A Basic Study on Establishing the Automatic Sewing Process According to Textile Properties

This study aimed to establish an automatic sewing process for garment production according to textile properties. An automatic feeding system and a self-made template were introduced to an industrial sewing machine. Two types of stitches were performed on fabrics with various physical properties and surface roughness using this automatic sewing machine. The appearance, stitch length and width, seam strength, and seam efficiency were evaluated according to the sewing conditions, such as presser height and sewing speed. In addition, the correlation between textile properties, sewing conditions, and sewability was analyzed to derive a regression equation for sewability. The evaluation showed no difference in the lock stitch condition. On the other hand, under the zigzag stitch condition, the stitch width differed according to the presser height, which also affected the seam structure. The optimal presser height for each fabric was derived from the experimental results. In terms of the sewing speed, however, the seam strength was the best at 200 RPM in the lock stitch and 400 RPM in the zigzag stitch. The moderating effect of the presser height between textile properties and sewability in the lock stitch condition was confirmed. This result can be used as basic data for establishing an automatic sewing process for smart factories.

Modeling the consumption of sewing thread for stitch class 301 through image analysis by using Fourier series

This research work aims at modeling the sewing thread consumption for stitch class 301 through image analysis by using Fourier series. A mathematical model was developed by using the geometry of stitch class 301 for calculating sewing thread consumption. The modeling of stitch class 301 was conducted by changing the stitch density and thickness of the stitched fabric. The stitch density was adjusted by varying the stitch length (2, 3 and 4 mm) and the thickness of stitched fabric (2, 3 and 4 plies of fabric).The interlacement of sewing thread between the needle and bobbin was used for the measurement of arc length of one stitch. The total consumption of sewing thread was determined by multiplying the arc length by 4. The developed model was verified by using nine different stitched samples for comparing the predicted and measured values of sewing thread consumption. This model predicted the sewing thread consumption with 95% accuracy. Error percentages were also calculated for determining the major influencing factors that affected the sewing thread consumption. The proposed model can effectively be employed in garment industries for determining sewing thread consumption.

A study to evaluate the effects of various abdominal closure techniques on midline laparotomy wounds in a tertiary care hospital in West Bengal

Background: Post-operative complications of wound repair after laparotomy pose a major threat to life as well as to the health economy of a developing nation. Among many other factors, the length of suture used during wound closure has been studied for long. A prospective randomized control study comprising of 104 patients was conducted in the department of surgery of Bankura Sammilani medical college for comparing the incidence of SSI, wound dehiscence and incisional hernia after using short stitch and long stitch for repairing midline laparotomy wounds.Methods: Out of 104 patients enrolled in the study, 51 patients were randomly allocated to short stitch group (suture length: wound length>4:1) and 53 patients were allocated to long stitch group (suture length: wound length=4:1) and both the groups were subsequently followed up for development of the three complications.Results: Data analysis revealed that 11.7 % patients in short stitch group developed SSI whereas 24.5% patients in long stitch group developed SSI. Wound dehiscence occurred in 5.8 % of patients in short stitch group against 15% in long stitch group. 7.8% patients in short stitch group developed incisional hernia against 20.7% patients in long stitch group. In all three situations, p value was significant (<0.05).Conclusions: It is concluded from our study that, the rate of SSI, wound dehiscence and incisional hernia is significantly lower in midline abdominal wounds closed with short stitch length than those closed with long stitch length.

Improvement of Elastic Property of Circular Weft Knit Three-Thread Fleece Fabric by Changing Stitch Length

The market demand for three-thread fleece fabric is increasing steadily due to its soft and bulky texture. Garments made from knitted fleece fabric, such as sweaters and jackets, are generally used for outdoor wear, especially in the winter season because of their warmth, moisture, and absorption properties. However, the elastic properties of three-thread fleece fabric is reduced significantly after the raising operation. This study aimed to increase the elastic recovery of three-thread fabric by changing the stitch length during the manufacturing process in industrial-scale production. The results showed that by varying the stitch length, the elastic recovery was improved by around 9%. Hence, the developed method can be used in textile knitting industries to improve the elastic recovery of fleece fabric.

Development of prediction model through linear multiple regression for the prediction of longitudinal stiffness of embroidered fabric

Embroidery through computer aided semi-automatic machines is one of the most widely used option for the surface ornamentation of apparel fabrics at present. Since the embroidery process includes addition of certain amount of embroidery-threads depending upon the design motif, it is quite obvious that basic physical and functional properties of fabric are subject to change. It is therefore important to develop an algorithm or empirical equation for proper prediction of the properties of the embroidered fabric, relevant to its required end-use in apparel industry. In this context, an effort has been made to determine a prediction equation through linear multiple regressions for the prediction of longitudinal stiffness of embroidered fabric in terms of flexural rigidity in warp direction of the base fabric, considering the input parameters as warp-way flexural rigidity of the base fabric, breaking load and linear density of the embroidery thread, stitch density, average stitch length and average stitch angle of the embroidery design. The final Prediction model is statistically verified taking new embroidery samples of different varieties. It is found that the model can predict with a very satisfactory level of accuracy. Also, the influences of the embroidery parameters in this context have been analyzed through the corresponding regression coefficients and the three dimensional (3D) surface curves. Stitch density has been emerged as the most influential parameter, followed by the stitch length and the stitch angle.

A study on porosity related aspects of cotton knitted fabric with single jersey structure for improved comfort application for garment

Knitted fabrics are the preferred structures in athletic wear in which demand for comfort is a key requirement. Heat and liquid sweat generation during athletic & exercise activities must be transported out and dissipated to the atmosphere. A key property influencing such behaviors is porosity. Two parameters that characterize it are pore size and pore volume. One of the objectives in this research was to come up with models that can predict inter yarn pore size and pore volume for simple weft knitted structures, from fabric particulars, such as courses and Wales, count, yarn size, stitch density, thickness and other geometrical details of the fabric, which characterize the structure. Such a model was developed that was based on the geometry of the unit cell of a single loop. The experimental work in this project involved using a set of 16 knitted fabrics that differ in course count and examining their pore structure and porosity related characteristics. The values of pore size and pore volume were calculated, those of pore size were measured with image analysis, and other parameters. The effects of course count and washing on stitch density, stitch length, fabric thickness and pore size are examined in details.

Performance evaluation of conductive tracks in fabricating e-textiles by lock-stitch embroidery

Lock-stitch embroidery has been the centre of much interest as a versatile and precise method of producing conductive tracks in the fabrication of wearable electronic devices. However, improper fabrication parameter settings could result in the nonconformity of the conductive tracks and damage the conductive coating of the conductive yarns. In this study, we evaluate the appearance quality, dimensional stability and electrical resistance of conductive tracks by taking into account the embroidering speed (ES), stitch length (SL), needle thread pre-tension (NTP) and embroidering direction (ED). The conductive tracks are embroidered onto knitted fabric in different directions with silver-coated polyamide yarn as the needle thread. The results show that stitching the conductive tracks in the wale direction results in a more uniform stitch lines in comparison to the other directions. To resolve the problem of floated stitches, it is recommended that an SL of 4 mm and a higher NTP are used. The percentage of shrinkage in the wale direction is lower than in the course direction. The electrical resistance of the conductive tracks increases with a higher ES and shorter SL. It is also found that a thicker yarn is more sensitive to the NTP and some of the silver coating is rubbed off with an NTP of 50 gf. We also carry out an overlay plot analysis, through which we predict and validate the optimal embroidery parameters that balance appearance quality and electrical resistance. The technique parameters in this study can be used to embroider conductive tracks for smart clothing.

An X-ray tomography approach to calculate air volume present in an insulation system sewn with lockstitch and spacer stitch

PurposeSewing is the most widely used and preferred method for manufacturing clothing products for extreme weather conditions and other industrial insulation systems. Multiple layers of functional fabrics in combination with insulation materials are used to thermally insulate precious body heat from its surrounding cold environment. The sewing process fixes the insulation material between the fabric layers. During conventional sewing, the insulation material is compressed along the stitch line. With the compression of the insulation material, entrapped air is forced to leave the insulation material internal structure, and heat loss occurs along the entire length of the stitch line. It results in the deterioration of thermal properties of the end product along the stitch line.Design/methodology/approachThe amount of air, which is a decisive factor for thermal properties of any insulation system, was investigated at the level of a unit stitch length of a lockstitch. Conventional microscopy methods are not suitable to study the compression along the stitch line. With the help of X-ray tomography, the three-dimensional data of a stitch was taken and studied to measure the volume of air. The samples were prepared with conventional lockstitch sewing and a newly developed innovative sewing method “Spacer Stitching.” The results are compared with each other in terms of the amount of air present in a unit stitch length.FindingsCalculations based on X-ray tomography images of lockstitch and spacer stitch revealed that, in the case of lockstitch, a unit stitch has a 15% of its volume made up of material and 85% of its volume by air. In comparison, the spacer stitch with the same sewing and fabric parameters has a material volume of 4.6 % and an air volume of 95.4% in a single stitch.Practical implicationsThe research can positively improve the thermal properties of sewn material made for insulating purposes of conventional clothing as well as of industrial insulations.Originality/valueThere is no literature available which investigates and calculates the amount of air and material present along with a stitch line.

Simulation and characterization of circular hexagonal braiding fabricstructure

Hexagonal braiding technology is a kind of state-of-the-art braiding method, which uses hexagonal horngears to driveyarn carriers and make yarns intertwined into fabrics. In terms of hexagonal braiding principles, the braiding parameterslike initial arrangement of yarn carriers, yarn number and horngears sequence were defined, and then the movementpaths of yarn carriers in hexagonal braiding process and stitch length were obtained, which could be converted intocoordinates on the xoy plane and the coordinates along z-axis. In that case, a group of spatial coordinates were got tocreate the yarn trajectories and fabric structures in Matlab. And then, B-spline curve was utilized to fit the yarntrajectories. Considering the compactness of hexagonal fabric, the coordinates conversion algorithm and conversionmatrix were utilized to optimize the fabric structure, so a more compact fabric structure was established. The braidingangle variation and volume fraction of fabric showed that after coordinates conversion the braiding angles became morestable than original fabric model, and the fiber volume fraction of fabric was improved too. So the fabric structure modelwas available to describe hexagonal fabric structure, which can offer the reference for the further study on properties ofhexagonal braiding technology and application of hexagonal braided fabric