GB/T 8289-2023Natural rubber latex concentrate - Centrifuged or creamed, ammonia-preserved types - Specifications (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1.Structure and Drafting Rules of Standardization Documents"

Drafting.

This document replaces GB/T 8289-2016 "Specifications for centrifuged or creamed latex preserved with ammonia in concentrated natural rubber latex" and is consistent with GB/T 8289-

Compared with.2016, in addition to structural adjustments and editorial changes, the main technical differences are as follows.

a) Added the applicable limits of the document (see Chapter 1);

b) The normative reference documents have been changed (see Table 1, Table 1 of the.2016 version);

c) The clot content (mass fraction, maximum) is changed from 0.03% to 0.02% (see Table 1,.2016 version of Table 1);

d) The residue content (mass fraction, maximum) is changed from 0.10% to 0.06% (see Table 1, Table 1 of the.2016 version).

This document has been modified to adopt ISO.2004.2017 "Specifications for Ammonia Preservation of Concentrated Natural Rubber Latex Centrifuged or Creamed".

The technical differences between this document and ISO.2004.2017 and their reasons are as follows.

---Added the applicable limits of the document (see Chapter 1) to comply with the requirements of GB/T 1.1-2020;

---Replaced ISO 123 (see Chapter 5) with GB/T 8290 to adapt to my country's requirements for concentrated natural rubber latex sampling;

---Replaced ISO 706 (see Table 1) with GB/T 8291 to adapt to my country's requirements for determining clot content;

---Replaced ISO 506 (see Table 1) with GB/T 8292 to adapt to my country's requirements for measuring volatile fatty acid values;

---Replaced ISO.2005 (see Table 1) with GB/T 8293 to adapt to my country's requirements for determining residue content;

---Replaced ISO 8053 (see Table 1) with GB/T 8295 to adapt to my country's requirements for measuring copper content;

---Replaced ISO 7780 (see Table 1) with GB/T 8296 to adapt to my country's requirements for the determination of manganese content;

---Replaced ISO 127 (see Table 1) with GB/T 8297 to adapt to my country's requirements for determining potassium hydroxide value;

---Replaced ISO 506 (see Table 1) with GB/T 8298 to adapt to my country's requirements for the determination of total solid content;

---Replaced ISO 126 (see Table 1) with GB/T 8299 to adapt to my country's requirements for determining dry glue content;

---Replaced ISO 125 (see Table 1) with GB/T 8300 to adapt to my country's requirements for measuring alkalinity;

---Replaced ISO 35 (see Table 1) with GB/T 8301 to adapt to my country's requirements for measuring mechanical stability.

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1 Scope

This document specifies the specifications for concentrated natural rubber latex prepared entirely or partially with ammonia and produced by centrifugation or paste.

This document applies to concentrated natural rubber latex produced by the centrifugation or creaming method of Brazilian Hevea tree latex.

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the dated quotations

For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to

this document.

GB/T 8290 Latex Sampling (GB/T 8290-2021, ISO 123.2001, MOD)

GB/T 8291 Determination of latex clot content (sieve residue) (GB/T 8291-2023, ISO 706.2004, MOD)

GB/T 8292 Determination of volatile fatty acid value of concentrated natural rubber latex (GB/T 8292-2008, ISO 506.1992, IDT)

GB/T 8293 Determination of residue content of concentrated natural latex (GB/T 8293-2019, ISO.2005.2014, MOD)

GB/T 8295 Photometric method for determination of copper content in natural rubber and latex (GB/T 8295-2008, ISO 8053.1995,

MOD)

GB/T 8296 Determination of manganese content in natural raw rubber and latex - Sodium periodate photometry (GB/T 8296-2008, ISO 7780.

1998,MOD)

GB/T 8297 Determination of potassium hydroxide (KOH) value of concentrated natural latex (GB/T 8297-2023, ISO 127.2018,

MOD)

GB/T 8298 Determination of total solid content of latex (GB/T 8298-2017, ISO 124.2014, MOD)

GB/T 8299 Determination of dry rubber content of concentrated natural rubber latex (GB/T 8299-2008, ISO 126.2005, IDT)

GB/T 8300 Determination of alkalinity of concentrated natural rubber latex (GB/T 8300-2016, ISO 125.2011, IDT)

GB/T 8301 Determination of mechanical stability of concentrated natural latex (GB/T 8301-2008, ISO 35.2004, IDT)

3 Terms and definitions

The following terms and definitions apply to this document.

3.1

Concentrated natural rubber latex containing ammonia and/or other preservatives.

3.2

Centrifugally concentrated natural rubber latex (3.1) preserved only with ammonia after concentration, with an alkalinity of at least 0.60% (mass fraction).

3.3

Centrifugally concentrated natural latex (3.1) preserved with ammonia and other preservatives after concentration, with an alkalinity not greater than 0.29% (mass fraction).