Note: Descriptions are shown in the official language in which they were submitted.
WO91/1~ ~ -1- PCT/US91/02268
2~792?~
TITLE
Making Rounded Clu6ters of Flber6
FIELD OF INVENTION
Thi6 invention relate~ to ~mprovement~ ~n
making rounded clu6ters fro~ ~taple f~be~, ~nd ~ore
partlcularly to a proces6 ~nd ~pp~ratus for m~king 6uch
cluster~, and the re6ulting rounded ~e.g. ball-llke)
clu~ter6, especially from re6ilient crimped flber of
denier 4 to 15 (about 4 to 17 dtex) 6uch a6 i6 u6eful
for filling purpo6es.
~AC~GROUND
Staple fiber ha6 long been u6ed a6 filllng
material, for support and/or in6ulating purpose6.
Polye6ter flberfill has b~en a p~rticularly de6irable
f~ber for such purposes, bec~u~e of its bulk,
reslllence, re61stance to att~ck by m~ldew and other
deslrable features. Conventionally, flberfill u6ed to
be proce6sed in the form of ba..~, af'~r :he flber6 were
parallellzed on a card (or garnett), becau6e thls wa6 an
economlcally attr~ctlve and u~eful way of handllng
flberflll.
Recently, however, Marcus ha6 dl6clo~0d ln
U.S. Patent No6. 4,61~,531 and 4,7B3,364 how
6plrally-crlmped fiberfill can be formed lnto fiberball6
that make a partlcularly desirable fllllng mater~al,
belng lofty, ~oft and refluffable ~n a way that 16
1milar to down filllng. Marcus has also dl~closed ln
U.~. Patent No.~4,794,03B how flberbalis can be made
6imilarly from blends of fiberfill wlth blnder fiber,
whlch can then be activated to make useful bonded
35 ; ~upp it ~truc.u~e~, 2.j. 'o; cu;~'_..'r.g ~..d matL c~ e~.
arcu6 has disclo6ed a useful batch process and
apparatu6 th-t take6 advantage of the spirally-crlmped
~ .
-
. ::
W091/~ 2- PCT/US91/02268
2 ~ 2 ~
nature of his feed materlal for mak~ng such flberball6,
which are belng produced commercially and h~ve proved
useful and lnteresting ball-llke flber ~tructure~,
becau6e of their lofty nature, becau6e they are ea6~1y
trAn6ported by air-conveylng dur~ng proce66ing, and
becau6e of the lnterest~ng and advant~geous propertie6
of the product6, which may be proce66ed into ~everal
lntere6ting v~riant6. We generally refer to the6e
ctrùcture6 herein a6 fiber clu6ter6.
An ob~cct of the present lnventlon 1B to
provlde a proce~6 and apparatu~ that can be op~rated to
provlde 6uch ball-like clu6ter6 of fiber6 continuou61y
at high throughput6. Another ob~ect 16 to provlde a
proce66 and apparatus that doe6 not nece6sar~1y require - :
a ~pecial feed flber, but can be operated ~ati6factorlly
alco wlth regular polye6ter 6t~ple flber, or lndeed
other fibrous materlal6, to form flber clu6ters of ruch
dens~tles and unlformlty ~6 ~y be requlred. ~ further ~`
ob~ect 16 to provlde a proce66 and apparatu6 that may be
used to form clu6ter6 from fiber6 of coar6er denier,
even abovo iO.
A6 will be noted herelnafter, we have made
60veral modlflcation6 to a type of cardlng mschine in
order to achieve our re6ult6.
8UMM~RY or TB~ INV~NTION
Aocordlng to one aspect o the pre~ent
inventlon, there i~ provided a proce6s for preparing
rounded clu~ter~ of flber6, compri6ing feeding a uniform
layer of 6taple fiber onto the perlpheral 6urface of a
rotatlng main cylinder covered with card clothing,
whereby the flber ic advanced around the perlpheral
surface by ~ald clothing and i~ brought lnto contact
with a plurallty of frictlonal 6urface6, whereby 6ald
fiDer i~ f~m~B into c;-~6te-8 .ha. are rOlleu into
rounded configuration~ on the peripheral 6urface,
charact~r~zed in that there i6 provided at leagt one
~, . . . . ~ , . . . , .;. . ; . ,~. . ,,. . . :
, . .. , , . ' ' :-' ', ' ' .: ~ ' . . . . , I' " , .. ... . .
~ ; ~ ~ . , , . :, . . .
Wos1/t64~ -3~ PCT/US91/02268
arcuate doff~ng 6creen, radlally-6paced from 6~1d
clothing, 6aid dofflng screen being provided with
opening6 of 6ufficient size for the clu6ter~ to p366
through 6aid openings, and to be doffed by emerging
through 6ald openi ngs .
U6e of a ~creen to doff clu~ter6 18 a
61gnlflcant dlfference from exl6ting cardin~ machine~,
whlch have generally u6ed a roll to doff carded flber
We have doffed clu6ter6 very éffeetlvely u~lng
an arcuate rlbbed 6creen that 16 provlded wlth
tran6ver6e rib6 with ba6e6 that are epaced radlally from
the clothng on the main cylinder, and wlth openlng6
that are the tran6ver6e spaee6 between the6e r'b6 It
will be under6tood herein that ~tran6ver6e mean6
transver6e to the machine dlrectlon, l e the directlon
of rotatlon of the maln cyllnder, eo the ~tràn~ver6e~
rlb6 of 6uch dofflng 6creen are parallel to the axl6 of
the main cyllnder
Aeeordlng to another aspeet of our lnventlon,
therefore, there 16 provlded a clu6ter-formlng maehlne
that 1B an lmprovement ln a staple flber cardlng machine
eomprl6ing a rotatable maln eyllnier havlng lt6
peripheral 6urfaee eovered with eard elothlng and
adapted to rotate ln elo~e proximlty wlth a plurallty of
eooperatlng frletlonal ~urfaee~, mean6 to fe-d ~taple
f'ber in ~ unform layer onto ~aid man eylinder, and
doffing mean6, the lmprovement eharaeterlzed ln that
6aid frletional ~urfaees eooperate wlth the eard
elothlng on the peripheral ~urfaee of the maln eyllnder
ln 6ueh a way that flber elu6ters aré formed by the
eooperation between the eard elothing and 6aid
frletional 6urfaee6, and the dofflng mean6 eomprl6es a
doffing 6creen provlded wlth openlng~ of ~ufflelent slze --
ror tne rioer elu6ter~ to emerge ~x~ffip;e~ o
"eooperating frlet'onal surfaee~ are de6erlbed herein,
and lnelude ~ationary element~ with frietion~l
. ~ ,
'
~.
. . . . . . . . .
:: . : .: ,. . . . .
. . . . . . . .. .
2 ~ 7 9 ~ 4 PCT/US91/02268
surf~ce6, 6uch ~6 plate~ and ~egment6 thit may b~ smooth
or covered with card clothing, and 6creen6, and al60
movable elements, including worker and 6tripper r~lls,
6uch a6 are used on roller-top cards, and belt-drlven
flat element6, ~uch a6 ~re u6ed on revolvlng fl~t cards.
An ~mportant advantage accordlng to the
lnventlon 16 that dofflng and tran6portatlon of the
emerglng cluster6 may be ~6616ted by ~uctlon and/or
blowing. ror in6tance, the rounded clu6ter6 ~ay be
blown directly into tlckings and formed lnto plllow6 or
other filled article6. Alternatively, thc clu6ter6 may
be packed and later proce66ed a6 de61red.
Ac~ordlng to another a6pect of our lnventlon,
there i6 provided an improved proce66 for preparing
rounded cluster6 of fibers, compr~sing feeding a unlform
layer of 6taple fibcr onto the peripheral ~urface of a
rotating main cylinder covered with card clothing,
provlding a plurality of e66entially arcuate frlctional
6urface6 that are 6paced r~dially from ~ald clothing,
wherein the radlal 6paclng and frictional
characteri~tic6 of 6a~d frictlonal surface6 and of 6aid
clothlng ~nd the rate of feed of said 6taple flber are
controlled so that ~aid clothing becomes loaded wlth a
co~pre~clble layer of flber6, whereby lofty rounded
clu6tor6 of fiber6 ~re formed ln the pcripheral 6pace
between ~aid clothing and said frictional 6urface6, and
doffing ~aid clu~ters. A6 will be de6crlbed herein, the
fact th~t the card clothing 16 loaded wlth flber 16
another 6ignlficant dlfference from operiting a
conventional carding machine of thl6 type. It i6 very
6urpr~6ing that rounded clu6ter6 are formed ln the
peripheral space when the6e (arcuate) frlctional
~urface6 ~re 60 ~paced and the proce6s i6 60 operated, ~-
a6 de6cr~bed hereln.
The 6taple flber that 16 fed to the maln
cyllnder may be in variou6 form~, e.g. a cros~-lapped
.~ .
.. . .
.. - .. , .. , .:. .. . , -, -, , , ., ~ , ;
,.- , ~................ ..
. --: , : : . :: ; .
WO91/1~ ~ _5_ PCT/US91/02268
2~79~7 -~
batt, or may be bale stock that has previousiy been
baled, but i8 fed to the main cylinder ifter havlng been
opened.
Preferably, especially for making pillow~,
filled articles of apparel, or like article6 where such
aesthetic6 are important, the 6taple fiber fed to the
main cylinder may have been 61ickened.
For lower density and better ln6ulatlon,
6taple fiber of hollow cro66-6ection i6 preferred.
If de6ired, for making bonded ~upport
artlcle6, the 6taple fiber fed to the maln cyllnder may
be a blend of polye6ter fiberflll or other hlgh meltlng
flber blended wlth lower melting blnder fiber.
The denier of the feed flber may be a6 hlgh a6
15 dpf ~about 17 dtex), ~nd wlll gcnerally be bt le~st 4
dpf ~about 4 dtex~ for u6e a6 filling m~terlal,
e6pecially for support purpo6e6, but wlll be 6elected
~ccordlng to the desired end u6e. For in6tance, u6eful
blend6 for apparel ln6ulatlon have been made from flber
of denier a6 low a6 1-2 dpf (about 1-2 dtex).
By u6e of our lnvention, a6 de~cribed ~ -
herelnafter, we have found it po66ible to proce66
~taple fiber that ha~ been mechanically crlmped, and to
produce desir~ble lofty flberball6 of uniform average
density.
According to another a6pect of our invention,
therefore, ther2 16 provided a ma6~ of lofty rounded
6taple flber clu6ter6 of average dimen6ion about 1 to
about-15 mm, ~nd of average denaity 1~66 than about 1
pound per cubic foot (about 16 Kg/cu m), con61stlng
ec6entially of randomly-entwined, mechanically-crimped
synthetic 6taple fiber of cut length about 10 to about
60 mm. The6e~ ~lofty cluster are randomly-brranged and
entw~ned ~6 i Marcusi riber ciu6~ers prcpared rrom
cpirally-crim ed feed fiber; they are qulte dirtinct
from the h~rd neps or nub~ that have been u~ed in
.;,'', . "
' ~ '
,, , - . " - .- ,~ . - . . : . - : .
: ~ , ~ .. , .... . ~, . ., .. . ; .
.:. . . . . . ~. .: . : ... . -. . . ;
..... " ~ . ., . ~:.,,, ,. : . . . . . . . ...
Wo91/1~ ~ 2 ~ r~ J ;~ -6- PCT/US91/U2268
novelty yarn6, and that are fimall knotted or t~ngled
clumps of 6ynthetlc fiber6 or indeed of n~tural fiber6,
~uch as cotton. Ac lndicated, preferred form~ of our
mechanically-crlmped 6ynthetlc f~ber may be cllckened
polye~ter 6taple flber, ~nd/or ~ blend wlth ~ lower
meltlng binder fiber, th~t may, if desired, be ~ ~
Ghe~th/core blcomponent wlth ~ 6he~th of lower ~elting -
binder material, and a core of polye~ter or like high
meltlng fi~er-forming material.
~RIEF DESCRIPTION or DRA~ING~
rigure 1 i6 a cchematic 61de-vlew ln elevatlon
of a preferred app~r~tu6 according to the pre~ent
invention.
Figure 2 16 a ~ketched repre6ent~tlon of how ~
6ectlon cut through cArd clothlng lo~ded with flber that
ha6 been removed from a main cyl~nder, mlght 6how the
topography of the surf~ce, D5 will be de6cribed
hereafter.
rlgure 3 i6 a 6ketched repre6entitlon of how
cardinq teeth grlp the flber6.
- Flgure 4 lc a 6chem~tlc v~ew ln pirs2e~tlv^ oS
a portlon of a preferred rlbbed 6creen accordlng to the
pre~ent ~nvention. ~ -
Figure 5 i6 a ~ketched repre6entatlon of an
25 end-view of a portion of the maln cylinder and doffing
6creen with the clu~ter6 emerg~ng.
D~TAIL~D D~SCRIPTION OF T~E INV~NTION
A preferred apparatu6 according to the
invention will be de~cribed wlth reference to the
accompanying dr~wing6. A6 indlcated, in 60me re6pect6,
~ome of the feature6 of thi~ apparatu~ re6emble a card
~or cardlng mach~ne) from which, for convenience, ~ucb
element6 ~nd feature6 have been adapted.
S~, :ef~r~r.c~ ~8 ~de to th~ ~rt cn. c~rdln.g,
including a Manu~l of Textile Technology, in the -
~hort-Staple Splnning ~erle6, Volume 2, entltled "A
,. ., : . 1 ~ ~ : .... ,
-.. ~. . ............ . . ........ . . ... . .
~ .~: , , . . , ~ . : ,........................ .
: , ~. . ,; ,. ... . : . , ,., . : ., :
Wo91/164~ -7~ PCT/US91/02268
2~79~ ~
Practlc~l Gu~de to Opening and Caedlng", by W. ~leln,
The Textile Instltute, 19~7, and to a 6umm~ry of
available types, in an article by s. Wolf, in
Intern~tional Textile sulletin 2/B5, page~ 9, 12, 16, 19
~nd 20, referred to on pAge 35 of ~leln~ Manu~l, both
the M~nual and the artlcle belng hereby lnco~porated
hereln, by reference.
The ta6k6 of a card are 116ted in the former
116S--
Opening to ~nd~vldual flber~-
~llmln~tlon of lmpuritle6- -
Ellmln~tion of du6t-
Dlsentangllng of nep6-
Ellmin~tion of 6hort fiber6-
Flber blending- -
Flber orlentatlon- and
Sllver formation.
Such are lndeed the ta6k6 of mo6t card6. In '-'
other word6, cuch ta6k~ ~of most card~) do not lnclude
formlng ball-llke flber clu6ter6. However, card6 have
been u6ed by ~ome to entangle fiber~ l..t~ bodlcs
variou61y referred to by terms 6uch ~6 nep6, nub6, and ''
other termlnology. Thl6 technology has been regarded ~6
proprletary, ~o the llterature on proces~e6 that may '''
have been u6ed for thl6 purpose 1~ 6parse. 8telnruek,
however, dl~closed ~n apparatu6 for maklng nubs in U.S.
P~tent No. 2,923,9BO.'"'8telnruck lndlc~ted that,
prevlou81y~ a6 many a6 10 machlne6 ln a row had been
used to reduce the flber 6tock to the de61red small hard ''
nub6. Stelnruck 6aid hi~ machlne could be operated to
form nub~ of the 6ize and hardne66 de61red by perhap6 ~6
$ew a6 2 machine6 ln 6equence. Even thl6 need for a
6eguence o 2 m~chlne6 ~, however unde~lrable, and 60
we have prov~ded a macnine tnat c~n m~ke u~ eBl rc~
clu6ter6 on a 61ngle machlne. 8telnruck wanted hard
nep6 or nub6. In contra6t, we want to make re6111ent
WO 91/16484 -8- PCI'/US91/02268
2 0 r~ sj
lofty ball-llke 6tructures of controlled and uniform
den61ty. Another difference from prior art nep lor nub)
formation i6 that the6e ha've generally been ~ade from
fiber6 of low dpf (denler or dtex per fllament of les
than 3) ~uch a6 cotton and other low denier fibers that
knot ea6ily and can form hard neps that are useful in
novelty yarn6. When a filling i6 u6ed for 6upport
purpo~e6, 6uch low dpf fiber i6 generally not a6
de6irable a~ higher denier6 of 4 (about 4 dtex) and
above ~even up to 15 denier, about 17 dtex) that are
generally preferred, beeau6e of their r~6111ence. This
property, however, lncrea6e6 the dlfflculty of maklng
clu6ter6 tbat will not later unravel. It 6hould be ~;
under6tood that our proce66 and machine may al60 be
operated with low denler feed flber that i6 ea61er to
form into clu6ter6. In other word6, although hlgher
denler 6ynthetic flber6 are generally preferred as
filling materlal, lower denler 6ynthetlc and natural
flber6 may al60 be'formed lnto flber clu~ter~ by our
proces6 and machine. ~'
A6 e~phO~lzed by 8telnruck, hi~ ob~ectlve of
formlng nub6 i6 almo6t the rever6e of the primary
functlon of operatlng an ordinary card (to lay
individual fiber6 a6 much a6 po66ible in parallel line6
and to remove any neps or nub6). Indeed, a book wa6 ''
publl~hed by Wlra, entltled "Nep Formation ln Carding",
by P.P. Townend, to advi6e how to avoid the ma~or ~; -
problem of nep formation in the carding of ~taple
fiber6. Steinruck wanted to convert his fibrou6 ma66
into nub6 which Steinruck would later incorporate lnto ''
web6 or ~liver6 on a card in a sub6eguént operation.
Steinruck u6ed a (modified) roller-top card, and it i6
believed that other exi6ting proce6~es for making nep6,
~v6, ecc., hove gBille~a~ UDed ~Gllêr~tOp ;:ard~. I;l
contra6t, for a preferred machine according to the
pre6ent invention, we have modlfied a card wlth carding
~ : .. ~ . : .. .: ; : : , . . :: ............ :
wo g~ 9- 2 ~ 7 ~ ;~3 2 ~ Pcr U 68
plates (60mewhat a6 6hown in Flgure 101 on page 45 of
th~ MOnu~l by Rleln, or in Flgure 22 on pay~ 20 of the
artlcle by Wolf, both referred to here~n~bove). our
o~ectlve i6 also the rever6e of the prlmary functlon of
operatlng an ordinary card.
our preferred machine i6 lllu6trated in F~gure
1 (which does not 6how the card clothlng) and consi~t6
e66entially of a main cylinder 10, of diameter 50
lnche~ (about 1.3 m), that i6 covered wlth card
clothing, and that 1~ ~hown drlven ln a clockwl~e
dlrectlon ~t a rate that largely determlne6 throughput,
bolng generally 6cme hundred6 of revolution6 per minute
~rpm), preceded by a roll 11 that 16 referred to a6 a
licker-in (~leln refer6 to thi6 a6 a "t~ker-ln"), of
diameter 9 inche6 ~sbout 23 cm), that i~ al60 covered
with clothlng (but of much lower polnt den61ty), and
that 16 chown driven ln a counter-clockwlOe dlrect~on,
l.e., oppozlte to that of maln cylinder 10, wlth an
undcrlylng ba6ket llA, and lt6elf preccded ~y a feed
roll 12, that 16 ~hown drlven al60 ln ~
c~unter-clockwi6e dlrectlon (llke licker-ln 11), ~nd
that cooper~tc6 with a fced plate 13 ln feedlng opened ~-
flbcr from a 60urce of 6upply (not 6hown) at a unlform
r~te evenly ~cros6 the width of licker-in 11. Tho
perlphery of maln cyllnder 10 18 6urrounded by a ~crle6
of Otatlonary cooperatlng frlctlonal 6urface elemcnts,
lndlcated generally by 14, and more speclflcally
(6erl~11y from llcker-in 11) a6 15, 16, 17, 1~ and 19,
all of which havc arcuate frictlonal ~urface6 that are
6paced-radlally from the (teeth of the card clothlng on)
main cyllnder.l0 to allow proce661ng llnto cluOter6)
fiber fed from licker-in 11 within the peripheral ~pace
~round main cyllnder 10, and def~ned on tbe outslde
PC-~2'2--i ' ~_h zp~ca by the ~roU'~o ~-C~-~n,~l
6urface6 of the6e 6tatlonary element6 14. The radial
; : ~p~clng ly toe ~diu-ted, ~nd thl~ c~n oe an l-portant
:
~:
~, -
wo 9l/l~ 2 ~ r~ O- PCT/VS91/02268
me~n~ for controlllng the proces6 ~nd the product6
produced. ~ :
A6 lndicated, opened fiber ls unlformly fed
between feed plate 13 and feed roll 12, whlch latter i8 .:
provided wlth teeth (or other means) to adv~nce the
f~ber toward6 l~cker-in 11, more or les~ a6 ~hown ~n
F~gure ~4, on page 39 of ~lein'6 Manual. The clothlng
on llcker-ln 11 forward~ the new flber ~fed fro~ feed
roll 12 and feed plate 13) pa6t underlylng ba~ket ll~ to
the clothlng on maln cyllnder lO. Both ~t6 of clothlng -
are tr~velling ln the ~me dlrectlon, but that on maln
cyllnder 10 i6 ~ovlng at a much higher 6peed. Thu6, the
new fibee i6 picked up by the teeth on main ~ylinder lO
and enter~ the 6pace between the arcuate frictlonal
surfaces of 6tatlonary element6 14 and maln cyllnder 10
(covered wlth card clothlng). Durlng 6tart-up, new
flber (fed from llcker-ln 11) wlll loid onto the card
clothlng on maln cyllnder lO, and ~o ~ome mlnute6 are
llkely to pa66 before any product i6 dellvèred in the
form of ball-llke cluster6. Al60, a6 will be evldent, a
certain amount of cmplr~cl6m m~y be needad ~o ad~u~t the
feed rate of any partlcular feed flber to the 6urface
~paed of the maln cylinder, clothed wlth approprlate
card clothlng, and currounded by approprlately ~paced
6tatlonary element6 14, ln order to obt~in a
~ati~factory dellvery of the de61red clu6ter6, and
6teady ~tate operatlon. Once the proc~680r reache6
6teady 6tate operation, ~.e. once the amount o flber
(in the }orm of rounded ball-llke clu6ter~) dellvered by
maln cyllnder 10 i6 the 6ame a6 the amount fed to the
proce~60r, the card clothlng on the ~aln cyllnder wlll
have become loaded w~th flber that ha6 worked lt6 way
down the teoth, 60 the now fiber can only be collected
~t lor near ~ tha ou.a. ax' -am' t' a~ o' tbe t~ath cf thi
card clothing. However, 6urpri6ingly, thl6 fiber ~6 not
loaded unlformly ln denslty or 6patlally (when the
, ''
:, .
.
.:': ' . ; :, ' . -. ','., . . ,' ,.
. . : . ..
w09t/164~ ~, i3 ~ 2 ? PCT/US91/02268
proce6~0r i6 run with a correct feed r~te of flber and
ma~n cyllnder 6peed~5 in other words, there are
relatively high locations loaded with m ie fiber and
contra6tingly lower locations loaded with le66 fiber
acro6s the w~dth of the main cyllnder and in the
direction of rotatlon.
Thi6 loading of fiber on the main cylinder,
~ccording to th~s preferred a6pect of our lnventlon, 16
an lmportant diference from a cardlng opcratlon (u61ng
thi6 type of machlne, before modlfication). Durlng 6uch
carding, lt ig de61rable to doff all the flber 60 that
only a very th~n l~yer of flber i6 fed ~nd 60 that all
~6 doffed. In other word6, durlng 6uch cardlng, it i6
lmportant to avoid load~ng the cyl~nder.
Such loading according to our inventlon i6
represented ln ~ cketch ln rlgure 2, ~howlng how a
typical 6ection might look lf cut through the c~rd
clothlng and fiber on ~ loaded main cyllnder ~not 6hown
in rigure 2) in a 61mpllfied and idealized vlew. The
upper portion 21 6how6 fiber while the lower portlon 22
indlcate6 tne ioc~tion of the card clothlng ( BO~e of
whlch *ould be grlpping fiber). Figure 3 16 a 6ketched
repregentatlon of how fiber6 24 are qripped by card~ng
teeth 25 of a type that we have u~d. Afi ~ome of the
fiber ~hown ln the upper portlon 21 of ~lgure 2 1B
relea~ed ln clu8ter6 23, and 1~ no longer grlpped by the
card clothlng, 6uch clu6ter~ pa66 through the 6pace
between the card clothlng (loaded wlth flbcr) and
~tatlonary frlctional 6urface element6 14, and are
belleved to follow tortuous path~, and 80 to be rolled
and become rounded clu6ter6. A6 the clu~ter6 progre~6
~round ~in cyllnd~r lO, they reach the 6pace between
the ~urface of maln cylinder 10 and ~ doffing 6creen,
wnicb i6 one or tne statiol~dry e~ehlent~ 14, ~peclfically ~ -
element 17, whlch i6 a rlbbed 6creen.
We have u6ed n6 6uch n ribbed doffing screen
. .
.-. .- -
. ,. ,. . . ... .~ . . ... .. ., ~,., - . . . ; . i .. . . . . . .. : . . . . .
, ~ " , . : . .. .. ....
W091/1~ ~ -12- PCT/US91/02268
17, a 6creèn suc~ as ha6 previously been used underneath
commercial card6 (probably shown under the maln cyllnder
in F19. 101 on page 45 of Klein'6 Manual) for the
different purpose of removing waste. we prefer,
however, to doff our fiber clu6ter6 through 6creen~ wlth
larger 6p~cing6 between the rib6. One type of preferred
~creen i6 de6crlbed now with reference to Figure 4. The
rlb6 31 of 6uch 6creen run tran6ver~ely (~.e. parallel
to the axi6 of main cylinder 10) and are 6haped
convenlently with tri~ngular cro66-6ectlon6, wlth 6mooth
ba6es that are 6paced radially from the 6urface of main
cylinder 10, and are 6eparated al60 tran6ver6ely along
thelr length8 fro~ each nelghborlng rlb, 60 the rounded
fiber clu6ter6 m~y contlnue to roll ln the arcuate 6pace
between ~in cylinder 10 and the frlctional 6urface6
that ar~ the ba6es o the rlbs of the rcreon, but may
also emerge between the rib6, becau6e of centrifugal
force. Thl6 16 repre6ented in Flg. 5, which 6how6
clu6ter6 23 emerglng between rlbs 31, after belng
relè~6ed from the loaded flber 21 ln the perlpheral
ap~ce between the rlbc 31 and maln cyllnder 10. .~ny
1006e flber or lncompletely-formed clu6ter 18 1eE6
llkely to omerge from the proce660r through the
tran6verse ~pace6, and 6uch flber ma~6e6 a~ do not
emerge may ro}l back down the slde6 of the rlb6 to
reenter the arcuate 6pace around maln cyllnder 10. Az
the flbér cluster6 emerge, they may be collccted, e.g.
under low 6uction, and delivered, e.g. for packlng and
shlpplng, or for further proce66ing, by an alr conveylng
~y6tem. An lmportant ~dv~ntage of flberflll ln the form
of round clu6ter6 which do not readlly entangle, 16 the
abllity to tran6port them ea6ily by blowing.
As will readily be under6tood, a-dofflng
~c;ce.. ~ d.~an.~7eouz~l be ueed to d^r~ ~luetere ~adn
on other type6 of machine6, different from the preferred
type accord~ng to our lnvention.
., :
.
: .
W091/164~ -13~ 9~2;~ PCT/US91/02268
The next element 18 may al60 be a 6~reen that
act6 a8 a furthec doffing screen, and performs a 6imilar
function. ~he last ele~ent 19 may al50 be ~ 6creen,
referred to as a back bottom screen; this element is
preferably, however, a plate to provide a frictional
surface w~thout doffing. Element 19 may be connected to
licker-ln ba6ket llA, as 6hown ln rig. 1, to avoid 106
of flber from the machine at thi6 point.
Although five frictional surface element~ 14
are 6hown in rlg. 1, it wlll be under~tood that the
invention iB not limited to only five 6uch elementc, and
moee or les6 may be u6ed, if de6~red. Indeed a larger
number were used i6 Example 3.
We have found the following a6pect6 affect the
process of our ~nvention and the re~ulting product~.
With regard to the card clothing on the main cylinder,
lncrea~lng point den6ity~generally reduces the potential
to form a compre6sible fiber loading on the main
cyllnder, whlch lead6 to making clu6ter6 that are more
den6e, le66 rounded and le66 acceptable for end u6e6
llke plllow6 ~nd bedding. Conver~ely, a ~ e- polnt
den61ty generally allow6 for more flber loadlng of the
ma~n cyllnder, and generate6 a topogr~phy that ic more
conducive to fiber clu~ter mak~ng. A more aggre66ive
tooth angle 16 preferred wlth fiber~ havlng higher
degree6 of ~llckne~6. Even a very aggre~slve tooth
angle may not be 6ufflcient when the point den61ty get6
extreme, e.g. more than 800 pp6i (point6 per sq in, and
eguivalent to about 124 polnt6 per 6q cm), a6 thl6 will
~ventually make loadlng practlcally lmpos61ble and zo
clu6ter formation wlll al60 not be po6slble. Les6
aggre~6ive teeth will not hold highly sllckened fiber6,
and thi6 will reduce the potential to form an a~ceptable
o'uzt_z. ~i~h s-3i-s~ick -r.d dry f~r5~ a less
aggre66ive tooth i6 required to ~1) prevent overloading ~ `
the ma~n cyllnder and ~2) allow a 6table load and
.: -
' .,; .
: '. .
.
' ~ " - ' '' '' ''' '-' .' '' .: ' . ' . " ' .: .' : ' . ' ' ' ' ',. ' .
W091/t~ ~ ~ -14- PCT/US91/02268
topography due to higher fiber-flber 6 fiber-metal
frlction to achieve good fiberball ~clu6ter) form~tlon.
The 6peed of the main cylinder 6hould be matched to the
fiber feed rate. If the 6peed i5 not high en~ugh, then
the main cyl~nder, ~s well ~6 the llcker-ln, can
overload, and overlo~ding le~d6 to unacceptable cluster
formation, and may even damage the machine. Once the
main cylinder ha6 reached a 6ufficient 6peed to sati6fy
the flber feed rate, 6table loading and good clu6ter
formation wlll occur. Increa61ng the 6peed wlthout
increa6ing flber feed will u6ually re6ult in ~maller,
den6er clu6ters. The fiber feed rate 6hould be tuned to
the spaclng6 between ths frictional 6urface6 and the
ma~n cylinder, and to the 6peed of the maln cyllnder.
If the clearance6 are too tight, then thl6 can overload
the maln cyllnder, or ~ake very tlght, den~e non-round
clu6ter6. A6 the clearan~e 15 lncreased, then the ball6
may become more halry, i.e. have more free end6. Higher
fced rate6 can be accommodated with approprlate --
clearance6 and speed to glve good clu~ter6. The
ClO~rallCe6 ~pacln;6: b~.ween the ~aln cyllnder and the
frlctlonal ~urface element6 6hould not be too tlght, or
this wlll cau6e very den6e loading of clothing and lead
to clu6ter form6 that may be unacceptable. ~he 6p~clng6
need to be ad~usted to achleve a ~table load~ng
~topography) and can be u~ed to help change the average
ball dlameter. These ~paclng6 may be ad~u~ted by
conventlonal mean6, 6uch a6 610t~ ln the rlm6 of the
element6 14, with bolt6 on the msin cyllnder ~nd nut6 tD
tlghten and flx the ele~ent6 at the de6ired 6paclng, a6
6hown ln Flg. 4.
A6 wlth conventlonal card6, the varlou6
~le~ent6 14 6urrounding the circumference of the main
cylir.ueL may .hau-~e'ic~ 'a BU;;_U..~ by :e~ov~ble
6ections of coverlng plate6 to retaln any 1006e fiber
that would otherwl6e e6cape, but the6e are not 6hown ln
... . : - : .
WO 91/16484 -15- ~ ~ j rJ rl 2 2 ~ PCI`/US91/02268
the lnterests of clarlty and 61mpllc~ty.
The lnveintlon 18 further de6crlbed wlth
reference to the followlng Example6, ln which ~11 p~rt6
and percentages are by weight, unless otherwlse
lndicated. For test procedure~ and in other respect~,
reference may be made to the Marcufi U.S. Patent Nos.
4,61~,531, 4,783,36i and 4,794,03~, and 4,~18,599, whlch
are all hereby ~pecifically incorporated herein, by
reference. Different feed fibers may require different
proce~ and/or mach~ne features for approprlate
clu6ter-formatlon to be performed, 60 different feed
fibers have been processed. Some of the different feed
fiber6 are exemplified below, and others may be
proce66ed, by 6ultable adjustment of the var~ous proce66
lS and apparatus feature6 mentioned. In the flr~t Example,
wè proce6sed 61~ckened 6plrally-crimped fiber, becau6e
the 3-d~menslonal cr~mp of zuch f~berg 1~ preferred for
ea6e of ball ormation, and 61~ekened f~berfill 16 al60
generally preferred for ae6thetlc6.
~hAMPLE 1
A tow of a6ymmetrically jet-quenched, dr~wn,
sllckencd, poly(ethylene terephthalate~ f~lament6 of 4.5
den (5 dtex) wa~ prepared conventionally, wlthout
mechanically crimping, us~ng a draw ratio of about 2.8X,
applying a poly6110xane sllckener ln amount ~bout 0.3~
Sl OWF, and relaxlng at a temperature of about 175DC ln
cope form. The rope was then cut lnto 32 mm (about 1.25 ;~
lncheE) fitaple, and relaxed aga~n at about 175C. The
crlmp developed by thi~ procez6 1~ 3-dimensional in
nature and is a non-chemical approach to achleving a
~piral-type of crimp. The staple w~s for~ed into a
bale, compres~ed to i density of approximately 12 lb/cu. ~ -
t (about 192 Kg/cu m).
.hai ;taple ~z~ oper.Pd uslng a Y.azte;clea
opener (available from John D. Holling6worth On Wheels,
Greenville, SC) and then manually charged to the hopper
.
: .
,., . ~ ., . .. - ... . ~ ............ , .~
' . ,. '.' "`, . ` ". ",, "' .' '~ '' ,.`. ~ `'. ' " " ' ~ '`' ' ' "'
W09t/164~ -16- PCT/US91/02268
2~.r?25
6ectlon of ~ CMC Evenfeed (~vailable from Rando M~chine
Company, Macedon, NY), whlch pre~ented a unlform amount
of opened feed fiber acros6 the width of the proees60r.
The processor was a6 6hown in Figure 1, belng
a 40 inch (1 meter) wide card (available from John D.
Holling6worth on Wheel6, Greenv~lle, SC) modlfied 60 ~6
to have the following e66entl~1 elements:
~1) Feed roll 12 (2.25 inch diameter, i.e. almost
6 cm) with feed plate 13 who6e function 16 to ~et~r
flber to llcker-ln 11. reed roll speed was controlled
independently with a 6eparate DC motor and drlve. Fiber
throughput6 were determined by weighing product
delivered by the proce660r over a prescribed tlme
perlod. Feed roll 12 rotate6 in a counter-clockwi6e
dlrection a6 6hown.
(2) Licker-ln roll 11 (9 lnch diameter, ~bout
23 cm) who~e function i6 to remove flber dellvered from
the 6pace between feed roll 11 and feed plate 12 and
pre6ent it to main cylinder 10. For thl6 Example, the
llcker-ln roll 6peed wa6 ratioed to the main cylinder,
i.e. both used the 6ame mechanlca~ drlve. (~hl6 16 not
lleCeCBary, a6 independent 6peed control of the llcker-in
ha6 been evaluated acro66 a wide range of 100-950 rpm
and found to have llttle effect on ball formatlon, or
even on thel~ unlformlty and/or den~ity). Tho licker-ln
clothlng wa6 ~tantard 24 pp6i ~about 4 pt6/sq cm) wlre
~avallable from John D. Holling6worth On Wheel6,
Greenville, SC). ~icker-in roll 11 rotate~ in the 6ame
direction a6 feed roll 12, but at a hlgher ~urface
6peed.
(3) A 50 lnch (about 1.3 meter6) diameter
main cylinder 10 clothed with a low point den6ity (132 : ~ -
pp6i, ~bout 20 pt6/sg cm), moderately aggre66ivc tooth
aDgl~ (about 25 po6it'-va/ c'~Lhi,.s ;~va~'aL'2 'ro~ uv~.,.
D. Holling6worth On Wheel~, Greenville, SC). Thi6 i6 a
preferred clothing for u6e with fiber6 coated wlth
, , ::: . , . . ; :
:.:: ~ . , : . : . . .
Wogl/164~ -17- PCT/US91/02268
2~7,922a
poly6iloxane ~llckeners. Thl6 clothlng allowed hlghly
61ickened fibers to load the main cylinder under the
conditions of operation here~n in 6uch a fashion a6 to
form an equilibrium 3-dimensional 6urface topography of
fiber~ embedded in the clothing voids, but 6till expo6ed
enough of the wiring points to draw fiber6 away from the
licker-in roll and not allow the licker-in to overload.
Main cyllnder 10 rotate6 in the opposite direction to
licker-in 11 and feed roll 12.
(4) A ~et of 6tationary frictional 6urface
element6 14 mounted on the perlphery of main cylinder
10. ror thi6 Example, the entire periphery wa8 covered
with rlbbed 6creens (available from Ell~ott Metal Works,
Greenville, SC). The fir6t 6creen 15 ~referred to
~ometime6 ~s the upper back 6~reen) was po6itioned where
a ctandard backplate would normally be po61tloned in a
carding machine. Screen 15 had a rib 6pacing of a
qua.ter of an inch (about 6mm) and contained 34
trlangular 6haped rib6, the ba6e of the trlangle being
located clo6e6t to, but ~paced from, main cyl~nder 10
and being nomlnally ~ ee eighth6 of an lnch ~about
lOmm) in width. The next (top) 6creen 16 had 11
rectangular-based rlb6, wlth one nnd a half lnche~
~about 4 cm) rlb wldth and guarter lnch (about 6mm)
6pacing. ~oth 6creen6 15 ~nd 16 were Otandard screen6
that we u6ed a6 proce66~ng screen6, becauOe of the
narrow ~paclng between thelr r~b6. The next (upper
front) 6creen 17 wa6 a doffing 6creen that wa6
cu6tom-made with 23 triangular rlb6, of wldth three
eighth~ ~nch (about lOmm), 6p~ced half an inch (about
13 mm) apart. The othee (bottom front and bottom back)
6creen6 18 ~nd 19 were proces~ing 6creen6, 6imilar to
upper back ~creen 15.
The cv~f lyu~utl v~ Oc .' e ocre~8 o~ th~
periphery of the main cyllnder was 6uch that 6taple
fiber6 were forced to unlte and begin rolllng ln the
WO91/1~ ~ -18- PCT/US9I/02268
perlph~ Rl ~pa~;i around the maln cylinder when lt
reached equillbr~u~ load~ng tl.e. A 6teady ~t~te
conditlon), whlch occurred within le6s than about 10
minutes. Spacing of all ~creens from the ma~n cylinder
wa6 6et at 0.080 ~nch (about 2mm) for thi~ Example.
The6e 6paclng6 are adju6table within limit6, ~nd ~y be
varled to control cluster den61ty ~nd 61ze.
~6 lndicated, r~bbed screen6 are not the only
statlonary element6 wlth frictlonal 6urface6 which can
be u6ed to achiove a good clu6ter product. We have
6ucce66fully u6ed elements with 6mooth ~olid 6urfaces ln
pl~ce of the upper back, top and lower back 6creen6, a6
~hown in Fi~re 1. Solid clothed element6 can ~160 be
u~ed when mounted wlth the cloth~ng reversied, ~o thot
the teeth polnt ln the dire~tion oppo~lte to that used
ln carding, and w~th a wlde range of po~nt den6itle~;
(thege are more expen6ive to make than 6mooth plate6).
Although the frictional element6 14 th~t we have u6ed
have been 6t~itlon~ry, ~pproprlate to the des~gn of the
type of card we h~ve modifled, 60me card6 w~th movable
fr~ct~cnal element6 may al80 be mod~f$ed for u6e
acccrding to our lnvention, for ~n6tance wlth roller6 or
belt-driven flat element6.
Control of product removal 16 acco~pll6hed by
u~lng one or more rlbbed doff~ng screen6 (with
adeguately wlde rib-to-r~b 6pacing) accordlng to our
inventlon. The~e have been located it the upper and
lower front screen locatlon6 on main cylinder 10,
corre6ponding to where a card 16 generally doffed. Thl6
dofflng locatlon 16 conventlonal but 16 not e66entlal,
and an advantage may be obtalned w~th other ioffing
locationc, depending on the design and layout of the
operation. Wider doffing 6paclngs have been more useful
wh~n doffing w~t~ a lowee ~creen~ ~uch a~ a6
centrlfugal force i6 assi6ted by grav~ty underneath maln
cylinder 10. On the upper front Idoffing) 6creen 17,
. : , , . . ~ :: .
: . ~
Wo g~ 9- 2 ~ ?, -~ PcT/US91/02268
6pacings wider than about half an inch ~about 13 mm)
have resulted in problems in getting the clu6ter6
propelled away from the proximity of the main cylinder.
we have also noted that free fiber may emerge w~th the
desired clu6ters if there ~8 a "wlndow" of w~dth ~ m~ch
a~ three inche6 ~8 cm). This may not be des~rable, ln
general, when the ob~ect 16 to make clu6ter~
efficiently. For bonded product6 however, a8 indlcated
by Marcus, it may be de6ired to provide a mlxture of
rounded fiberball6 and loose binder fiber, in wh~ch case
free fiber may provide an advantage.
Several varlat~on6 may prove effective and
de6irable. For in6tance, a 6creen and rib design
6imilar to ~ venetian blind concept, u6ing ad~u6table
openings, and de6igns prov~ding a Coanda effect may be
u6ed to a6si6t eentrifugal force in removing the ~ - -
clu6ters from the main cylinder.
rOr ~xample 1, the-speed of main cylinder 10
wa6 ~et and controlled at 250 rpm, and the 6peed of
licker-in 11 was ad~ugted to provide ~ normali~ed fiber
feed rate of about 00-90 pph/meter (of the ord~r of 40
~g/hr/m) card wldth. The 6peed of llcker-ln 11 wa~
ratioed to the maln cylinder, and wa6 measured at 180
rpm. Spacing of the peripheral frictlonal element6 14
from the main cylinder (clothing) was 6et at 0.080 inch
~about 2 mm). U~ing the~e 6etting~, 6atisfactory
clustors were produced having free fall bulk densitie6
that were satisfactorily uniform, and me~ured between
0.55 ~nd 0.70 lbs/cuft (about 9 to about 11 ~g/cu m).
The6e clu~ters of our invention ~INV) were
te6ted, ~nd compared with refluffable commercial
cluster6 (ART) made from 6imilar fiber u~ing the prior
art air-tumbling process described in U.S. Patent No.
3~ 4,51~,531, me~suri~g their cohns;~n !in NewtQns! and
their bulk ~measured as heights, in cm, of the 1Oo6e
clu~terr., rather than for pillow6) under load6 of 0.01
WO 91/16484 . r -20- PCl`tUS91/02268
2a~
p6i and of 0.2 p6i, (corre6pondlng to ~bout 7 and about
140 Kg/6q m~ e66entially ag de6cr~bed in U.S. Patent No.
4,61a,531. The clu6ters compared well w~th 6uch prior
clu6ters in the6e test6, a6 can be seen from the result6
ln Table 1.
T~LE 1
Cohe610n Heiqhts (cm)
(Newtons) ~t 0.01 p8i at 0.2 psi
INV 2.6 22.8 7.6
~RT 3.3 22.3 6.2
E~AMPLE 2
Four different feed flber6 were fed in opened
cond~tion to the proce660r a6 de6crlbed in Example 1
above, under e6sentlally the ~ame conditlon6, to
demon6trate that ball-like clu6ter6 can be made from
varlou6 type6 of mechanically-crlmped flber. ~11 four
dlfferont feed iber6 were 6pun from poly~ethylene
terephthalate) polymer supply on a 6ingle po6ition of a
multi-porltion eommercial opinning machine. Sufflclent
endo of each type were creeled together to m~ke a
~ult~ble erimper denier on a low eapacity technical draw
mach~ne, were oubsequently drawn, mochanically crimped, ;~
polyoiloxane-61ickened ~approximately 0.3 ~ 8i OWF),
relaxod at 175'C to 6et the crimp 6tructure and cure the
olickener, and then eut to 1.125 ~neh ~bout 3 cm)
~taple hav~ng the follovlng propertie6: . -
35: ~
,~ :
~ .
WO 91/16484 -21- 2 ~ 7 9 ? ?, r~j PCr/US91/02268
TABLE 2A
Item Cro66-Section DPF Crimp6/ln~erimp6/cm)
-
8calloped oval 6.7 6.7 (2.6)
T Trilobal (MR about 2.0) 6.1 6.5 ~2.5)
RH Round (one hole) 6.1 5.2 (2.0) - ;
RS Round ~6011d) 6.2 5.4 (2.1)
A6 ln Example 1, the cohe6$0n and bulk of the
clu~tor6 wete ~ea~ured ~nd comp~red w~th co~merci~l
clucter6 ~ART). The6e mea6urement6 ~glven in Table 2B)
lndlcate that thelr cohe610n and bulk under load varled
~lgnificantly, depending on the fiber u6ed, and it6
crimp and configuration, and their cohesion value6 were
not a6 good a6 for the ~p~ral cr~mp flber~ of Example 1.
Some aspeet6 of the cluster products from there
dlfferent fiber~ could pos6iaiy be ~mproved by varylng
the proce6~1ng condition6.
TABLE 2B
It_mCohe610n Heiqht6 ~cm)
(Newton6)at 0.01 p~i at 0.2 p~
~0 5.~ 22.2 7.0
T 9.0 24.B 9.2
RH 5.1 23.7 9.0
RS 4.6 23.1 7.1
ART 3.3 22.3 6.2
E~A~PL~ 3 - -
- The feed fiber for thi~ ~xample wa6 6pun from
poly~ethylene terephthalate), of 5.5 dpf ~about 6 dtex),
mechanically crimped ~about 7 cpi, about 3/cm),
9;3il~zly p~ ; lo~.ane-~lickened (about 0.3 ~ Ei Q~F~;
7-hole flber ~total void content about 12%), cut to 1.25
Inch (about 3cm) ~taple. Thi6 fiber wa6 opened on a
: .
' ~
WO91/16484 -22- PCT/US91/02268
Ma6t~rQ~eànR opener, as in Example6 1 and 2, prlor to
feedlng to a flberball making apparatu~.
For this Example, the configuratlon of the
frictional 6urfaces 14 was 60me~hat different from that
u6ed in Example 1 (and as shown ln Figure 1) but the
apparatu6 wa6 otherwise as described hereinbefore The
frictional surfaoes 14 were, in order 6tarting from
licker-in 11 as follows, with 6pacing6 mea6ured from the
card clothlng on the main cylinder, it being under6tood
that the plateD were all 6mooth or with their card ..
clothing rever6ed from the normal carding d~rection, ~o
a6 not to be oppo6ed to the agqres6ive clothing on main
cyllnder 10.
TA~LE 3
~paclng
No. ~lement lnche6 (mm)
: .
ctandard backplate l9.5 inch - 6mooth) 0.08 2
20 l5A cardlng ~egment ~6 lnch - 72 pp6i rever6ed) 0.01 0.25 ~ :
16A Cardma6terR plate (15 lnch - rmooth;0.08 2
16B Elliott ~creen (a6 top 6creen in Example 1~ 0.08 2
16C carding 6egment t7 inch - 378 pp6~ reversed) 0.01 0.25
17 doffing 6creen (a6 ln Example 1) O.OB 2
25 lB bottom front ~creen (a6 in Example 1) 0.08 2
19 bottom b~ck screen (a6 in Example 1) 0.08 2
Maln cylinder lO wa6 driven àt 270 rpm, and
licker-in 11 at obOut 195 rpm, with a feed rate of fiber
to provide about 80-90 pph of clu6ter6. The~e clu6ter6
were well rounded, were ea6ily tran6por~ed by air, and
remained di6crete even after repeatedly being compre~sed
by h~nd, although they had Dignlficantly ~ore free endD
35 than .he C1UDterD from Examyle '. The p:oduct ~ bl_~n
into commercial pillow tick6 of regular 6ize, uslng 22
oz (625 g) f~lling weight6 equivalent to commerclal ..
' ':' " '
.
' ~ ': , ' "' ~ ' . .: ' - . , . ' . " ' ' ' '
WO91/16484 -23- 2 ~ 7 J ~ '7J ~i PCr/US91/02268
,
plllow6 (filled w~th clu6ters), 60 that they could be
r~ted vi6ually, both when newly-filled and after three
6tandardized 6tomp and laundry cycle6, and were found
only 61ightly le6s lofty and refluffable than 6uch
commercial clu6ter filling.
Although much empha6i6 ha6 been given to the
desirabllity of making round ball-llke fiber cluster6,
6uch a6 have proved very de6irable for fllling
purpo~e6, our proce66 and machlne may be operated to
make rounded clu6tcr6 or other 6hape6, e.g. elllp601ds, -- -
if thl6 i6 de6ired, by u6ing a higher point den6ity for
the card clothing, and ad~u6ting the clearance6. Al60
hard, more compact fiber clu6ter6 may be produced by our
proce66 and machine if 6uch are de6ired, a6 our
invention provide6 for flexibility of operation.
': -
. .
" - ' ~ ' .
` :
' ' '
~.
