KR102344155B1 - Test method for ladder characteristics of finer interlock knitted fabrics - Google Patents

Abstract

The present invention relates to an ultra-fine double-sided knitted fabric that is thinly manufactured with a foil structure, has excellent elasticity and tear strength, and is knitted using 1.67 to 3.333 tex polyester DTY filament as a yarn to minimize the occurrence of laddering and improve shape stability. It provides a laddering test method.

Description

TEST METHOD FOR LADDER CHARACTERISTICS OF FINER INTERLOCK KNITTED FABRICS

The present invention relates to a laddering test method of an ultrafine double-sided knitted fabric, and more particularly, 1.67 to 3.333 tex poly It relates to a laddering test method of an ultra-fine double-sided knitted fabric knitted using an ester DTY filament as a yarn.

Recently, as the leisure activity population increases and interest in well-being increases, the demand for sportswear is increasing, and a new lightweight sportswear market based on fashion is being formed.

Conventional ultra-light sportswear is mainly made of fabrics, but since ultra-fine fabrics have little elasticity, improvement in elasticity and abrasion properties was required as products such as windshields, down jackets and mountaineering jackets using materials less than 1-2 tex were released. .

Accordingly, lightweight sportswear products made of knitted materials with excellent elasticity and tear strength have been released instead of fabric jackets or fabric shirts.

However, the knitted material has several weaknesses compared to the woven material, and in particular, as the loop (knitted ring) falls out during use, so-called laddering occurs in which the thread is unwound in a ladder shape, and thus has a weak shape stability.

Conventional studies on shape stability mainly focus on dimensional change, such as dimensional change according to the composition or knitting structure, dimensional change due to washing, and the effect of knitting conditions of knitting machine on dimensional change. There are also some studies that try to express morphological stability.

However, it is preferable that shape stability be expressed as factors for shape change such as laddering of single jersey in addition to dimensional change.

On the other hand, high-density double-sided knitting using ultrafine linear density filaments exhibits defects such as laddering or shoving in single jersey, but a laddering test method capable of quantitatively indicating shape stability has not yet been disclosed. .

Registered Patent Publication No. 10-1957035

Paper 1: D. J. Spencer, Knitting Technology, 3rd Ed., Woodhead Publishing Ltd, Cambridge, 2001, 280-282

The present invention was devised in consideration of the above problems of the prior art, and can have excellent elasticity and tear strength while being thinly manufactured with a thin paper structure. A main object is to provide an ultra-fine double-sided knitted fabric that minimizes the phenomenon and improves shape stability.

It is also an object of the present invention to provide a laddering test method and a test apparatus for ultra-fine double-sided knitted fabrics capable of quantitatively testing the occurrence of laddering of ultra-fine double-sided knitted fabrics.

In one aspect of the present invention, a tensile test is performed by a strip method in which the upper and lower parts of the ultra-fine double-sided knitted fabric are respectively fixed with an upper jaw and a lower jaw so that the upper and lower intervals are 2 cm, and then pulled in the vertical direction, the ultra-fine double-sided knitted fabric is , to have a length of 6 cm in the wale direction, and form a 1 cm long flaw at the center in the coarse direction and one end in the wale direction. After several tests, calculate the average value of strength and elongation at the time of laddering occurrence to calculate the laddering load, but use the tightness factor (K, tightness factor) and the laddering analysis factor 1/l ² Let the ring be quantitatively evaluated, the tightness fact can be obtained from Equation 1 below, tex is the texturing value of the yarn, and l is the loop length (cm) of the ultra-fine double-sided knitted laddering test method to provide.

--- 수학식 1

--- Equation 1

In another aspect of the present invention, the upper and lower parts of the ultrafine double-sided knitted fabric are arranged at an interval of 2 cm vertically so that the upper and lower parts can be fixed, respectively, and the upper part having a size in which the ultra-fine double-sided circular knitted fabric having a length of 6 cm in the wale direction can be fixed. jaws and lower jaws; a driving unit for moving the upper jaw and the lower jaw apart in the vertical direction so that the ultra-fine double-sided knitted fabric is pulled in the vertical direction; and a measuring unit for measuring the strength and elongation of the ultra-fine double-sided knitted fabric when laddering occurs in the ultra-fine double-sided knitted fabric; After several tests, the average value of strength and elongation at the time of laddering occurrence is calculated by the measurement unit to calculate the laddering load, but the tightness factor (K, tightness factor) and the laddering analysis factor 1/l ² to quantitatively evaluate laddering using A laddering test apparatus for double-sided knitting is provided.

--- 수학식 1

--- Equation 1

According to another aspect of the present invention, a plurality of loops (knit) formed by a plurality of rows of courses, and loops formed by a plurality of rows of wales disposed to cross the course are double-sided knitted fabrics formed by weaving each other In, by using 1.67 to 3.333 tex polyester DTY filament as yarn, the stitch density is 7.5 to 9.3 and the loop length is 0.144 to 0.184 cm. It provides an ultra-fine double-sided knitted fabric that prevents stitching from occurring as laddering occurs.

According to a preferred feature of the present invention, the ultrafine double-sided knitted fabric is divided into a central first region in the wale direction and two second regions respectively located on both sides of the first region, and the two second regions are It may be knitted to have a lower tonsil neck compared to the first region.

According to a preferred feature of the present invention, the two second regions may each have at least 10 or more wales.

According to a preferred feature of the present invention, the tonsil throat of the first region may be greater than 7.5 and 9.3 or less, and the tonsil throat of the second region may be 7.5.

According to a preferred feature of the present invention, in the ultrafine double-sided knitted fabric, a length ratio of the second region to the first region in the wale direction may be 4 (first region):6 (sum of both side second regions).

According to an embodiment of the present invention, it is possible to manufacture an ultra-fine double-sided knitted fabric made of a thin foil structure while having excellent elasticity and tear strength, and the ladder-like shape of the all-leaf as the loop falls out during use by increasing the laddering load of the ultra-fine double-sided knitted fabric By minimizing the unwinding laddering phenomenon and improving shape stability, there is an effect that high-quality lightweight sportswear can be manufactured using such an ultra-fine double-sided knitted fabric.

In addition, there is an effect of quantitatively representing the shape stability of the ultra-fine double-sided knitted fabric by testing the occurrence of laddering of the ultra-fine double-sided knitted fabric.

1 is a plan view schematically illustrating an ultrafine double-sided knitted fabric according to an embodiment of the present invention.
2 is a schematic diagram schematically illustrating a coupling relationship between a knitted fabric and an upper jaw and a lower jaw during a laddering test of the present invention.
3 is a photograph showing the main part of the apparatus for measuring laddering of the present invention.
4 is a photograph showing the progress of laddering of specimen #1-1 according to the interval G1 between the upper and lower jaws 21 and 22. Referring to FIG.
5 is a graph showing a general load-displacement curve of the ladder according to the spacing between the upper and lower jaws.
6 is a graph showing the change in the laddering load when the interval between the upper and lower jaws is 2-3 cm.
7 is a graph showing the laddering load according to the loop length when the linear density is the same.
8 is a graph illustrating a difference in laddering load according to a texturing method.
9 is a graph showing the comparison of the ladder loads of #1-1 and #2 knitted at different linear densities when the loop length is the same.
10 is a graph showing the comparison of the ladder load of the DTY15 series and the DTY30 series by changing the loop length when the linear density is the same.
11 is a graph showing a relationship between a laddering load and a tightness factor of the DTY15 series shown in FIG. 7 .
12 is a graph comparing laddering loads of DTY15-1 and DTY20 as a tightness factor.
13 is a graph in which the results of FIG. 10 are reinterpreted using a tightness factor.
14 is a graph showing that 1/l ² can be used as a laddering analysis factor instead of a tightness factor.
15 (a) and 15 (b) are graphs showing the strength and elongation of Examples 1 to 3 by comparing them in the wale direction and the coarse direction, respectively.
16 is a graph showing a comparison of loads generated by laddering of Examples 1 to 3;
17 is a graph showing the comparison of tensile strength (tenacity) of Example 1 and Example 4.
18 is a graph showing comparison of the extension (extension) of Example 1 and Example 4.
19 is a graph showing a comparison of the load generated by laddering in Example 1 and Example 4. FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

In addition, in the entire specification, 'including' a certain element means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

In general, laddering is known to occur well in plain fabrics and is not believed to occur in double-sided knitting fabrics.

However, a high-density knitted fabric made of fine filaments has a disadvantage that laddering easily occurs even with interlock stitches. A test method for evaluating laddering for a knitted fabric is not yet specified.

The present invention proposes a laddering test method that can quantitatively evaluate the laddering of ultra-fine double-sided knitted fabrics, and investigates which factors affect the laddering through this test method to minimize laddering while minimizing laddering, elasticity and strength To provide a high-quality, ultra-fine double-sided knitted fabric with excellent thermal strength.

In the laddering test method of the present invention, the tension test is performed by a strip method in which the upper and lower parts of the ultrafine double-sided knitted fabric are respectively fixed with an upper jaw and a lower jaw so that the upper and lower intervals are 2 cm, and then pulled in the vertical direction.

The ultrafine double-sided knitted fabric is made to have a length of 6 cm in the wale direction, and a 1 cm long flaw is formed in the center in the coarse direction at a position where one end is in the wale direction, and the part where the flaw ends during the tensile strength test is cut off It causes laddering to occur.

In addition, after several tests, the average value of strength and elongation at the time of laddering occurrence is calculated to calculate the laddering load, but laddering is performed using the ^{tightness factor (K) and the laddering analysis factor 1/l 2} This should be evaluated quantitatively.

Here, the tightness fact can be obtained from Equation 1 below, tex is the texturing value of the yarn, and l is the loop length (cm).

According to the present invention, it can be seen that the knitted fabric with thick filaments is less prone to laddering than the knitted fabric with thin filaments due to contact interference between loops in the knitted fabric with similar firmness ratio.

Also, laddering test results may appear differently depending on several factors. Among them, the elongation in the coarse direction is not an absolute factor that affects the occurrence of laddering, and it can be seen that the loop length affects the laddering load. .

Statistically, there is a linear correlation between the stiffness coefficient of the knitted fabric and the laddering strength when the number of yarns used for knitting is the same. At this time, it can be seen that the occurrence of laddering decreases as the tightness factor increases, and the present invention limits the physical properties of the ultrafine double-sided knitted fabric based on these contents.

Hereinafter, the laddering test method of the ultrafine double-sided knitted fabric of the present invention will be described in more detail.

The laddering test method of the present invention uses yarns of 1.67 tex, 2.222 tex and 3.333 tex polyester DTY filaments, and uses two types of double-sided circular knitting machines of 48G (gauge) and 52G to cut the yarns by 30 inches. Prepare the psalms by knitting with

At this time, the loop length of each specimen is set as shown in Table 1 below, and all specimens are knitted with an interlock structure under the same conditions. In addition, a yarn of 5 tex polyester FDY filament is used as a comparative example.

2 is a schematic diagram schematically showing a coupling relationship between a knitted fabric and an upper jaw and a lower jaw during the laddering test of the present invention, and FIG. 3 is a photograph showing the main part of the apparatus for measuring laddering of the present invention. In FIG. 2, W represents a wale direction, and C represents a course direction.

2 and 3, the test device used in the laddering test method of the present invention is arranged at an interval of 2 cm vertically so as to fix the upper and lower parts of the ultrafine double-sided knitted fabric 10, respectively, in the wale direction. The ultrafine double-sided knitting having a length of 6 cm includes an upper jaw (jaw) 21 and a lower jaw 22 having a size that can be fixed.

In addition, the test device includes a driving unit (not shown) that moves the upper jaw 21 and the lower jaw 22 apart in the up-down direction so that the ultra-fine double-sided knitted fabric 10 is pulled up and down, and the ultra-fine double-sided knitted fabric 10 ) may include a measuring unit that measures the strength and elongation of the ultra-fine double-sided knitted fabric when laddering occurs.

# knitting name yarn Gauge &
Stitch loop length
(Loop length)
(cm) 1-1 DTY15-1 Polyester
100% DTY, 1.67tex/12f 52 G, interlock 0.144 1-2 DTY15-2 0.156 1-3 DTY15-3 0.168 2 DTY20 Polyester
100% DTY, 2.222tex/48f 0.144 3-1 DTY30-1 Polyester
100% DTY, 3.333tex/48f 48 G, inter width 0.150 3-2 DTY30-2 0.164 3-3 DTY30-3 0.184 4 FDY45 Polyester
100% FDY,
5tex/72f 0.208

Then, by using each specimen 10, the spacing G1 between the upper and lower jaws 21 and 22 is set to 2, 2.5, 3, 4, 5 and 10 cm, respectively, and a laddering test is performed.

2 and 3, each specimen 10 has a length L2 of 6 cm in the wale direction (W), and has one end in the wale direction (W) in the center in the coarse (C) direction. After making a scratch 11 of 1 cm length (L1) at the location where it is used, a tensile strength test is performed.

For the tensile strength test used in the present invention, the strip method (KS K ISO 0521: 2011) is applied, and the test is performed 15 times for each embodiment.

At this time, the scratch 11 serves to control the generation position of the ladder. During the tensile strength test, the end portion of the scratch 11 is widened and laddering occurs.

Table 2 shows the laddering failure rate according to the spacing between the upper and lower jaws 21 and 22, and FIG. 4 shows the laddering progress of specimen #1-1 according to the gap G1 between the upper and lower jaws 21 and 22. It's a photo.

4 (a) is a case in which the interval G1 between the upper and lower jaws 21 and 22 is 2 cm, and FIG. 4 (b) is a case in which the interval G1 between the upper and lower jaws 21 and 22 is 3 cm, 4(c) is a case where the interval G1 between the upper and lower jaws 21 and 22 is 4 cm, and FIG. 4(d) is a case where the interval G1 between the upper and lower jaws 21 and 22 is 5 cm, Figure 4 (e) is a case where the interval (G1) between the upper and lower jaws 21 and 22 is 10 cm.

upper and lower jaw
interval
(cm) Failure ratio (%) note #1-1 #2 #3-3 #4 DTY15-1 DTY20 DTY30-3 FDY45 2 0 13.3 13.3 0 - 2.5 13.3 13.3 26.7 0 3 33.3 53.3 33.3 13.3 partial occurrence 4 33.3 46.7 46.7 20.0 5 53.3 73.3 66.7 40.0 10 86.7 100* 100* 60.0 Nothing special

Referring to Table 2 and FIG. 4 , it can be seen that when the distance between the upper and lower jaws is 3, 4, and 5 cm, the ladder is not completely generated, that is, in a “partially generated” state.

When the distance between the upper and lower jaws is 10 cm, the number of times that the ladder does not occur occurs in all specimens, and in particular, in the case of #2 and #3-3, it can be confirmed that the ladder does not occur in all the times.

When the distance between the upper and lower jaws is 2.5 cm, it can be seen that the laddering failure rate is reduced to less than 30% in all specimens.

When the distance between the upper and lower jaws is 2cm, it can be seen that laddering occurs at all times in #1-1 and #4, and the laddering failure rate is reduced to less than 15% in #2 and #3-3.

That is, it can be seen that if the interval between the upper and lower jaws is narrow, the laddering failure rate is also reduced.

5 is a graph showing a general load-displacement curve of the ladder according to the spacing between the upper and lower jaws. It can be seen that the load at the occurrence of the ladder represents the tensile strength of the specimen.

Referring to FIG. 5 , when the distance between the upper and lower jaws is 2 to 3 cm, the ladder is generated at once, so that the laddering load can be easily measured from the curve. However, when the distance between the upper and lower jaws is 4 cm or more, it is difficult to measure the laddering load because the ladder gradually appears like a slip phenomenon.

6 is a graph showing the change in the laddering load when the distance between the upper and lower jaws is 2-3 cm. In general, when the distance between the upper and lower jaws increases in a laddering test, the laddering load increases, but referring to FIG. 6 , in the area where the distance between the upper and lower jaws is 2 to 3 cm, the laddering load increases as the distance between the upper and lower jaws increases. decrease can be seen.

Therefore, in the laddering test method of the present invention, the interval G1 between the upper and lower jaws 21 and 22 is determined to be 2 cm based on these results.

7 is a graph showing the laddering load according to the loop length when the linear density is the same. 7 shows the laddering load of an ultrafine double-sided knitted fabric made of a filament yarn of polyester DTY 1.67tex/12f.

Referring to FIG. 7 , it can be seen that the laddering load decreases as the length of the loop increases. This is because the inter-loop becomes loose as the loop length increases. Therefore, it can be seen that the loop length must be reduced in order to reduce the occurrence of laddering.

8 is a graph illustrating a difference in laddering load according to a texturing method. Referring to FIG. 8 , Comparative Example #4 knitted with a flat yarn shows a very low laddering load compared to samples made of other DTY filaments.

This is because in the case of #4, the surface of the filament is smooth and the frictional disturbance caused by the curl of the DTY filament is relatively small. it can be seen that

9 is a graph showing the comparison of the ladder loads of #1-1 and #2 knitted at different linear densities when the loop length is the same.

Referring to FIG. 9 , it can be seen that the ladder load of #1-1, which has a small linear density, shows a relatively slightly higher value than #2. This is due to the difference in fineness constituting the filaments of multiple filaments, and therefore it can be seen that the linear density must be lowered to reduce the occurrence of laddering.

10 is a graph showing the comparison of the ladder load of the DTY15 series and the DTY30 series by changing the loop length when the linear density is the same.

Referring to FIG. 10 , it can be seen that the laddering load decreases as the loop length increases. In addition, it can be seen that the finer the gauge, the smaller the laddering load.

Hereinafter, a method of analyzing laddering using a tightness factor will be further described.

As shown in Fig. 10, it is difficult to determine directly from the knitting factors how well the ladder is generated. Therefore, there is a need for a standardized factor that can help interpret the laddering result and introduce the tightness factor (K) disclosed in Paper 1 of the non-prior literature. The tightness factor may be used to express the degree of sparseness of the knitted fabric by paying attention to the contact interference of the loop.

11 is a graph showing a relationship between a laddering load and a tightness factor of the DTY15 series shown in FIG. 7 . Referring to FIG. 11 , the linear regression analysis between the laddering load and the tightness factor shows that the raster load increases linearly with the correlation coefficient r=0.995 according to the increased tightness factor.

12 is a graph comparing laddering loads of DTY15-1 and DTY20 as a tightness factor. Referring to FIG. 12 , it can be seen that the laddering load increases as the tightness factor increases at the same linear density.

In addition, when the linear density is different at the same loop length, it can be seen that the laddering load of the specimen having a higher linear density is smaller even if the tightness factor is increased.

13 is a graph in which the results of FIG. 10 are reinterpreted using a tightness factor. Referring to FIG. 13 , it can be seen that laddering occurs more easily in a fine gauge.

Also, although the laddering load of the 52G gauge was smaller than that of the 48G, if the tightness factor is increased, the laddering load of the fine gauge may be larger than that of the 48G. This can be interpreted as, since the tightness factor is introduced, laddering is more difficult to occur if the tightness factor of the fabric with a finer gauge can be increased.

Referring to Paper 1, which is a non-prior literature, Doyle ^{mentions that the spacing between wales and coarse is proportional to l 2} and the knitting density is proportional to 1/l ^{2 .} 14 is a graph showing that 1/l ² can be used as a laddering analysis factor instead of a tightness factor.

Referring to FIG. 14 , it can be seen that the linear correlation of the correlation coefficient r = 0.997 between the laddering ^{load and 1/l 2 is very high.} Therefore, 1/l ² can also be used as a laddering analysis factor together with the tightness factor.

And, it can be seen that, in a knitted fabric having a similar tightness factor, it is relatively difficult to generate laddering in a knitted fabric knitted with thick yarn compared to a knitted fabric knitted from a thin yarn due to contact interference between loops.

It can be confirmed that the elongation in the course direction is not an absolute factor influencing the laddering from the results of the laddering test of knitted fabrics with different lengths of the same count and the evaluation results of knitted fabrics with different counts. have.

Therefore, as a result of statistical confirmation, there was a linear correlation with a correlation coefficient of 1 between the tightness factor and the laddering generation strength of knitted fabrics using yarns of the same thickness, and the larger the tightness factor, that is, the smaller the tonsil neck, the smaller the laddering. It can be seen that the occurrence is relatively suppressed.

According to these results, in order to reduce the occurrence of laddering by increasing the laddering load, it is necessary to reduce the loop length, knit with a DTY having a low linear density, and increase the tannicity factor.

That is, the characteristics of the ultra-fine double-sided knitting that can minimize the occurrence of laddering are to be knitted with 1.67 tex/2f polyester DTY, and the loop length to be 0.144 cm.

The ultra-fine double-sided knitted fabric according to the present invention may be formed by weaving a plurality of loops formed by a plurality of rows of courses and loops formed by a plurality of rows of wales intersecting the courses. .

In this embodiment, in order to reduce or prevent the occurrence of laddering of the ultra-fine double-sided knitted fabric, the thickness of the yarn used for manufacturing the ultra-fine double-sided knitted fabric and the knitted ultra-fine double-sided knitted fabric are limited.

The ultra-fine double-sided knitting of this embodiment can be used as a yarn with a very thin yarn having a thickness of 100 or more, and preferably using 1.67 to 3.333 tex polyester DTY filament as a yarn. It can be knitted in a double-sided knitting structure .

In this case, the yarn may have a thickness of 30 to 35d (denier). If the thickness of the yarn used for knitting is thinner than 35d, the contact friction between adjacent loops becomes too small, so the load generated for laddering becomes lower, and laddering occurs frequently in ultra-fine double-sided circular knitted fabrics. . In addition, if the thickness of the yarn used for knitting is thicker than 30d, since the double-sided circular knitted fabric cannot form a thin paper structure, it is difficult to apply it to lightweight sportswear and the like.

Such an ultrafine double-sided knitted fabric may be knitted so that the stitch density (knit density of the knitted fabric) is 7.5 to 9.3. The smaller the number of one-sided knitting, the more advantageous it is to prevent the occurrence of laddering by increasing the strength of the ultrafine double-sided knitted fabric. It may cause problems when applied to sportswear that requires elasticity. In addition, if the one-way neck of the ultra-fine double-sided knitted fabric is larger than 9.3, the effect of reducing the occurrence of laddering is significantly reduced, so that the shape stability of the product is caused such as loosening during use.

Due to these characteristics, even if both ends of the ultra-fine double-sided circular knitted fabric of the present embodiment are cut and pulled from the top and bottom, it is possible to prevent laddering from occurring in the wale direction and to prevent slipping in the wale direction.

Therefore, when sportswear is manufactured with the ultra-fine double-sided knitted fabric of the present invention, it is possible to not only minimize the weight as it has excellent elasticity and a thin paper structure, but also prevent the occurrence of all-out phenomenon in the wale direction due to laddering during use. It is possible to manufacture high-quality lightweight sportswear with excellent shape stability.

1 is a plan view schematically showing a microfine double-sided knitted fabric according to an embodiment of the present invention. Here, W represents a wale direction, and C represents a course direction.

1, the ultra-fine double-sided knitted fabric 10 of this embodiment is located on both sides of the first region 12 in the center in the wale direction (W) and the first region 12 in the wale direction (W), respectively. It is divided into two second regions 13 and 14 , and the second regions 13 and 14 may have a lower tonsil neck than the first region 12 .

Laddering occurs from both ends in the wale direction of the knitted fabric. As such, when the second regions 13 and 14 located on both sides in the wale direction W of the ultrafine double-sided knitted 10 are knitted to have a low one-way neck, The effect of preventing the occurrence of laddering can be improved, and the center of the ultrafine double-sided knitted fabric 10 has high elasticity, so that the first region 12 in the center, which has a relatively low probability of occurrence of laddering, is knitted with high density by raising the one-way neck. Thus, if sportswear is manufactured with this extra-fine double-sided knitted fabric, it is possible to increase the strength of sportswear as lightweight sportswear with a thin paper structure while having excellent shape stability.

In this case, the two second regions 13 and 14 may each have at least 10 wales. In order to prevent the occurrence of laddering, the second regions 13 and 14, which are regions knitted at a relatively low density at both ends of the extra-fine double-sided knitted fabric 10, must secure a sufficient length to withstand the load generated by the laddering. If the 2 regions 13 and 14 have less than 10 wales, it is impossible to provide sufficient strength to withstand the load generated by laddering to both ends of the ultrafine double-sided knitted fabric 10. As a result, the load generated by laddering is low As time goes on, the frequency of laddering increases.

Also, the tonsil neck of the first region 12 may be greater than 7.5 and less than or equal to 9.3. If the one-way neck of the first region 12 exceeds 9.3, the average strength of the ultrafine double-sided knitted fabric 10 is too low, so it may be difficult to provide tear strength suitable for use as sports wear.

At this time, the tonsil neck of the second regions 13 and 14 is a high-density region differentiated from the first region 12 , and is preferably set to 7.5, which is lower than the first region 12 and is within the numerical range of the present invention.

In addition, in the knitted fabric of this embodiment, the length ratio of the second regions 13 and 14 and the first region 12 in the wale direction W may be 4 (first region):6 (sum of the second regions on both sides). have.

In order to prevent the occurrence of laddering, the second regions 13 and 14, which are located at both ends of the relatively ultra-fine double-sided knitted fabric 10 and are knitted at low density, must have sufficient length to withstand the load generated by the laddering. , when the second regions 13 and 14 are formed to a length of less than 6 of the entire ultra-fine double-sided knitted fabric 10, it is impossible to provide sufficient strength to withstand the load generated by such laddering to both ends of the ultra-fine double-sided knitted fabric 10 , as a result, the laddering occurrence frequency is increased as the laddering occurrence load is lowered.

Hereinafter, the samples used in the experiment for explaining the laddering measurement method of the present invention in more detail are 48G, 64″ double-sided thick gauge circular knitting machine (Terrot) with a polyester DTY 30d/48f filament yarn. It was knitted in double-sided knitting fabric at three stitch densities of 7.5, 8.4 and 9.3 using

Hereinafter, the double-sided knitting knitted in Figure 7.5 is referred to as Example 1, the double-sided knitting knitted in Figure 8.4 is referred to as Example 2, and the double-sided knitting knitted in Figure 9.3 is referred to as Example 3.

And, in order to further observe the effect of the thickness of the yarn on the occurrence of laddering, using the same circular knitting machine with a filament yarn of polyester DTY 35d/73f thinner than Examples 1 to 3, a double-sided knitting structure was knitted in the figure of 8.4. .

Hereinafter, the double-sided knitting structure made of the polyester DTY 35 d/73 f filament yarn is referred to as Example 4. In the following description, the ultrafine double-sided knitted fabric will be referred to as a specimen and described.

The length L2 of the specimen 10 in the wale direction W was 6 cm, and a flaw 11 having a length L1 of 1 cm was made in advance at one end of the sample 10 in the wale direction W. . In the present embodiment, laddering may be generated at the portion where the scratch 11 ends in each sample 10 .

15(a) and 15(b) show the effects of the tonsils on the tensile properties of Examples 1 to 3 in which other knitting conditions were fixed and the tonsils were knitted into three types of 7.5, 8.4, and 9.3. It is a graph showing strength (strength) and elongation (extension) compared after measuring each in the wale direction and the coarse direction. Hereinafter, in the test, the test is performed 5 times for each example.

Referring to FIG. 15( a ), in the wale direction, it can be seen that Example 2 has greater strength than Example 1 and Example 3 has greater strength than Examples 1 and 2 . In addition, in the coarse direction, it can be seen that Example 2 has less strength than Example 1, and Example 3 has less strength than Examples 1 and 2.

Referring to FIG. 15(b) , in the coarse direction, it can be seen that Example 2 has a greater elongation than Example 1, and Example 3 has a greater elongation than Examples 1 and 2. And, in the wale direction, Examples 1 to 3 did not show a significant difference in elongation.

That is, in the case of strength, it can be seen that as the tonsil neck increases, the strength in the wale direction increases but the strength in the coarse direction decreases. It can be seen that there is no effect

16 is a graph showing the results of the laddering experiment of Examples 1 to 3 in which the tonsil neck was different and the fungus was compared, and the load generated by laddering according to the change of the tonsil neck was compared.

16, Example 1 shows a load of 2N or more, Example 2 has a smaller laddering load than Example 1, and Example 3 has a smaller laddering load than Examples 1 and 2, which is less than 1N. can be checked

Therefore, as the value of the knitted fabric increases, the load generated by laddering becomes smaller, and when the yarn thickness is the same, it can be seen that the elongation in the course direction is not a factor affecting the laddering, even if the thickness of the knitted fabric is different. can

17 is a graph showing the comparison of tensile strength (tenacity) of Example 1 and Example 4, Figure 18 is a graph showing comparing the elongation (extension) of Example 1 and Example 4.

17 and 18 , Example 1 and Example 4 showed no significant difference in tensile strength, but Example 4 showed a larger value than Example 1 in elongation.

It can be seen that the elongation is large in Example 4, in which the one-way neck is relatively large due to the difference in the one-way neck since the one-way neck is selected in consideration of the loop density of the knitted fabric according to the thickness of the yarn.

19 is a graph showing a comparison of the load generated by laddering in Example 1 and Example 4. FIG.

Referring to FIG. 19 , in the case of Example 4 having a thick yarn, it can be seen that laddering does not occur easily compared to Example 1. In general, it is considered that a knitted fabric with good elasticity suppresses the occurrence of laddering, and when this result is compared with the tensile test results of FIGS. 17 and 18 , the elongation in the coarse direction seems to have an effect here as well.

However, these results are contrary to the results of FIG. 16 described above. Therefore, rather than the effect of elongation, it is reasonable to interpret that as the thickness of the constituent yarns of the knitted fabric increases, the contact friction between the loops increases, and the tension that causes the loops to fall is dispersed, thereby increasing the strength of laddering.

In this way, factors affecting laddering were derived and reviewed from the results obtained from factors that are different from those generally used through the previous test. The occurrence of laddering is compared using the tightness factor that expresses .

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited by the appended claims. Therefore, various types of substitution, modification and change will be possible by those skilled in the art within the scope not departing from the technical spirit of the present invention described in the claims, and it is also said that it falls within the scope of the present invention. something to do.

10: ultra-fine double-sided knitting
11: Scratches
12: first area
13, 14: second area
21, upper jaw
22: lower jaw

Claims (7)

Using a laddering test device for ultra-fine double-sided knitted fabrics, the upper and lower jaws of the ultra-fine double-sided knitted fabric are respectively fixed with an upper and lower jaw so that the upper and lower intervals are 2 cm
The ultrafine double-sided knitted fabric is made to have a length of 6 cm in the wale direction, and a 1 cm long flaw is formed in the center in the coarse direction to control the generation position of the ladder at a position that becomes one end in the wale direction. The part where the scratch ends is opened so that laddering occurs,
After several tests, the average value of strength and elongation at the time of laddering occurrence is calculated to calculate the laddering load, but using the tightness factor (K) and the laddering analysis factor 1/l ² to be evaluated as
The tightness fact can be obtained from Equation 1 below, tex is the texturing value of the yarn, and l is the loop length (cm).

--- Equation 1 According to claim 1, wherein the laddering test apparatus of the ultra-fine double-sided knitted fabric,
The upper and lower jaws are arranged at an interval of 2 cm above and below to secure the upper and lower parts of the ultra-fine double-sided knitted fabric, respectively, and have a size in which the ultra-fine double-sided circular knitted fabric having a length of 6 cm in the wale direction can be fixed. ;
a driving unit for moving the upper jaw and the lower jaw apart in the vertical direction so that the ultra-fine double-sided knitted fabric is pulled in the vertical direction; and
a measuring unit that measures the strength and elongation of the ultra-fine double-sided knitted fabric when laddering occurs in the ultra-fine double-sided knitted fabric; including,
A laddering test method for extra-fine double-sided knitted fabrics, characterized in that the average value of strength and elongation at the time of laddering occurrence after several tests is calculated by the measurement unit to calculate the laddering load. According to claim 1, wherein the microfine double-sided knitted specimen,
Using 1.67 tex, 2.222 tex, and 3.333 tex polyester DTY filament yarns, and knitting yarns in 30 inches with two types of double-sided circular knitting machines of 48G (gauge) and 52G. Ladder test method for double-sided knitting. delete delete delete delete

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