GB/T 21988-2008Plastics -- Vinyl chloride homopolymer and copolymer resins -- Sieve analysis in water (English PDF)

Foreword

This revised standard adopts ISO 1624:2001 "Plastics - Vinyl chloride homopolymer and copolymer resins in water sieve analysis" (English Version) (2007 February 27 confirmed).

This standard is based on ISO 1624. redraft 2001 (E), and its main technical differences are as follows.

--- Increase the types of wetting agents (ISO 1624:2001 Chapter 5, Chapter 5 of this standard);

--- Modify the weighing accuracy requirements (ISO 1624:2001 Chapter 7, Chapter 7 of this standard);

--- Increase the filtering funnel or filtration crucible drying time (this standard 7.3.1);

--- Modify the formula of sieve residue (ISO 1624:2001 Chapter 8, Chapter 8 of this standard).

For ease of use, this standard made the following editorial changes.

a) "this International Standard" be replaced by "this standard";

b) use a decimal point instead of a decimal comma ",". ",";

c) Remove the preface to the international standards.

This standard replaces GB/T 13453.1-1992 "vinyl chloride homopolymer and copolymer resins - Sieve analysis in water method." this standard and the former version of the standard main technical differences.

--- Modify the standard English name;

--- Modify the scope of the regulations (1992 edition Chapter 1, Chapter 1 edition);

--- Increased (Chapter 2 edition) chapter "normative references";

--- Increased (Chapter 3 edition) chapter "Terms and Definitions";

--- Modify the balance requirements (1992 version 4.2, this version 6.2);

--- Modify the oven requirements (1992 version 4.3, this version 6.3);

--- Modify the drying temperature requirements (Chapter 5, 1992 edition, Chapter 7);

--- Added "precision" chapter (Chapter 9 edition).

The standard proposed by China Petroleum and Chemical Industry Association.

This standard by the National Standardization Technical Committee of plastic PVC resin product Club (SAC/TC15/SC7) centralized.

This standard was drafted. Jinxi Chemical Industry Research Institute.

1 Scope

This standard provides the water for sieve analysis of vinyl chloride homopolymer and copolymer resins of sieve residue method for the determination. Control of these features help to ensure Consistent with the predicted feed processing performance.

This standard applies to vinyl chloride homopolymer and copolymer resins, particularly the determination of sieve residue resin emulsion and micro-suspension PVC.

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 6005 Test sieves - Metal wire cloth, perforated plate and basic dimensions electroformed sheet mesh (GB/T 6005-1997, ISO 565:1990, NEQ)

3 Terms and Definitions

After the screening test resin remaining on the sieve, expressed as a percentage by mass.

Principle 4

Use standard aperture sieve that sieved sample under water.

Note. Due to the presence of static dry sieving method, the results under the water than dry sieve sift get more real. The process is particularly applicable to emulsion resin.

5 Reagents

Wetting agents, e.g., (5-10)% solution of sodium alkylsulfonate, 1% of sodium dodecyl sulfate and the like.

6 Instruments

6.1 pairs of screen group, diameter (200 ~ 300) mm, high (30 ~ 50) mm, 0.063mm sieve aperture and 0.250mm, and equipped with deflector to avoid loss of sample sputtering (see Fig. 1).

Note. If the following conditions are met, then the other aperture sieve can also be used.

--- Have used the predetermined sieve;

--- The new screen group selected from GB/T 6005 is provided in the series.

6.2 Balance, accurate to 0.01g, the scope and size of the group and the screen should meet the screening requirements of the resin (see 7.1b).

6.3 oven can be controlled at (110 ± 2) °C.

6.4 filter interposed between the tap and the instrument used to remove impurities in the water.

6.5 Sprinklers, one or preferably a plurality of screens designed to.

--- Sieve and thoroughly spray the entire surface of the inner wall of the sieve;

--- Jet agitation to the resin, such as the injection hole is inclined at an angle to the screen;

--- Oblique flow should prevent the formation of the flow path in the resin. For example, make a direction intersecting jet;

--- Sprayed water to flow through the screen immediately, and screened in the screening process resin medium should not have a lot of water accumulation.