6 ottobre 2017

Cashmere, improvisation is forbidden

What skills you should require for the analysis of raw fibers and artifacts

Mongolia, grazing of sheeps. Photo by Primo Brachi

Cashmere is a precious and complex fiber to be evaluated, especially when it is mixed with wool of different origin and other special protein fibers.
The laboratory’s specific skills are a key requirement if you want to be sure of the analysis’s reliability on cashmere. Factors such as the analyst’s experience and intuition play a key role, as well as the knowledge of the production sites and the work of collecting and selecting fibers, the study of the morphological changes due to the animals selection and crossing, the continuous confrontation with other experts in this field.

Brachi Testing Services’ authorityis based on exactly these elements and is the result of over 40 years of work in the sector. Our laboratory today is an absolute benchmark for cashmere testing, as evidenced by the numerous international accreditations and recognition by organizations that have always been involved in the protection of this fiber.
Our latest generation instrumentation is constantly updated to the latest innovations and include, besides optical microscopy equipments, a special electronic scanning microscope (SEM) whereby composite tests according to ISO 17751 Part 2 : 2016 can be performed.

Brachi Testing Services is accredited by ACCREDIA – in accordance with ISO 17025 standard – for numerous tests, listed in the second part of this article.
Moreover, for over 20 years it is accredited by INTERWOLLABS - International Association of Wool Textile Laboratories for fineness tests on fibers through airflow, projection microscope and OFDA (Optical Fiber Diameter Analyzer).
Accredited tests include the determination of qualitative and quantitative composition of wool, cashmere, yak and their mixture through proteomic method, by high pressure liquid chromatography with a mass detector.
Brachi directly contributes to this research field, so as to developing an objective method that uses, in addition to the microscope, an instrumental chemical technique. Our laboratory, in fact, collaborates with the Working Group 22 of ISO – International Organization for Standardization to turn this method into an international standard.

With regard to the ISO DIS 20418-1 proteomic method for quantification of cashmere, wool and yak, we add that the comments and requests for clarification sent to ISO by various Member States have slowed the conversion of the draft into standard.
At the ISO/TC38/WG22 meeting held last September at the CITEVE - Technological Center for Textile and Clothing Industries of Portugal in Vila Nova de Famalicão, Portugal, the assembly agreed on the method’s advancement to the Final Draft phase (FDIS). The publication is scheduled for the first months of 2018, after a final step for editorial comments.

Cashmere quality assessment requires uncommon skills. Make sure that a product is entirely made of cashmere, for example, may not be enough, as the prices of this fiber fluctuate from a few tens of euros per kilogram to over one hundred.
A true jewel of our laboratory is in this sense the accreditation according to the Chinese SB/T 10629 technical standard, which classifies cashmere - whether it be staple or manufactured - in Quality Degrees from Premium Grade to Grade I, Grade II, Grade III and Grade IV.
Brachi Testing Services is one of the few laboratories in the world accredited to establish the products placement in one of these categories, assessing requirements such as purity, length, finesse and degree of fiber cleansing, as well as the presence of damaged or discolored fibers and of ordinary fibers.

TESTS ON CASHMERE ACCREDITED BY ACCREDIA
- Determination of wool fibers diameters by projection microscope: UNI EN ISO 137 : 2016 ;  UNI 5423 : 1964;  GB/T 10685 : 2007
- Determination of the diameter and percentage of medullated fibers in wool and other animal fibers by projection microscope: IWTO 8 : 2011
- Determination of the diameter of delaine wool fibers (core samples) by air-flow: IWTO 28 : 2013
- Determination of the diameter of wool washed in tops, carded ribbons, by air-flow: IWTO 6 : 2013; ASTM D 1282 : 2005/2009
- Determination of the average diameter and distribution of fiber diameter by Optical Fiber Diamater Analyzer (OFDA): IWTO 47 : 2013; ASTM D 6500 : 00 / 2012e1; GB/T 21030 : 2007
- Determination of the average length and the length distribution of fibers by the measurement of single fibers: ISO 6989: 1981 Method A
- Determination of the quantitative composition of mixtures consisting of cashmere, special animal fibers and wool: GB / T 16988: 2013
- Qualitative and quantitative analysis of some animal fibers, wool, cashmere and yak and their mixtures by high-pressure liquid chromatography LC-ESI-MS: proteomic method MI-MI016 : 2016 according to ISO DIS 20418 part 1
- Cashmere: determination of the average fiber length with hand platoon method: GB/T 18267 : 2013 part 6.2.3.5
- Cashmere: determination of impurities and the content of ordinary hairs: GB/T 18267: 2013 part 7.2.3.1
- Determination of the content of fatty oils and vegetable residues in washed wool: GB/T 6977 : 1986
- Technical requirements for the classification of the quality of cashmere fibers and their products: SB/T 10629 : 2011

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