Volume 4, Issue 4, Summer2005
`
`Three-Dimensionally Knit Spacer Fabrics:
`A Review of Production Techniques and Applications
`Shanna M. Bruer, Ph.D. Student
`Professor Nancy Powell
`Dr. Gary Smith, Associate Professor
`NCSU College of Textiles
`ABSTRACT
`As the textile complex is faced with increasing competition, innovation and specialization have
`been employed by many machinery and product manufacturers to create a niche in the
`marketplace. In an effort to compete and appeal to the end-use market, products that go beyond
`the current range of performance and style have been developed. This paper will focus on the
`development of such specialized production through the use of knitted spacer fabrics. Basic
`knitting concepts will first be introduced followed by a review of literature on the history,
`technologies, advantages, disadvantages and potential end uses of knitted spacer fabrics.
`Keywords: Spacer fabrics, knitting, automotive textiles, technical textiles
`
`1.0 INTRODUCTION
`As control of the textile complex has
`shifted further downstream to the consumer,
`manufacturers have been faced with greater
`and more specialized demands. In order to
`compete and appeal to the end-use market, it
`is therefore important to offer products that
`go above and beyond the current range of
`performance and style offerings.
` One
`industry striving to meet such demands is
`the manufacturers of knitting machinery and
`knitted fabrics.
`This paper will first introduce some
`necessary knitting concepts and then discuss
`the topic of spacer fabrics. Literature on the
`
`advantages,
`technologies,
`history,
`disadvantages and potential end uses of
`knitted spacer fabrics will then be presented
`to create a complete understanding of spacer
`fabric’s purpose and means of production.
`2.0 KNITTING FUNDAMENTALS
`the
`Simply
`stated, knitting
`is
`interlooping of yarns to form a textile
`structure. There are two classifications of
`knits – weft and warp. Weft formations have
`yarns which are knit across the width of the
`fabric while warp formations have yarns
`being knitted along the length of the fabric
`(Spencer, 2001) (see Figures 2.0a and 2.0b).
`
`Article Designation: Scholarly
`
`1
`
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 1
`
`

`
`Figure 2.0a: Weft Knit Structure
`
`Figure 2.0b: Warp Knit Structure
`
`Source: Raz, 1987. Page 17
`There are three primary loops, each
`having their own characteristics used to
`produce knit fabrics – the knit loop, the float
`loop and the tuck loop (Brown, 1973). In
`addition to having three primary loops there
`are three needles used in the production of
`knitted fabrics – the spring-bearded needle,
`the latch needle and the compound needle.
`The latch and compound needles, however,
`are more prevalent because of
`their
`efficiency
`and
`ability
`to
`increase
`productivity (Spencer, 1983).
`
`Source: Raz, 1987. Page 17
`2.1 Variations of Weft Knit Fabric
`Structures
`The three primary classifications of
`weft knit structures are the jersey (plain)
`structure and derivatives, rib fabric and
`derivatives and purl fabric and derivatives
`(Shinn, 1957; Smith, 1984; Smith, 2004).
`Jersey fabrics and their derivatives are
`single-sided structures and include fabrics
`such as plain jersey, feed stripe, pique, flat
`jacquard, fleece and plated jersey (Spencer,
`2001; Smith, 2004). The two structures
`important for reference in this paper are the
`plain jersey fabric which is a single layer
`fabric in which the same yarn is being knit
`on the front and back of the fabric and a
`variation of the plain jersey called plated
`jersey (see Figures 2.1a and 2.1b).
`
`Figure 2.1a: Technical Face of Plain Jersey Fabric Figure 2.1b: Plated Jersey Fabric
`
`
`Source: Shinn, 1957. p. 10
`
`Source: Spencer, 2001. Pg. 57
`
`Article Designation: Scholarly
`
`2
`
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 2
`
`

`
`Plated jersey has the same basic
`structure as single jersey, but it uses two
`yarns which are knitted at the same time
`under controlled tension so that one yarn is
`always on the designated side of the fabric
`(Spencer, 2001; Smith, 2004). It is still a
`single jersey fabric, but with two layers of
`yarns which may be used to manipulate the
`characteristics of the fabric to control such
`
` Figure 2.1c: 1x1 Rib Fabric
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Source: Shinn, 1975. Pg. 12.
`
`1x1 rib is a single layer fabric that has the
`same yarn knitting loops on both sides of the
`fabric. Interlock fabrics are a form of rib
`that use two sets of needles that knit back-
`to-back in an alternate sequence to create
`two sides of the fabric that are exactly in
`line with each other and hide the back of the
`loops on the inside of the structure and show
`identical face loops on both the front and the
`back of the fabric. The final product has the
`appearance of a plain jersey fabric on the
`front and back with the two yarns alternating
`sides of the fabric (Spencer, 2001; Smith,
`2004). It should be noted that interlock
`fabric (like 1x1 rib and other stated fabrics)
`cannot be called spacer fabric because there
`is no separation of fabric layers.
`
`Double-faced fabrics use two sets of
`needles that can be set between one another
`(rib gaiting as found in the 1x1 rib fabrics)
`or directly aligned with one another
`(interlock gaiting) to form a class of fabrics
`that can have the same or different types of
`yarns on both sides of the fabric. The yarns
`on both sides are held together by tuck loops
`(Spencer, 2001; Smith, 2004).
`
`3
`Article Designation: Scholarly
`
`
`
`
`
`
`
`
`qualities as moisture transfer, comfort, hand
`and stretch.
`
`Rib fabrics and derivatives include
`1x1 rib, cardigan, interlock, flat jacquard
`and double-faced fabrics (Spencer, 2004).
`The three structures important for later
`discussion of spacer fabrics are the 1x1 rib,
`interlock and double-faced fabrics (see
`Figure 2.1c and 2.1d).
`
`Figure 2.1d: Interlock Fabric
`
`
`
`
`
`
`Source: Spencer, 2001. Pg. 73
`Purl fabric is the final classification in
`which there is also the possibility of making
`double-faced fabrics using the same idea
`presented with the rib fabrics. However,
`due
`to slow machine speed and
`low
`productivity they are not typically used for
`such production.
`
`2.2 Weft Knitting Machines
`
`There are two types of weft knitting
`machines – circular and flat. Circular
`machines can be classified in one of three
`categories – 1) single jersey machines which
`have one set of needles and make only
`jersey fabrics, 2) dial and cylinder machines
`which have two sets of needles and are
`capable of making jersey and rib fabrics, and
`3) double cylinder purl machines which use
`double-ended latch needles and make purl
`fabrics (Iyer, et al, 1995; Spencer, 2001;
`Smith, 2004). The two primary forms of flat
`knitting machines are the V-bed machine,
`which is useful in the production of spacer
`fabrics and the flat purl machine which is
`nearly non-existent in today’s applications
`(Raz, 1993; Smith, 2004). The V-bed has
`the potential for making both jersey and rib
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 3
`
`

`
`fabrics, as well as their derivatives including
`double-faced fabrics. Figures 2.2a and 2.2b
`show and explain
`the knitting action
`
`
`Figure 2.2a: Knitting Action of Dial and Cylinder Knitting Machines
`
`
`associated with the dial and cylinder and v-
`bed knitting machines.
`
`Needle Positions of Dial and Cylinder
`Knitting Machine
`
`Position 1: Base Position.
`
`Position 2: Clearing of dial needle
`for opening dial needle latches
`
`Position 3: Dial needle in holding-
`down position
`
`Position 4: Cylinder needle in
`forwarding position
`
`Position 5: Dial needle in receiving
`position
`
`Position 6: Transition position of
`needles to following knitting feeder
`
`
`
`D
`
`3
`
`
`
`D
`
`6
`
`
`
`D
`
`1
`
`D
`
`C
`
`D
`
`2
`
`D
`
`C
`
`C
`
`4
`
`C
`
`
`
`C
`Source: Iyer, Mammel & Schach (1995). Pg. 149
`Figure 2.2b: Knitting Action of V-Bed Machine
`
` Back Bed
`
`Front Bed
`
`
`5
`
`C
`
`
`
`1
`
` 2
`
` 3
`
` 4
`
`
`
`
`
`Position 1: The rest position. The tops of the heads
`of the needles are level with the edge of the knock-
`over bits.
`
`Position 2: Clearing. The needle butts are lifted
`until the latches clear the old loops
`
`Position 3: Yarn Feeding. Yarn is fed to the needles
`as they begin to descend.
`
`Position 4: Knocking –over. The new loops are
`drawn through the old loops, thus completing the
`cycle.
`
`
`
`
`
`
`
`
`
`
`Source: Spencer (2001). Pg. 212
`4
`Article Designation: Scholarly
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 4
`
`

`
`machine has the ability to make more
`complex structures, but
`is considerably
`slower in production speed (Reisfeld, 1966;
`Spencer, 2001; Smith, 2001). It is important
`to mention that as gauge is increased, finer
`yarn is used and it is more likely that
`production flaws will occur (Smith, 2001).
`
`
`The second means of classification is
`the number of bars or sets of yarns used in
`production. With the addition of bars,
`fabrics become more expensive, more
`stable, denser and more versatile (Smith,
`1984). Typically a Tricot machine uses 2-6
`bars (i.e., making a 2-bar fabric, 3-bar
`fabric, 4-bar fabric, etc.). Sub-categories of
`Tricot
`fabrics
`include
`traditional solid
`fabrics (also called standard full set fabrics)
`such as Locknit or Full Tricot, Openwork
`fabrics or Laid-in fabrics (Raz, 1987;
`Spencer, 2001). Raschel machines found in
`industry vary significantly, but for spacer
`fabrics discussed in this paper will range
`from 5-8 bars (Smith, 2001). Further sub-
`classification of Raschel fabrics can be
`broken down into solids, lace, open-work,
`mesh, laid-in and spacer fabrics (Raz, 1987;
`Spencer, 2001; Smith, 2001). It will be
`noted that even though production of one
`bar fabrics is possible, it is not common
`because they are weak and unstable, but
`such structures can be used to produce fabric
`structures that are components of warp knit
`spacer fabrics.
`
`
`
`2.3 Weft Knitting Notation
`
`the
`In order
`to fully understand
`structures to be discussed, it is necessary to
`introduce the concept of notation. The two
`methods of notating weft stitches used in
`this paper are the graphic and diagrammatic
`techniques.
` The graphic method uses
`pictures or photographs to illustrate the
`fabric structure and is used in Figures 2.1a-c
`to depict basic weft knit structures. Figure
`2.3 shows the diagrammatic method which
`is often more useful. The dots represent
`needles, while the lines represent the path of
`the yarns. The type of machine being used
`can be identified by the number of needles
`(i.e. dots) per course (one set per course
`being jersey while two sets per course
`indicate rib or interlock fabric created on
`dial and cylinder or v-bed machines), the
`way the needles are arranged and the
`notation used.
`
`2.4 Warp Knitting Classifications and
`Machines
`Warp knit structures have yarns that
`knit parallel to the length of the fabric and
`can be classified in three ways (Raz, 1987;
`Reisfeld, 1966; Smith, 2001). The first
`method of classification is the machine used
`in production – Tricot or Raschel. The
`Tricot machine makes fabrics that are less
`complicated, finer
`in gauge and more
`rapidly produced, while
`the Raschel
`
`
`
`
`
`5
`Article Designation: Scholarly
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 5
`
`

`
`
`
`6
`Article Designation: Scholarly
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 6
`
`

`
`a fabric similar to interlock (Brown, 1973;
`Spencer, 2001; Smith, 2001). Raschel
`machines may also have one or two sets of
`needles. Single needle bar fabrics look
`different on both sides and do not have two
`distinct layers. Double needle bar fabrics
`differ from the Simplex fabrics introduced
`with the Tricot machine in that the two sets
`of needles are parallel and have an alternate
`knitting action so that the front and back sets
`of needles knit separate layers of fabric
`while yarn travels back and forth to join
`them together (Thomas, 1976; Spencer,
`2001; Smith, 2001). Figure 2.4 shows the
`knitting action associated with Raschel
`machines.
`
`Position 1: Starting point.
`Needles are extended fully
`upward and the front guide bar
`swings to the back of the
`machine.
`
`Position 2: Movement left.
`Guide bars move to the front
`of the needles and to the left.
`
`Position 3: Swing between
`needles. Guide bars are
`swinging between the needles
`and back to the front side of
`the machine.
`
`Position 4: New loop
`formation. Needles are taken
`down causing the loops to
`slide from the latches into the
`hook.
`
`Position 5: Knocking over.
`The new loops are drawn
`through the last row of loops.
`
`Position 6: Completion. The
`needles rise and the new loops
`slide down from the hook,
`open the latch and slip over its
`edge onto the stem.
`
`
`
`
`
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`
`
`The final means of classifying warp
`structures is by the number of needle bars
`used under each machine classification.
`Traditional tricot machines have one set of
`needles that move simultaneously and create
`fabrics that look different on each side
`(Paling, 1965; Spencer, 2001; Smith, 2001).
`The front and back of the fabric can be
`easily
`identified by
`the diagonals or
`underlaps being observed on the back-side
`of the fabric. Simplex Tricot machines have
`two sets of needles that are arranged
`similarly to a V-bed machine and knit
`alternately. The fabric created on this
`machine has only one layer with one set of
`yarns going from front to back while another
`set of yarns goes from back to front to make
`
`Figure 2.4: Knitting Action of Raschel Machine
`
`
`
`1
`
`2
`
`
`
`4
`
`
`
`5
`
`
`
`Source: Reisfeld, et. al,1953. Pgs. 8-18.
`
`3
`
`6
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`7
`Article Designation: Scholarly
`
`IPR2017-00351
`Fredman EX1030 Page 7
`
`

`
`2.5 Warp Knitting Notation
`
`Similar to the concept of notation introduced
`in weft knitting, warp knitting requires a
`means of communicating how a structure
`should be knitted. The three methods of
`notating warp stitches used in this paper are
`graphic, diagrammatic representation and
`numbers (Reisfeld, et al, 1953; Reisfeld,
`1966; Spencer, 2001; Smith, 2001). The
`graphic method uses pictures or photographs
`to
`illustrate
`the
`fabric structure and
`examples can be seen in Figures 2.6 a-c.
`Figures 2.5 a-c show the diagrammatic
`method which is more useful as the warp
`structures become increasingly complex.
`The dots represent needles, while the lines
`represent the path of the yarns as the guide
`
`
`Table 2.5a: Single Guide Bar Warp Structures
`
`
`bars move between and around the needles.
`The type of machine being used (Tricot or
`Raschel) can be identified by the numbers
`between the wales at the bottom of the
`diagram. Sequential numbers (i.e., 0, 1, 2, 3,
`etc.) indicate that the structure being knitted
`is on a Tricot machine while even numbers
`(i.e., 0, 2, 4, 6, etc.) indicate a Raschel
`machine is being used. Additionally, each
`row of needles is labeled as either the front
`bar (FB) or the back bar (BB). As will be
`noted
`later, when spacer
`fabrics are
`produced, it is necessary to identify front
`and back needle bed knitting actions. Tables
`2.5a and 2.5b show notation for single guide
`bar fabrics while Table 2.5c shows notation
`for fabrics that are produced on machines
`with two guide bars.
`
`
`
`
`
`
`
`8
`Article Designation: Scholarly
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 8
`
`

`
`
`Table 2.5b: Single Guide Bar Atlas Fabrics
`
`
`Table 2.5c: Two Guide Bar Structure Representations
`
`
`
`
`
`
`9
`Article Designation: Scholarly
`
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 9
`
`

`
`
`2.6 Variations in Warp Knit Fabric Structures
`Warp structures can be composed of stitches containing both open and closed loops as can
`be seen in Figures 2.6a and 2.6b.
`Figure 2.6a: Open Loop
`
`
`
`
`
`
`
`
`
`
`
`
`
`Figure 2.6b: Closed Loop
`
`
`
`
`Source: Smith, 2001.
`
`Figures 2.5 a-c show fabric notations, some
`of which contain what are referred to as
`open loops (two examples include the open
`chain stitch, and open half tricot stitch)
`which tend to be flimsy, and lack stability
`because the yarns do not cross at the bottom,
`however, they are easier to knit (Raz, 1987;
`Spencer, 2001; Smith, 2001). Closed loops
`are those that do cross at the bottom and
`create a more fixed fabric. It should be
`noted that the chain stitch is used to lock
`fabrics in place and is successful at adding
`
`
`Figure 2.6c: Full Tricot
`
`length stability, but if used alone cannot
`make a fabric (Raz, 1987; Smith, 2001).
`
`
`Warp knit fabrics can be classified in
`many ways. For example they can be
`solid/full-set fabrics or open-work fabrics
`(Reisfeld, 1966; Smith, 2001). Examples of
`solid fabrics include Locknit, Full Tricot and
`Queenscord (see Figures 2.6 c-e). In order
`to have a two bar solid fabric both guide
`bars must be full set meaning that each wale
`will have two yarns (Reisfeld, 1966; Smith,
`2001).
`Figure2.6d: Locknit
` Figure 2.6e: Queenscord
`
`
`
`
`
`Source: Reichman, et al, 1967. Pg. 36
`
`
`
`
`Source: Reichman, et al, 1967. Pg. 36
`
`
`Source: Reichman, et al, 1967. Pg. 36
`
`
`
`
`
`
`
`10
`Article Designation: Scholarly
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 10
`
`

`
`
`Open-work or mesh fabrics are often created using either the Van Dyke/Atlas or laid-in approach
`(see Figures 2.6f and 2.6g for illustrations).
`
`Figure 2.6f: Single Atlas Fabric
`
`
`Figure 2.6g: 2-Bar, Full-Set, Laid-In Fabric
`
`
`
`
`
`
`
`
`Source: Paling, 1965. Pg. 76
`
`An Atlas lapping is a movement where the
`guide bar laps progressively in the same
`direction for a minimum of two consecutive
`courses, normally followed by an identical
`lapping movement in the opposite direction
`(Spencer, 2001). Used alone, atlas lapping
`makes poor fabrics, but can generate desired
`effects such as interesting design and open-
`work fabrics. The concept of laid in yarns
`allows for a fancy or special yarn to be
`incorporated into the fabric. Laid-in yarns
`are typically locked in place by a knitting
`yarn and must therefore be placed on a back
`guide bar (Spencer, 2001; Smith, 2001).
`Yet another way an openwork fabric
`may be created is through the use of ‘partial
`set threading’ or if the number of guides left
`empty equals the number of guides threaded,
`‘half set threading’ (e.g. with a threading of
`1 in 1 out or 2 in 2 out) (Wheatley, 1972).
`By having full set threading the weight of
`the fabric is increased. Additional means of
`increasing fabric weight include heavier
`yarn (lower cotton count or higher denier),
`using full set threading as opposed to partial
`
`
`
`
`
`
`
`
`Source: Paling, 1965. Pg. 175
`set, adding pile bars, and moving needle
`beds further apart (Smith, 2001).
`Figures 2.6h and 2.6i show openwork
`or mesh fabrics and Figures 2.6j and 2.6k
`show laid-in, open work fabrics and their
`notations. The fabric depicted in both
`Figures 2.6j and 2.6k are full set and can be
`modified by changing the way in which the
`yarns are laid-in, ultimately changing the
`size and shape of the openings. Figure 2.6k
`is more rigid and has greater vertical
`stability because it has three sets of yarns
`being knitted rather than the two seen in
`2.6h. It is important to note that the variety
`of fabrics that can be created is many and
`significant
`in
`the production of spacer
`fabrics. Because solid or open-work fabrics
`can be used independently or as a basis for
`both sets of fabric in a warp knit spacer
`fabric, meaning that each side of the spacer
`fabric can have a different construction (i.e.
`the front may have the construction of
`Figure 2.6h and the back could have the
`construction of 2.6i).
`
`
`
`
`
`
`
`
`
`
`11
`Article Designation: Scholarly
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 11
`
`

`
`
`Figure 2.6h: 2-Bar, Half-Set Net
`
`
`
`Figure 2.6i: 2-Bar, 2-in, 2-out Net
`
`
`
`
`
`
`
`Source: Paling, 1965. Pg. 118
`
`
`
`
`Source: Paling, 1965. Pg. 110
`
`Figure 2.6k: 2-Bar, Full Set Open Work
`
`
`Figure 2.6j: 2-Bar, Full Set
` Open-Work Fabric
` Fabric with 3 Sets of Yarns
`
`
`
`
`
`
`
`Source: Smith, 2001.
`
`fabrics made with 2 or more guide bars
`(Reisfeld, 1953; Raz, 1987; Smith, 2001).
`By adding guide bars, the fabric becomes
`more balanced and stable. Figures 2.6l and
`2.6m show fabrics made with one and two
`guide bars.
`
`Source: Smith, 2001.
`
`
`
`
`
`the second way of
`Identified as
`classifying warp knits, the number of guide
`bars on Tricot and Raschel machines can
`vary. Fabrics knitted using only a single
`guide bar use only one set of yarns and tend
`to be less stable and more distorted leading
`manufacturers and consumers to demand
`
`
`Figure 2.6m: Two Guide Bar Fabric
`Figure 2.6l Single Guide Bar Fabric
`
`
`
`
`(Technical Face)
`
`
`(Technical Face)
`
`
`
`Source: Spencer, 2001. Page 296
`
`Source: Spencer, 2001. Page 316
`
`12
`Article Designation: Scholarly
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 12
`
`

`
`pleat or other engineered forms, which gives
`the entire three-layer fabric a wide and ever-
`expanding range of potential applications”
`(pg. 20) (see Figure 3.0a for illustration).
`
`
`3.0 Introduction to Spacer Fabrics
`
`According to Cass (2000), spacer fabrics are
`much like a sandwich and feature “two
`complementary slabs of fabric with a third
`layer tucked in between. The inner layer
`can take a variety of shapes, including tubes,
`
`Figure 3.0 a: Spacer Fabric
`
`
`
`Top
`Layer
`Connecting
`Layer
`Bottom
` Layer
`
`
`
`Source: Knitting International. (2002, February 2002). Breathing Room. Knit Americas.
`http://www.inteletex.com/FeatureDetail.asp?PubID=27&NewsId=191. [2005, January 17].
`
`pile
`fabrics
`that have not been cut
`Although increasing in popularity and
`consisting of two layers of fabric separated
`exposure, the innovation of spacer fabrics is
`by yarns at a 90 degree angle. Typically,
`not new, commercial developer Matthew
`double plush or “plush” fabrics are created
`Townsend of Leicester took out an initial
`by knitting two separate layers of fabric that
`patent for spacer fabrics in 1868. The patent
`are connected by pile yarns then sliced down
`was for knitting mattresses on a two needle-
`the middle to create two separate fabrics
`bed hand
`frame with
`interconnecting
`(Smith, 2001). Figure 3.0b illustrates a side
`“threads”
`(Bremner,
`2004; Knitting
`view of a two needle-bed Raschel machine
`International, 2002). More prevalent in the
`using one pile bar.
`marketplace, spacer fabrics are essentially
`
`Figure 3.0b: Cut Plush Fabric Made on Five Guide Bar Raschel Machine
`
`
`
`
`Source: Spencer, 2001. Page 368
`13
`Article Designation: Scholarly
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`IPR2017-00351
`Fredman EX1030 Page 13
`
`

`
`Three examples of different notation and structures used to produce double plush fabrics on
`Raschel machines having 5 guide bars are given in Figures 3.0c – 3.0e.
`
`
`Figure 3.0c: Here a pile fabric is made with one
`pile bar (3). Bar 3 is moving between wales in
`order to make a design effect. Bar 3 is lapping
`over both needle bars and is alternating courses
`which results in a fabric with less overall weight.
`
`Figure 3.0d: Here is a variation on Figure 3.0c,
`however, Bar 3 is moving straight up and down in
`a single wale. Bars 1 and 5 are making longer
`movements creating a heavier, more stable fabric
`than seen in Figure 3.0c.
`
`Figure 3.0e: Here a variation of the pile fabric
`shown in 3.0d is made. Here we have a fabric
`with more movement and less stability because
`Bars 2 and 4 are making open chain stitches as
`opposed to closed chain stitches seen in Figures
`3.0c and 3.0d.
`
`and safety exist and will be noted later in the
`paper.
`
`3.1 Spacer Fabric Production on Weft
`Knitting Machines
`Spacer fabrics are two distinctive
`layers of fabric
`joined
`together by a
`connecting layer. Weft knitting machines
`with two sets of needles have the ability to
`create two individual layers of fabric that are
`held together by tucks. Such a fabric was
`referred to as a double-faced fabric in
`Section 2.1, but can also be called a spacer
`fabric. Double-face fabrics can be produced
`on dial and cylinder, v-bed and purl
`machines.
`
`
`
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`
`
`
`
`
`
`Source: Smith, 2001
`
`
`
`
`
`Source: Smith, 2001
`
`
`
`
`
`Source: Smith, 2001
`More recently these uncut pile fabrics have
`attracted new attention with one use
`established in 1982 when A.W. Fischer of
`Germany applied for a patent for the
`production of fabric for padded bras. The
`innovation offered great opportunity to the
`market since
`it would allow for
`the
`elimination of foam or other
`layering
`options
`traditionally
`found
`in
`such
`undergarments
`that were
`subject
`to
`deformation, deterioration and difficulty in
`disposal (Reisfeld, 2002).
`
`
`As a result of unique attributes,
`applications to various industries such as
`automotives, medical
`textiles,
`technical
`textiles, geotextiles, sportswear and other
`apparel products, environmental protection
`14
`Article Designation: Scholarly
`
`IPR2017-00351
`Fredman EX1030 Page 14
`
`

`
`3.1.1 Dial and Cylinder Spacer Fabrics
`
`Producing knitted spacer fabrics on
`dial and cylinder machines can be done
`using a variety of combinations of stitches
`that ultimately connect two independent
`layers of fabric together. All techniques
`require the use of at least three different
`yarns for each course of visual fabric: 1)
`yarn for the cylinder needles; 2) yarn for the
`dial needles; and 3) a spacer yarn, normally
`monofilament yarn connecting the two
`layers (Anand, 2003b).
` The distance
`between the two fabrics can be manipulated
`by the dial height adjustment, ultimately
`determining the amount of pile yarn being
`put between the two ground fabrics. Anand
`(2003a, pp. 10), describes two techniques of
`producing spacer fabrics that are explained
`and depicted below. It should be noted that
`using high and low butt needles refers to the
`
`Figure 3.1.1a: Circular Knitted Spacer Fabric Formed by Tucking on Dial and Cylinder
`Needles
`
`
`different types of needles in the cylinder and
`dial. In the following notation, long lines
`represent high butt needles and short lines
`represent low butt needles. Interlock needle
`gating is shown.
`
`1.
`Tucking on dial and cylinder needles
`at the same feeder (see Figure 3.1.1a):
`a)
`tucking on the dial and cylinder
`needles on feeders 1 and 4 on low
`and high butt needles alternately
`(this connects
`the
`two
`layers
`together);
`b) knitting dial needles with dial yarn
`at feeders 2 and 5 on low and high
`butt needles alternately; and
`c) knitting cylinder needles with
`cylinder yarn at feeders 3 and 6 on
`low
`and
`high
`butt
`needles
`alternately
`
`Face Fabric
`
`Connecting
`Layer
`
`Face Fabric
`
`D C D C
`D C D C
`
`D C D C
`D C D C
`
`D C
`D C
`
`D C
`D C
`
`Feed 1
`
`Feed 2
`
`Feed 3
`
`Feed 4
`
`Feed 5
`
`Feed 6
`
`
`
`
`
`
`
`
`
`Source: Anand, S. (2003). Recent Advances in Knitting Technology and
`Knitted Structures for Technical Textiles Applications. Istek, 2003.
`
`knitted at the same feeder (feeders 1
`2. Knitting/plating on the dial needles
`and 3):
`and knitting on cylinder needles (see
`Face yarn knitted on the dial needles
`Figure 3.1.1b):
`on
`low and high butt needles
`A special yarn feeder is required with
`alternately; and spacer yarn knitted on
`two holes to enable two yarns to be
`15
`
`Article Designation: Scholarly
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`a.
`
`IPR2017-00351
`Fredman EX1030 Page 15
`
`

`
`dial needles and tucked on cylinder
`needles, as shown in feeders 1 and 3;
`
`cylinder yarn knitted on cylinder
`needles at feeders 2 and 4 on low and
`high butt needles alternately.
`
`Figure 3.1.1b: Circular Knitted Spacer Fabric Formed By Knit/Plating on Dial and Tuck
`on Cylinder
`
`b.
`
`
`Source: Anand, S. (2003). Recent Advances in Knitting Technology and Knitted
`Structures for Technical Textiles Applications. Istek, 2003.
`
`Note that the concept used in the second
`technique is similar to the concept of
`producing a plated single jersey fabric. It
`should also be noted that a single jersey
`fabric is not a spacer fabric because there is
`
`Figure 3.1.1c: Cylindrically Shaped Double -Face Fabric
`
`no separation of fabric layers present.
`Figure 3.1.1c depicts a circular knit
`spacer fabric before it has been cut to make
`an open-width fabric.
`
`
`
`
`
`Face
`
`Pile / Connecting layer
`
`Rear
`
` Source: USPTO (2004). Decorative Faced Multi-Layer Weft Knit Spacer Fabric, Method,
`and Articles Made Therefrom. US Patent Application. 0097151.
`
`layers are coupled together with spacer yarn
`Another example of a spacer
`fabric
`connected in each layer on alternate needles
`produced on a dial and cylinder machine is
`of the cylinder or dial (USPTO, 2004) (see
`created using jacquard patterning. In this
`Figure 3.1.1d; Appendix 1 shows full
`case a jacquard pattern layer is weft knitted
`figure).
`on the cylinder needles, a plain layer is weft
`knitted on the dial needles, and the two
`
`
`16
`Article Designation: Scholarly
`
`
`JTATM
`Volume 4, Issue 4,Summer 2005
`
`
`
`IPR2017-00351
`Fredman EX1030 Page 16
`
`

`
`
`Figure 3.1.1d: Knitting Structure Diagram for Flat Pattern Jacquard Spacer Fabric
`
`D C
`
`D C
`
`D C
`
`D C
`
`D C
`
`D C
`
`
`
`
`Feed 1: Sporadic
`knitting and floating on
`the cylinder needles to
`make pattern
`
`
`
`Feed 2: Knitting on
`long dial needles
`
`
`
`Feed 3: Tucking on
`long dial and cylinder
`needles to connect
`fabric layers
`
`
`
`Feed 4: Knitting on
`the long cylinder
`needles
`
`
`
`Feed 5: Knitting on
`the short dial needles
`
`
`
`Feed 6: Tucking on
`short dial and cylinder
`needles to connect
`
`
`
`Source: USPTO (2004). Weft Knitted Spacer Fabrics. US Patent No. 6,779,369.
`and absence in industrial production (it
`Both of the examples given show fabrics
`should be noted that purl machines have
`having the same structure on the front and
`fewer feeds and knit slowly, making the
`back and do not indicate what type of yarns
`production of spacer
`fabrics on purl
`are being used, however, it is possible to
`machines economically unfeasible) (Raz,
`produce the two outer layers from different
`1993; Spencer, 2001).
`materials and with completely different
`structures.
`
`to dial and cylinder
`In addition
`machines, double cylinder purl machines fall
`under the classification of circular knitting
`(Raz, 1993). As mentioned in Section 2.2,
`double cylinder purl machines have only one
`set of needles. However, these needles are
`double-ended and thus have the ability to
`knit two separate fabrics with a connecting
`layer (i.e. double face or spacer fabrics)
`(Raz, 1993).
` These
`fabrics are not
`documented
`in recent
`literature on
`the
`production of spacer fabrics because of the
`inefficiency associated with the technology
`17
`Article Designation: Scholarly
`
`
`
`3.1.2 V-Bed Spacer Fabrics
`When a flat-bed knitting machine is used
`in the production of three-dimensional spacer
`fabrics, two types of products can be created: 1)
`two independent structures connected by cross-
`threads, and 2) two independent fabric structures
`connected by fabric layers (de Ar