Ntc Project Knit

NTC Project: S09-NS02

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National Textile Center Annual Report: October 2009

Integrated System to Design/Produce Engineered Knit Garments

Code Number: S09-NS02

Project Team:

Leader: Traci A.M. Lamar, [email protected]

Nancy B. Powell, [email protected]

Lisa Parillo Chapman, [email protected]

Graduate Students: Reva Erskin

Cuicui Ruan

Goal Statement: The purpose of this project is to develop an expert knowledge base incorporating yarn structure,

knit structure, end product requirements and finishing, and to create an integrated system for the design,

visualization, development and production of engineered knitted garments.

Abstract:

Innovations in knitting technology, such as integral and seamless knitting, have intrinsically connected the

creative designer and technical designer with the production of knitted garments. Currently, there is no recognized

system for producing engineered knit garments that integrates yarns, knit process and structure, visualization, and

finishing with the aesthetic and performance attributes required of knitted garments suited to the unique demands of

varied end uses. We seek to develop an integrated system for engineered knit garment creation that will enable

production of a unique, knitted garment engineered to a specific purpose or end-use. The system is envisioned to

support creation and modification of aesthetic and technical design attributes in a virtual environment, followed by

the addition of technical knit production data, all through an integrated process. Our approach includes building

upon existing industry capabilities to define and create the fundamental linkages required to bridge industry

segments and produce an integrated “concept to production” system for engineered knit garments.

Objective:

Knitted garments hold tremendous potential for providing innovative design solutions for aesthetic and

performance challenges in applications such as medical, sports, fashion and military apparel. Paradigm changing

innovations in knitting technology, such as integral and seamless knitting, have intrinsically connected the creative

designer and technical designer with the production of knitted garments (see Figure 1). Currently, there is no

recognized system for producing engineered knit garments that integrates yarns, knit process and structure,

visualization, and finishing that will deliver the aesthetic and performance attributes necessary to realize the

expanding opportunities for knitted garments; an entirely new body of knowledge is needed. This lack of

fundamental knowledge prohibits integral knitting and other component technologies from being fully utilized in the

creation of engineered knits. This work will address the problem by laying the foundation of fundamental

knowledge needed to exploit the potential of engineered knits in research, consumer and business applications.

The purpose of this project is to develop an expert knowledge base incorporating yarn structure, knit

structure, end product requirements and finishing, and to create an integrated system for the design, visualization,

development and production of engineered knitted garments. The system is envisioned to enable production of a

unique, knitted garment engineered to a specific purpose or end-use via creation and modification of the aesthetic

and technical design in a virtual environment followed by the addition of technical knit production data all through

an integrated process. In three years, the team plans to develop the system and supporting databases and validate

them through application to sample production. Once developed, the system will have application for not only

garments, but for creating any type of knitted textile covering for any product that can be simulated with 3-D

technologies, such as transportation, commercial and residential seating.

mailto:[email protected]




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This project addresses the objectives of NTC through the development of a knowledgebase and an

integrated system that will provide a fundamental understanding of how the technologies that support engineered

knit garment production can be integrated in an efficient concept through a product realization chain. In the last few

years, component technologies for integral knitting and non-contact body measurement equipment have advanced in

terms of capabilities like 3-D virtual model import and export, but each remains an unconnected, isolated island of

technology. The cross-disciplinary work and integration of technologies required for successful engineered knit

garment design and production is virtually undocumented by researchers. Research that is undertaken is almost

exclusively in the private sector and not disseminated to the industry as a whole. Development of a knowledgebase

and integrated system is a critical step in realizing the potential of engineered knits on a broad scale. Moving

forward, this project will provide an academic foundation to support researchers and practitioners working within a

single location or globally, and the intellectual framework needed to drive engineered garment innovation in

industry. Such a fundamental foundation is not currently available.

Background:

The term integrally knitted garment refers to apparel items that have typical cut and sew operations that are

knitted on the machine. These operations include addition of button holes, collars, and pockets and attachment of

sleeve to the garment body [1]. Integral knitting differs from cut and sew, and fully fashioned knitted apparel in that

no seaming is required to complete production. Seam failure in knitted products poses a significant reduction in

quality [2]; therefore by eliminating seams, the comfort, fit and longevity of a product can be improved.

In addition to the benefits posed by seam elimination, integral knitting allows for multiple types of knit

stitches to be strategically placed, or body mapped, on the knitted product. Body mapping allows increased control

of shaping and elastomeric properties by enabling the product developer to engineer knit stitches within the product

shape. Shaping by integral knitting is far superior to cut and sew or fully fashioned because the product is actually

knitted as a 3D shape, rather than as flat panels that acquire a shape by seaming [3,4]. Applications for performance

textiles, medical textiles, and shapewear garments would benefit from 3D shaping, as the knitted products could be

“molded” to the shape of the wearer. The ability to produce a 3D shaped knitted product coupled with strategic

stitch placement allows increased control of compression. The ability to engineer compression levels to the wearer‟s

body shape and size would be beneficial for athletic support and performance, medical or health needs, and aesthetic

knit products such as hosiery and shapewear. Seamless knitting introduces new capabilities; however, a fundamental

body of knowledge on this type of product development process does not yet exist, making full adoption and

exploitation of integral knitting difficult.

Design and production of integrally knitted products, particularly more advanced engineered knitted

garments, requires a comprehensive system for design and production, supported by a knowledge base and

integrated system that supports the translation of concept to final product. The ideal system must incorporate and

consider all aspects of knitted product manufacture such as raw materials (yarn and fiber), product shaping and

sizing, knit structure placement, coloration and finishing processes. Integral knitting machine manufacturers, such as

Shima Seiki, have associated CAD software that will accept virtual body images such as those producible with body

scanning technology [5], and then virtually simulated on a 3D image for accurate placement of knit structures [6].

However, the fundamental research needed to understand how to integrate such virtual information effectively into

the knit design process is unavailable. Globally, few people have the diverse knowledge needed to realize the

potential of engineered knit garments in their work, scholarly or commercial. The development of a system to

integrate design with production would enhance the performance, comfort, fit, and desirability of knitted garments.

Moreover, garments engineered to enhance the figure, improve functional movement or athletic performance, or

provide compression for health benefits and rehabilitation could be more easily customized to unique needs

supported by an integrated system and fundamental knowledgebase. With a smooth flow of information from the

creative design environment to the technical design environment supporting the knitting machine, to the knit

garment production and to the finishing, engineered knit garment producers would have the flexibility to adapt

product specifications as opportunities arose. In niche markets, such as medical compression garments and athletic

performance apparel, the process would offer not only efficiency in creation of existing products, but also offer

improved potential for innovation in products. Furthermore, the potential for a streamlined supply chain may well

reconfigure the relationships between designer, manufacturer, and consumer.


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Approach:

The approach we are taking with this project is to build upon existing industry capabilities to define and

create the fundamental linkages required to bridge industry segments and produce an integrated “concept to

production” system for engineered knit garments. We will conduct interviews and qualitative investigations to build

the knowledgebase needed to support an integrated system. Data collected from these investigations will determine

existing industry capabilities for body mapping (or engineered design), and also determine which linkages still need

to be developed. Intensive software and machine training, and observation of current product development sections

will occur at an integral knitting facility. This facility also conducts R&D for both domestic and international

companies, and has agreed to allow access for the investigators. A group of experts comprised of integral knitting

machine engineers, CAD developers, and integral knitting designers will be interviewed. When possible, the

principal investigators will conduct onsite training and observation of state-of the art integral knitting technologies.

We will analyze component technologies and engineered knitting variables including a) product requirements, b)

design parameters including machine capabilities, yarn structure, 3-D shaping and fit, performance, and finish, and

c) CAD functionality. Simultaneously, we will undertake a fundamental investigation of how engineering of knitted

garments is impacted by knit structure, yarn and finishing within the constraints of a specific knitting machine and

among machines. This fundamental investigation will focus on woman‟s integrally knitted apparel using cotton,

cotton/blend yarns in order to reduce variables. Fundamental knowledge gleaned from a focus on woman‟s apparel

will be applicable to other end products markets such as medical textiles or automotive seating. These learnings will

be incorporated into a knowledge base which can be merged into knitting CAD systems along with design

information for incorporation of knit structure and production data in a virtual environment. System validation will

be through application in actual production of engineered knit samples and evaluation from key industry players.

Progress Toward Established Goals:

The team established four midpoint goals to be reached within the first 17 months of the project. Since project

inception on August 1, 2009, in addition to recruiting and engaging two graduate students in the research, we have

made progress toward our research goals in several areas, as discussed in the following paragraphs.

Goal 1: Identification of experts and conducting interviews regarding relevant technologies, materials and

processes.

We have initiated work in this area by beginning to document relevant technologies, materials and processes

(Figure 1). We have concentrated efforts so far on the most critical elements – integral knitting equipment producers

and direct suppliers to the knitting process, that is yarn producers. In parallel work, we have started to identify

companies and individuals knowledgeable regarding seamless and integral knitting. We have already built a list of

experts including 63 contacts representing various segments of the industry.

In support of this project, we have also established an electronic literature database to house citations for, and links

to, relevant published work in the field. Each entry in the database will represent a relevant piece of academic,

patent or trade literature useful to the project. We have also built a print database of similar documents not available

electronically. The print database also houses some samples. Both databases are at the disposal of all team members

as we engage in project related work.

We have already confirmed support for the project from key industry players including representatives of

Lectra North America, Celanese Ltd., Shima Seiki U.S.A. Inc. and others. These parties represent essential

components for the success of the project. In moving forward, we will continue to dialogue with other equipment

vendors such as Stoll and Santoni, raw material vendors and industry organizations such as The Hosiery Association

and Cotton Incorporated. Through these dialogues, we hope to cultivate additional partnerships to enhance the

project.


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Figure 1: Initial Framework of Identified Technologies, materials, processes and linkages

Goal 2: Complete an analysis of the current status of existing processes including examination of different

approaches, successes and barriers to integration and implementation, and gaps to be addressed.

Figure 2 represents visually how an integrated process might flow. There are rare examples of this process

currently utilized by practitioners such as Shima Seiki (http://www.shimaseikiusa.com/shima7102_001.htm or

http://www.shimaseiki.com/wholegarment/and Santoni (http://www.santoni.com/en-azienda-seamlessstory.asp).

However, it is important to note that those with expertise to implement this type of integrated process are the

machine developers themselves. Only those entities have sufficient breadth and depth of explicit and tacit

knowledge of creative and technical design and production to implement such a process in a real world scenario.

Enabling implementation of such a business model on a broader scale will require the support of a knowledgebase

and system such as being developed here.

http://www.shimaseikiusa.com/shima7102_001.htm

http://www.santoni.com/en-azienda-seamlessstory.asp


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Figure 2. Process for Creation of Engineered Knit Garment (Images and concept taken from Factory Boutique Shima [7])

To initiate examination of existing processes, we have compiled a preliminary list of knitting machine

manufacturers and the seamless knitting equipment each offers. In a very general way we have documented the

approach utilized by each for the identified knitting equipment (see Table 1).

Color/Yarn SelectionInput to Design System

Sizing

Production KnittingSimulation

Style Selection

Knit Production


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Table 1. Seamless knitting machinery and approaches to knitting seamless

Goal 3: Determine relationships that will shape the selection of yarns, knit structures, gauge, etc. to achieve the

desired outcome for a garment.

It will be essential to understand the contribution that each component and its supplier provide to the

process and the finished product. Information available from industry organizations, publications, and events

focusing on seamless products will be utilized to establish the issues, trends, and barriers to further success of this

technology. Our initial research has identified over 60 companies from fiber to retail apparel who are engaged in the

development and marketing of seamless products.

Our early work has already revealed some relationships that influence aesthetic and technical design

decisions in relation to seamless and integrally knit garments. Seamless knitwear differs from integral knitting in

that seamless items are typically knit on a circular, body-size knitting machines that produce a shaped tube that then

requires further shaping by cutting around armholes and neck openings. In contrast, with integral knitting, the

product is knit to shape on a V-bed knitting machine (see figure 3). Seamless garments are prevalent in intimate

apparel at the higher gauge of knitting machines whether v-bed, circular or warp knit technologies. Seamless

Company Machine Name Type Knitting Approach

MACH2X WHOLEGARMENT

MACH2S WHOLEGARMENT

SWG041N/061N/091N WHOLEGARMENT

SWG-FIRST WHOLEGARMENT

SWG-X WHOLEGARMENT

NewSWG-V WHOLEGARMENT

NewSES-S·WG WHOLEGARMENT

NewSES-C·WG WHOLEGARMENT

NewSFG

SPG

SPF-W Seamless Sock Flat Knitting Machine

CMS 730 S knit&wear

CMS 740 knit&wear

CMS 730 T knit&wear

CMS 830 C knit&wear

CMS 822 HP knit&wear

CMS 830 S knit&wear

SM8-TOP1V

SM8-EVO4

SM8-TOP1 MP

SM8-TOP2

SM8-EVO4J(New)

SM4-C

SM4-PLUS3

SM4-TL2(New)

SM-TR2

SM12-EVO3

SM9-3W(New)

SM9-MF(New)

SWD8 Warp Seamless Knitting Machine Warp Seamless Knitting Machine

Fantasia 1C HT

Fantasia 2C HT

Fantasia HTA

4100 HT

Star HT

Jumbo Chroma

Jumbo power

Uniplet EDIS 4.1C SIngle-cylinder Seamless Hosiery Knitting Machine

Shuishan SW8-W Seamless Knitting Machine Circular Knitting Machine

Flat Knitting Machine

Circular Knitting Machine

Shima Seiki

Circular Knitting Machine

Santoni

Stoll

Sangiacomo

WHOLEGARMENT Flat Knitting Machine

Seamless Flat Knitting Machine

Single Jersy Seamless Circular Knitting Machine

Double Jersy Seamless Circular Knitting Machine

Seamless Sock Circular Knitting Machine

Seamless Glove Flat Knitting Machine


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outerwear development has been primarily focused on heavier gauge sweaters for men and women. The growth of

shapewear and activewear has demanded a more complex combination of materials and structures in garments

beyond the basic “no or minimal side seams” construction. With the development of performance active wear, each

component has a role to play in creating the optimum garment to enhance the athlete‟s physical performance,

comfort and confidence. Additionally the aesthetic appearance of the garment for a professional athlete has a role to

play in promoting the brand.

Figure 3. A Comparison of Shaping Methods for Integral Knitting vs. Seamless Knitting

From fiber characteristics to yarn and complex structures, a finished integrally knitted garment must be

carefully engineered to provide the required attributes customized to the activity and the individual‟s

anatomy/physique. Body scanning technology and repeated fit sessions provide sizing dimension information for

better fit, appearance, and comfort. Selection of fibers and yarns with moisture and temperature management will

provide comfort advantages for the competitive athlete or intimate apparel.

The advancement of the knit machine technology such as transfer needles, variable gauge capability, and

sophisticated shaping methods can provide the designer with multiple possibilities to apply various knit

structures in different „zones‟ in the garment. Improvements in the seamless knitting process may also provide

reduction in materials waste, and savings in time, transportation and energy costs. Providing the market with better

products at competitive prices through an effective integrated system allows value to be recaptured in the

compressed supply chain.

Goal 4: Produce the preliminary integrated model.

All of the work described above in relation to our other goals is moving the team toward Goal 4. Our plan is to

integrate the information we glean in achieving each of the previous goals into a preliminary integrated model of our

system.

Project Website: S09-NS02

Acknowledgements:

Traci A.M. Lamar, Nancy B. Powell, Lisa Parillo Chapman, Reva Erskin, Cuicui Ruan

http://www.ntcresearch.org/projectapp/?project=S09-NS02


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References:

1 Spencer, D. J., Knitting technology : A comprehensive handbook and practical guide (3rd ed.). Cambridge,

England; Lancaster, Pa.: Woodhead Publishing Limited, 2001

2 Clapp, T., Gunner, M., Dorrity, J., Olson, L., The Online Inspection of Sewn Seams, Project S94-41, National

Textile Center, Annual Report, 1994

3 Powell, N.B., Mass Customization in Transportation Textiles through Shaped Three Dimensional Knitting ,

Proceedings: International Textile Design and Engineering Conference, Edinburgh, Scotland, Heriot-Watt

University , Netherdale, Galashiels TD1 3HF, UK. September , 2003.

4 Hunter, B. (2005). Novel seamless sweater technique. Knitting International, 112(1324), 26-27.

5 TC2. (2004) Body Measurement Software System. Available online at:

http://www.tc2.com/products/body_software.html

6 Shima Seiki. (2006, August). The Future of Knitting Available Today. Available online at:

http://www.shimaseiki.co.jp/wholegarmente.html

7 Factory Boutique Shima, (2009) Our Products. Retrieved September 29, 2009 from http://fbshima.co.jp/

http://www.tc2.com/products/body_software.html

http://www.shimaseiki.co.jp/wholegarmente.html

Documents

Ntc Project Knit