MỘT SỐ THUẬT NGỮ DÙNG TRONG KÉO SỢI XƠ NGẮN (Anh-Anh)

Bài viết này giới thiệu một số thuật ngữ hay dùng trong kéo sợi xơ ngắn bằng tiếng Anh

Bale – pressed and bound cotton fibre

Bale Lay-Down – Cotton bales set in a row for the start of mill processing. The start of mill processing is called ‘opening’.

Carded Yarn – Yarn spun from carded and drawn sliver. Carding and drawing are steps in the mill used to clean and parallelise fibre in preparation for yarn production. Carded yarn is less expensive than ‘combed’ yarn but is inferior in terms of yarn quality because short fibres and neps are still present.

Colour – Colour is a primary indicator of grade. Discolouration is due to range of influences including trash and dust content, rain damage, insect secretions, UV radiation, heat and microbial decay. Colour in cotton is defined in terms of its reflectance (Rd) and yellowness (+b), which are measured by a photoelectric cell.

Combed Yarn – Sliver from the card is combed to remove short fibre and nep and to make fibres parallel to the sliver axis. Combed sliver translates into more uniform and stronger yarn.

Contamination – The International Textile Manufacturers Federation (ITMF) identifies 18 sources of contamination in its bi-annual survey of spinning mills.

Cotton wax – Exists as a layer on the cotton fibre surface and is composed of natural waxes, fats and pectins. The wax layer is a water resistant coating that protects and lubricates the fibre during mechanical processing.

Dyeing Ability – A qualitative description to describe how evenly or unevenly a cotton dye is taken up by yarn or fabric.

Extension – Also called elongation, this value is the percent extension (elongation) of a fibre bundle before it breaks.

Fineness – Cotton fineness is described in terms of linear density or weight per unit length of fibre, the unit for which is usually milligrams per kilometre (mtex).

Ginning – The separation of fibre (lint) from cotton seed.

Grade – Historically grade is a subjective interpretation of fibre colour, preparation and trash content against ‘official’ standards.

Length Uniformity (UNI) – This measurement is expressed either as the uniformity index or uniformity ratio. Both terms are ratios of measurements from the fibrogram, where uniformity index refers to the ratio between the mean length and the upper half-mean length and the uniformity ratio refers to the ratio of the 50% span length to the 2.5% span length

Maturity – The cotton fibre is single elongated plant cell and maturity refers to its degree of cell wall thickening.

Micronaire (MIC) – Airflow measurement based on the pressure difference obtained when air is passed through an accurately weighed plug of cotton fibres. Originally calibrated to give fineness (in micrograms per inch) the method actually measures specific surface area (surface area per unit mass) and therefore reflects a combination of the sample’s fineness and maturity.

Nep (NEP) – Neps are fibre entanglements that have a hard central knot or nucleus that is detectable. There are a variety of test instruments and methods to measure nep content although the Uster Advanced Fiber Information System (AFIS) nep module has the status of being the only method with a recognised standard procedure.

Short Fibre Content (SFC) – The most common definition of SFC is the proportion by mass of fibre shorter than one half inch. Short fibre content is not measured directly by any instrument employed in high volume instrument (HVI) lines. Instead SFC or short fibre index (SFI) is estimated indirectly using the 2.5% span length and 50% span length or the 2.5% and uniformity index

Spinning Ability – There is a wide range of indices used to measure spinning ability. The most commonly applied index is the number of (yarn) ends down per thousand spindle hours.

Staple Length – This measurement is usually based on a photoelectric scan of fibres protruding from a ‘Fibrosampler’ comb. The fibres protruding from a comb make up the figrogram from which the upper half-mean length or 2.5% span length are measured. Both of these measures correspond closely with the physical classer’s staple or modal length of the sample.

Stickiness – A reference to when cotton is made sticky from cotton plant and/or insect exudates. Sticky cotton does not process well especially through the card and drawframe. Stickiness can be objectively measured although none of the current methods determines the source of the sticky exudate. Exudate from insects such as whitefly and aphids is the cause of most ‘stickiness’ problems in mills.

Strength (STR) – The strength of cotton fibres is usually defined as the breaking force required for a bundle of fibres of a given weight; the test value being a measure of breaking stress or tenacity, expressed in terms of grams per tex (g/tex).

Trash – Any material other than cotton fibre in a sample is referred to as trash or non-lint content. Trash in cotton usually consists of leaf and other parts of the cotton plant. Trash can be measured in number of ways although the most common method, in HVI testing, involves measuring the area of trash (leaf) in a compressed bale sample image using image analysis software.

Yarn Count (Ne) – Yarn count is a measure of yarn linear density or mass per unit length. Cotton spinners use English cotton count system or Ne to measure yarn linear density. Ne is equivalent to the number of 840 yard lengths (wraps) in one pound of yarn. The metric unit grams per kilometre (or tex) is obtained by dividing 590.5 by the Ne yarn count.

Còn đây là một số thuật ngữ viết tắt

AFIS	Advanced Fiber Information System
ASTM	American Society of Testing and Materials
C.S.P	Count Strength Product
CSITC	Commercial Standardization of Instrument Testing of Cotton
CV	Coefficient of Variation
ELS	Extra long staple
HVI	High Volume Instrumentation
HVI	High Volume Instrument
ICAC	International Cotton Advisory Committee
NLS	near-long staple
NRE	nep removal efficiency
S.D	Standard Deviation
SCF	seed-coat fragment
SFC	short fiber content
SFCn	short fiber content by number
SFCw	short fiber content by weight
UHM	upper-half mean
UQL	upper-quartile length
USDA	United States Department of Agriculture
ICA	International Cotton Association
ICAC	International Cotton Advisory Committee
ICM	Integrated crop management
IFCP	International Forum for Cotton Promotion
IFOAM	International Federation of Organic Agriculture Movements
IIC	International Institute for Cotton
ISO	International Organization for Standardization
ITMF	International Textile Manufacturers Federation
JOCA	Japan Organic Cotton Association
LS	Long staple
LUI	Length uniformity index
ML	Mean length
MMF	Man-made fibre
NYCE	New York Cotton Exchange
OE	Open-end
SFC	Short fibre content
SG	Saw-ginned
SITC	Standard Instrument Testing
SLM	Strict low middling
UHML	Upper half mean length