GB/T 9751.1-2008Paints and varnishes -- Determination of viscosity using rotary viscometers -- Part 1: Cone-and-plate viscometer operated at a high rate of shear (English PDF)

Foreword

GB/T 9751 Paints and varnishes - Determination of viscosity using rotary viscometers

is divided into four parts.

-- Part 1.Cone-and-plate viscometer operated at a high rate of shear;

-- Part 2.Disc or ball viscometer operated at a single specified speed;

-- Part 3.Disc and spindle viscometer operated at different speeds;

-- Part 4.Paddle viscometer operated at a single specified speed.

This part is Part 1 of GB/T 9751.

This part is identical to ISO 2884-1.1999 Paints and varnishes - Determination of

viscosity using rotary viscometers - Part 1.Cone-and-plate viscometer operated at a

high rate of shear (English version).

For ease of use, the following editorial changes have been made to ISO 2884-1.1999.

-- This part deletes the Foreword and References of the international standard.

This part replaces GB/T 9751-1988 Determination of viscosity of coatings at a high

rate of shear.

The main technical differences between this part and the previous version GB/T 9751-

1988 are.

-- The standard has been changed into a series of standards; this part is Part 1, and

the name has been changed to "Paints and varnishes - Determination of viscosity

using rotary viscometers - Part 1.Cone-and-plate viscometer operated at a high

rate of shear";

-- The applicable shear rate range has been narrowed from 5000 s-1~20000 s-1 to

9000 s-1~12000 s-1;

-- The cylinder type viscometer and the immersion type viscometer have been

cancelled;

-- The requirement that the test specimen must be filtered through a sieve with an

aperture of 125 µm before testing has been cancelled, but it is required that there

shall be no foreign impurities or lumps in the test specimen;

-- Appendix A (Informative) has been added.

Paints and varnishes - Determination of viscosity using

rotary viscometers - Part 1.Cone-and-plate viscometer

operated at a high rate of shear

1 Scope

This part is one of a series of standards related to sampling and testing of paints,

varnishes and related products.

This part is a supplement to GB/T 6753.4-1998 Paints and varnishes - Determination

of flow time by use of flow cups.

This standard specifies the general procedure to be followed when determining the

dynamic viscosity of paints, varnishes and related products at shear rates in the range

of 9000 s-1~12000 s-1.

The measured values can provide information about the resistance generated by the

material during the construction process, such as brushing, spraying and rolling.

The method described in this part is applicable to all paints and varnishes, whether

Newtonian or not. Materials containing large particle dispersions will give unrealistic

results.

2 Normative references

The clauses in the following documents become the clauses of this part through

reference in this part. For all the referenced documents with dates, all the subsequent

amendments (excluding errata) or revisions are not applicable to this part. However, the

parties who reach an agreement based on this part are encouraged to study whether the

latest versions of these documents can be used. For all the referenced documents

without dates, the latest versions are applicable to this part.

GB/T 3186 Paints, varnishes and raw materials for paints and varnishes - Sampling

(GB/T 3186-2006, ISO 15528.2000, IDT)

GB/T 20777 Paints and varnishes - Examination and preparation of samples for

testing (GB/T 20777-2006, ISO 1513.1992, IDT)

test can be carried out according to the steps listed in Chapter 7 using the standard oil

with the highest viscosity indicated by the instrument reading.

After the instrument has been allowed to measure the standard oil continuously for 5

min, the reading shall not drop by more than 10%. If the drop exceeds 10%, the

instrument is considered unsuitable for measuring viscosity at high shear rates in

accordance with the requirements of this standard.

7 Procedure

8 Cleaning of instruments

After each measurement, carefully clean the stator and rotor with a suitable solvent.

The procedure depends on the instrument used, but be sure to remove all the test

materials and the cleaning solvent. Cleaning utensils that will damage the equipment

shall not be used, and metal cleaning tools must never be used.

9 Precision

When the same operator uses the same instrument in the same laboratory, the difference

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