Apparel and Sewn Product Automation
Addressing the Need for Data Exchange
Many ASTM standards address technical topics that are difficult to relate to or even understand, but apparel and sewn products are tangible and common everywhere. Garments have a long history predating modern technology and their production is a straightforward process, so many people ask, “Why does ASTM need standards for sewn products?” The key lies in the last word of the name of Subcommittee D13.66 on Sewn Product Automation.
Sewn product industries, especially the apparel industry, have long depended upon contractual arrangements among several companies to create and deliver a product. Before the days of automation and electronic data, paper provided the means of communicating garment design information. Work was primarily done in a single country or region and most of the products stayed within local markets. Like many industries, this simple model was torn down by advances, first in transportation, then in data transfer. Today, global sourcing strategies and markets continually increase pressure on the creators of sewn product production processes to reduce time-to-market and production cost. The day of the vertical apparel manufacturing process is past. It has been replaced by smaller contract companies that rely on automated processes to deliver goods on time and at competitive prices.
The multiple companies that make up the sewn product supply chain likely all reside in different countries, use different automation technologies, and speak different languages. The typical sewn product manufacturer does not have the internal technical expertise to either deal with the translation of electronic data from foreign design systems or export to another format to pass down the chain to the next supplier. In the past, incompatible data were discarded, paper copies of the data were printed and sent to the producer, then manually re-entered in the native system. This was inefficient at best and, at worst, introduced costly errors downstream.
Enhancing Information Transfer Around the World
ASTM Subcommittee D13.66 focuses on creating an internationally recognized data framework that ensures consistent and seamless information transfer along the entire automated sewn product production process. The most important design constraint for these standards is that they must not jeopardize the powerful capabilities of the individual software and hardware systems, and that they preserve the design intent during transfer between them. This allows users to mix data from all design systems without concern for lost information. It is also critical that these standards be developed for use in the global production environment.
The benefit of this effort comes from eliminating the need to translate or re-enter data as it moves between suppliers, even if each of their design or output systems come from different manufacturers. Design intent is also preserved without the need to give direction in a language not native to the producer. ASTM sewn product automation standards ensure that companies that subcontract for large producers can receive data, use it for their part of the process, then send the data to the next supplier in the chain if necessary, all without affecting the integrity of the data.
Before ASTM standards were available, the transfer of automated sewn product production data between suppliers was analogous to e-mailing an electronic spreadsheet to someone who does not have a compatible program to read the data. To convey the information, data had to be exported to a generic format such as comma-separated values at the expense of formatting and formulae (design intent). New ASTM standards such as D 6959, Practice for Data Exchange Format for Sewn Product Plotting Devices, allow users to send data to any marker output device in the same way that Web pages written in standardized languages such as HTML, or hyper text markup language, provide universal compatibility. Both of these formats offer rich formatting options that are preserved independently of the software or hardware with which they are used. They are much more robust because international corporations adopt them in their products and work together to preserve and update the standards that describe them. ASTM D13.66 standards are supported by the largest sewn product automation companies in the world. The work of the committee makes it possible to read pattern data from a Gerber design system on a Lectra design system or to send marker data from these systems to an output device like an Ioline FlexJet printer or an Assyst flatbed cutter.
Challenges of the Sewn Product Process
Sewn products, which consist primarily of apparel but also include products such as upholstery and airbags, are unique in their processing and manufacturing requirements. Producing them is a labor intensive process that is difficult to automate. For this reason, the production of sewn products has chased cheap labor around the globe. While the production of goods has moved offshore, some parts of the process, like pattern design, remain part of the U.S. economy. The fractured nature of the production chain requires intense data flow and movement of raw materials over long distances. (See the apparel flow chart.)
An apparel process may start in a design studio in New York, N.Y., where the product is conceptualized, materializes as a sample garment on the other side of town, then moves to another part of the country for conversion from a three-dimensional garment to a group of individual two-dimensional pattern pieces. Detailed specifications for the manufacturing process are added depending on the type of material from which the product is made. Finally, the single sample size is “graded” into all the sizes required to fit the target market. This is only the pattern-making process, a first step in producing a garment. (See Figure 1.)
All of these data are then used to create markers. A production order will typically consist of multiple sizes, so the individual parts for each size will be nested together like a jigsaw puzzle in order to minimize fabric waste.
The markers act as templates and are sometimes reused hundreds of times to make tens of thousands of garments. The more skillfully the marker is laid out, the less fabric is wasted and the lower the production cost. This is the marker-making process. (See Figure 2.)
Once the markers are complete, they are sent to the production facility, increasingly found in China since the lifting of global production quotas on Jan. 1. Commonly the marker data are sent electronically by e-mail, but sometimes they are printed on long columns of paper that are rolled up and sent by mail.
Once an order is placed, the producer begins the spreading process, which deposits multiple layers of fabric into stacks on long tables. (See Figure 3.)
Hand cutters place a printed marker (either received in the mail or printed on wide-format printers from the electronic file) on the stack. It is used as a guide to cut the stacked cloth into pieces that are eventually sewn into the final garment. (See Figure 4.)
The cutting process is also accomplished with numerically controlled equipment that uses an electronic form of the marker, specially formatted for cutting machines. (See Figure 5.)
So far the data have taken many forms as they moved through the process: three-dimensional design data, two-dimensional pattern data, manufacturing specifications, graded two-dimensional patterns, electronic markers, printed markers and markers formatted for automated cutting. Some of these steps were taken by people who probably do not speak the same language. More pieces of process require data flow, the assembly of pieces into a completed garment (even the stitches have a standard check out the ASTM stitching standard D 6193, Practice for Stitches and Seams), special handling such as stone washing, pre-ship steps such as adding hang tags and bar codes, shipping to global distribution centers, and, of course, invoicing and getting paid for all this challenging work. (See Figure 6.)
This example illustrates how many ways data are used and must move between different parts of the process and, in many cases, company-to-company and country-to-country. This is why sewn product automation standards are so important.
History of Success
Work on sewn product automation standards was started by the then-American Apparel Manufacturers Association (now the American Apparel and Footwear Association) in the 1990s with rudimentary standards for cutting and pattern data. The standards were later issued by the American National Standards Institute, then transitioned to ASTM in 2000. AAFA continued to support the effort in a semi-official role. ASTM officially established Subcommittee D13.66 of Committee D13 on Textiles in January 2000. A task force was formed to address revisions to the pattern data exchange standard. Kurt Chang of 3D Custom Fit volunteered to chair the task group and was instrumental in its startup and success.
An excerpt from Bobbin Magazine’s October 2000 issue, “Solving Pattern Data Exchange Problems: Standards Development Revived,” illustrates the work that was undertaken: (1)
“One of the major challenges in today’s global business-to-business (B2B) e-commerce world is the ability to share and exchange information between computer applications. For the sewn products industry, CAD/CAM data compatibility issues have become especially critical, as more companies increase their outsourcing programs and expand their market share through consolidations and acquisitions.
“In such an environment, it is essential that the industry establish standard methods for presenting CAD/CAM data, in formats that can be easily understood and utilized by different computer applications. Such standards would allow apparel and sewn product producers to utilize a choice of machinery and software from different vendors, and to exchange information with contractors and third parties that may not have the same machinery and software.”
At the first ASTM task group meeting, there were representatives from suppliers in Canada, France, Germany, Israel, Spain, and the United States, as well as users from the apparel, shoe, and automotive upholstery industries. In an intense two-and-a-half day working meeting, 25 users and suppliers from all over the world drafted a pattern data exchange standard. This meeting was unique because of the high level of professional cooperation among competing suppliers and candid recommendations from users. The group successfully produced the standard, which was quickly adopted as an ASTM international standard.
The successful pattern data exchange standard showed that the collaborative development process fostered by ASTM worked. It also illustrated the value of international participation to ensure global acceptance of the standards. Because they participated, companies were eager to adopt them in their software and hardware.
An exciting new area of committee work is body scan data exchange. (2) The process starts in a special scanner that converts the shape of a body into a set of three-dimensional point cloud data. (See Figure 7.)
These points are used to extract body measurements based upon a measurement definition. The measurement data are used to create patterns for apparel items. (See Figure 8.)
The processes to create the data are a function of each proprietary system, but the transfer of the data may be among dissimilar systems, hence the need for data exchange standards. (See Figure 9.)
To create these data transfer standards, the pattern data exchange task group is working with and using definitions for the measurements from Subcommittee D13.55 on Body Measurement for Apparel Sizing.
Since 2000 the committee has addressed standards for five major data types:
1. Pattern data (garment design);
2. Marker data (garment production layout);
3. Plotter data exchange (hardware that prints markers for hand-cutting);
4. Cutter data exchange (hardware that cuts markers); and
5. Body scan data (three-dimensional body measurement used to make custom garments).
These data types are continually updated to address new computer languages and hardware formats because design software and manufacturing equipment change constantly. For this reason the standards must not remain tied to older technologies or languages. For example, XML, or extensible markup language, is the core of new pattern and marker standards due out soon. Committee task groups are also updating cutter file data exchange, body measurement data exchange, body scanner output data exchange, and body scanner system evaluation criteria.
It was evident the first time subcommittee D13.66 met in March 2000 that the international makeup of the group demanded virtual meetings. E-mail continues to serve as the primary method of exchanging information. This was recently enhanced with the creation of Yahoo groups for each of the technical committee members to share files, service e-mail lists and archive conversations. The telephone is now only occasionally necessary for discussion.
The successful efforts of the members and associates of Subcommittee D13.66 are amazing. Many robust and useful standards have come from the group over the last five years. The greatest challenge is to keep the level of involvement high despite reduced staffing at many companies and a general waning of support within companies for industry groups. Keeping user associates involved is also critical so that the committee truly understands what the customer needs. Subcommittee D13.66 standards are now recognized internationally by corporations as the single accepted data format for sewn product production processes. The committee continues to update and publish ASTM standards for the world market. Continued review of the work of other standards bodies and working with them directly on universal adoption of ASTM D13.66 standards will ensure that work is not duplicated. Ultimately both the corporate user and the consumer benefit from this approach. //
The author would like to thank Committee D13 members Lynsey Cooper (Nester Software), Jeff Monroe (Gerber Technology), and Kevin Reed and Amy McElroy (Ioline Corporation), who contributed to this article.
(1) Bobbin Magazine, Oct. 2000, “Solving Pattern Data Exchange Problems: Standards Development Revived,” by Kurt Chang, 3D Custom Fit Corp.
(2) An Introduction to the Body Measurement System for Mass Customized Clothing. By David Bruner, Director, R & D, Textile/Clothing Technology Corporation [TC]2 211 Gregson Dr., Cary, NC 27511-7909, January 2004, www. techexchange.com/thelibrary/bmsdes.html.