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What is Fibre Curvature?mean fibre curvature is the average curvature of fibre snippets measured by the OFDA

the value is expressed in degrees per millimetre (deg/mm) fibre length

the correlation between staple crimp frequency and fibre curvature is hightherefore low staple crimp frequency wools have low fibre curvature while high staplecrimp frequency wools have a high fibre curvature

fibre curvature can be measured throughout processing in the raw wool top roving yarnand even the fabric whereas it is impossible to measure staple crimp frequency past thegreasy wool stage! "his ma#es fibre curvature a potentially more useful measurementthan crimp frequency

curvature could be used as a specification for wool throughout the processing pipelinefrom farm to fabric! Diameter is the only other measurement which can also be used fromfarm to fabric

the variation in curvature or standard deviation of curvature has been related to crimpdefinition or the degree of character or boldness in the staple crimp pattern

at a certain level of curvature a high standard deviation would indicate a staple with poorcharacter while a low standard deviation would indicate a staple with good character

Measuring Fibre Curvature

the diagram shows how the curvature of a fibre snippet is measured! "he angle Arepresents the amount the fibre turns in degrees from point $ to point %!"heOFDAmeasures a &''m section of the fibre snippet and multiplies this value by toconvert the degrees per &''m to degrees per millimetre (deg/mm)! All measuredsnippets are averaged to give the mean fibre curvature! "he standard deviation orvariation in fibre curvature is also calculated

"heOFDAis able to measure fibre curvature at the same time as it measures themeanfibre diameterand variation in fibre diameter! "herefore curvature can be easilymeasured on samples sent to your OFDAfleece testing laboratory for fibre diametertesting

Fibre Curvature Data on the OFDAHistogram

"he fibre curvature data measured by the OFDA is presented at the top of thehistogram!"he following example is used in describing the data*

Curve=74.6[57]deg/mm

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"his is the mean fibre curvature and standard deviation of curvature in brac#ets!

Curve Number=2647

"his is the number of fibre snippets measured for curvature! "his is less than thesample si+e set for measuring fibre diameter due to the fact that some fibres in thesample overlap in theOFDAslide and hence cannot be measured for fibre curvature!

"he above was reproduced with the permission of ,iverina Fleece "esting -ervices.000!

Qu es la fbra de curvatura?

curvatura media de fbra es la curvatura media de ragmentos de fbra

medida por la OFDA

el valor se expresa en grados por milmetro ( mm grados! longitud de la

fbra

la correlaci"n entre la recuencia de engarce de grapas # la curvatura de la

fbra es alto

$or lo tanto% ba&o la grapa de engarce lanas recuencia tienen poca

curvatura de la fbra% mientras 'ue la alta recuencia de grapas engarado

lanas tener una curvatura alta en fbra

curvatura de la fbra se puede medir a travs de procesamiento% en la lana

en bruto% superior% mec)a% )ilo e incluso la tela% mientras 'ue es imposible

medir la recuencia de grapas engarado m*s all* de la etapa de lana sucia+

,sto )ace 'ue la fbra curvatura una medida potencialmente m*s -til 'ue la

recuencia de engarado

curvatura podra ser utiliado como una especifcaci"n para la lana a lo

largo de la canaliaci"n de procesamiento de la gran&a a la tela+ ,l di*metro

es la -nica otra medida 'ue tambin se puede utiliar desde la gran&a )asta

la tela

la variaci"n de la curvatura o desviaci"n est*ndar de curvatura se )a

relacionado con engarce defnici"n o el grado de car*cter o confana en el

elemento b*sico de engarce patr"n

en un cierto nivel de curvatura de una desviaci"n est*ndar de alta indicara

una grapa con mal car*cter% mientras 'ue una desviaci"n est*ndar ba&a

indicara un elemento b*sico con buen car*cter

.a medici"n de la curvatura de la fbra

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,l diagrama muestra c"mo se mide la curvatura de un ragmento de fbra+

,l *ngulo A representa la cantidad de la fbra se convierte en grados desde

el punto / al punto 0+ .a OFDA mide una secci"n 1223m del ragmento de

ibra # se multiplica este valor por 4 para convertir los grados por 1223m a

grados por milmetro (grados mm!+ 5odos los ragmentos medidos se

promedian para dar la curvatura media de las fbras+ .a desviaci"n est*ndaro la variaci"n en la curvatura de la fbra tambin se calcula

,l OFDA es capa de medir la curvatura de la fbra al mismo tiempo 'ue

mide el di*metro medio de fbra # la variaci"n en di*metro de la fbra+ $or lo

tanto% la curvatura se puede medir *cilmente en las muestras enviadas al

laboratorio de pruebas para las pruebas de vell"n OFDA di*metro de la fbra

Fibra de datos de curvatura en la OFDA 6istograma

.os datos de fbra de curvatura medidos por la OFDA se presenta en la parte

superior del )istograma+

,l siguiente e&emplo se utilia en la descripci"n de los datos7

0urva 8 9:%;