60 | 6 | 48 | 4 | 3 | 8/50 |
O3 | 5/58 | 14/13 | 0/09 | 17/83 | 38 | 70 | 33 | 7/6 | 5/77 |
O4 | 8/74 | 21/27 | 0/16 | 17/05 | 16 | 74 | 2 | 1/7 | 8/20 |
A summary of ANOVA statistical result (Duncan test) for tensile strength*.
Yarn type | Tensile Strength | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Tenacity | Breaking elongation | Work of rupture | |||||||||||||
R1 | O1 | O2 | O3 | O4 | R1 | O1 | O2 | O3 | O4 | R1 | O1 | O2 | O3 | O4 | |
R1 | — | + | + | + | + | — | − | + | + | − | — | + | + | + | + |
O1 | + | — | + | + | + | − | — | − | + | − | + | — | + | + | + |
O2 | + | + | — | + | − | + | − | — | + | − | + | + | — | + | − |
O3 | + | + | + | — | + | + | + | + | — | + | + | + | + | — | + |
O4 | + | + | − | + | — | − | − | − | + | — | + | + | − | + | — |
*At 5% confidence limit, “+” means statistically significant and “−” means statistically in-significant.
A summary of ANOVA statistical result (Duncan test) for evenness*.
Yarn type | Evenness | |||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
CV% | Thin | Thick | Nep | |||||||||||||||||
R1 | O1 | O2 | O3 | O4 | R1 | O1 | O2 | O3 | O4 | R1 | O1 | O2 | O3 | O4 | R1 | O1 | O2 | O3 | O4 | |
R1 | — | + | − | + | + | — | − | − | + | − | — | − | − | + | + | — | − | − | + | − |
O1 | + | — | + | + | + | − | — | − | + | − | − | — | − | + | + | − | — | − | + | − |
O2 | − | + | — | + | + | − | − | — | + | − | − | − | — | + | + | − | − | — | + | − |
O3 | + | + | + | — | + | + | + | + | — | + | + | + | + | — | − | + | + | + | — | + |
O4 | + | + | + | + | — | − | − | − | + | — | + | + | + | − | — | − | − | − | + | — |
*At 5% confidence limit, “+” means statistically significant and “−” means statistically insignificant.
A summary of ANOVA statistical result (Duncan test) for hairiness and abrasion resistance*.
Yarn type | Hairiness | Abrasion resistance | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
R1 | O1 | O2 | O3 | O4 | R1 | O1 | O2 | O3 | O4 | |
R1 | — | + | + | + | + | — | + | + | − | + |
O1 | + | — | + | + | − | + | — | − | + | − |
O2 | + | + | — | + | + | + | − | — | + | − |
O3 | + | + | + | — | + | − | + | + | — | + |
O4 | + | − | + | + | — | + | − | − | + | — |
*At 5% confidence limit, “+” means statistically significant and “−” means statistically in-significant.
The effect of navel type on nylon/cotton blended rotor spun yarn tensile properties is illustrated in Figure
Effect of navel type on tensile properties of nylon/cotton rotor spun yarn.
From the test result in Tables
Figure
Figure
The effects of navel type on nylon/cotton blended rotor spun yarn irregularity (CV%) and imperfection are shown in Figure
Effect of navel type on yarn irregularity and imperfection of nylon/cotton rotor spun yarn.
Figure
As shown in Figure
As shown in Figure
Figure
Effect of navel type on hairiness and abrasion resistance of nylon/cotton rotor spun yarn.
Effect of navel type of nylon/cotton blended rotor spun yarn is shown in Figure
Figure
Effect of navel types on wrapper formation (a) smooth navel, (b) spiral navel, (c) 3 grooved navel, (d) 4 grooved navel.
First group is loose and concentrated wrapper fiber; second is loose and distributed wrapper fiber; third, tough and concentrated wrapper fiber; fourth, tough and distributed wrapper fiber.
As shown in Figure
Test result shows that navel types statistically have significant effect on tenacity and smooth navel has the highest value. According to the result of breaking elongation of 100% cotton rotor spun yarn, cotton rotor yarn has more elongation than similar ring yarn but in nylon/cotton blend it was not observed (except 3 grooved navel). Also navel type has considerable effect on yarn irregularity and imperfection; in contrast with written result for 100% cotton yarn, the higher CV% of nylon/cotton rotor spun yarn was obtained and generally, yarn imperfection of rotor spun yarn is more than similar ring spun yarn. In contrast with this subject that says that 3 grooved navel has lower yarn bulk and hairiness than 4 grooved navel [