Computer-Aided Design (CAD) has become an indispensable tool in the textile industry, transforming traditional weaving and knitting processes into efficient, precise, and innovative practices. By integrating advanced software tools with traditional textile techniques, designers and manufacturers can achieve complex designs while reducing material waste and production time.
Computer Aided Designing (CAD) and Computer Aided Manufacturing (CAM) were first introduced in 1970, and since then, CAD is used by designers to create product design, and the designs are transferred to CAM machines to manufacture the final product. These computer-aided tools or systems have replaced old mechanical shaping and patterning devices on machines in both weaving and knitting industry.
The CAD systems dedicated to textiles industry offer solutions that not only help in the design stage but also in the manufacturing process, bridging the gap between design and the production stages. This electronic communication between the design package and the production tool (weaving and knitting machines, etc.) helps to improve the efficiency and quality of the industrial process. The vibrant textile industry has always been innovating in terms of new materials, machinery, and the processing cycle, with an ever-increasing demand for new designs. Therefore, creating newer designs for textile and fashion articles has become a great challenge for the designers than ever before and necessitated the use of CAD packages. The manufacturer can have regular interactions with the customer and make frequent and quick changes to the design, meeting the latest trends in textile and fashion industry. It not only helps to reduce the pressure on manufacturer but also provides the customer satisfaction, with improved designs.
Application of CAD in Weaving
Computer-Aided Design (CAD) has become an essential tool in the weaving industry, transforming how textiles are conceived, designed, and produced. The textile designers were more confined to the fabric design and did not correlated the yarn and fabric characteristics. Now, the entire fabric design process has been revolutionized incorporating yarn characteristics into the design process. Previously, the designers had laborious work on the graph paper and stencil, which is now simplified using a mouse or stylus pen and computer to produce innovative designs. Introduction of the CAD technology through implementation of designs and color combinations is making the textile fabrics more striking and viable. CAD software for weaving allows designers to create detailed fabric patterns by digitally arranging warp (longitudinal) and weft (transverse) threads. It is also helping to meet the quick-changing expectations of the consumers for fashion designs.
Woven fabrics are the most thoroughly investigated textile structures. A lot of research is in progress in this domain. The use of CAD for woven fabrics is highly dependent on the end use of fabric. The two most important groups of woven fabric simulation are as follows:
- CAD for esthetic or artistic design
- CAD for the woven fabric structure/geometry
Both of these categories have their own importance in different fields. The aesthetic or artistic design perspective is of utmost importance for the fabric designers. They use different color combinations of yarn along with linear density, thread density, weave, etc. to get a particular appearance. In contrast, the 3D simulation of woven fabric structure/geometry is further used by mechanical in engineering calculations (mechanical, thermal, etc.) as well as for the artistic design.
The different CAD packages used for weaving are listed in Table 2.1. These CAD packages make use of different modules for the graphical representation of the fabric structure and appearance.
1. CAD for esthetic or artistic design
It is the computer-aided designing from a designer’s perspective, focusing on the esthetic/artistic appearance of fabric. These simulations are probably the earliest commercially available simulations of woven structures, developed to replace the sophisticated work of designers, preparing punch cards for jacquard machines. These CAD systems permit the user to visualize the pattern in various fabrics and alter its appearance in a user-friendly (i.e., usable without extensive knowledge) environment. All of these simulations start from the weave pattern definition since it contains the information about the appearance of the yarns from both sides.
This principle is being used by most computer programs to simulate the appearance of the woven structure, without re-constructing the real appearance of the fabric. Using pictures of real or created yarns, appropriately placed and rotated, it is possible to present a realistic view of the structure. Nowadays, most programs provide a visual representation of the fabric.
The major modules involved for the fabric appearance include Dobby, Jacquard, and Terry. In addition, there are some ancillary modules helping to simulate the fabric, comprising of the yarn, color, and weave library. Information about these modules and libraries has been provided in brief below.
a) Color Library
The aim of this module in the CAD software is to enable the user create a library of colors according to his own choice. This module also helps to create, save, and load the color pallets when required. In addition, the color specifications are also available, which allow the user to edit a certain color using its specifications. More the number of colors in the library, easy it will be for the user to view the fabric in different color combinations. The different CAD packages have a varying number of colors in its library, depending on the specificity of its end use and area of application. Using the color library helps to view the simulation of fabric in 16.7 million color combinations.
b) Yarn Library
Various kinds of yarns (either regular or fancy) are used in the textile industry, and the yarn library stores these yarns for fabric simulation. It also offers the facility of yarn creation, which retains all of the technical details of a particular yarn. The user can specify the yarn fineness/linear density (in terms of thickness or tex/denier system), twist direction (S or Z), yarn color (from color library), etc. in the yarn information dialog box. This particular yarn can also be stored for fabric simulation at a later stage.
Some basic CAD systems make use of colored rectangles as yarn to give the fabric simulation. The width and height of these rectangles help to specify the yarn thickness and yarn spacing. Such systems give only a rough appearance of the fabric, not taking into account the yarn imperfections. Other CAD systems have a library of scanned yarns (taking into account the imperfections) or have the capability to scan a particular yarn and use it for the simulation.
c) Weave Library
The woven fabrics are constructed by interlacing two sets of yarns (warp and weft) perpendicular to each other. The interlacement pattern known as weave can vary greatly, affecting the fabric geometry and appearance. The weaves are usually classified into basic weaves, derived weaves, combined weaves, and complex weaves. Weave is the starting point for CAD of a particular fabric as it contains information about the appearance of yarns from both sides.
The fabric simulation is the virtual fabric produced of a certain design before the production of actual fabric. Simulation helps the user to make any amendments to the weave design, yarn specifications (thickness, type, density), or color combination to get the desired appearance. The fabric simulation and actual fabric are almost alike, giving authenticity and reliability to the CAD process. The great quality of the simulations reduces the costs of samples and economizes the time of response to the clients. The CAD packages use different modules of fabric simulation based on the fabric appearance and properties.
d) Dobby Module
This module is dedicated to the dobby industry. The dobby is a shedding system, and looms with this system are designated as dobby looms, irrespective of the picking media. Dobby is a relatively complex shedding system, and it controls up to 32 heald shafts. The old systems of providing lifting plan/peg plan included peg chain, peg cylinder, punched papers, and plastic pattern cards. All of these techniques had a limited pick repeat, and dobby fabrics having a small repeat could be produced. Currently, the pick repeat is provided by the computer programs (dobby module) and is virtually unlimited. This system offers more design possibilities as compared to the old dobby-shedding systems. Some of the dobby modules are capable of creating specialty fabric simulations, for example, seersucker, double fabrics, and double-face fabrics.
e) Jacquard Module
The jacquard design is a unique combination of artwork, weave, and yarn specifications. The jacquard design module provides a wide range of possibilities such as designing tools, simplifying the process, and obtaining real simulations of the fabrics that will be woven later. The software helps to generate the loom file that contains loom layout, according to the machinery with which the company works. Therefore, it is possible to save different loom layouts and reuse them for later works, which saves time in future designs. Once the loom layout has been realized, the looms can be connected directly to the management system of the company. The user can then export the information for direct connection to the looms or management systems. In the same way, the CAD system can create the manufacturer order to control the production. The major realizable functions of jacquard design are as follows:
- Color reduction in artwork
- Elimination of spots
- Wide range of drawing tools
- Elimination of floats
- Visualizing different repeat compositions in the same image
- Weft control according to design
Many luxury fashion brands use CAD to design bespoke Jacquard fabrics for haute couture.
f) Terry Module
The piled fabrics are produced by loops or strands of yarn (termed as pile) raised over the surface of a fabric. Some common examples of piled fabrics are carpets, velvet, corduroy, and terry towels. The textile and fashion companies are developing new tools that allow the designers to work easier and faster. With the incorporation of the software into the current process of loop fabric design, the following advantages are obtained:
- Capture images with the scanner or a digital camera
- Filter the colors in image and improve the image quality
- Create multidensity graphs and define drawing with a different weave for every color
- Possibility to work with layers
- Facility at conversion of images to a graph
- Assignment of elementary weaves in a multidensity graph
- Simulation of a terry fabric in high quality
- Define the length and thickness of the loop
- If looms connected to a network, send design directly to loom or management system
2. CAD for the woven fabric structure/geometry
Nowadays, textile fabrics are used extensively in technical applications. In such application areas, precision in structural design and its properties (behavior of the fabric) are of primary importance rather than only esthetics. The textile-based composite materials are widely used in advanced applications such as aircraft. Thus, the behavior of fabric structure is vital in achieving the overall aircraft efficiency and safety. The performance of fabric is basically a function of the geometrical construction of yarns in it. The behavior of textiles under different loading conditions, whether mechanical, thermal, or fluid, is of utmost importance for the designer.
In order to create CAD for such fabrics, mathematical expressions of their weaves are also essential. It simulates the entire yarn geometry in 3D space. Such models are based on the description of yarn path on its plane. The cross section of weft yarns is shown in the plane of warp yarn path. It allows the definition of contact points and types of lines between them. The simplest model is based on circular cross section of yarn and modeling yarn path using circular arcs and lines.
Application of CAD in Knitting
Computer-Aided Design (CAD) has made the life of textile engineers easy, and it has added a new taste to the technology of knitting. CAD has transformed the knitting industry, enabling more efficient, creative, and precise production of knitted fabrics and garments. Its applications span from design conceptualization to machine programming and manufacturing, supporting both fashion and technical textiles. Whole garment knitting or seamless knitting is a new and novel concept in knitting, which has distinguished features. It is done only for CAD system. There is a thousand years old history of knitwear. With the introduction of the computer, simulation of knitwear emerged as a promising field for the researchers. Simulating a knitwear is more efficient and more realistic approach for new developments. Thus, hit and trials for production of samples on the machine is eliminated, which helped to save time and money. It also makes possible to minimize errors, and the design can be transferred by a single click from one computer to another. Simulation of knitted fabrics therefore became a major research interest in recent years. Applications of CAD in knitting can be broadly categorized as follows:
- Knitting structures design
- Design of knitting pattern shapes
In first technique, knitting structures design, some standard construction are used to make conventional designs like the model of jacket, sweater, etc. Here, construction means whole style of the desired end product, including shape and sizes. The CAD has facilitated the designers to make use of different knitting techniques including jacquard, intarsia, gusset and lace in an effective manner. While second technique, knitting pattern shapes, is capacity of the machine to make fully fashioned products. The machine knits and cuts the product. Knitting machine knits the whole products to avoid separate cutting and sewing.
Starfish Software, ProCad, ProFab, Shima One are some CAD software used to produce knitted structures and designing knitting pattern shapes.
Advantages of CAD in Weaving and Knitting
Computer-Aided Design (CAD) has transformed the weaving and knitting sectors by streamlining processes, enhancing creativity, improving overall efficiency, faster turnaround times, cost and material savings, greater creative potential, and a more sustainable and integrated production workflow. Here are the key advantages of CAD in weaving and knitting:
a) Faster Design Development:
Speeds up the creation and modification of designs.
b) Enhanced Accuracy:
Reduces errors in pattern drafting and technical calculations.
c) Increased Productivity and Efficiency:
Designers can work on multiple projects simultaneously. Minimizes material wastage by simulating designs before physical sampling.
d) Improved Customization:
Facilitates easy alterations in color, pattern, and weave/knit structures.
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e) Better Visualization:
Offers realistic 2D/3D previews, aiding decision-making for designers and clients.
Limitation of CAD in Weaving and Knitting
Although CAD systems are used in weaving and knitting to make machines or products user friendly, increase production, and get right thing at right time, it has some disadvantages as well. Its major disadvantages are high capital cost and highly skilled and trained operators or designers.
Conclusion
CAD has revolutionized weaving and knitting, bridging creativity and technology to meet modern demands to innovate with precision, flexibility, and efficiency while reducing production costs and time, sustainability, and customization. As the industry evolves, advancements in AI and VR promise to further enhance textile design, solidifying CAD’s role as a cornerstone of innovation. By embracing these tools, manufacturers can stay competitive in a dynamic global market while advancing toward a more sustainable future. Applications of CAD in weaving and knitting will undoubtedly play a crucial role in future advancements.
References
[1] Nawab, Y., Hamdani, S. T. A., & Shaker, K. (2017). Structural textile design: Interlacing and Interlooping. CRC Press.
[2] Gandhi, K. (2019). Woven textiles: Principles, Technologies and Applications. Woodhead Publishing.
[3] Ray, S. C. (2012). Fundamentals and advances in knitting technology. In Woodhead Publishing Limited eBooks. https://doi.org/10.1533/9780857095558
[4] Behera, B. K., & Hari, P. K. (2010). Woven textile structure: Theory and Applications. Woodhead Publishing.
[5] Textile and Clothing Design Technology. (2017). In CRC Press eBooks. https://doi.org/10.1201/9781315156163
