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Proposes an algorithm for the computation of maximum needle penetration force; it introduces the direct dependence of penetration force on fabric structural parameters and warp and weft geometrical and mechanical properties. Uses the approach to the simulation of local deformation of woven material which accounts for the thread resistance to crimp change and friction forces when the thread is shifted from its original position in the fabric structure as the result of its interaction with a needle. The resistance of threads to tension caused by a needle pushing them from their straight‐line paths is also accounted for. The resulting formulae give the dependence of needle penetration force for a plain‐woven fabric on the following parameters: needle diameter and surface angle; warp and weft spacing, dimensions, crimp height and bending rigidity; friction coefficients thread‐thread and thread‐needle. For a non‐plain‐woven fabric the linear dependence of penetration force on the fabric tightness is suggested. The comparison with the published and specially measured penetration force data proves the predictive ability of the model to be qualitatively accurate and quantitatively reasonable.

The purpose of this paper is to theoretically compute and predict the needle penetration force (NPF) in woven denim fabrics with twill 3/1 weave pattern on the basis of geometrical, physical, and mechanical properties of yarns and fabric, and characteristics of sewing needle.

To predict the NPF by mathematical relations, the proposed models by Stylios and Xu (1995) and Lomov (1998) are extended for a twill woven structure. The NPF is calculated based on resistance forces due to yarn tensile elongation, yarn resistance to bending in the near of the sewing needle while the needle penetrates into the fabric, friction between weft and warp yarns, needle profile shape, and friction between sewing needle and yarns. In order to evaluate the obtained results, nine different denim fabric samples are produced, and five sewing needles with different sizes are used. The NPF is measured on the Instron tensile tester to simulate sewing process.

The results show that there is a good relationship between the predicted and experimental values of the NPF (R2=0.831, MSE=0.079, and MAPE=9.51 percent). Moreover, it is found that the performance of developed model to predict the NPF for needle sizes of 80, 90, 100, and 110 (Nm) is better than that of needle size of 120 (Nm). Generally, the developed theoretical model can predict the NPF in fabrics with twill 3/1 weave pattern.

The fabrics with twill weave pattern have a complicated structure than plain pattern. So, in this research work, the NPF of denim fabric with twill 3/1 weave pattern was theoretically predicted on the basis of yarn elongation, changing of yarn bent shape in the near of the sewing needle, and friction between warp and weft yarns. The NPF was measured in the successive cycle loading conditions similar to sewing machine process by using a designed and constructed instrument, which is mounted on the Instron tensile tester.

The purpose of this paper is to theoretically calculate and predict the needle penetration force (NPF) in woven denim fabrics with twill 3/1 weave pattern, based on the geometrical, physical, and mechanical properties of fabric and constituent weft and warp yarns.

In order to calculate the NPF by mathematical relations, the suggested model by Stylios and Xu (1995) is extended. While the needle penetrates into the fabric, the NPF is calculated on the basis of yarn tensile elongation, needle profile shape, and friction between needle and yarns. To accurately evaluate the developed model, nine different commercial denim fabric samples with various weft densities and linear density of weft yarns are produced, also five needles with different sizes are utilized. The NPF is measured in the successive cycle loading conditions similar to sewing machine process by using a designed and constructed instrument, which mounted on the Instron tensile tester.

Comparing the predicted and experimental values indicated that the accuracy of model to predict the NPF is partly acceptable (R2=0.734). To improve the developed model, in addition to the forces which applied on needle due to yarn elongation, the other forces such as friction between weft and warp yarns, and yarn resistance to bending in the near of the sewing needle, which resist against needle penetration, can be considered.

The fabrics with twill weave pattern have a complicated structure than plain pattern, therefore, in this paper the NPF of denim fabrics with twill 3/1 weave pattern were theoretically calculated based on yarn elongation. The spacing between centers of yarns in these fabrics is obtained by deriving a new formula. The NPF is measured on the Instron tensile tester to simulate sewing process.

The purpose of this paper is to investigate the effect of joint clearance on the behavior of a needle driver mechanism (a slider-crank linkage) of a typical sewing machine with an imperfect joint between the coupler and the slider (including needle).

In order to model the clearance, the momentum exchange approach is used. The Lankarani and Nikravesh’s continuous contact force model is used to model the contact force, and the modified Coulomb’s friction law represents the friction between sliding members. The penetration force applied on the needle by fabric is chosen based on an experimental data in the literature. The dynamic response is validated for the existing properties in the literature without considering the penetration force.

It is shown that the clearance joint made considerable effect on the dynamic response of the system. The rough changes of the needle acceleration and jerk are obvious. The base reaction force changed roughly and did not vary as smooth as that of the mechanism with ideal joint. So, clearance joint in the mechanism could lead to an undesirable vibration in the system. Furthermore, the crank driver must provide a non-smooth moment on the crank to keep the crank rotational velocity constant. Moreover, reducing the clearance size sufficiently could make the dynamic response closer to that of the mechanism with ideal joint. In addition, smoother crank moment could be required if the clearance size is reduced sufficiently. Furthermore, the rough change of the base reaction force which can represent the vibration caused by the mechanism on the fixed frame could be reduced if the clearance size is small enough.

Lockstitch sewing machine is one of the most common apparel industrial machines. The needle driver mechanism of a sewing machine could have an important role for proper stitch forming. On the other hand, clearances are inevitable in assemblage of mechanisms to allow the relative motion between the members. This clearance is due to machining tolerances, wear, material deformations, and imperfections, and it can worsen mechanism performance such as precision, dynamic behavior and vibration. Unfortunately, despite the importance of the dynamic behavior of the needle driver mechanism from practical point of view, very little publications have focused especially on the investigation of the effect of clearance joint on the dynamic behavior of the sewing machine which could lead to undesired vibration of the system and shorter lifetime as a result. In this paper, the dynamic behavior of the system including, needle velocity and acceleration, crank moment and base reaction force was compared with that of the ideal mechanism. Finally, the effect of clearance size on the dynamic behavior of the system was investigated.

The purpose of this research is to study the effect of softener treatment on plain jersey fabrics with properties made of cotton and spandex yarn.

Samples with 100 percent cotton yarns, spandex yarns in alternating courses (half plating) and spandex yarns in every courses (full plating) were produced on a circular knitting machine where the two latter cases were produced at five different levels of spandex extension. After the dyeing process, fabrics were treated with fabric softener using two softener types (cationic and silicon) and all type two concentrations (3 percent, 6 percent) to evaluate the most appropriate softener type and concentration on fabric friction force, sewing needle penetration force and weight loss percent under different levels of spandex extension.

Results showed that silicon softener treatment results in high decreases in fabric sewing needle penetrating force, friction force and while treatment with cationic softener results in high decreases in weight loss percent for 100 percent cotton, half and full plating fabrics.

There is a growing need to study the effect of softeners when spandex yarns are used in the production of knitted fabric which results in high increase of stitch density. This research compares the effects of two different softener types at different concentrations on the properties of both plain jersey fabric produced from 100 percent cotton yarns and from cotton/spandex yarns with different stitch density.

Demonstrates the modelling of the kinetic process when the sewing needle enters the fabric. To get an adequate mechanical model of the given problem, the function ‐ the mathematical model ‐ of the penetration force with respect to the fabric, the needle and the mechanism in the sewing machine must be developed. The fabric was modelled as a combination of warp and weft threads. Each thread from the fabric is modelled as an ideal elastic Hook’s material. Outlines the restrictions which needed to be made to get the mathematical model of the problem.

The purpose of this review paper is to define the dominating factors (such as fiber, yarn, fabric structure, sewing thread, sewing needle and machine parameters) that affect the seam damages and causing defects. It also describes the various explanations of sewing defects in garment production and critically analyzes them for optimum selection of parameters and speeds for minimizing such faults. Hence, the knowledge of various factors which affect the sewing damages/defects will be helpful for garment manufacturers/researchers to know influence of the parameters and control the quality of producing seam.

This section is not applicable for a review paper.

Sewing damages such as needle cut and other sewing damages/defects are studied mostly in woven fabric. There are very few studies conducted on knitted fabric sewing damages/defects. The sewing damage problems do not have single solution that is capable of removing these damages in fabric. All the determined and affecting parameters related to fiber, yarn, fabric construction, sewing thread and sewing machine must be examined to design appropriate remedial measurement related to machine design, fabric parameters and sewing thread. This could help in minimizing or eliminating the needle cut and other sewing damage problems.

It is an original review work and is helpful for garment manufacturers/researchers to reduce the defects and be able to produce good quality seam.

Use of programme package ADAMS to simulate the sewing machine mechanisms is presented within this contribution. The simulation of needle bar mechanism was carried out. The influence of velocity changes of the main shaft on velocities and acceleration of sewing needle in the penetration area is described on the basis of simulation results. Achieved data could be used for calculation of needle penetration force. The influence of length modification of needle bar mechanism elements on sewing needle velocity and acceleration is also presented. This analysis could contribute to better understanding of sewing machine activity.

This paper aims to predict the needle penetration force (NPF) in denim fabrics using the artificial neural network (ANN) and multiple linear regression (MLR) models based on the effects of various sewing parameters.

In order to design the ANN and MLR models, four parameters including fabric weight, number of fabric layers, weave pattern, and sewing needle size are taken into account as the input parameters and NPF as the output parameter. According to these parameters, 140 samples of data were resulted. Each sample was tested five times. From these 140 data (input-output data pairs), 112 were used for training the ANN and MLR models and 28 samples were used to test the performance of ANN and MLR. Also, the NPF was measured on the Instron tensile tester to simulate sewing process.

The results indicated that the NPF in denim fabrics can be well predicted in terms of sewing parameters by using ANN and MLR models, in which the ANN model exhibits greater performance than MLR (RANN=0.989> RMLR=0.901).

The NPF measurement method is limited at low speed.

Using the ANN model for forecasting NPF in denim fabrics can help the garment manufactures to produce high-quality denim products and improve the sewing process through reducing seam damage. The NPF could be also measured in the cycle loading conditions similar to sewing machine process by using a special designed tools mounted on the Instron tensile tester.

This paper suggests a new method for determining the sewing damage that occurs in single jersey fabrics based on the calculation of the needle hole area. This paper also aims to investigate the effects of material type, sewing parameters, and repeated washing cycles on sewing damage by using this method.

Six knitted fabrics, differing in structure and raw material, were produced. Samples were sewn using different sewing parameters, and they were subjected to ten washing cycles. Values of average needle hole area, an objective indicator of sewing damage, were calculated before and after repeated washing cycles using image analysis software and were evaluated statistically.

The results showed that the average needle hole area calculated via the image analysis software effectively estimates sewing damage as the results obtained were compatible with those stated in the literature. Furthermore, fabric type, sewing direction, sewing thread type, and needle size significantly affected the sewing damage. However, stitch density did not affect the sewing damage. When the effect of washing cycles was compared, it was seen that washing leads to an increase in sewing damage.

A review of the existing literature shows that no previous study has evaluated sewing damage using image analysis software. This study proposes a novel objective method to determine the sewing damage that occurs in knitted fabrics.