Minimizing waste in the 2-dimensional cutting stock problem

The 2-dimensional cutting stock problem is an important problem in the garment manufacturing industry. The problem is to arrange a given set of 2-dimensional patterns onto a rectangular bolt of cloth such that the efficiency is maximised. This arrangement is called a marker. Efficiency is measured by pattern area I marker area. Efficiency varies depending on the shape and number of patterns being cut, but an improvement in efficiency can result in significant savings. Markers are usually created by humans with the aid of CAD software. Many researchers have attempted to create automatic marker making software but have failed to produce marker efficiencies as high as human generated ones. This thesis presents a mathematical model which optimally solves the 2-dimensional cutting stock problem. However, the model can only be solved in a practical amount of time for small markers. Subsequently, two compaction algorithms based on mathematical modelling have been developed to improve the efficiency of human generated markers. The models developed in this thesis make use of a geometrical calculation known as the no-fit polygon. The no-fit polygon is a tool for determining whether polygons A and B overlap. It also gives all feasible positions for polygons B with respect to polygon A, such that the two polygons do not overlap. For the case when both polygons A and B are non-convex, current calculation methods are either time consuming or unreliable. This thesis presents a method which is both computationally efficient and robust for calculating the no-fit polygon when polygons A and B are non-convex. When tested on a set of industrial markers, the compaction algorithms improved the marker efficiencies by over 1.5% on average

Transforming shape: a simultaneous approach to the body, cloth and print for garment and textile design (synthesising CAD with manual methods)

Printed textile and garment design are generally taught and practised as separate disciplines. Integrated CAD software enables textile and clothing designers to envisage printed garments by assimilating graphic imagery with 2D garment shapes, and 3D visualisations. Digital printing can be enlisted to transpose print-filled garment shapes directly onto cloth. This research challenges existing 2D practice by synthesising manual and CAD technologies, to explore the integration of print design and garment shape from a simultaneous, 3D perspective. This research has identified three fundamental archetypes of printed garment styles from Twentieth Century fashion: 'sculptural', 'architectural' and 'crossover'. The contrasting spatial characteristics and surface patterning inherent in these models provided tlýe theoretical and practical framework for the research. Design approaches such as'textile-led', 'garment-led'and 'the garment as canvas' highlighted the originality of the simultaneous design method, which embraces all of these concepts. This research recognises the body form as a positive influence within the printed textile and printed garment designing process, whereby modelled fabric shapes can be enlisted to determine mark making. The aim of the practice, to create printed garment designs from a 3D perspective, was facilitated by an original method of image capture, resulting in blueprinted toiles, or cyanoforms, that formed the basis of engineer-printed garments and textiles. Integrated CAD software provided the interface between manual modelling, design development and realisation, where draping software was employed to digitally craft 3D textiles. The practical and aesthetic characteristics of digital printing were tested through the printing of photographic-style, integrated garment prototypes. The design outcomes demonstrate that a simultaneous approach to the body, cloth and print can result in innovative textile vocabulary, that'plays a proactive role within the design equation, through its aesthetic integration with garment and form. The integration of print directly with the garment contour can result in a 3D orientated approach to printed garment design that is empathetic with the natural body shape

The Basic Layout of a Denim Textile Industry: A Basic Review

Denim was produced in the city of Nîmes in France and was originally called the serge de Nîmes. The word denim is an English colloquialism of the French term: “denim.” Day by day Bangladesh denim sector very much developed and helps to increase productivity. Bangladesh have seen a significant increase in investing in denim fabric manufacturing, increasing the country’s production performance by reducing fabric dependence on imports. It is important due to its aspects of durability, and not easily torn which benefited physical laborers much. The government also plays a vital role in denim textile industry. This paper shows different section of denim textile industry such as: sewing section, cutting section, washing, IE and finishing department. The main aim of this paper is how to role all the section of denim textile industry. Textile education is insufficient without industry attachment, which bridges the gap between theoretical and practical aspects and acclimates students to the industrial world. We can gain about theoretical development on an industrial level from this attachment. We can understand more about the machines used in various departments, their technical specifications, characteristics, operating system, and so on, and we believe that without this type of industrial connection, it is impossible to obtain industry-based information about textile engineering adequately. The Industrial Attachment on Denim Manufacturing Technology was used to organize this study (sewing section, cutting, IE, washing section, CAD Section, and finishing department. Various operating procedures for the production of denim in the industry are presented in this paper. The technique and process of several procedures and processes are presented here such as machine specifications, manpower, maintenance, layout of the different section, dye processes and wet processes

Transforming shape: hybrid practice as group activity

Printed textile and garment design are generally taught and practised as separate disciplines. Integrated CAD software enables textile and clothing designers to envisage printed garments by assimilating graphic imagery with 2D garment shapes and 3D visualizations. Digital fabric printing can be employed to transpose print-filled garment shapes directly onto cloth. During a recently completed practice-led PhD (1998-2003), I researched the aesthetic design potential of combining new CAD technology with garment modelling methods to create new innovative printed textiles/garments. The merging of physical and screen-based making resulted in a hybrid 3D approach to the body, cloth and print referred to as the 'simultaneous design method'. In 2001 this hybrid practice provided the catalyst for a collaborative textile research project at the Nottingham Trent University, UK. The group included surface, shape and multimedia designers. The key group aim was to explore the transforming effects of computer-aided textile design through dialogues between two and three dimensions. In parallel with my own practice, print and embroidery were considered from a 3D starting-point through the relating of geometric cloth shapes to the form. Each designer took an idiosyncratic approach to the selection and integration of imagery with the shapes. The novel consideration of the final modelled textile at the start of the designing process influenced each designer in different ways, leading to a collection of contrasting, original outcomes that were displayed in the exhibition Transforming Shape (UK 2001, Denmark 2003). The exhibition demonstrated the design opportunities (and limitations) of new and existing technologies, specifically the relationship between innovative textile imagery and three-dimensional form. The designs illustrated the premise that surface designs can be engineered through different pattern shapes and that engineer-printed shapes transform the body

Design For Movement: Block Pattern Design For Stretch Performancewear

This thesis is in 2 volumesPattern drafting techniques for woven block patterns have been well established. Applying existing techniques with modifications to generate patterns for modern stretch fabrics can be successful but it is often at a cost. In the development of a stretch pattern, an acceptable fit cannot be guaranteed merely by using a rationalised simple pattern profile shape. Producing a pattern, without darts, to closely adhere to the contours of the body without restricting movement, is a contradiction in design terms. In woven fabric, darts and ease are used to manipulate the fabric around the form and allow movement. However, in stretch knit fabric the development of a block pattern involves the synthesis of information from a variety of disciplines and requires a more specialist approach. This study has endeavoured to show that a new interpretation of pattern design principles is needed to create an improved stretch block pattern for stretch knit performancewear. This work has been refined based on a new method of classifying stretch fabric parameters and personal observation of the effect of stretch distortion characteristics and the changes that occur in the twodimensional pattern profile, when stretched to conform to the threedimensional body. The results of this study will provide a more SCientific and practical approach to assessing stretch fabric parameters as an integral part of block pattern design for stretch performancewear. The fabric stretch potential has been maximised to contour the body for optimum fit, providing comfort and mobility without the need for redistribution of the fabric when activity ceases. A method of creating a stretch block pattern from direct measurements to replicate the body shape and proportions was devised which can be reduplicated. This study addresses primarily the designer/pattern cutter who has a passion for good fit, which enhances comfort and mobility, who does not necessarily have a scientific background. However this study is relevant to the textile technologist concerned with proposing a standard to compare stretch fabrics for garment production. It should also appeal to the computer programmer concerned with the link between 3D body scanning and interpreting the body profile accurately in the 2D pattern draft

Applying and evaluating 3D bodyscanning technology and landmarking within the clothing product development process to improve garment fit for mature women aged 55+

Women aged 55+ are recognised to have non-standard body morphologies and may present with further functional considerations. Existing practice bases clothing development on younger bodies, exasperating misfit issues that exist already. This research therefore focuses on the assessment and provision of garment fit for mature women aged 55+. It applies and critically analyses the application of 3D bodyscanning technology and landmarking practice for the clothing product development process for mature women. Compared to traditional methods in anthropometric body measurement, 3D bodyscanning procedures have perceived benefits in speed, privacy and accuracy. It is therefore ideal in capturing the measurement of mature women aged 55+. However, bodyscanning may deal less well with non-standard bodies, which may complicate further pattern creation. Whilst bodyscanning has recognisable benefits (speed, convenience, consistency), the technology is not readily accessible to practitioners and necessitates its study and testing. A pragmatic, mixed method approach was developed to gather and analyse qualitative and quantitative data related to body scanning and pattern applications. A theoretical framework was established from the knowledge base informing six propositions, a null and alternative of hypothesis. This research applied a mixed methods approach, allowing the exploration of the technology, the application of the data in pattern practice and the testing of its success with a suitable 55+ population. The research developed novel approaches to understand the data and ensure its validity. Processes found that landmarking errors were not confined to 55+ demographic. Landmark errors concerning armscye, bust and crotch points were common; but the t-test revealed that older age was the variable most likely to impact on landmarking accuracy concerning bust and crotch points. Scan analysis added time to the scanning process which made the technology less time conserving as widely perceived. The study discovered that non-contact landmarking methods allowed errors that were not easily detectable without a reliable system in place; hence established a system for validation. Body measurements from the pattern guidance and body scan data measurements did not have comparable landmark definitions; therefore scanner landmark definitions needed to be modified for pattern construction, adding time to the process. Comparison of patterns constructed from unmodified and modified scan data revealed that landmark error had a substantial impact on key areas of pattern geometry. Changes in pattern shape translated into poor fit of the bodice, where armholes were either too tight/loose and the shoulder seam too short for the body. The bodice fit trials confirmed that participants favoured the fit of the bodice that had undergone landmark modification and had used their self-selected waist position. Methods are necessary to ensure scan data is suitable for the application of pattern construction, this study provides clear approaches that allow this

Gestural patterns: a new method of printed textile design using motion capture technology

The aim of this research is to develop a new method, Hybrid Printing System (HPS) to explore digital craft methods to create surface patterns for printed textile design. This novel method of creating ‘handcrafted’ prints is a result of the integration of two technologies such as motion-capture (MOCAP) and digital textile printing (DTP). The research towards such an innovation required a current, historical, contextual and experimental study of use of motion capture in Art &Design. The research contextualises the hand and its relationship to digital crafting methods in printed textile design, the digital medium and the process of audience participation in printed textile design to create a new conceptual framework balanced in practice and theory. The practical research then develops three new methods of motion capture such as, motion tracing, motion sensing and motion tracking to generate gestural motifs and gestural patterns. This thesis and the accompanying set of experimental work demonstrates that HPS culminates in developing new aesthetics through a new mode of creation in a new medium, which will impact the user, the designer and the product as a part of the cyclical process. HPS is an advancement of printed textile design, centred in active participation of its audience at the generative stage of design. This results in a shifting role of a designer and subverts the current model of printed textile design practice. HPS is a democratic design process where the participants design for themselves, have their own voice, which induces a sense of community, togetherness and harmony in the creative process

Compaction and Separation Algorithms for Non-Convex Polygons and Their Applications

Given a two dimensional, non-overlapping layout of convex and non-convex polygons, compaction can be thought of as simulating the motion of the polygons as a result of applied "forces." We apply compaction to improve the material utilization of an already tightly packed layout. Compaction can be modeled as a motion of the polygons that reduces the value of some functional on their positions. Optimal compaction, planning a motion that reaches a layout that has the global minimum functional value among all reachable layouts, is shown to be NP-complete under certain assumptions. We first present a compaction algorithm based on existing physical simulation approaches. This algorithm uses a new velocity-based optimization model. Our experimental results reveal the limitation of physical simulation: even though our new model improves the running time of our algorithm over previous simulation algorithms, the algorithm still can not compact typical layouts of one hundred or more polygons in a reasonable amount of time. The essential difficulty of physical based models is that they can only generate velocities for the polygons, and the final positions must be generated by numerical integration. We present a new position-based optimization model that allows us to calculate directly new polygon positions via linear programming that are at a local minimum of the objective. The new model yields a translational compaction algorithm that runs two orders of magnitude faster than physical simulation methods. We also consider the problem of separating overlapping polygons using a minimal amount of motion and show it to be NP-complete. Although this separation problem looks quite different from the compaction problem, our new model also yields an efficient algorithm to solve it. The compaction/separation algorithms have been applied to marker making: the task of packing polygonal pieces on a sheet of cloth of fixed width so that total length is minimized. The compaction algorithm has improved cloth utilization of human generated pants markers. The separation algorithm together with a database of human-generated markers can be used for automatic generation of markers that approach human performance.Engineering and Applied Science

Resizable outerwear templates for virtual design and pattern flattening

The aim of this research was to implement a computer-aided 3D to 2D pattern development technique for outerwear. A preponderance of total clothing consumption is of garments in this category, which are designed to offer the wearer significant levels of ease. Yet there has not previously been on the market any system which offers a practical solution to the problems of 3D design and pattern flattening for clothing in this category. A set of 3D outerwear templates, one for men’s shirts and another for men’s trousers, has been developed to execute pattern flattening from virtual designs and this approach offers significant reduction in time and manpower involvement in the clothing development phase by combining creative and technical garment design processes into a single step. The outerwear templates developed and demonstrated in this research work can provide 3D design platforms for clothing designers to create virtual clothing as a surface layer which can be flattened to create a traditional pattern. Point-Cloud data captured by a modern white-light-based 3D body-scanning system were used as the basic input for creating the outerwear templates. A set of sectional curves, representative of anthropometric size parameters, was extracted from a virtual model generated from the body scan data by using reverse engineering software. These sectional curves were then modified to reproduce the required profile upon which to create items of men’s outerwear. The curves were made symmetrical, as required, before scaling to impart resizability. Using geometric modelling technique, a new surface was generated out of these resizable curves to form the required 3D outerwear templates. Through a set of functionality tests, it has been found that both of the templates developed in this research may be used for virtual design, 3D grading and pattern flattening