High tenacity and high modulus polyvinyl alcohol ultra-short fibre
1 Scope
This document specifies the terms and definitions, categories and identification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage for high tenacity and high modulus Polyvinyl alcohol (abbrev. HTHM PVA) ultra-short fibre. This document is applicable to HTHM PVA ultra-short fibre that takes polyvinyl alcohol resin as raw material without acetalization. Other types of PVA fibre may refer to this document as well.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 3291.1, Textiles—Terms of textile material properties and test—Part 1: Fibre and yarn
GB/T 3291.3 Textiles—Terms of textile material properties and test—Part 3: General
GB/T 4146.1 Textiles—Man-made fibres—Part 1: Generic names
GB/T 4146.3 Textiles—Man-made fibres—Part 3: Terms of inspection
GB/T 6503 Man-made fibres—Test method of moisture regain
GB/T 6504 Man-made fibre—Test method for oil content
GB/T 6529 Textiles—Standard atmosphere for conditioning and testing
GB/T 6682 Water for analytical laboratory use—Specification and test methods
GB/T 8170 Rules of rounding off for numerical values & expression and judgement of limiting values
GB/T 14334 Sampling method for man-made staple fibres
GB/T 19466.1 Plastics—Differential scanning calorimetry(DSC) —Part 1:General principles
GB/T 19466.3—2004 Plastics—Differential scanning calorimetry(DSC) —Part 3:Determination of temperature and enthalpy of melting and cyrstallization
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 3291.1, GB/T 3291.3, GB/T 4146.1, GB/T 4146.3 and the following apply.
3.1
High tenacity and high modulus Polyvinyl ultra-short fibre fibre which is produced by spinning process with Polyvinyl alcohol(PVA) resin as raw material with cut
length less than 20 mm, breaking tenacity no less than 10 cN/dtex and initial modulus no less than 220 cN/dtex
3.2
dispersity
state shown in single fibre status after fibres dispersing in water
3.3
reduced quantity in hot water
hot water reduction
HWR
ratio of dried mass difference of fibres before and after soak to dried mass before soak
Note 1 to entry: It is expressed in percentage. Note 2 to entry: Fibres are soaked in hot water at 90 ℃ and stirred for 1 h.
3.4
extrapolated onset temperature
temperature corresponding to the intersection point of the extrapolated baseline and the tangent line
at the maximum slope of the curve corresponding to the beginning of the transition
[SOURCE: GB/T 19466.3—2004, 3.5]
4 Categories and identification
4.1 Product categories
According to two main performance items as breaking tenacity and initial modulus, there are four categories coded as HTM 1, HTM 2, HTM 3 and HTM 4.
4.2 Product identification
HTHM PVA ultra-short fibre is identified by its category, nominal linear density and length. The unit is decitex (dtex) for linear density and millimeter (mm) for length.
EXAMPLE HTM 1 - 2,00 dtex×5 mm
the length of the fib
5 Technical requirements
The requirements listed in Table 1 shall be met.
Table 1 —Technical requirements
