Search result: GB/T 17821-2025 (GB/T 17821-2008 Older version)
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| GB/T 17821-2025 | English | 219 |
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Rubber latex - Determination of density between 5 ℃ and 40 ℃
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GB/T 17821-2025
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| GB/T 17821-2008 | English | 134 |
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Rubber latex -- Determination of density between 5 Celsius and 40 Celsius
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GB/T 17821-2008
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| GB/T 17821-1999 | English | 279 |
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Rubber latex--Determination of density between5 Celsius and40 Celsius
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GB/T 17821-1999
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| Standard ID | GB/T 17821-2025 (GB/T17821-2025) | | Description (Translated English) | Rubber latex - Determination of density between 5 �� and 40 �� | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | B72 | | Classification of International Standard | 83.040.10 | | Word Count Estimation | 10,144 | | Date of Issue | 2025-04-25 | | Date of Implementation | 2025-11-01 | | Older Standard (superseded by this standard) | GB/T 17821-2008 | | Issuing agency(ies) | State Administration for Market Regulation, National Standardization Administration |
GB/T 17821-2025.Determination of density of latex at 5℃ to 40℃
ICS 83.040.10
CCSB72
National Standard of the People's Republic of China
Replace GB/T 17821-2008
Determination of density of latex at 5℃ to 40℃
(ISO 705.2015, MOD)
Released on 2025-04-25
2025-11-01 Implementation
State Administration for Market Regulation
The National Standardization Administration issued
Table of contents
Preface III
Introduction IV
1 Range 1
2 Normative references 1
3 Terms and Definitions 1
4 Principle 1
5 Instruments 1
6 Sampling 2
7 Test Step 2
8 Results show 3
9 Test Report 4
References 5
Preface
This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1.Structure and drafting rules for standardization documents"
Drafting.
This document replaces GB/T 17821-2008 "Determination of density of latex at 5℃ to 40℃". Compared with GB/T 17821-2008,
In addition to structural adjustments and editorial changes, the main technical changes are as follows.
a) The scope has been changed (see Chapter 1, Chapter 1 of the.2008 edition);
b) the term “concentrated natural rubber latex” has been deleted (see 3.2 of the.2008 edition);
c) Added a chapter on “Principles” (see Chapter 4);
d) The sampling procedure has been changed (see Chapter 6, Chapter 5 of the.2008 edition);
e) Added provisions on temperature correction (see 7.2);
f) Added the recommendation on determination at standard temperature (see 7.4).
This document is modified to adopt ISO 705.2015 "Determination of density of latex at 5℃ to 40℃".
This document has the following structural adjustments compared to ISO 705.2015.
--- Added the introduction and placed the content of ISO 705.2015 Chapter 1 that belongs to the purpose statement.
The technical differences between this document and ISO 705.2015 and their reasons are as follows.
--- Changed the scope (see Chapter 1, Chapter 1 of ISO 705.2015) to adapt to the provisions of GB/T 1.1-2020;
--- The term "concentrated natural rubber latex" (see 3.2 of ISO 705.2015) has been deleted to adapt to the modification of the scope;
--- Changed the principle (see Chapter 4, Chapter 4 of ISO 705.2015) to provide a reasonable explanation of the principle;
--- ISO 123 (see Chapter 6) has been replaced by the normative reference GB/T 8290 to adapt to the provisions of my country on latex sampling;
--- Added provisions on temperature correction (see 7.2) to adapt to my country's technical conditions and increase operability;
--- Change "should be as close as possible to the temperature of latex" to "preferably as close as possible to the temperature of latex" (see 7.3, ISO 705.2015
7.3), to avoid contradictions;
--- Added recommendations on determining the density of latex samples at standard temperature (see 7.4) to better meet the test requirements.
Please note that some of the contents of this document may involve patents. The issuing organization of this document does not assume the responsibility for identifying patents.
This document was proposed by the China Petroleum and Chemical Industry Federation.
This document is under the jurisdiction of the National Technical Committee on Rubber and Rubber Products (SAC/TC35).
This document was drafted by. Agricultural Product Processing Research Institute of Chinese Academy of Tropical Agricultural Sciences, Yunnan Natural Rubber and Coffee Product Quality Supervision and Inspection
Testing Station, Chinese Academy of Tropical Agricultural Sciences.
The main drafters of this document are. Luo Zirong, Tao Jinlong, Xu Yongyuan, Li Yimin, Pu Ju, Li Jihua, Li Fengwei, Li Bowei, Zhang Beilong, Lu Guang,
Li Tao.
This document was first issued in.1999, revised for the first time in.2008, and this is the second revision.
introduction
This document is intended for use in calculating the density of a measured volume of glue where direct weighing or controlled laboratory temperature is not possible.
Formulated for the quality of milk.
Determination of density of latex at 5℃ to 40℃
Warning. People who use this document need to have practical experience in formal laboratory work. This document does not address all possible safety issues.
The user is responsible for taking appropriate safety and health measures and ensuring that the conditions stipulated by relevant national laws and regulations are met.
1 Scope
This document describes the principle of determining the density of latex at a temperature of 5°C to 40°C and specifies the measuring instrument, sampling, test procedures,
Expression of results and contents of test report.
This document is applicable to various natural rubber latexes as well as synthetic latexes, compounded latexes and pre-vulcanized latexes, and also to rubber aqueous dispersions.
The temperature corrections listed in 8.2 of this document may not always apply to the above latexes.
2 Normative references
The contents of the following documents constitute essential clauses of this document through normative references in this document.
For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to
This document.
GB/T 8290 Latex Sampling (GB/T 8290-2021, ISO 123.2001, MOD)
3 Terms and definitions
The following terms and definitions apply to this document.
3.1
density
The mass divided by the volume at a specified temperature.
Note. Density is expressed in megagrams per cubic meter (Mg/m3).
4 Principle
Fill a density bottle with latex sample and calculate the density of the latex sample from the mass of latex in the density bottle and the known volume of the density bottle.
5 Instruments
5.1 Density bottle (specific gravity bottle)
The capacity is 50 mL, with a ground glass stopper, a capillary passing through the stopper, and a ground glass cover (see Figure 1).
......
GB/T 17821-2008
Rubber latex. Determination of density between 5 Celsius and 40 Celsius
ICS 83.060
B72
National Standards of People's Republic of China
GB/T 17821-2008/ISO 705.1994
Replacing GB/T 17821-1999
Determination of latex 5 ℃ to 40 ℃ Density
(ISO 705.1994, IDT)
Posted 2008-05-15
2008-11-01 implementation
Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China
Standardization Administration of China released
Foreword
This standard is identical with ISO 705.1994 "latex 5 ℃ to 40 ℃ Density Determination" (in English).
In Chapter 2, normative references cited GB/T 8290, the Standard and ISO 705.1994 is not part of the respective technical
difference.
For ease of use, the editorial changes made the following standard.
--- "This International Standard" be replaced by "this standard";
--- Delete international standards foreword.
This standard replaces GB/T 17821-1999 "latex 5 ℃ to 40 ℃ density determination."
The main difference compared with the standard GB/T 17821-1999 is based on GB/T 1.1-2000 and GB/T 20001.4-2001 to
Seeking to GB/T 17821-1999 made editorial changes.
The standard proposed by China Petroleum and Chemical Industry Association.
This standard by the National Rubber and rubber products natural rubber Standardization Technical Committee Technical Committee (SAC/TC35/SC8)
Centralized.
This standard is drafted by. China Tropical Institute of Agro Agricultural Sciences, Ministry of Agriculture, Food Quality Supervision and Testing Center
(Zhanjiang).
The main drafters. Zhang North Long, Chen Chenghai.
This standard replaces the standards previously issued as follows.
--- GB/T 17821-1999.
GB/T 17821-2008/ISO 705.1994
Determination of latex 5 ℃ to 40 ℃ Density
Warning --- the use of this standard laboratory personnel should have regular experience. This standard does not point out all possible security issues.
Users have the responsibility to take appropriate safety and health practices and to ensure compliance with the conditions relevant national regulations.
1 Scope
This standard specifies at a temperature of 5 ℃ ~ 40 ℃ in concentrated natural rubber latex density method. This standard is not directly in order to weigh
Or can not control the temperature of the case of the use of laboratory density determination has been measured to calculate the volume of quality latex made. For measuring density
The same amount of air quantity of air contained in the latex samples to be measured and included in the volume. Therefore, before sampling the latex should be allowed to stand
At least 24h, in order to be able to remove air bubbles. Temperature should be measured density and temperature measurement by volume is the same, otherwise it should be corrected.
This standard applies to all kinds of natural rubber latex and synthetic latex, latex and with pre-vulcanization latex rubber is also applicable to an aqueous dispersion. but
7.2 temperature correction listed on these latex are not necessarily applicable.
2 Normative references
The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent
Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research
Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.
GB/T 8290 Natural rubber latex concentrate sampling (GB/T 8290-1987, eqv ISO 123. 1985)
3 Terms and Definitions
The following terms and definitions apply to this standard.
3.1
In the mass divided by the volume at standard temperature. Density expressed in grams per trillion cubic meters (Mg/m3).
3.2
Ammonia and (or) other preservatives and by a sort of concentration methods treated natural rubber latex.
4 Instrument
4.1 density bottles (pycnometer)
Capacity of 50cm3, with a ground glass stopper, plug in through a capillary tube, and is equipped with a ground glass lid (see Figure 1).
GB/T 17821-2008/ISO 705.1994
......
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