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Noobing: A Nonwoven 3D Fabric-forming
Process Explained
N. Khokar
Biteam AB, Landalabergen 39, 41129 Gothenburg, Sweden
Received 10.05.2001 Accepted for publication 29.11.2001
A unique nonwoven 3D fabric-forming process, designed to bind a set of linear yarns that is
arrayed in either uniaxial or multiaxial orientation, was identified, characterised and termed
noobing five years ago. The produced 3D fabric, usually intended for composite materials
application, is layerless and comprises crimpless yarns. This process has been mistaken to be
3D'weaving and multiaxial/3D-knitting. It is thus necessary to explain its non-compliance with
the well-estahlished technicalities of hoth these processes. A dozen patents are therefore
exemplified and discussed collectively according to a new classification of this noteworthy
process, for the first time. The factors causing misrepresentation of this process, such as its
incorrect technical description and patent classification, are also considered to complement
the discussions.
1. INTRODUCTION
Tbe attempts to solve the problem of delamination associated witb the use of plied-andstitched fabrics for composite materials application during the last four decades have
quietly led to the evolution of a unique 3D fabric-forming process. It produces a fabric
that comprises crimpless yams in the directions of the fabric's thickness, lengtb and
width. Interestingly, it originated in tbe aerospace not the textile industry, as the former
needs lightweight and strong materials.
The principle of this 3D fabric-forming process is fundamentally different from that of
the weaving, knitting and braiding processes. A set of linear yams, arrayed in either
uniaxial or multiaxial orientation, is bound/tied using required sets of binding yams, to
produce a corresponding layerless 3D fabric that basically comprises three orthogonal
sets of yams, which do not interlace, interloop and intertwine. The fabric happens to be
inextensible, as it comprises linear/crimpless yams. This process is capable of producing
3D fabrics with profiled cross-sections.
By definition now, this process cannot produce 2D and 2.5D fabrics. Obviously,
this process and its products are unlike anything seen earlier in textile practice. Yet. this
process has been mistaken to be 3D-weaving and multiaxiaI/3D-knitting, despite
its product being neither interlaced nor interlooped. The discrepancy in its assumed
theory and actual practice becomes evident when examining tbe only source of
infomiation: tbe patents. Nearly all methods have been described using terms associated
with weaving and knitting, as certain machine elements of tbese processes, not principles,
are sometimes employable. As a result, all these methods occur in the incorrect categories
of the patent classification system. Interestingly, the technicalities of this process have
never been presented in textile and composite material literature during all these years.
Khokar (1996, 1997a) examined the technicalities of this process and its products and
determined them to be nonwoven. Tbe new terms proposed to distinguish them are:
noobing (from an acronym for Non-interlacing, Orthogonally Orientating and Binding)
52
X Text. Inst.. 2002. 93 Pan I, No. I © Texiile Institute
Noobing: A Nonwoven 3D Fabric-forming Process Explained
and noobed fabric. Khokar and Peterson (1997, 1999) have discussed this process in
considerable detail and demonstrated its principle to be fundamentally different from that
of weaving and knitting. To explain clearly how the noobing process does not comply
with the well-established technicalities of the weaving and knitting processes, reference
to the patents is unavoidable. Accordingly, a dozen patents are illustrated now.
These methods are exemplified through a new classification of the process. A
collective presentation of them is necessary to show readily the common fabric-forming
principle. The factors causing misrepresentation of this process, such as their incorrect
technical description and patent classification, are also considered to complement the
discussions.
2. PROCESS PRINCIPLE AND EABRIC STRUCTURE
As either a uniaxially or a multiaxially oriented set of yams is bound/tied using required
sets of binding yams, this process can be divided into two distinct types: uniaxial and
multiaxial noobing. Botb these process types are described below to acquaint the reader
with them. They would be found correspondingly common in all methods, including
production of tubular fabrics.
Uniaxial noobing: A set of longitudinal/axial yams (Z) is disposed in uniaxial orientafion
in a grid-like array. It is then bound by drawing the sets of vertical binding yams (Y) and
horizontal binding yams (X) beside tbe columns and rows of the Z yams respectively.
Tbe binding yams could be of either single or double types. Tbe corresponding bindings
occur outside of the set of longitudinal yams (Z) and it forms four surfaces of the fabric.
The resulting 3D fabric thus has the three sets of linear yams (X, Y, Z) in a mutually
perpendicular configuration and is a non-interlaced structure as shown in Fig. la
(excluding the bindings). It needs to be pointed out that the yams of a given direction
occur distinctly separated from one another by the yams of at least one other direction. As
no two yams of a given direction occur side by side, it is a single-fabric system having no
layers of yams.
Multiaxial noobing: A set of linear yams Z, X, ±9, arrayed in multiaxial orientation in
tbe directions of tbe fabric's length, width, and two bias angles respectively, is bound
using a set of binding yams Y in the fabric-thickness direction. The yams Y could be of
either single or double type. The corresponding bindings occur above and under the set of
Z, X, ±6 yams and tbey form two surfaces of the fabric. The resulfing 3D fabric has tbe
three sets of linear yams X, Y and Z in a mutually perpendicular configuration and,
additionally, the linear yams ±6 in bias directions. Tbe fabric is a non-interlaced
structure as shown in Fig. lb (excluding the bindings). It may be pointed out again tbat
the yams of a given direcfion occur distinctly separated from one another by the yams of
(b)
Fig. 1
Structures of (a) uniaxial and (b) multiaxial noobed fabrics
J. Text. Inst., 2002, 93 Pan I, No. I © Textile Institute
53
Khokar
at least one other direcfion. As no two yams of a given direction occur side by side, it is a
single-fabric system having no layers of yams.
3. CLASSIEICATION OF NOOBING METHODS
The classification of noobing methods is shown in Fig. 2. The noobing process comes
under 'nonwoven processes'. As a set of linear yams is initially required to be arrayed in
either uniaxial or multiaxia! orientation and their binding has to be carried out to produce
the fabric, these characteristics form the essential basis of the classification. The bindings
can be either direct or indirect, depending on wbetber the binding yams are laid as
singles (e.g. using a shuttle) or looped/hair-pin/doubled (e.g. using a knitUng needle)
respectively. The former type of binding results from the back and forth traversal of tbe
binding yams of a given direction that entraps the outermost yams in its fold. The latter
comes from either binding/tying by replacement of temporary inserts or linking of the
emergent loops of the doubled binding yams outside of the arrayed set of linear yams by
either interlocking tbem, one into the other, or by passing a connecting yam through the
emergent loops.
For the purpose of this classification, a method is of indirect binding type when binding
yams either replace temporary inserts or it is of the looped/doubled type in at least
one binding direction of the fabric. Inclusion of primary aspects sucb as the types of
Nonwoven Processes
1
_
Needle
Punching
Chemical
Bonding
1
Presaure
Bonding
Thennal
Bonding
1
Fluid Jet
Fntangling
Spun
Elonding
1
Arrayed ^'anw'
Binding
Nnohing Process
Type Multiuial
Type Uniaxial
Indirect
Bimilng
Modiried
2 D. Weaving
Machine
Spedfically
Designed
Machine
Modified
2D-Weaving
Macliinc
Thick
Panel
Pronied
Bar/Beum
PmHled
Bar/Beam
Grti'lKood
11974)-4.1
Fig. 2
54
Kh.>kar A
Dnmeij
0999)-4.2
Specirically
Pronicd
Bar/Beam
M«h<imfil d
'litany
Fukuui eiiil
tI992)-4.i
0974) - 4.4
King
(1976) • 4.5
Wrinhrrg
11995). 4.6
Thick
Tubular
Bann.i el nl
119801-4.7
1
1
Direcl
Binding
Indirect
BlmUne
Specifically
[lesigned
Madiines
Mndifled
Warp knitting
Machine
Thick-wallcd
Tubular
Tlilo
Panel
tlilisik
f2000) - 4.H
Specifically
IX-dgned
Machines
Thick
Panel
Mt'himied &
Bilisik
5)-4.10
Panel
Wunner
I9S9}-4.I2
ClassificatiCMi diagram of noobing methods
J. Text. Inst.. 2002, 93 Pan I, No. I © Textile Institute
Noobing: A Nonwoven 3D Fabric-forming Process Explained
employable machines {modified, specifically designed) and producible products (panels,
beams, tubulars) is necessary to give a broader picture of the process. A modified
machine is one tbat is made to function differently from its normal sense to produce a
correspondingly different fabric structure. Products listed are for exemplification purpose
only; other products could also be considered. A 'thin' material type is regarded so when
linear yams are supposed to be disposed in up to four parallel planes in the fabric-thickness
direction. Secondary aspects such as the device format (vertical and horizontal types) and
processing strategies (like mobile and stationary fabric take-up units and collective/
grouped/and individual binding yams insertion) are not necessary to include at this stage.
Tbe methods indicated bear the names of the respective inventors. The years are a
reflection of tbe developmental activity and do not indicate that no work has been carried
out earlier and later. The reference numbers 4.1^.12 relate to the sections of this paper in
wbicb the methods are described. Each method is summarised using the original terms
given in the patents to show how the use of conventional terms conceals the uniqueness
of the process and causes misrepresentation. The patent's primary main class is also given
to self-conclude whether or not the methods technically correspond to it. The
accompanying illustration/s from patents should obviate confusion. The comments
clarify certain technicalities based on the understanding of the too-well established
principles of weaving and knitting processes and woven and knitted stmctures that
require no detailing here.
it needs to be stated here that this paper, which exemplifies the various methods,
should not be construed to constitute a permission or recommendation to practice any of
the inventions without a license from the respective patent owners.
4. OPERATIONAL PRINCIPLE OE DIEEERENT METHODS
4.1 Greenwood (1974): Patent's Main Class - Weaving
A weaving machine is adapted to produce a three-dimensional fabric (Fig. 3) that has
ground warps GW disposed in rows and columns and which is bound at upper and lower
and two side surfaces by using binder warp threads BW and wefts W respectively. Rows
of threads GW are controlled by horizontal separating bars SBR (1-5) and SBL (1-5).
Binder warp threads BW are controlled by heald wires HW attached to a frame HF. Bars
SBR/SBL are vertically moved, one at a time, to make a corresponding gap in warp
layers for inserting weft W. After all wefts W of a given weft column have been inserted,
tbe reed beats them up. Frame HF is lowered or raised to insert binding threads BW
between adjacent columns of GW to bind the outermost lying weft in its fold. Wefts W,
laid by a shuttle, bind the outermost columns of GW in its fold.
Comments: In this adapted (i.e. modified) weaving machine, warps GW are not controlled
by healds HW but by horizontal separating bars SBR (1-5) and SBL (1-5). These bars
raise/lower corresponding rows of GW to increase/decrease the gap between adjacent
warp layers for laying wefts W therein. Sucb an action does not, and cannot, create any
shed and it is not the shedding operation. The healds HW lay the binding threads BW
between adjacent columns of the warp GW to bind the outermost weft in its fold. The
healds are lowered/raised only after the insertion of all the wefts of a weft column, and
not after the insertion of every weft. Its action does not help create any shed either.
Therefore, tbe obtaining process is technically not weaving. All yams occur linearly in
their respective direcfions and the resulting fabric is, of course, a three-dimensional
fabric but a non-interlaced fabric and not a woven (interlaced) fabric. (Refer also to
comments on method in Section 4.3.)
J. Text. Inst.. 2002, 93 Part I, No. 1 © Textile Institute
55
Khokar
Fig. 3
Fabric and device according to Greenwood (1974). USP 3 818 951
4.2 Khokar and Domeij (1999): Patent's Main Class-Nonwoven
This method of producing an integrated nonwoven 3D fabric F (see Fig. 4) comprises
disposal of axial yams Z in a grid form and in accordance with the required crosssectional profile, and traversing horizontal and vertical sets of binding yams X and Y
about the corresponding rows and columns of axial yams in a closed-loop path to bind the
fabric directly. The device is essentially composed of a plate (P) having two sets of
profiled tracks (D and C) existing in a mutually perpendicular configuration and in the
same plane on ihe front face of the plate (P); two sets of binder yam .spool carriers (K and
L); two pairs of tracking arrangement such that each pair is situated at the terminal sides
to contain between it ail the tracks of sets D and C respectively for guiding the binder
yam carriers in a ciosed-loop path; and openings (B) in plale (P), arranged in rows and
columns, to allow the axial yams Z to pass through, a creel (J) to supply axial yams Z,
and a fabric take-up unit (H).
Comments: This method is not claimed to be weaving because it has no shedding
operation. Accordingly, the produced non-interlaced fabric F comprises three sets of
yams X, Y, and Z that occur linearly in their respective directions. It is therefore regarded
as a nonwoven fabric. (It may be noted that the production of this nonwoven 3D fabric is
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/ Text. Inst.. 2002. 93 Part 1. No. I © Textile Institute
Noobing: A Nonwoven 3D Fabric-forming Process Explained
X
B C
Fig. 4
Fabric and method according to Khokar and Domeij (1999), SE 509 944
described without using any terms that are associated with the weaving and knitting
processes.)
4.3 Mohamed and Zhang (1992): Patent's Main Class - Weaving
Horizontally and vertically aligned warp yams X, arranged in multiple layers and forming
the required cross-sectional profile (here an inverted T), are passed between the heddles
of hamesses 11 a, l i b and 12a, 12b and the reed 5 (see Fig. 5). Vertical yams Z (Za-Zd)
are drawn through the heddles of the hamesses. Two groups of filling yams Y1 and Y2 (Y
in Fig. 5) are used for producing the T profile, one inserted for the flange portion from one
side of the warp and the other inserted for the web portion from the opposite side. The
fillings Y are inserted in the spaces between the warp layers in a looped form using
inserting needles (2). The fore-end loops of the inserted fillings Yl and Y2 are held by the
selvage yams Sa and Sb. The vertical yams Za, Zb and Zc, Zd are used for locking-in the
wefts of the flange and web portions of the T profile, respectively. The reed 5 beats-up
the system of fillings to the fabric-fell. The selvage loops of one cycle are interconnected
to the loops of the next cycle by rod 4, latch needles 9, selvage needles 3 and loop holding
J. Text. Inst., 2002, 93 Part I, No. I © Textile Institute
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Khokar
Z-d
Fig. 5
Device and fabric according lo Mohamed and Zhang (1992). USP 5 085 252
rod 8. This type of three-dimensional fabric formation does not allow for the formation of
integrally woven fabric constructions.
Comments: As stated, this process type does not allow for the formation of integrally
woven fabric constructions (i.e. interlaced fabrics). This is because it technically does not
follow the normal course of the weaving process. Here, warp yams X are not controlled
by the heddles of hamesses 11/12, but they pass between neighbouring heddles.
Consequently, warp yams X cannot be subjected to the shedding operation. Thus, using
heddles 11/12 to draw yams Za~Zd beside the columns of warp yams X does not
constitute the shedding operation. Apparently, no shed/s are formed and the filling yams
Y are inserted in the spaces between the warp layers only, and not into any sheds. There is
thus no interlacing between X and Y yams. The back and forth traversal of vertical yams
Z between the fabric's top and bottom sides is not, and cannot be, regarded as intedacing
because it does not interlace with any of the filling yams Y, including the two outermost
ones, which always occur in the folds of Z yams. As the obtaining process is not weaving,
the producible non-interlaced 3D fabric cannot be specified by any weave pattem (plain,
iwili etc.). The three sets of yams thus occur linearly in their respective directions. (This
explanation also applies to the method in Section 4.1. See also the method in Section 4.4.)
4,4 Fukuta et al. (1974): Patent's Main Class-Weaving
The weaving method requires multiple layer warp yams Y to pass through a reed I that
has a number of holes at uniform intervals in horizontal and vertical directions (see Fig. 6).
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J. Text. Inst., 2002, 93 Part I, No. 1 © Textile Institute
Noobing: A Nonwoven 3D Fabric-farming Process Explained
Fig. 6
Method according to Fukuta et al. (1974), USP 3 834 424
The wefts X, in a double fold forming loop at the fore end, are inserted between the warp
layers by the weft-inserting device 6 made up of plates 7. The device 6 is temporarily
stopped when the looped fore ends of the weft yams are projected out of the warp yams
on the opposite side for threading a binder yam P. After the device 6 has been retracted
from the warp yams Y, the upper and lower sets of vertical yam-picking pipes 4 and 5,
through which yams Z are threaded, are moved into the warp yams until the curved fore
ends of the pipes are projected outwardly from the opposite upper and lower side of the
aligned warp yams Y. The yams X are then inserted again in the space created by the
curved fore end of the pipes 4 and 5. The integrity of the resulting fabric is obtained by
securing the weft yams by a binder yam P at one side of the fabric and outermost Z yam
at the other side, and the upper and lower vertical yams Z and Z' connect topmost and
bottom-most yams X together.
Comments: There is neither any shedding operation involved here, nor is it possible,
because warp yams Y do not pass through any means for shedding but through 'reed' 1,
which is only a plate with holes. The insertion of vertical yams Z is regarded as vertical
picking, which is anyway not the shedding operation technically and hence the process is
not weaving. Without any interlacing of yams Y with yams X and Z, the fabric integrity
has to be compulsorily achieved by binding yams Y with yams X and Z. Thus, yams X, Y
and Z occur linearly in their respective directions. (It may be noted that, in comparison
with the method of Section 4.3 wherein healds/heddies are employed to insert the vertical
yams Z, the same is achieved here by employing curved pipes. Yet, the basic fabric
structure produced by both these processes is the same.)
4.5 King (1976): Patent's Main Class - Weaving
As shown in Eig. 7, the loom 10 comprises movable upper and lower frames 12 and !3
with holes for supporting a plurality of filaments 15 that extends in the vertical/Z-axis
orientation in ranks and rows. Identically working filament feed units 20 and 20'
alternately insert yams in the X- and Y-axes directions, respectively. Eirst, filaments 21
J. Text. Inst.. 2002. 93 Pan I. No. I © Textile Institute
59
Khokar
25
27
20
Fig. 7
Method according to King (1976), USP 3 955 602
from supply bobbins are woven through the spaced rows between filaments 15 along the
X-axis by advancing the needles 22 by pushing rods 25. A pin 30 is inserted in the Y-axis
direction to lie across the top of filaments 21 outside the last row of filaments 15 to tamp
filaments 21 down. Needles 22 are then retracted from filaments 15, forming a tightly
looped first course of X-axis filaments that is restrained by pin 30. Similarly, the course of
Y-axis filaments is woven next by advancing threaded needles 22', inserting pin 30' on
top of filament 21' in the X-axis direction and retracting needles 22'. As the filament
layers build up, pins 30 and 30' are removed. To increase the fabric's density, all the
filament layers are compressed. The fabric integrity results primarily from inter-yam
friction.
Comments: This method is technically not weaving because there is no shedding
operation involved. Yams 21/21' are altemately and linearly laid between spaced ranks
and rows of linear filaments 15 in X and Y directions respectively. The three sets of yams
X, Y and Z thus occur linearly and mutually perpendicularly. Without any interlacing and
binding, the fabric integrity has to be necessarily realized from inter-yam friction. (It is
interesting to note that in this method the emergent loops are not interconnected.)
4.6 Weinberg (1995): Patent's Main Class - Weaving
Arrayed warp yams 3 are threaded through the top perforated plate 1 (see Fig. 8). Warp
layers of X-direction are threaded through slots of upper reed 4X and warp layers of the
Y-direction are threaded through slots of bottom reed 4Y. Finally warp yams 3 pass
through perforated base plate 6 and are fastened underneath. Reeds 4X and 4Y are tumed
alternately to form open sheds. Combs 5ay and 5bx, which have laterally movable teeth
and are distanced from each other at this point, are inserted correspondingly into the
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Text. Inst., 2002, 93 Pan I, No. 1 © Textile Institute
Noobing: A Nonwoven 3D Fabric-forming Process Explained
WEFT YARNS
3D FABRIC
Fig. 8
Method according to Weinberg (1995), USP 5 449 025
formed sheds. Parallel weft yams are respectively inserted in X and Y directions. After
altemately inserting weft yams of each direction, reeds 4X and 4Y are likewise tumed
back to close the sheds. The teeth of combs 5ay and 5bx accordingly come closer to each
other to match with the density of warp yams. The combs are likewise altemately moved
down to beat-up the inserted weft yams and are eventually pulled out. The described
cycle of operations starts again.
Comments: The shedding operation cannot be performed using a reed. Increasing/
decreasing distance between parallel warp layers by tuming the reed is not forming/
closing a shed. As a shed is formed by crossing warp yams, the described operation is
technically not shedding. Hence, the obtaining process is also technically not weaving.
The produced 3D fabric is thus a non-interlaced structure having linear yams in the three
mutually perpendicular directions.
4.7 Banos et al. (1980): Patent's Main Class - Knitting
The method and machine (Fig. 9) for producing hollow reinforcements of revolution (10)
by three-dimensional weaving uses a network of rods (II) between which is laid
circumferential yams (12). The radial yam (13) is introduced by a knitting needle (28) in
the form of a chain stitch and encloses in its loops the successive bunches of rods (11) and
exists between the successive courses of circumferential yams (12) and in the direction of
the fabric's thickness. The network of rods (11) rotates around the axis (16). The helical
layers of yams thus formed rest on a plate (20) to which is imparted a progressive
downward movement. The assembled yams slide along the rods (11) as they are tamped
/ Text. Inst.. 2002, 93 Part I, No. I © Te.xtile Institute
61
Khokar
13
10
34
23
Fig. 9
Fabric and method according to Banos et al. (1980). USP 4 183 232
by fingers (30). The rods (11) can be either fibre-resin type, in which case they constitute
the longitudinal filling of the woven structure, or metallic rods, which are replaced by any
suitable longitudinal filling yams after weaving.
Comments: The process of laying circumferential yams (12) between a network of
replaceable linear rods (11) and enclosing bunches of rods 11 in the loops of stitching radial
yam (28), which itself occurs between successive helically placed yams 12, is technically
not weaving or knitting. Thus, all yams occur 'linearly' in their respective directions and
the structure is non-interlaced and non-interlooped. (It is interesting to note that the
inventor regards the process as weaving but the patent authorities regard it as knitting.)
4.8 Bilisik (2000): Patent's Main Class-Weaving
A three-dimensional multiaxial cylindrical woven fabric (Fig. 10) having a core,
comprises five sets of yams: axial (14), circumferential (16), radial (18) and two sets of
bias yams (12) that are orientated ±45" with reference to the longitudinal axis of the
cylindrical fahric. The bias yams (12) occur at the outer and inner surfaces. The fabric is
produced using a multiaxial circular weaving apparatus (100) that comprises mainly four
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J, Text. Inst., 2002, 93 Part I. No. I © Textile Institute
Noobing: A Nonwoven 3D Fabric-forming
114
112
Fig. 10
Fabric and device according to Bilisik (2000). USP 6 129 122
units: feeding unit (110), machine bed (130), beat-up unit (180) and take-up unit (190).
The steps in the operation of the weaving machine are: rotation of positive and negative
bias yam carriers by one carrier distance; rotation of circumferential yam carriers by one
carrier distance; moving radial yam carriers between outer and inner edges of the
machine bed; beating-up the inserted yams; and taking-up the woven preform from the
weaving zone.
Comments: As there is no shedding step involved, the method is technically not weaving
(including circular weaving). The moving of radial yam carriers between outer and inner
edges of the machine bed cannot be regarded as a shedding operation because such an
action does not enable interlacing of radial yams (18) with either circumferential yams
(16) or axial yams (14). Hence, the fabric is evidently a non-interlaced structure wherein
the axial (14), circumferential (16) and two sets of bias (12) yams are bound by radial
yams (18) and all these yams occur 'linearly', that is without interlacing, in their
respective directions. (See also the method of Section 4.10.)
4.9 Wilkens (1985): Patent's Main Class - Layered Product
The fabric (5) (see Fig. 11) comprises a plurality of parallel inlaid weft threads (I), a first
plurality of diagonally (-1-45°) inlaid threads (2), a second plurality of diagonally (-45°)
inlaid threads (3) and longitudinal (warp) inlaid threads (4). Each set of these reinforcing
threads can be had in relatively different planes. These threads are bound by
a substantially thinner warp thread following the knitting technique to form stitches
/ Text. Inst., 2002, 93 Part I. No. I © Textile Institute
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Khokar
Fig. 11
Fabric according to Wilkens (1985), USP 4 518 640
(7) with needle loops (8) creating running wales (9) in the warp direction and stitch rows
in the weft direction. Thus, a fabric enmeshed in stitched ground ware is produced.
Comments: As the sets of linear yams ( 1 ^ ) are only bound together using yam (6) by a
knitting technique, these sets of yams do not interloop one into the other, and hence the
resulting fabric (5) does not have the characteristic knitted stmcture. (It is important to
note that ihe inventor describes the material as "a fabric enmeshed in stitched ground
ware'.) Contrary to the belief that it is a warp knitted material, the patent authorities
consider it a layered product. However, as can be seen, all the yams of a given direction
(1-4 and 6) occur distinctly separated by the yams of the other directions, and hence
there are no individual layers of yams. It is therefore not a layered product either.
(This .structure is similar to the one indicated in Fig. lb.) Employing an altemative
stitching technique would also result in a similar non-interlooped structure, as would
become clear from the methods discussed next. Hence, technically the use of knitting
needles for the purpose of binding a set of predisposed yams does not necessarily produce
a knitted structure, which in tum indicates that the obtaining process ceases to be
technically knitting.
4.10 Mohamed and Bilisik (1995): Patent's Main Class - Weaving
The fabric F (Fig. 12) basically comprises grid-like multiple layer warp yam (12),
multiple filling yams (14). multiple Z-yams (16) extending in fabric-thickness direction,
and ± bias yams (18) located on the front and back surfaces of the warp yams (12).
After bias yarns (18) have begun to be oriented at ±45° to each other on the front
and back surfaces of the preform, doubled filling yams (14) are inserted between the rows
of warp yams (12) and the loops of the yams (14) are secured by two selvage yams S at
both edges of the structure. Z-yams (16) are next inserted between the columns of warp
yams (12), followed again by filling yam (14) and Z-yam (16) insertions to complete one
cycle of operations. In this way, the bias yams (18) and filling yams (14) are locked in
place by Z-yams. The inserted yams (14 and 16) are beaten-up and the fabric taken-up.
The weaving apparatus (100) comprises eight main elements: warp creel (110), ±bias
yam laying assembly (120), yam support tube bars (130), tension units (140), one filling
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Noobing: A Nonwoven 3D Fabric-forming Process Explained
T45''YARN
WARP (AXIAL) YARN
FILLING ^ R N
UNIT CELL WIDTH
180
160
Fig. 12
150
Fabric and method according to Mohamed and Bilisik (1995), USP 5 465 760
yam inserting unit and two Z-yam inserting units (150), selvage and latch needle unit
(160), fabric beat-up unit (170) and fabric take-up unit (180).
Comments: The absence of a shedding unit from the apparatus shows clearly that it is
technically not a weaving process. The insertion of Z-yams (16) between the columns of
warp yams does not constitute the shedding operation. In the absence of shed/s, the filling
yams (14) are inserted only between the rows of warp yams. Consequently, and as
evident, fabric F has a non-interlaced structure wherein Z-yams (16) lock the bias
/ Text. Inst., 2002. 93 Part I. No. I © Textile Institute
65
Khokar
yams (18) aiid filling yams (14) in place together with the warp yams (12). Hence, all
yams occur linearly in their respective directions. (This structure is basically like the one
given in Fig. 10.)
4.11 Anahara et al. (1993): Patent's Main Class-Weaving
The fabric F (see Fig. 13) comprises a plurality of warp layers Z, a plurality of first and
second bias-yam layers Bl and B2, and a plurality of weft layers X and vertical yams Y
that run through the stacked layers of Z, Bl, B2 and X to interconnect the yam layers.
The fabric is formed by looping one or multiple yams back and forth several times about
pins 2 supported on a flat base 1 and over a support bar 3 that is disposed between the
pins 2. After the multilayer structure has been formed in a predetermined order, the layers
are compressed to increase density. Next, the compressed structure 4 and the pins 2 are
separated from the base 1. Vertical yams Y then replace ihe pins 2 by pushing pins 2 out
with needles 5 to bind the structure.
Comments: Looping yams linearly back and forth about pins 2 in different directions to
produce stacked layers Z, Bl. B2, and X and then binding them with yams Y by pushing
out pins 2 with needles 5 does not make the obtaining process technically weaving. Thus,
fabric F is not a woven fabric, but a non-interlaced structure comprising linear yams in
their respective directions. (It is important to note that the yams Z, B1, B2, and X, though
arranged in stacked layers, eventually occur distinctly separated from one another in the
B
P Q O o o o o o ofo o & ft o
[ O o o o Q o o o o o o o oo
o o o Q o o o o o o o o o"o)
( o o o o o o o o o o o o oo
oooooooooooood;
(o p o
o o o •ooo o
'o o o o o o_o o 'o o o o o"q)
(oooooooooooo OQ
Fig. 13
66
asdrc
»to
-}.
I
1
1
"^
Fabric and method according to Anahara et al. (1993), USP 5 270 094
J. Text. Inst.. 2002. 93 Pan I. No. I © Textile Institute
Noobing: A Nonwoven 3D Fabric-forming Process Explained
fabric. Hence, it cannot be classified as a layered product. In reference to the fabric
stmcture shown in Fig. 11, which is classified as a layered product, this one is classified
as a woven material although, in principle, both have similar constmction, like the one
shown in Fig. lb.)
4.12 Wunner (1989): Patent's Main Class - Knitting
The apparatus, shown in Fig. 14, comprises carriages with thread guides (8, 9) to lay
successive groups of transverse weft threads as layers (1, 2) on two longitudinal
conveyors (10, U) running to the needle bed of a warp-knilting unit. The weft threads are
laid by means of the carriages, which are reciprocated between, and transversely to the
direction of travel of, the longitudinal conveyors. The weft threads are laid as layers one
above the other, forming an angle that can be varied from at least 20° between them. To
this basic disposal arrangement of the transverse weft yam layers (1, 2), either a third
weft threads layer (13) orientated perpendicular to Ihe conveyors (10, 11) or a stationary
threads layer (15) orientated parallel to the conveyors (10, 11) can be incorporated.
Additionally, a web of fleece or prefabricated material can be also included. The various
12'
•2
Fig. 14
6
II
Method and fabric according to Wunner (1989), USP 4 872 323
/ Text. Inst.. 2002. 93 Part I, No. I © Textile Institute
67
Khokar
Stacked layers, the order of which can be altered as desired, are connected together by
using stitching warp thread (59).
Comments: The apparatus huilds up a stack comprising linear yam layers that are oriented
in warp, weft and ±9 directions, and an additional fihrous web/material, and connects
them together by stitching with thread (59). The possibility of including a web of fieece/
prefabricated material along with other linear yams shows that the process cannot be
knitting. Also, as this apparatus follows a different technique from that of the method of
Section 4.9, and yet both produce identical structures, it becomes clear that this process
happens to he fundamentally different from knitting. (As the material indicated in Eig. 11
is similar to this one, this fabric too is neither a knitted fabric nor a layered product.
Whereas the stmcture shown in Eig. 13 is classified as woven, this one is assigned to the
knitting class, although in principle they are alike.)
5. UNIQUE TECHNICAL FEATURES
From the foregoing collective presentation of different methods, their non-compliance
with the well-established technicalities of the weaving and knitting processes becomes
obvious:
• The methods of Sections 4.1 to 4.7 invariably require a set of 'warp' or axial yams to
be arranged in rows and columns and it is always bound/tied from two mutually
perpendicular sides. The yams of the three directions occur linearly in a mutually
perpendicular configuration (in 4.7 the yams occur in axial, circumferential and
radial directions).
• The bindings occur at four surfaces and the structural integrity comes by linking the two
opposite exteriors in the horizontal and vertical directions of the 'warpVaxial yams.
• Excepting the method of Section 4.2, others make use of weaving and knitting
machine elements. Yet all the produced structures, whether 'woven' or 'knitted', are
basically alike.
• The produced material is a layerless 3D fabric wherein yams of a given direction
occur distinctly separated from one another by the yams of at least one other
direction.
• The foremost and indispensable shedding operation is non-existent in all the claimed
weaving processes.
• The healds are not used to displace the so-called warp yams to form shed/s, but for
the purpose of drawing the vertical binder yams beside the columns of the 'warp'
yams. The so-called wefts are always inserted in the spaces between the warp layers,
and not into any shed/s. As a consequence, a fabric of any specific weave pattem is
not producible.
• The methods of Sections 4.8 to 4.12 require the various sets of yams to be oriented
in different directions before effecting binding/tying, wbich is mostly carried out in
one direction only (fabric-thickness) using another set of binding yams. The 3D
fabric comprises linear yams in three mutually perpendicular directions and,
additionally, in bias directions (in 4.8 the yams occur in axial, circumferential, radial
and two bias directions).
• The bindings usually occur at two opposite surfaces and the structural integrity
comes by linking the opposite exteriors in the direction of fabric-thickness.
• Use is made of either weaving or knitting machine elements, except in the method of
Section 4.11. but still all the structures, whether 'woven' or 'knitted', are basically
the same and without the characteristics of woven and knitted structures.
68
J. Text. Inst.. 2002. 93 Pan I. No. I © Textile Institute
Noobing: A Nonwoven 3D Fabric-forming Process Explained
• The produced material is again a layerless 3D fabric wherein yams of a given
direction occur distinctly separated from one another by the yams of at least one
other direction.
• The claimed weaving methods do away with the shedding operation.
• The claimed knitting methods only perform the binding operation and do not
interloop the yams of one direction into the yams of other directions. Dissimilar
binding techniques also produce basically similar 3D fabric structures.
In the light of these observations it becomes clear that the obtaining processes happen
to be fundamentally and technically different from weaving and knitting processes and,
consequently, the resulting fabrics are also characteristically different from woven and
knitted fabrics. It therefore becomes imperative to discuss these matters.
6. DISCUSSION
6.1 Resolution of Misconceptions
To resolve the obtaining misconception, four points need to be discussed: the basis of the
processes, the resulting fabric structures, their technical description and the patent
classification system.
6.2 Basis of the Process
The employment of heald wires for the purpose of drawing vertical binder yams beside
the columns of 'warp' yams, to entrap in their folds the topmost and bottom-most 'weft'
yams that are laid beside the rows of 'warp' yams to bind the fabric in a vertical
direction, does not constitute the shedding operation. This is because these healds do not,
and cannot, displace individual warp yams from a column of grid-like warp yarns to form
a shed. The healds for each of the yams of a given column of warp yams cannot occupy
the same plane, as displacing one of them would cause the yam threaded through it to be
over-lapped or obstructed by the neighbouring warp yams of that column. In the event, no
shed can be formed and hence the weaving process cannot come about. As a
consequence, an interlaced structure of any weave pattem is evidently not producible.
Therefore, technically the obtaining process cannot be regarded as weaving.
On the same lines, using knitting needles to bind/tie a set of yams arrayed linearly in
either uniaxial or multiaxial orientation cannot be regarded as the knitting process. This is
because the yams of difFerent sets are not interiooped one into the other. Using a knitting
needle for the purpose of binding does not necessarily make the process knitting. In
narrow/band weaving, a knitting needle is employable to intedock the loops of the
doubled weft that is laid to produce the edge of the selvedge at one side. However, the use
of this knitting needle will not transform the weaving process into a knitting process
because the weft would be inserted into a shed that is formed by crossing the warp yams.
The obtaining process would thus fully comply with the principle of weaving in
producing an interiaced structure notwithstanding the use of knitting needles for the
purpose of binding the selvedge edge. The possibility of stitching a web of fleece or a
prefabricated material either onto or between laid parallel yams with knitting needles, as
indicated in Section 4.12, demonstrates clearly that the process cannot be technically
knitting.
The discrepancy in regarding this process as weaving and knitting becomes selfevident when both healds and knitting needles are employed together. Whereas the healds
would draw the vertical binder yams beside the columns of the grid-like warp, the
J. Text. Inst.. 2002. 93 Part I, No. I © Textile Institute
69
Khokar
knitting needles would draw the horizontal binding yams beside the rows of the grid-like
warp. In the circumstances, wherein all the sets of yams are incorporated linearly without
interlacing and interlooping in their respective directions, the obtaining process cannot be
technically both weaving and knitting at once (and the fabric cannot be woven in one
direction and knitted in the other).
6.3 Basis of the Fabric Structure
Considering all the presented 3D fabric structures, whether 'woven' or 'knitted', two
things evident are that all the yarns occur linearly or without crimp in their respective
directions and beneath the bindings that occur at four surfaces of the fabric. Accordingly,
the distinguishing feature of all these fabrics is that they uniquely possess the property of
being resistant to extension. (Incorporation of linear yams is regarded favourable for
composite materials applications as it allows exploiting fully the high-performance
properties of the constituent fibres.) However, incorporation of linear yams also makes
the fibre pull out relatively easy. Further, the bindings, which always occur at the
surfaces, if destroyed, would make the fabric structure vulnerable lo fall apart readily.
These properties are, however, unlike those of the woven and knitted structures wherein
the constituent yams are characterized by crimp, which renders the fabric extensible and
pulling oul a yam from the fabric is not easily possible. Also, integrity resulting from
interlacing and interlooping of yams allows a fabric to be cut without the risk of its
falling apart. In the circumstances, a fabric that is neither interlaced nor interiooped, but
comprises linear/crimpless yams, cannot be technically regarded either as woven or
knitted. And a fabric cannot be woven in one direction and knitted in the other.
6.4 Technical Description
An important point that needs to be briefly considered here concems the technical
description of this process. Looking at the various descriptions of the presented methods,
it would be observed that, other than the method of Section 4.2, they are described using
conventional technical terms associated with weaving and knitting. Method 4.2 thus
demonstrates two things. First, that it is possible to describe the new process technically
without u.sing the terms related to weaving and knitting. Second, that a fabric principally
similar in constmction to the rest is producible without employing healds and knitting
needles. These points, in tum, confirm that the process happens to be fundamentally
different from weaving and knitting. As can be seen now, the use of the terms associated
with weaving and knitting, although avoidable, conceals the uniqueness of an entirely
different 3D fabric-forming process and causes misrepresentation. As this process is a
whole new subject in itself, it ought to have its own set of specific terms to make its
description, and that of the related mattere, clear and easy. As already mentioned, Khokar
(1996) has proposed a set of new technical terms for this nonwoven process: noobing and
noohed fabric to meet with these objectives. The fact that these proposed terms have been
used in other refereed publications as well by Khokar since 1996. without objection,
confirms the technical basis to be sound and acceptable.
6.5 Aspects of Patent Classification System
As would be obvious now, a method's compliance with the established principles and
definitions has been overlooked. A method is designated either weaving or knitting
depending on the choice of terms used in describing it. As technical matters ought to be
70
J. Text. Inst.. 2002, 93 Part I, No. 1 © TextUe Institute
Noobing: A Nonwoven 3D Fabric-forming Process Explained
definite, it becomes relevant to consider here certain aspects of the classification system
to enable proper classification of future patents under the category of the nonwoven
processes.
Figure 15 shows the Intemational patent classification system in reference to the
current discussion. Textiles and paper, i.e. fibrous materials, have a section of their own,
namely section D. This section is further subdivided into main classes, which are
indicated as D 01 to D 07 and D 21. Each of these main classes is further subdivided into
one or more subclasses. The three subclasses relating to the main class weaving are
indicated as D 03 C, D 03 D and D 03 J. These subclasses are further subdivided into
main groups and main groups into subgroups, and it is unnecessary to elaborate on them
here. The specifics of an invention are accordingly classified under appropriate main
class, subclass, main group and/or subgroup.
What needs to be seen here is that the two subclasses D 03 C and D 03 D jointly belong
to the weaving main class D 03 and are complementary to each other. In other words,
these two subclasses are inseparable aspects of a single process, namely, weaving. The
shedding operation is indispensable to the weaving process because without first effecting
it the weaving process cannot technically progress. This fact is reflected in the order of
these subclasses: D 03 C precedes D 03 D. Therefore, the separate existence of these two
subclasses does not imply that devices devoid of a means for shedding could be placed
under the subclass D 03 D as a loom or weaving machine. This is because the two
subclasses can only jointly bring about interlacement of the warp and weft yams.
Iniemational Pateni ClassiHeaiion
1
Section
A
Human
Necessiiict
B32
DOl
1
Suction
Section
Section
Section
Seciion
Section
E
F
G
B
C
D
Performinn Chemixiry: Textiles: Fixed
Mechanical Physics
Operatims: Metallurgy Paper Constructions Engineering:
Ughxing:
Transporting
Heating:
Weapons:
Blasting
D02
D03
D04
D07
D06
D05
1
Seetioti
H
Electricity
D2I
Lay:ered
pro,'duel
Natural or
Artificial
Threads or
Fibres:
Spinning
Yams:
Weaving Braidin/i: Sewing: Treatment
/iMce-making: Emhroiof Textiles
Mechanical
Knitting; Bering: oriheiike:
Finishing
Trimmings: Tufting Laundering:
of Yarns
Nan-woven
Flexible
or Ropes:
Fabrics
Materials
Warping
not oikenvixe
or
provided for
Beaming
1
1
1
1
B32B
D 0-1 C
D03D
D03J
D04B
D04C
D04D
D04G
D04H
Product
built-up of
strata of
Jlat/non-flat
form
Shedding
mechanisms,
Designing
pattems.
etc.
Woven
fabrics.
Methods of
weaving.
Looms
Auxiliary
weaving
apparatus.
Weaver's
tools, etc.
Knitting
Braiding
Trimmings:
Ribbonx.
Tapes.
or Bands
Knotting
Making
Textile
Fabrics/
Non-woven
Fabrics
Fig, 15
Iniemational patent classification system in reference to the current discussion
J. Text. Imt.. 2002, 93 Pan I, No. I © Textile Institute
Ropes;
Cables
mherihan
Electric
Paper
71
Khokar
In isolation, the subclass D 03 D cannot weave a fabric and without the shedding
operation the process will technically cease to be weaving. It is thus imperative to regard
these two subclasses as an inseparable whole of the weaving process so that compliance
with the definition of the weaving process is fully maintained. Now, as the described
produced materials lack the characteristic interlacing feature of a woven material, they
cannot be technically assigned to the subclass D 03 D. In short, because the main class is
weaving, all subclasses must also relate to aspects of weaving. The existence of
subclasses is to cover different aspects of the main class.
The reason for having a separate subclass D 03 C for the shedding mechanism is
perhaps the large inventive possibilities it presents in warp manipulation compared with
the subclass D 03 D that singly represents woven constmctions, looms (e.g. handloom,
circular, teny etc.), mechanisms conceming picking, beating-up, letdng-off, taking-up,
etc. Whereas shedding (D 03 C) alone has ten main groups, the rest combined together
(D 03 D) has only twenty-six.
Although knitted products are classified in the subclass D 04 B only if they have
'constructional features which are of interest from the knitting aspect', on the basis of the
foregoing discussions relating lo the process and fabric structure, it has been seen now
that the non-interlooping process and non-interlooped fabric stmcture are technically
different from the conventional aspects of knitting and knitted materials. The possibility
of producing similar crimpless 3D fabric stmctures without employing knitting needles
shows that the process cannot be knitting. Also, the process of stitching or binding a
fibrous web onto another set/s of yams using knitting needles cannot be technically
regarded as knitting. As the constructional features of a noobed fabric entirely differ
from the aspects of a knitted fabric, the knitting subclass D 04 B is unsuitable for
accommodating the noobing process and the noobed fabric.
Apart from di.scussing section D relating to textiles, it is also necessary to consider here
section B because the material described in Section 4.9 is assigned to this section. This
material comes under the subclass B 32 B (products built-up of strata of flat or non-flat,
e.g. cellular or honeycomb form) of the main class B 32 (layered products).
(Interestingly, the fabric structures according to Sections 4.9 and 4.12 are identical yet
they come under difFerent subclasses.) Although at first instance it appears that the fabrics
comprise bound/tied layers of yams because yams are supplied in that form, a closer
examination of the structure shows clearly that the fabric is not made up of yarn layers at
all. It is a unique single-fabric system in which the yams of a given direction occur
linearly and distinctly separated from one another by the yams of at least one other
direction, as shown in Fig. 1. No two yams of a given direction occur side by side.
Because the yams are so incorporated in the fabric, pulling out a yam will not disturb the
neighbouring yam in the fabric. This would not be possible if, for example, sheets of
woven or knitted materials are plied and stitched. Such a plied stmcture is not a singlefabric system but composed of different fabric layers (sheets) and a given yam belongs to
a layer (sheet) of fabric and pulling it out will affect that whole fabric sheet as also the
entire plied structure. Therefore, it is incorrect to regard noobed fabrics as layered
products and assign them to the subclass B 32 B.
As the noobing process produces a 3D fabric without interlacing, interlooping and
intertwining the employed yams, and it is not capable of producing 2D and 2.5D fabrics,
it is fundamentally unlike the weaving, knitting and braiding processes. Therefore, it is a
novel process and, in the absence of a direct provision for its classification, it can be
placed in the nonwovens category. The subclass D 04 H (making textile fabrics)
recognizes nonwoven fabrics as fabrics formed wholly or partly of textile material by
72
J. Text. Inst., 2002. 93 Part 1. No. 1 © Textile Institute
Noobing: A Nonwoven 3D Fabric-forming Process Explained
processes comprising operations other than weaving, knitting, braiding, lacing or knotting
of yams, threads, or filaments for which provision is made in other subclasses of section D.
In fact the existing main group of the subclass D 04 H, namely 3/00 (nonwoven fabrics
formed wholly or mainly of yams or like filamentary material of substantial length), is a
satisfactory slot for noobed fabrics. The particular subgroup 3/04 (in rectilinear paths, e.g.
crossing at right angles) of the subclass D 04 H is appropriate to locate the noobed fabric.
The classification of the method of Section 4.2 in the nonwovens category (D04H 3/04)
by the patent authorities confirms the soundness of the presented technical basis.
Nevertheless, some amendments to this subclass appear necessary to include different
process specifics of the types indicated in this classification for the rapidly advancing
technologies in this area. Such amendments are possible to make because new main
groups and subgroups are not fixed but created when an invention does not fit into the
existing scheme of things.
7. COMPARISON WITH 3D-WEAVING AND 3D-KNITTING PROCESSES
That the presented methods are technically neither weaving nor knitting also become
evident when comparing them with the 3D-weaving and 3D-knitting processes developed
by Khokar (1997b, 1997c, 1999, 2001) and Sheffer and Dias (1998) respectively. The
fabric stmctures producible by these processes are fully interlaced and interiooped as
shown in Figures 16a and 16b, respectively. The described noobing methods, although
usually called 3D-weaving and 3D-knitting, as can be understood now, simply cannot
produce any of these stmctures.
(a)
WarpZ
Fig. 16
Weft Y
Weft X
tuffer warp
(a) The shell, tubular and solid structures producible by interlacing the multiple layer warp (Z)
with vertical (Y) and horizontal (X) sets of wefts by the 3D-weaving process according to
Khokar (2001), and (b) the warp knitted layers (vertical) held together by looped connections made
from the yarns forming the stitches (horizontal) by the 3D-knitting process according to ShefFer
and Dias tl998J
8. CONCLUDING REMARKS
The noobing process is devised to produce a characteristic 3D fabric wherein a set of
linear yams, arrayed in either uniaxial or multiaxial orientation, is bound/tied using sets
of binding yams. By definition, it can produce a 3D fabric only. The noobed fabric's
integrity comes from the linking of opposite exteriors. The bindings thus occur at the
surfaces of the 3D fabric. The noobed fabric happens to be inextensible as it comprises
linear/crimpless yams. It is thus unlike the woven and knitted fabrics. The noobed fabric
is a single-fabric system wherein yams of a given direction occur distinctly separated
from one another by the yams of at least one other direction. It is thus not a layered
material. Tbe noobing process cannot interlace and interloop the involved sets of yams,
and hence technically it cannot be regarded as either weaving or knitting. Accordingly,
the noobing process is a nonwoven process that should be classified under the subclass
J, Text. Inst., 2002, 93 Part I. No. I © Textile Institute
73
Khokar
D 04 H of the Intemational Patent Classification system. A technical explanation has
been provided to discem practically the noobing process from the weaving and knitting
processes and noobed fabric from woven and knitted fabrics.
ACKNOWLEDGEMENTS
Deepest gratitude is expressed to Mr. Fredrik Winberg, Chairman, Mr. Hans Jacob Wa:m,
Senior Advisor - Project and Mr. Gunnar Sail, Senior Advisor - Finance, al! at Biteam
AB, Professor StafTan Toll at the Department of Polymeric Materials, Chalmers
University, Professor Emeritus Bengt Edberg and Dr. Ejert Peterson for their fullest
support and encouragement at all times. Sincere thanks are also due to Mr. Urban Lind,
Patent Attomey at Awapatent, for his valuable comments.
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