A ustralian Patents Act 1990 - Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title Bale wrap The following statement is a full description of this invention, including the best method of performing it known to me/us: P/00/0 I I BACKGROUND OF THE INVENTION Field of the Invention [01] The present invention relates to a wrapping net fabric, and more particularly, to a wrapping net fabric having a high tensile strength to weight because of .an improved structure of wrap yarns. Background Art [02] In general, a wrapping net fabric includes warp yarns spaced apart from each other at predetermined intervals; and a connection yarn, which is woven between the warp yarns in zigzags into the mesh. [03] The wrapping net fabric is easily used for wrapping goods instead of a rope, and recently, is frequently used for tying sedges by units at the stage before a bale-wrapping silo. [04] A conventional net fabric for the bale-wrapping silo includes: single-ply warp yarns made of 350-450 denier of 0 polyethylene monofilament, which are spaced apart from one another at an interval of one inch; and a single-ply connection yarn made of 350-450 denier of polyethylene monofilament, which is woven between the warp yarns in zigzags into the mesh. - la - [05] In the case of the most of the net fabrics, when the sedges are wrapped and tied by a predetermined unit, because the warp yarns are under more power than the connection yarn, the connection yarn is made with a single-ply yarn but the warp yarns are made with triple-ply looped threads. [06] However, in order to make the net fabric with the looped threads, because the thread must be bent to form loops, the looped threads gets 30% to 40% less in tensile strength than straight threads before the treads are bent. [07] Moreover, because it take lots of time to produce the warp yarns finely but the warp yarns to which the external force is applied are not durable and easily broken, the net fabric may be unraveled, and hence, work of tying the sedges cannot be carried out smoothly. In order to solve the above problems, Korean Patent No. 1,019,465 discloses a net fabric 2 for a bale-wrapping silo including: double-ply warp yarns 4 made of 350-450 denier of polyethylene monofilament, which are spaced apart from one another at an interval of two inches; and a single-ply connection 0 yarn 6 made of 350-450 denier of polyethylene, which is woven between the warp yarns 4. [08] In the net fabric 2, the warp yarns 3 to which much power is applied are made with double-ply threads and made of a polyethylene monofilament yarn, which is higher in tensile -2strength than a polyethylene film yarn, but are spaced apart from one another at an interval of two inches, and hence, the net fabric 2 is durable and has a higher production yield to weight of yarns. [09] However, because the above-mentioned net fabric is also made with triple-ply looped yarns, the net fabric has a loss of tensile strength by 30% to 40% while the process of forming the looped yarns and does not have a sufficient tensile strength to weight of yarns, and hence, the net fabric is not economical due to expensive manufacturing costs. SUMARY OF THE INVENTION [10] Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior arts, and it is an object of the present invention to provide a wrapping net yarn, which has a higher tensile strength to weight of yarns and has good competitive price because of inexpensive manufacturing costs. [11] To accomplish the above object, according to the 0 present invention, there is provided a wrapping net yarn, which includes warp yarns and a connection yarn woven between the warp yarns in zigzags into the mesh, wherein the warp yarn has single ply (t1) looped yarns of 150-400 denier and a single-ply (t2) straight column yarn of 400-1,000 denier arranged between the -3warp yarns and the sum of the product of total plies (3t1) of the looped yarns and 0.6 and the ply (t2) of the straight column yarn is 900 denier to 1,500 denier. [12] In the wrapping net fabric according to the present invention, the warp yarns has the looped yarns of the smallest thickness because of a loss of tensile strength and the straight yarn arranged between the looped yarns because it has no loss of tensile strength, so that the wrapping net fabric has a higher tensile strength to weight of yarns and has good competitive price due to inexpensive manufacturing costs because weight of the yarns can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS [13] The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiment of the invention in conjunction with the accompanying drawings, in which: [14] FIG. 1 is a perspective view of a wrapping net fabric according to a preferred embodiment of the present invention; and 0 [15] FIG. 2 is a plan view of the wrapping net fabric of FIG. 1. -4- DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [16] Description will now be made in detail of preferred embodiment of the present invention with reference to the attached drawings. [17] In warp yarns of a net fabric according to the present invention includes warp yarns, looped yarns having a great loss of tensile strength have the smallest thickness to just keep the form, and a straight column yarn, which is thicker than the looped yarns in order to reinforce the tensile strength of the warp yarns, is arranged between the looped yarns so as to maximize the tensile strength to weight of yarns. [18] FIG. 1 is a perspective view of a wrapping net fabric according to a preferred embodiment of the present invention, and FIG. 2 is a plan view of the wrapping net fabric of FIG. 1. [19] Referring to FIGS. 1 and 2, the wrapping net fabric 2 according to the preferred embodiment of the present invention includes: warp yarns, each of which has the looped yarns 8 and the straight column yarn 10, being space apart from one another at predetermined intervals; and a connection yarn 6 woven between 0 the warp yarns 4 in zigzags into the mesh. The weaving of the wrapping net fabric 2 may be performed using a raschel knitting machine. -. 5 - [20] The warp yarns 4 and the connection yarn 6 may be made with polyethylene yarns, nylon yarns, polypropylene yarns, and so on, but the most preferably, polyethylene yarns. [21] Polyethylene monofilament yarns out of the polyethylene yarns are higher in draw rate than polyethylene yarns, and in this instance, because the draw rate is proportional to the degree of crystalization and density and density is proportional to tensile strength, the polyethylene monofilament yarns are greater in tensile strength than the polyethylene film yarns. [22] In fact, in Korea, the polyethylene monofilament yarns are 30% to 40% greater in tensile strength than the polyethylene film yarns but 30% to 40% cheaper than the polyethylene film yarns. 5 [23] In the wrapping net fabric 2 of the present invention, the looped yarns 8 and the connection yarn 6 are made with polyethylene monofilament yarns, and the straight column yarns 10 are polyethylene film yarns of different colors arranged by turns so as to provide an esthetic sense of the wrapping net fabric 2. 20 [24] The warp yarn 4 of the wrapping net fabric 2 is constructed of the looped yarns 8 and the straight column yarn 10 arranged between the looped yarns 8. The looped yarns 8 are constructed of three strands woven and knitted into loop knots -6- (k), and the straight column yarn 10 passes through the loop knots (k) of the looped yarns 8. [25] In general, the looped yarns 8 are woven through the process that the machine produces more than 1,000 loops per a minute while rotating at rapid rate of 800rpm to 1,200rpm, and most of the looped yarns 8 lose much tensile strength due to frictional heat and repetition of twisting and bending during the weaving process, and the woven form is very insecure due to a continuation of the loop knots, which are formed by the yarns bent. [26] In this field, it is generally supposed that the looped yarns 8 lose 30% to 40% of tensile strength, and in the present invention, it is supposed that the looped yarns 8 lose 40% of tensile strength. [27] In the present invention, the looped yarns 8 having a great loss of tensile strength are made of single-ply (ti) yarns of 150 to 400 denier, which is the smallest thickness to keep only the form of the wrapping net fabric 2, and the straight column yarn 10 having no loss of tensile strength is made of 0 single-ply (t2) yarns of 400 to 1,000 denier. [28] The numerical values of the looped yarns 8 and the straight column yarn 10 were obtained through various experiments by the inventor of the present invention in order to keep the -7form of the looped yarns 8 of the wrapping net fabric 2 and to maximize the tensile strength to weight. (29] Within the range of the above-mentioned numerical values, if the thickness (ti) of the looped yarn 8 is inferior to the lowest limit, the form of the looped yarns 8 cannot be kept in the wrapping net fabric 2, but if the thickness (ti) of the looped yarn 8 exceeds the upper limit, the yarns may become too heavy and may have a decreased tensile strength to weight. [30] Moreover, within the range of the above-mentioned numerical values, if the thickness (t2) of the straight column yarn 10 is inferior to the lowest limit, the tensile strength to weight is reduced because the thickness (ti) of the looped yarns 8 is increased, but if the thickness (t2) of the straight column yarn 8 exceeds the upper limit, the looped yarn 8 may not keep its form because the thickness (ti) of the looped yarns 8 is relatively reduced. [31] Weight of yarn is proportional to the sum of thicknesses of yarns, and the total weight of the warp yarns 4 can be calculated by 'Thickness of warp yarn x length of yarn + 0 9,000 x the number of warp yarns' based on that weight of a 9,000m yarn of 1 denier is 1g. [32] Therefore, on the supposition that length of the yarn is equal to the number of the warp yarns 4, smaller thickness (3t1+t2) of the warp yarns 4 leads less weight of yarns. -8- [33] In the present invention, based on the single-ply (t1) of the looped yarn 8 of 150 to 400 denier and the single-ply (t2) of the straight column yarn 10 of 400 to 1, 000 denier, it is confirmed that thickness (3t1+t2) of the warp,yarns 4 is within a range of 850 to 2,200 denier. [34] Compared to Korean Patent No. 1,019,465 disclosing the wrapping net fabric in which the warp yarn is the double-ply yarn of 350 to 450 denier and the sum of the thicknesses of the warp yarns is ' (350 to 450)x2x3 = 2,100 to 2,700', the numerical value of the thickness of the warp yarns 4 according to the present invention is very small. Moreover, the present invention is smaller in weight of yarns than the wrapping net fabric disclosed in Korean Patent No. 1,019,465. [35] Furthermore, the tensile strength of the warp yarns 4 having the looped yarns 8 and the straight column yarn 10 can be indicated by the sum of 'thickness (ti) of the looped yarn 8x3x0.6', which is a numerical value of the tensile strength of the looped yarn 8 in consideration of the 40% loss, and 'thickness (t2) of the straight column yarn 10', which is a 0 numerical value of the tensile strength of the straight column yarn 10. (36] In other words, tensile strength of the warp yarn 4 can be calculated by 'thickness (ti) of the looped yarn 8x3x0.6 + thickness (t2) of the straight column yarn 10' , and in the case -9that the looped yarns 8 are double-ply yarns, multiply 'thickness (t1) of the looped yarn 8x3x0.6 + thickness (t2) of the straight column yarn 10' by two. [37] Tensile strength of the wrapping net fabric 2 of the present invention must exceed the tensile strength of the conventional wrapping n6t fabric, and hence, the numerical value of tensile strength was calculated based on the tensile strength of the wrapping net fabric disclosed in Korean Patent No. 1,019,465. [38] The wrapping net fabric disclosed in Korean Patent No. 1,019,465 uses double-ply warp yarns of 350 to 450 denier of polyethylene monofilament, which are two times higher in tensile strength than warp yarns of the wrapping net fabric made with single-ply polyethylene film yarns of 350 to 450 denier, which are generally used in the field. [39] Because the wrapping net fabric disclosed in Korean Patent No. 1,019,465 uses double-ply looped yarns of 350 to 450 denier, in consideration of the 40% loss, thee tensile strength of the yarn is 350x0.6x2x3 to 450x0.6x2x3, namely, 1,260 to 1,620 0 denier. [40] In the present invention, in consideration of the above-mentioned numerical value, the tensile strength of the warp yarn 4 may be within in a range of 900 to 1,500 denier, which is -10calculated by 'thickness (ti) of the looped yarn 8x3x0.6 + thickness (t2) of the straight column yarn 10'. [41] A user can regulate the thickness (t1) of the looped yarns 8 and the thickness (t2) of the straight column yarn 10 within a range that 'thickness (ti) of the looped yarn 8x3x0.6 + thickness (t2) of the straight column yarn 10' keeps 900 to 1,500 denier. [42] Because the looped yarns 8 and the straight column yarn 10 are different from each other in draw rate, if they are arranged in the same warp yarns 4, it may cause a problem. However, in the present invention, the looped yarns 8 and the straight column yarn 10 of the warp yarns 4 can have similar draw rates while the wrapping net fabric 2 completely woven is thermally treated through a heat treatment device. [43] In the meantime, the connection yarn 6 of the wrapping net fabric 2 of the present invention may be woven in zigzags every two knots of the warp yarn 4. When the wrapping net fabric 2 wraps and ties sedges by a predetermined unit, because the connection yarn 6 receives weaker power than the warp yarn 4, 0 thickness (t3) of the connection yarn 6 is within a range of 150 to 300 denier, which is smaller than that of the warp yarn 4. [44] Additionally, the warp yarn 4, which receives much power, is constructed of the looped yarns 8 and the straight column yarn 10 arranged between the looped yarns 8 in order to -11Ienhance the tensile strength, and a distance (d) between the warp yarns 4 is once or twice wider than a distance between the warp yarns of the conventional wrapping net fabric woven with polyethylene film yarns, preferably, one to two inches. [45] The wrapping net fabric 2 according to the present invention may have one of various sizes, for instance, 1m, 1.25m, 1.30m and 1.60m, according to sizes of bale-wrapping silos. [46] Now, in order to find out the tensile strength to weight of the wrapping net fabric 2 according to the present invention, the wrapping net fabric 2 according to the present invention will be compared with the wrapping net fabric disclosed in Korean Patent No. 1,019,465. [47] It is assumed that all of the two wrapping net fabrics are 1.25m in width and 3,000m in length and has 34 warp yarns and 33 connection yarns per one breadth. Additionally, it is assumed that the connection yarn is a single-ply yarn of 300 denier in thickness (t3). [48] In the case that the wrapping net fabric 2 of the present invention has looped yarns 8 of 250 denier and the 0 straight column yarns 10 of 800 denier, tensile strength of the looped yarns 8 is 250x3x0.6 denier when multiplying the looped yarn by three in consideration of the 40% loss because there are three strands of yarns of 250 denier, and tensile strength of the straight column yarn 10 is 800 denier because there is no loss. -12- [49] Moreover, tensile strength of the warp yarn 4 having the looped yarns 8 and the straight column yarn 10 is 250x3x0.6 + 800 = 1,250 denier to keep the tensile strength of the yarns. [50] Furthermore, based on that weight of a 9,000m yarn of 1 denier is lg, weight of the yarn is denier x length of yarn+9,000mxthe number of yarns. [51] Accordingly, the looped yarns 8 according to the present invention weigh 2.83kg, which is calculated by 250 denierx3,000+9,000mx 3 4 , and the straight column yarns 10 weigh 9.07kg, which is calculated by 300 denierx3,000+9,000mx 3 3 . [52] Additionally, the sum of the weight of the looped yarns 8 and the weight of the straight column yarns 10 is '2.83+9.07+3.3=15.2kg', and the wrapping net fabric 2 according to the present invention requires yarns of 16.72kg when an ease of 10% is added. [53] In the meantime, assuming that the wrapping net fabric disclosed in Korean Patent No. 1,019,465 includes the warp yarns having just the looped yarns and uses the double-ply yarns of 350 denier, which is the lowest value within the range of 350 to 450 denier described in Claim 1, tensile strength of the warp yarn is '350x6x0.6=1,260 denier' because there are three strands of double-ply yarns of 350 denier. -13- [54] Moreover, the warp yarns weigh 23.8kg, which is calculated by 350x6x3,000+9,000mx34, and the connection yarns weigh 3.3kg, which is calculated by 300x3,000+9,000mx33. [55] In addition, the sum of the weight of the warp yarns and the weight of the connection yarns is '23.8+3.3=27.1kg', and the wrapping net fabric 2 in which the wrap yarns have just the looped yarns requires yarns of 29.81kg when an ease of 10% is added. [56] As a result, the wrapping net fabric 2 according to the present invention can keep the tensile strength of the yarns of 1,250 denier using the yarns of 16.72kg, but the wrapping net fabric disclosed in Korean Patent No. 1,019,465 keeps the tensile strength of the yarns of 1,260 denier using the yarns of 29.81kg. [57] That is, the wrapping net fabric 2 according to the present invention has similar tensile strength using yarns, which are a half heavier than the yarns of the wrapping net fabric disclosed in Korean Patent No. 1,019,465. [58] Accordingly, the wrapping net fabric 2 according to the present invention has a higher tensile strength to weight of 0 yarns and has good competitive price because of inexpensive manufacturing costs and a minimized weight of the yarns. [59] While the present invention has been described with reference to the particular illustrative embodiment, it is not to -14be restricted by the embodiment but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiment without departing from the scope and spirit of the present invention. The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. The reference numerals in the following claims do not in any way limit the scope of the respective claims. - 15-