GB/T 8086-2019Rubber, raw natural - Determination of dirt content (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB/T 8086-2008 "Determination of the content of natural raw rubber impurities". Compared with GB/T 8086-2008, the main technology

The changes are as follows.

--- Change GB/T 6038 and ISO /T R9272 in the normative references in Chapter 2 to references (see References,.2008)

Chapter 2 of the edition);

--- Added warnings (see Chapter 3);

--- The boiling range of petroleum solvent was changed from "155 °C ~ 196 °C" to "155 °C ~ 198 °C" (see 3.2, 3.2 of.2008 edition);

--- Place an optional supplemental description of the screen in the general requirements for the screen (see 4.5, 4.5.5 of the.2008 edition);

--- Increased the immersion of the sieve in petroleum solvent as a means of reducing rubber blockage (see 5.4.3);

--- Revised the expression formula for the impurity content calculation (see Chapter 6, Chapter 6 of the.2008 edition);

--- Change the precision clause to informative Appendix B "Precision" and update the precision data (see Chapter 7 and Appendix)

B, Chapter 7 of the.2008 edition).

This standard uses the redrafting method to modify the use of ISO 249.2016 "Determination of the content of natural raw rubber impurities."

The technical differences between this standard and ISO 249.2016 and their reasons are as follows.

--- Regarding the normative reference documents, this standard has made technical adjustments to adapt to the technical conditions of China. Adjustment

The situation is reflected in Chapter 2, "Regulatory Citations", and the specific adjustments are as follows.

* Replace ISO 565 with GB/T 6005 modified to international standards (see 4.5);

* Replace ISO 1795 with GB/T 15340 equivalent to the international standard (see 5.1.1).

--- The heater has been added with an adjustable closed electric furnace (see 4.4).

--- Change the nominal diameter of the metal mesh "44µm ~ 45µm (325 mesh)" to "45µm" in order to comply with China's regulations (see 4.5,

4.5.4, ISO 249. 4.5, 4.5.4, 4.5.5 of.2016).

--- Place an optional supplemental description of the screen in the general requirements for the screen (see 4.5, ISO 249.2016, 4.5.5).

--- Increased the requirement to use glass rods for agitation so that there are more ways to prevent overheating (see 5.3.3, 5.3.4, ISO 249.2016)

5.3.3, 5.3.4).

--- Increased the method of storing the sieve in petroleum solvent to reduce the blockage of the rubber (see 5.4.3).

--- Modified the formula for calculating the impurity content for ease of use (see Chapter 6, ISO 249.2016, Chapter 6).

--- Added "Guidelines for the use of precision results in Appendix A" (see Chapter 7, ISO 249.2016, Chapter 7).

This standard was proposed by the China Petroleum and Chemical Industry Federation.

This standard is under the jurisdiction of the National Rubber and Rubber Products Standardization Technical Committee (SAC/TC35).

This standard was drafted. Agricultural Products Processing Institute of China Academy of Tropical Agricultural Sciences, Shanghai Entry-Exit Inspection and Quarantine Bureau, industrial products and raw materials

Testing Technology Center, Hainan Natural Rubber Quality Inspection Station, Yunnan Natural Rubber and Coffee Product Quality Supervision and Inspection Station, National Rubber and

Latex Products Quality Supervision and Inspection Center.

1 Scope

This standard specifies the method for determining the content of natural raw rubber impurities.

This standard applies to the determination of impurities contained in natural rubber, not applicable to the determination of surface contamination impurities.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article.

Pieces. For undated references, the latest edition (including all amendments) applies to this document.

Basic dimensions of GB/T 6005 test sieve wire mesh, perforated plate and electroformed sheet mesh (GB/T 6005-

2008, ISO 565.1990, MOD)

GB/T 15340 Natural and synthetic raw rubber sampling and its sample preparation method (GB/T 15340-2008, ISO 1795.2000, IDT)

3 reagents

Warnings - All identified health and safety precautions should be implemented during this analysis, with particular emphasis on the use

Safe operation of flammable solvents. The solvent used should be anhydrous and free of impurities.

Confirmed analytical reagents should be used whenever possible during the analysis.