CN110662860A

CN110662860A - Double raschel fabric

Info

Publication number: CN110662860A
Application number: CN201880027058.1A
Authority: CN
Inventors: 水上范隆; 白崎文雄
Original assignee: World Federation Corp
Current assignee: World Federation Corp
Priority date: 2017-06-22
Filing date: 2018-06-15
Publication date: 2020-01-07
Also published as: JPWO2018235738A1; JP7152108B2; US20210130993A1; WO2018235738A1

Abstract

A double Raschel braid which has excellent strength despite having an opening. The double raschel fabric comprises a front surface and back surface ground structure and a connecting part connecting the front surface and back surface ground structures, wherein the front surface ground structure has an opening, and the total superposed fineness of the sinker loops of the back surface ground structure calculated by the following formula is 400 to 1800dtex [ formula 1]]

Description

Double raschel fabric

Technical Field

The present invention relates to a double raschel knit.

Background

Conventionally, a double raschel fabric in which a front ground structure and a back ground structure are connected by a connecting portion formed of connecting yarns has been known as a structure in which a plurality of openings are formed in the front ground structure and the back ground structure. For example, in the invention of patent document 1, such an opening functions as a vent hole. Generally, such an opening is formed by a knitted structure, and penetrates through a surface ground structure and a back ground structure of a double raschel knit fabric.

However, the strength of the double raschel knit is reduced because of the formation of the openings. Further, if the double raschel knit fabric having the openings formed therein is used for a long period of time, there is a risk that the strength of the base structure having the openings formed therein is further reduced.

However, attempts have been made to improve the strength of the entire warp knitted fabric, not only the double raschel knitted fabric. For example, patent document 2 proposes a warp knitted fabric elastic material including: "the warp knitted cloth elastic material is a cloth elastic material composed of warp knitted fabric, the warp knitted fabric is composed of more than 95 wt% of a plurality of fibers, characterized in that, the bottom structure of the warp knitted fabric is composed of more than 3 guide bars, at least 1 guide bar forms chain knitting, at least 2 guide bars form tricot knitting with more than 1 needle and less than 8 needles, the shogging direction of at least 2 guide bars forming the tricot knitting is different shogging direction, the relationship between the number of courses (C) and the number of wales (W) of the bottom structure is 0.8W ≦ C ≦ 1.5W". According to the description of patent document 2, the warp knitted fabric elastic material having such characteristics has high surface rigidity and high strength.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-

Patent document 2: japanese patent laid-open publication No. 2013-7143

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made as one of the above-mentioned attempts, and an object thereof is to provide a double raschel knit fabric which has excellent strength despite having an opening.

Means for solving the problems

The double Raschel knitted fabric of the present invention comprises a front surface ground structure, a back surface ground structure and a connecting portion for connecting the front surface ground structure and the back surface ground structure, wherein the front surface ground structure has an opening, and the total fineness of a sinker loop of the back surface ground structure, which is calculated by the following equation, is 400 to 1800dtex,

[ equation 1]

[ Effect of the invention ]

The double raschel knit fabric of the present invention has a total fineness of superposed sinker loops of 400 to 1800dtex in the back ground structure, and therefore has excellent strength despite having openings in the front ground structure.

Drawings

Fig. 1 is a view illustrating an opening of a surface ground structure.

Fig. 2 is a diagram illustrating the number of sinker loops overlapping when the back ground structure is formed of two warp flat knitted structures.

Fig. 3 is a view illustrating the number of sinker loops overlapping when the back surface base structure is formed of a warp plain weave structure and a 2-needle laterally shifted rib weave structure.

Fig. 4 is a view illustrating the number of sinker loops overlapping when the back surface base structure is formed of a warp plain weave structure and a 3-needle-lateral-movement rib weave structure.

Fig. 5 is a diagram illustrating the number of sinker loops overlapping when the back ground weave is composed of two warp flat weaves and a 3-needle-side wale weave, and the yarn laying direction of the back of the needle of the two warp flat weaves is different.

Fig. 6 is a cross-sectional view of a double raschel braid.

Fig. 7 is a view of the knitting unit of the double raschel knitting machine viewed from the lateral direction (the same direction as the direction in which knitting needles are arranged).

FIG. 8 is a schematic organization chart of example 1.

FIG. 9 is an organization chart of example 2.

FIG. 10 is an organization chart of example 3.

FIG. 11 is an organization chart of example 4.

FIG. 12 is an organization chart of example 5.

FIG. 13 is an organization chart of example 6.

FIG. 14 is an organization chart of example 7.

FIG. 15 is an organization chart of example 8.

FIG. 16 is an organization chart of example 9.

FIG. 17 is an organization chart of example 10.

FIG. 18 is a schematic structural view of comparative example 1.

FIG. 19 is a schematic structural view of comparative example 2.

FIG. 20 is a schematic structural view of comparative example 3.

FIG. 21 is a schematic structural view of comparative example 4.

FIG. 22 is a schematic structural view of comparative example 5.

FIG. 23 is a schematic structural view of comparative example 6.

Detailed Description

In order to implement the mode of the invention

The double raschel knit of the present invention is explained below. In the following description, when a range is expressed as "(numerical value)" to (numerical value) ", numerical values on both sides of the range are included in the range. In the following description, the three components "a and B", "a" and "B" may be collectively expressed as "a and/or B".

The double raschel knit is one of warp knit fabrics, having a surface ground and an inner ground, i.e., a surface ground and an inner ground. The double raschel knit fabric further has a joining portion joining the surface ground structure and the back ground structure. The connecting part is formed by connecting yarns.

In the double raschel knit fabric of the present invention, the surface ground structure has an opening. The opening is formed of a woven structure, and penetrates the surface base structure in a direction perpendicular to the surface of the surface base structure. The opening is formed at a portion where adjacent coils are not connected in the lateral direction, for example, as indicated by a two-dot chain line denoted by symbol H in fig. 1. Fig. 1 shows a knitting structure formed by 2 guide bars, and yarns are arranged on the 2 guide bars so as to be 3in3out (3-in and 3-out), respectively. In fig. 1, the solid line indicates the weave of the yarn fed from 1 bar, and the broken line indicates the weave of the yarn fed from the other 1 bar. The weave structure of the surface ground weave having the openings is not limited, but may be, for example, a mesh weave composed of yarns fed from 2 guide bars. The specific structure of the surface base structure having the opening is described later.

Further, in the double raschel knit fabric of the present invention, the total fineness of overlap of sinker loops in the back ground structure is 400 to 1800 dtex. Here, the total fineness of the sinker loop overlapping in the back ground structure was calculated by the following equation.

[ equation 1]

In this equation, the ground yarn means a yarn forming the back ground weave. The needle back lapping yarn number of the ground yarn means the needle back lapping yarn number of the ground yarn in the back ground weave. The guide bar is a guide bar for knitting the back ground weave, and n is the number of guide bars used for knitting the back ground weave. The yarn passing ratio of the guide bar means a ratio of the number of guides through which the yarn passes to the number of all guides included in the guide bar. For example, the yarn passing ratio when the yarn is supplied to the guide bar to the maximum is 1.00, the yarn passing ratio when the yarn is supplied to the guide bar to 2in2out or 3in3out is 0.50, the yarn passing ratio when the yarn is supplied to the guide bar to 3in1out is 0.75, and the yarn passing ratio when the yarn is supplied to the guide bar to 1in3out is 0.25.

According to the above equation, for example, in the case where the back ground weave is constituted by yarns supplied from 1 bar,

overlap Total denier of settling arc (dtex)

The fineness (dtex) of the ground yarn is multiplied by the number of the needle back laying yarns of the ground yarn and the yarn passing ratio of the guide bar is multiplied.

In addition, for example, in the case where the back ground stitch is composed of yarns fed from 2 guide bars,

overlap Total denier of settling arc (dtex)

Fineness (dtex) of ground yarn supplied from the 1 st guide bar

X number of underlaps of ground yarns fed from the 1 st bar

Through ratio of x No. 1 guide bar

+ fineness (dtex) of ground yarn supplied from the 2 nd guide bar

X number of underlaps of ground yarn fed from the 2 nd bar

X the draft ratio of the 2 nd bar.

In addition, for example, in the case where the back ground stitch is composed of yarns fed from 3 guide bars,

overlap Total denier of settling arc (dtex)

Fineness (dtex) of ground yarn supplied from the 1 st guide bar

X number of underlaps of ground yarns fed from the 1 st bar

Through ratio of x No. 1 guide bar

+ fineness (dtex) of ground yarn supplied from the 2 nd guide bar

X number of underlaps of ground yarn fed from the 2 nd bar

Through ratio of x No. 2 guide bar

+ fineness (dtex) of ground yarn supplied from the 3 rd guide bar

X number of underlaps of ground yarns supplied from the 3 rd guide bar

X the draft ratio of the 3 rd bar.

In the present invention, the fineness of the ground yarn in the back ground weave, the number of the underlaps of the ground yarn, and the number of the guide bars used for knitting the back ground weave are determined so that the total overlap fineness of sinker loops in the back ground weave falls within the above-described range. The specific structure of the back ground weave including the fineness of the ground yarn and the like will be described later.

Since the total overlap fineness of the sinker loops of the back ground structure is 400 to 1800dtex as described above, the double raschel knitted fabric is excellent in strength despite the opening portion in the front ground structure. Here, examples of the strength which shows particularly excellent characteristics include rupture strength, tensile strength, and joint fatigue strength.

Since the total fineness of the sinker loop overlap of the back ground structure is 400dtex or more, the double raschel knitted fabric is excellent in strength as described above. Further, since the total fineness of the double layer of the sinker loop of the back ground structure is 1800dtex or less, the flexibility and elongation characteristics of the double raschel knitted fabric can be secured, and as a result, the workability such as the sewing property and the nest-attaching property can be improved.

The double raschel knit fabric is more excellent in the above-mentioned effect because the total fineness of the sinker loops of the back ground structure is preferably 500 to 1600 dtex.

The total fineness of the sinker loop in the surface base structure can be calculated from the above-mentioned equation. In the calculation of the total fineness of the sinker loop in the surface ground structure by the above equation, the ground yarn is a yarn forming the surface ground structure, the back lay yarn number of the ground yarn is the back lay yarn number of the ground yarn in the surface ground structure, and the guide bar is a guide bar for knitting the surface ground structure.

The sum of the total fineness of the sinker loops of the surface ground structure and the total fineness of the sinker loops of the back ground structure (hereinafter referred to as "the sum of the total fineness of the sinker loops of the surface and back ground structures") is preferably 650 to 2000 dtex. Since the sum of the total fineness of the sinker loops of the front and back ground stitches is 650dtex or more, the double raschel knitted fabric has excellent strength as described above. Further, since the sum of the total fineness of the sinker loops of the front and back ground stitches is 2000dtex or less, the flexibility and elongation characteristics of the double raschel knitted fabric can be ensured, and as a result, the workability such as the sewing properties and the nest-attaching properties can be improved.

The sum of the total number of overlapped fineness of the sinker loops of the front and back ground textures is more preferably 650 to 1700dtex, and still more preferably 750 to 1600 dtex. If the sum of the total fineness of the sinker loops of the surface and back ground stitches is 650 to 1700dtex, the strength, flexibility and elongation properties of the double raschel knit fabric can be satisfactorily maintained. Further, if the sum of the total fineness of the sinker loops of the surface and back ground stitches is 750 to 1600dtex, the strength, flexibility and elongation properties of the double raschel knit fabric can be further improved.

The fineness of the yarn used in the double raschel knit fabric of the present invention is preferably 84 to 550 dtex. Since the fineness of the yarn is 84dtex or more, the double raschel knitted fabric is excellent in strength. Further, since the fineness of the yarn is 550dtex or less, the flexibility of the double raschel knit fabric is improved, and workability such as sewing property is improved. The material, shape, and the like of the yarn used for the double raschel knit fabric are not particularly limited.

Here, the single fiber (also referred to as single fiber fineness) of the yarn for a double raschel knit fabric of the present invention is preferably 2.3 to 8.3dtex, and more preferably 2.3 to 4.6 dtex. Since the single-fiber of the yarn is 2.3dtex or more, the double raschel knitted fabric is excellent in strength. Further, since the single-fiber of the yarn is 8.3dtex or less, the flexibility of the double raschel knitted fabric is excellent, and workability such as sewing property is excellent. In particular, in the surface ground weave, the ratio of the single-fineness yarn (i.e., 2.3 to 8.3dtex or 2.3 to 4.6dtex) to the entire ground weave (i.e., the ratio of the number of single-fineness yarns to the number of all yarns used in the surface ground weave) is 70% or more, and therefore a double raschel knit fabric having a good quality and texture can be obtained.

When the single-fiber yarn and the multi-fiber yarn are used as the double raschel knit fabric of the present invention, the ratio of the number of the single-fiber yarn to the number of all the yarns used as the double raschel knit fabric is preferably 8 to 40%, and more preferably 8 to 30%. Since the ratio of the number of the single-fiber yarns is 8% or more, the shape retention and strength of the double raschel knit fabric are excellent. Further, since the ratio of the number of the single-fiber yarns is 40% or less, the flexibility of the double raschel knit fabric becomes good, and workability such as sewing property becomes good.

Next, preferred specific structures of the front and back ground structures of the double raschel knit fabric of the present invention will be described.

First, in the double raschel knit fabric of the present invention, the back ground weave is preferably composed of a plurality of knit weaves. That is, the back ground stitch is preferably formed of yarns supplied from a plurality of guide bars, and the yarns supplied from the guide bars form different knitting stitches.

When the back ground stitch is formed of a plurality of knitting stitches, when the directions of the back lapping yarns of the knitting stitches are different, or when the numbers of the back lapping yarns of the knitting stitches are different, sinker loops of the knitting stitches overlap each other as shown in fig. 2 to 5. In the figure, F denotes a course of knitting by the front knitting needle, and B denotes a course of knitting by the back knitting needle.

For example, as shown in fig. 2, the back ground stitch is composed of two knitting stitches, 1 of which is a warp-flat knitting stitch indicated by a broken line, and the remaining 1 is a warp-flat knitting stitch indicated by a solid line, and the directions of the back lapping yarns of the two warp-flat knitting stitches are different. In this case, sinker arcs overlap each other crosswise as in fig. 2. The number of overlapping sinker loops of the inner bottom structure of fig. 2 is 2.

Here, the number of sinker loops of the back ground structure that overlap refers to the number of sinker loops that overlap between 1 wale and 1 course in the back ground structure (in other words, in the back ground structure, within a range surrounded by two adjacent courses in the wale direction and two adjacent courses in the course direction, that is, within a range surrounded by a two-dot chain line in fig. 2 to 5).

The number of the sinker loops of the back ground stitch overlapped with each other is changed depending on the number of the needle back lapping yarns of the knitting stitch constituting the back ground stitch, the number of the knitting stitch constituting the back ground stitch (in other words, the number of the guide bars for knitting the back ground stitch), and the like.

For example, as shown in fig. 3, when the back ground stitch is composed of a warp plain stitch indicated by a broken line and a rib stitch of 2-needle lateral movement indicated by a solid line, the number of sinker loops of the back ground stitch overlapped with each other is 3. As shown in fig. 4, when the back surface stitches are composed of a warp plain stitch indicated by a broken line and a rib stitch of a 3-needle lateral shift indicated by a solid line, the number of sinker loops of the back surface stitches overlapped with each other is 4. As shown in fig. 5, when the back ground weave is composed of a warp flat knit weave indicated by a broken line, a warp flat knit weave indicated by a one-dot chain line, and a rib knit weave of a 3-needle lateral shift indicated by a solid line, and the direction of yarn laying on the back of the two warp flat knit weaves is different, the number of sinker loops of the back ground weave overlapping 5.

In this way, when the back ground weave is composed of a plurality of woven weaves and the sinker loops overlap each other, the average value of the number of overlapping sinker loops of the back ground weave is preferably 2 to 10 pieces/(wale/course).

Here, the average value of the number of the sinker loops of the back surface texture is a value obtained by obtaining the number of the sinker loops at all the portions in one pattern of the back surface texture, obtaining the average value of the obtained number of the sinker loops, and rounding up to a decimal point or less. The reason for obtaining the average value in this way is as follows. First, when all knitting structures constituting the back ground weave are arranged in a full set of yarns (in other words, when knitting is performed by a guide bar that feeds yarns in a full set), the number of sinker loops overlapping is the same at any portion of the back ground weave. However, when at least 1 yarn constituting the knitting structure of the back ground weave is arranged as a cast-off yarn (in other words, when the knitting is performed by a guide bar to which the yarn is supplied in a cast-off state), the number of sinker loops overlapping in the back ground weave differs depending on the portion. This is because, in this case, the average value of the number of overlapping sinker loops of the back ground structure is related to the strength of the double raschel braid and the like.

Since the average value of the number of sinker loops of the back ground structure superimposed is 2 pieces/(wale/course) or more, the double raschel knitted fabric is excellent in strength. Here, examples of the strength which shows particularly excellent characteristics include rupture strength, tensile strength, and joint fatigue strength. Further, since the average number of the sinker loops of the back ground structure superimposed is 10 or less/(wale/course), the flexibility and elongation characteristics of the double raschel knitted fabric can be ensured, and as a result, the workability such as the sewing property and the nest-attaching property can be improved.

The average value of the number of the sinker loops of the back ground structure overlapping is more preferably 3 to 7 pieces/(wale/course). Thereby, the above-described effect of the double raschel knit becomes more excellent.

In the case where the surface ground structure is composed of a plurality of knitting structures and the sinker loops of the knitting structures overlap with each other, the average value of the number of overlapping sinker loops of the surface ground structure can be obtained by the same method as that of the back ground structure. In addition, when the sinker loops of the plurality of knitting structures overlap each other in each of the front ground structure and the back ground structure, the sum of the average value of the number of the sinker loops of the front ground structure and the average value of the number of the sinker loops of the back ground structure, which overlap each other, is preferably 4 to 15 pieces/(wale/course).

Since the sum of the average value of the number of sinker loops of the surface ground structure superimposed on the average value of the number of sinker loops of the back ground structure is 4 pieces/(wale/course of stitches) or more, the double raschel knit fabric is excellent in strength. Here, examples of the strength which shows particularly excellent characteristics include rupture strength, tensile strength, and joint fatigue strength. Since the sum is 15 pieces/(wales/courses) or less, the flexibility and elongation characteristics of the double raschel knit fabric can be ensured, and as a result, the workability such as the sewing properties and the fitting properties can be improved.

The sum of the average value of the number of sinker loops of the surface base structure superimposed on the average value of the number of sinker loops of the back base structure is more preferably 6 to 11 pieces/(wale/course of coil). Thereby, the above-described effect of the double raschel knit becomes more excellent.

Next, a case where the back surface base structure has a rib knitting structure will be described. In the case where the back ground weave is composed of a plurality of weave weaves, at least 1 of the plurality of weave weaves is preferably a rib weave. Thus, the number of the underlaps of the rib knit stitch can be adjusted to set the total fineness of the sinker loops superimposed on the back ground stitch to a desired range.

Further, when at least 1 of the plurality of knitting structures of the back surface layer structure is a rib knitting structure, the remaining knitting structure of the back surface layer structure is preferably a warp flat knitting structure and/or a chain knitting structure. That is, the back surface base structure is preferably a combination of a rib knitting structure and a warp flat knitting structure, a combination of a rib knitting structure and a chain knitting structure, or a combination of a rib knitting structure, a warp flat knitting structure, and a chain knitting structure. Since the back ground structure is a combination of these structures, the double raschel knit is excellent in the balance of elongation in each direction. Alternatively, the inner ground structure may be a combination of a rib knit structure and a warp flat knit structure and/or a chain knit structure. Alternatively, the back ground weave may be a combination of a plurality of rib weave weaves and a warp flat weave and/or a chain weave.

In this way, in the case where the back ground stitch is formed of a combination of the rib stitch and the warp flat stitch and/or the chain stitch, the needle loops of the rib stitch and the needle loops of the warp flat stitch and/or the chain stitch may be overlapped in different directions. That is, in the case where the back ground stitch is a combination of a rib knitting stitch and a warp flat knitting stitch, the needle loops of these two stitches may be overlapped in different directions; under the condition that the inner bottom texture is the combination of the wale knitting texture and the chain knitting texture, the needle rings of the two textures can be overlapped in different directions; in the case where the inner ground structure is a combination of the rib knit structure, the warp flat knit structure, and the chain knit structure, the needle loops of the rib knit structure may be overlapped with the needle loops of the other two knit structures in different directions. As a result, the ground yarn of the rib knitting structure and the ground yarn of the warp flat knitting structure and/or the chain knitting structure are pulled in the opposite direction to the wale direction at the needle ring position, and the needle ring becomes large, and as a result, the stretchability of the double raschel knitted fabric is improved.

In the case where the back ground stitch has at least a combination of a rib knitting stitch and a warp flat knitting stitch, it is preferable that the rib knitting stitch and the warp flat knitting stitch are knitted in the same direction to form sinker loops. This makes the double raschel knit fabric excellent in elongation in the longitudinal direction, facilitates knitting and processing of the double raschel knit fabric, and makes it difficult for wrinkles to enter the double raschel knit fabric even when the ground yarn is shrunk.

In the case where the back ground stitch is composed of a rib knitting stitch and a warp flat knitting stitch and/or a chain knitting stitch, the needle loop formed by the rib knitting stitch is preferably a closed loop. This increases the shape of the needle ring. Since the shape of the needle ring is increased, the longitudinal and lateral elongation balance of the double raschel knit fabric is improved, and since the needle ring has meltability, wrinkles are less likely to enter the double raschel knit fabric.

In the case where the back ground stitch is formed of a combination of a rib knitting stitch and a warp flat knitting stitch and/or a chain knitting stitch, the needle loops formed by the warp flat knitting stitch and/or the chain knitting stitch are preferably open loops. Thus, the yarn length of the ground yarn formed by the flat warp knitting structure and/or the chain stitch knitting structure is shortened, the elongation in the transverse direction of the double raschel knitted fabric is suppressed, and the elongation balance is improved.

In the case where the back ground structure is formed of a combination of a rib knitting structure and a warp flat knitting structure and/or a chain knitting structure, it is preferable that the rib knitting structure is arranged on the needle ring side of the back ground structure, and the warp flat knitting structure and/or the chain knitting structure is arranged on the sinker loop side of the back ground structure. In general, the rib knitting structure is a structure having good elongation, but the flat knitting structure suppresses the sinker loop of the rib knitting structure by the above arrangement, and therefore, the longitudinal and lateral elongation can be suppressed.

As described above, when the wale knitting structure is arranged on the needle ring side of the back surface structure and the warp knitting structure and/or the chain knitting structure is arranged on the sinker loop side of the back surface structure, the warp knitting structure and/or the chain knitting structure on the sinker loop side have a large influence on the elongation of the double raschel knitted fabric in the longitudinal direction. Therefore, in this case, if the needle loops formed by the warp plain weave and/or the chain stitch on the sinker loop side are open loops, the above-described effect of suppressing the elongation in the longitudinal direction of the double raschel knitted fabric and improving the elongation balance becomes remarkable, which is particularly preferable.

The case where the back ground weave is composed of a plurality of knitting weaves has been described above, but the back ground weave may be formed of only one knitting weave. For example, the inner ground structure may also be formed from 1 piece of wale weave.

Regardless of the number of knitting structures of the back ground structure, in the case where the back ground structure has a rib knitting structure, the rib knitting structure is preferably laterally shifted by 2 to 8 needles. This facilitates the total fineness of the sinker loops of the back surface ground structure to be overlapped in a desired range. Further, since the rib knitting structure is 2-needle-side shift or more, the double raschel fabric is excellent in strength. Further, since the rib knitting structure is not more than 8-needle-lateral-movement, flexibility and elongation characteristics of the double raschel knit fabric can be secured, and as a result, workability such as sewing properties and nest-attaching properties can be improved.

When the back ground stitch has a wale weave stitch, the wale weave stitch is particularly preferably 3 to 6-needle lateral movement. Thus, the above-described effect of the double raschel knit becomes a more excellent effect.

Regardless of the specific structure of the surface and back ground stitches, the angle formed by the surface and back ground stitches and the connecting yarns in the state where no stress is applied to the double raschel knit fabric is preferably 30 to 85 degrees. The angle formed by the front and back ground stitches and the connecting yarn is an angle θ formed by the front and back ground stitches 1 and 2 and the connecting yarn 4 (an angle at a portion where the angle is smallest) shown in fig. 6. Since the angle formed by the front and back ground stitches and the connecting yarns is 30 degrees or more, even if a force in the thickness direction is applied to the double raschel knit fabric, the double raschel knit fabric maintains the thickness without being crushed. Further, since the angle formed by the front and back ground stitches and the connecting yarn is 85 degrees or less, even if tension is applied to the front and back ground stitches in the longitudinal and transverse directions, the connecting yarn sheet does not largely shift, and deformation is less likely to occur in the double raschel knit fabric.

The angle formed by the surface and back ground stitches and the connecting yarns varies among the connecting yarns, but the angle formed by the surface and back ground stitches and the connecting yarns is preferably 75% or less of the total connecting yarns, which is a ratio of the connecting yarns (ratio calculated by the number of the connecting yarns) of 30 to 85 degrees.

The angle formed by the front and back ground weaves and the connecting yarns is preferably 40 to 85 degrees. The ratio of the binder yarns (the ratio calculated by the number of binder yarns) at which the angle formed by the surface and back ground stitches and the binder yarns is 40 to 85 degrees is more preferably 75% or less of the total binder yarns. This makes the above-described effects, such as the double raschel fabric being less likely to crush, more excellent.

In addition, regardless of the specific structure of the surface and back ground structure, the density of the double Raschel knit fabric is preferably 18 to 60 courses/25.4 mm and 16 to 50 wales/25.4 mm. Since the density is not less than the lower limit, the double raschel knit fabric has good flexibility and workability. Further, since the density is not more than the upper limit, the elongation property is good.

The thickness of the double raschel knit fabric is preferably 2 to 12mm regardless of the specific structure of the surface and back ground structures. Since the thickness is 2mm or more, the seam fatigue strength and the rupture strength of the double raschel knit fabric are excellent. Further, since the thickness is 12mm or less, the flexibility and workability of the double raschel knit fabric are improved.

The thickness of the double raschel knit fabric is more preferably 2 to 8 mm. Since the thickness is 8mm or less, the flexibility and workability of the double raschel knit fabric are further improved.

The breaking strength of the double raschel knit fabric is preferably 1800 to 3800Pa regardless of the specific structure of the surface and back ground textures. Here, the fracture strength refers to the fracture strength measured by the method of the example described later. Since the rupture strength is 1800Pa or more, sufficient durability can be obtained for applications such as vehicle interior materials, and shoes. Further, since the breaking strength is 3800Pa or less, the texture is hard and hard, and wrinkles are hard to enter.

The preferred breaking strength of the double Raschel braid is 1900-3200 Pa. This improves durability, quality and style.

The seam fatigue strength of the double raschel knit is preferably 2.5mm or less, regardless of the specific structure of the surface and back ground textures. Here, the joint fatigue strength refers to the joint fatigue strength measured by the method of the example described later. Since the seam fatigue strength is 2.5mm or less, the ground yarn is less likely to break from the seam, and the double raschel fabric is less likely to break, so that the durability of the double raschel fabric is improved.

The double raschel knit fabric described above is knitted by a double raschel knitting machine which is one type of warp knitting machine. As shown in fig. 7, the double raschel knitting machine has 2 rows of knitting needles N1, N2; guide bars L1 to L6 (shown as L-1 to L-6 in the figure) each having a plurality of guides G1 to G6; and warp beams B1 to B6 for supplying yarns to guide bars L1 to L6, respectively. The symbols M1 and M2 in fig. 7 denote syringes.

The double Raschel knitting machine is preferably 14-28 needle pitches. If the double raschel knitting machine is 14 gauge or more, the quality and style of the knitted double raschel knit fabric are less likely to be coarse and stiff, and the weight per unit area of the double raschel knit fabric is less likely to be heavy, so that workability is less likely to be impaired. Further, if the double raschel knitting machine is at a gauge of 28 gauge or less, the quality and style of the knitted double raschel knit fabric are less likely to be coarse and stiff, and the double raschel knit fabric has good elongation and is less likely to be wrinkled or deformed during use.

Such a double raschel knitting machine knits the double raschel knit of the present invention. When the double raschel knitting machine is operated, the knitting yarns a1 to a6 supplied from the warp beams B1 to B6 are knitted into the double raschel knitted fabric 10 composed of the front ground stitch 1, the back ground stitch 2, and the coupling portion 3 by the movements of the guide bars L1 to L6 and the knitting needle rows N1 and N2.

The double raschel knit fabric knitted by the double raschel knitting machine can be subjected to conventionally known post-processing such as dyeing, heat setting, and the like.

The manufactured double raschel knit fabric of the present invention is used as, for example, interior materials, vehicle interior materials, and shoes. Examples of the vehicle interior material include a seat surface, a backrest, and a headrest of a seat. The double raschel knit fabric of the present invention is excellent in quality and texture and cushioning properties, and has good air permeability and good comfort during sweating because of the openings in the surface ground structure. Further, the double raschel knit fabric of the present invention is excellent in strength as described above. Thus, the double raschel knit of the present invention is at least suitable for the above-mentioned uses.

Next, examples and comparative examples will be described.

[ example 1]

The double raschel knit was knitted using a 22-gauge double raschel knitting machine (RD6 DPLM-77E-22G, manufactured by karl meier). As shown in FIG. 8, 167dtex/48f polyester multifilament yarn was arranged in a full set on a guide bar L-1 to form a 3-needle shogging stitch (1-0/3-4), and 167dtex/48f polyester multifilament yarn was arranged in a full set on a guide bar L-2 to form a warp plain stitch (0-1/2-1), and an inner ground stitch was knitted. Further, a 33dtex/1f polyester monofilament yarn was arranged in a full set on the guide bar L-3, and the front and back ground stitches were connected. Further, 167dtex/48f polyester processed yarn was arranged to 3in3out on the guide bar L-4, and 167dtex/48f polyester processed yarn was arranged to 3in3out on the guide bar L-5, and the surface ground weave was knitted.

The knitted double raschel knit was preset at 190 ℃ for 1 minute by a heat setting machine, dyed with a disperse dye at 130 ℃, then dried, and finally set at 150 ℃ for 1 minute by the heat setting machine to finally obtain a double raschel knit of 34 courses/25.4 mm, 23 wales/25.4 mm, and 3.0mm in thickness. The number of properties of the obtained double raschel knit and the structure of the knit are shown in table 1.

Examples 2 to 10 and comparative examples 1 to 6

Fig. 9 to 23 and tables 1 to 2 summarize the double raschel fabrics of examples 2 to 10 and comparative examples 1 to 6. Unless otherwise stated, the methods for producing the double raschel fabrics of examples 2 to 10 and comparative examples 1 to 6 are the same as in example 1.

Next, evaluation items and evaluation methods of the double raschel knitted fabrics of examples and comparative examples will be described.

[ fatigue strength of joint ]

For the pieces of knitted fabric having a width of 100mm and a length of 100mm, 2 pieces were selected as 1 group in the longitudinal and transverse directions, respectively. Then, the front sides of the 2 knitted fabric pieces were matched with each other, and a position of 7mm from the end of 1 side thereof was sewn up to prepare a test piece.

The conditions for stitching were, knitting needles: DP × 1721 BPD (manufactured by accordion needle corporation), stitch yarn: polyester #8, seam form: flush joint, seam spacing: 5.0 + -0.5 mm. Further, 2 cuts were placed on each of 2 sides parallel to the sewing seam (stitch) of the test piece. Slits were placed at positions 25mm inside from both ends of the side parallel to the sewing seam, respectively. The length of the slit is made 88 mm. 2 sets of such test pieces were prepared in the longitudinal and lateral directions, respectively.

An Amsler type joint fatigue tester (ATD-200L, product of Daorhiki science and precision industries, Ltd.) was used to hold the test piece at an interval of 120mm in the central part of the 3-division by the two slits, and a load of 30N was applied to each side. A2500 stroke test was conducted at a stroke of 150mm and a speed of 30 strokes/min. After the reciprocating test, the maximum value of the size of the hole due to the deviation of the seam of the test piece was measured in a state where a load was applied.

The joint fatigue strength was represented by a value larger in both the longitudinal and transverse directions among 2 sets of test pieces. When the result is 2.5mm or less, the fatigue strength of the joint is excellent.

[ breaking Strength ]

A tensile tester for fabric (TGE-10 kN, product of Membenzama) equipped with a press bar type bursting tool having a diameter of 25mm was used. A press bar was pushed at a speed of 100 mm/min into a round test piece having a diameter of 44mm and taken out of a double Raschel knit fabric, and the maximum point (N) of the test force at that time was converted into Pa to obtain a breaking strength.

[ tensile Strength/elongation ]

3 test pieces having a width of 50mm and a length of 250mm were selected from the longitudinal direction and the lateral direction, respectively, and the reticle was added to the test pieces so that the distance between the reticles became 100 mm. Subsequently, the test piece was mounted on a jig of an instron tester at a gripping interval of 150mm, and an initial load of 1.0N was applied to remove wrinkles and slack. The distance between the gauge lines at the time of maximum load and breakage was measured by drawing at a speed of 200 mm/min.

The average of the maximum loads of the 3 test pieces in the longitudinal direction and the transverse direction was defined as the tensile strength. As long as the results were 392N/50mm or more, it was said to be excellent in tensile strength.

The elongation was calculated from the following formula and represented by the average value of 3 test pieces.

Elongation (L1-L0)/L0 × 100

L0: distance (mm) between marked lines when initial load is applied

L1: distance (mm) between the marking lines at rupture

[ tensile Strength ]

3 test pieces having a width of 50mm and a length of 250mm were selected from the longitudinal direction and the transverse direction, respectively. Next, a 10mm slit was cut at the center of the test piece in the longitudinal direction at right angles to the sides of the test piece, and an isosceles trapezoid mark having a short side of 100mm and a long side of 150mm was added so that the slit became the center of the short side of the isosceles trapezoid. Next, the portions on both oblique sides of the isosceles trapezoid marked on the test piece were attached to the grips of the Instron-type testing machine at a 100mm gripping interval. Here, the trapezoidal shape is attached so that the short side is in a tensioned state and the long side is in a relaxed state. Then, the specimen was pulled apart at a rate of 200 mm/min until the specimen was cut, and the maximum load was measured. The average value of the maximum load was obtained for each of the 3 test pieces in the vertical direction and the 3 test pieces in the horizontal direction, and the average value was defined as the respective tensile strength in the vertical direction and the horizontal direction. As long as the result was 78.4N or more, it was said to be excellent in tensile strength.

The evaluation results of the double raschel knitwear of the examples and comparative examples are shown in tables 3 to 4. The evaluation results of the examples were confirmed to be good.

[ TABLE 3 ]

[ TABLE 4 ]

Description of symbols:

A1-A6: braided yarn

B1-B6: warp beam

G1-G6: guide member

H: opening part

L1-L6: guide bar

M1-M2: needle cylinder

N1-N2: knitting needle row

1: surface ground texture

2: inner bottom texture

3: connecting part

4: connecting yarn

10: a double raschel braid.

Claims

1. A double Raschel knitted fabric comprising a front surface and a back surface ground structure and a connecting portion connecting the front surface and the back surface ground structure, characterized in that the front surface ground structure has an opening portion, and the total fineness of the back surface ground structure at which sinker loops calculated by the following equation overlap is 400 to 1800dtex,

[ equation 1]

2. A double raschel knit fabric according to claim 1, wherein the sum of the total fineness of the sinker loops of the surface ground structure and the total fineness of the sinker loops of the back ground structure is 650 to 2000 dtex.

3. A double raschel knit fabric according to claim 1, wherein the back surface base structure is composed of a plurality of knit structures, and the average value of the number of sinker loops of the back surface base structure that overlap is 2 to 10 pieces/(wale/course).

4. A double raschel knit fabric according to claim 3, wherein the surface ground structure is composed of a plurality of knit structures, and a sum of an average value of the number of sinker loops of the surface ground structure superimposed on an average value of the number of sinker loops of the back ground structure is 4 to 15 pieces/(wale/course).

5. A double raschel fabric as defined in any one of claims 1 to 4, wherein the back ground weave is composed of a plurality of weave weaves, and at least 1 of the weave weaves is a rib weave.

6. A double raschel knit according to claim 5, wherein the back ground structure is a combination of a rib knit structure and a warp flat knit structure and/or a chain knit structure.

7. A double raschel fabric as defined in claim 5 or 6, wherein the wale weave forming the back ground weave is a 2-8 needle-traverse.

8. A double raschel knit fabric according to claim 6, wherein the needle loops of the wale knit structure forming the back ground structure and the needle loops of the warp flat knit structure and/or the chain knit structure forming the back ground structure are overlapped in different directions to form needle loops.

9. A double raschel fabric as defined in claim 6 or 8, wherein the wale weave forming the back ground weave and the warp flat weave perform needle back lapping in the same direction to form sinker loops.

10. A double raschel knit according to any one of claims 6, 8 and 9, wherein the needle loops formed by the wale knit forming the back ground stitch are closed loops.

11. A double Raschel knitted fabric according to any one of claims 6, 8, 9 and 10, wherein the loops formed by the tricot flat knitting structure and/or the chain stitch forming the back surface ground structure are open loops.

12. A double Raschel braid according to any one of claims 1 to 11, wherein the breaking strength is 1800 to 3800 Pa.

13. A double Raschel braid according to any one of claims 1 to 12, wherein the fatigue strength of the seam is 2.5mm or less.