Wool fiber crimp &

its fiber properties tester equipments

Presented by :

horas magdy

presented to :

eng :nermin

What is THE Crimp?

.Crimp : is the natural wave formation found in the Huacaya fleece

Crimp : is the term given

to the natural wave that occurs in wool fibers

THE CRIMP-FINENESS RELATIONSHIP IN WOOL fiber

Grade and Crimps in Wool-:

Morphological and Chemical Structure of Wool

Bilateral Structure of a Wool Fiber

Cross-Section of a Coarse Wool Fiber

paracortex

orthocortex

Arrangement of interior cells creates fiber crimp:

There are 2 main types of cell in the cortex – orthocortex and paracortex – and each has a slightly different chemical composition.

In finer fibers, these cells are arranged in 2 distinct halves. In coarser fibers, the arrangement is less distinct. These cells create the crimp in wool. The 2 types of cell expand differently when they absorb moisture, causing

the fiber to bend. When the cells are arranged in 2 halves, there is more crimp, and the

more random arrangement in coarser fibers creates less crimp, so crimp relates directly to fiber diameter.

Frequency : is the number of times the fibre crimps (waves) per inch (CPI).

Amplitude :

is the height (deepness) of the wave. Deep crimp is said to have high amplitude.

Deep Frequency : is defined as having high amplitude.Bold Frequency : is a low frequency wave that maintains high amplitude.

IS CRIMP IMPORTANT? (WHAT DO YOU THINK)

_The crimp in wool fibers makes it soft and springy to touch.

_It also adds bulk and traps a large volume of air between the fibers, giving it good insulation properties.

Helical geometry of crimp

Testing device

OFDA 100the OFDA is the only image analysis system to be recognized with a Test Method from the IWTO

Operating Principles

The OFDA is essentially an automatic microscope set above a moving sample of fibers.

The instrument magnifies and captures images of the individual fibers using a video camera, and then identifies and measures each fiber.

The fibers and measurement points can be seen on the video screen.

The width of each identified fiber image is measured with a resolution of 1 micron whilst the combined mean diameter and standard deviation are calculated to a resolution of 0.01 micron.

OFDA's histogram data include the mean fiber diameter, standard deviation (SD), coefficient of variation (CV), prickle factor (PF) and spinning fineness.

Colour of

wool fiber

Colour property:

the normal color of wool from the improved breeds of sheep is white, but a small percentage of it may be brown, black, or grey. generally, manufacturers demand that the wools used in processing be scoured out completely white to ensure that the future color of the fabric will not be affected by the natural color of the fibers.

Type of natural colour

Testing device

Vibrochrom 400

Tester principle:

Thank you