GB/T 6030-2006Rubber - Assessment of carbon black and carbon black /Silica dispersion - Rapid comparative methods (English PDF)

1 Scope

This standard specifies qualitative visual methods for the rapid and comparative assessment of the degree of macrodispersion of carbon black and carbon black/silica in rubber. Ratings are made relative to a set of standard reference photographs, and the results are expressed on a numerical scale from 1 to 10.

In addition, a method is given for rating the presence of large agglomerates on a numerical scale (ratings 1 to 10).

2 Normative references

The following normative documents contain provisions which, through reference in this standard, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding any corrigendum), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the latest editions of the standards indicated below. For undated references, the latest edition applies.

GB/T 6039 Rubber physical tests and chemical tests -Terms (GB/T 6039-1997, eqv ISO 1382:1996)

3 Terms and definitions

For the purposes of this standard, the terms and definitions given in GB/T 6039 apply.

4 Principles

The carbon black or carbon black/silica filled rubber compound is cut to expose a fresh surface for examination under magnification.

Five methods are described:

Method A: Visual microscopic or photographic microscopic inspection with ×30 magnification (for carbon black).

Method B: Split-field microscopic inspection with ×30 magnification (for carbon black).

Method C: Visual microscopic or photographic microscopic inspection with ×100 magnification (for carbon black or carbon black/silica).

Method D: Split-field microscopic inspection with ×100 magnification (for carbon black or carbon black/silica).

Method E: Large-agglomerate count with ×100 magnification (for carbon black).

In methods A to D, the dispersion level is compared with a series of ten hard-copy or electronically stored standard references under oblique illumination at 30° and with an effective magnification of ×30 for methods A and B (see Annex A) and ×100 for methods C and D (see Annexes B to E), and then rated numerically from 10 (excellent) to 1 (very poor).