F20: Fluidity Of Cotton Fibres

AWTA TEST CODE

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F20

OTHER NAMES

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TEST METHODS

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AATCC 82
AS 2001.3.6
AWTA 57

IMAGES

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Close-up of Viscometers

Viscometers in Water-Bath Measuring Fluidity

APPLICATION

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This method is applicable to cotton, cupro, modal, viscose or deacetylated acetate fibre.

PRINCIPLE

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The rate of flow from a standard capillary viscometer of a standard solution of the fibre in cuprammonium fluidity is calculated by means of a formula containing two constants obtained by calibrating the viscometer with a liquid of known kinematic viscosity.

SAMPLES REQUIRED FOR TESTING

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Approximately 0.1g of cotton or 0.4g of man-made fibre is required for each test specimen. Specimens representative of the lot (or area) of material should be selected. 1m2 of fabric is usually sufficient for all tests. Fluidity tests, when conducted during laundry trials, are usually carried out on WFK Tensile Laundry Swatches (with green threads).

INTERPRETATION

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Fluidity may be expressed as:

(i) arbitrary units of cuprammonium fluidity or

(ii) reciprocal pascal seconds (Pa.S)-1

Fluidity

Arb Units

(Pa.S)-1

Raw Cotton

1.5 to 2.5

15 to 25

Processed Cotton (e.g. Bleached)

<5

<50

Chemical Damage in Laundering

Requirements After 50 Washes

Change in Fluidity (F)

% Damage Uc = 0.165 F

Arbitrary

(Pa.S)^-1

F in (Pa.S)^-1

Food-related wash loads

Less than 10

Less than 100

17

Non-food related wash loads

Less than 5

Less than 50

8

SERVICE TARGET

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10 days.

COST

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See Fee List.