National Standard of the People’s Republic of China

      GB12436--1990

Explosive Function Test: Lead Cast

1 Main Context andApplicationRange

 The standard regulates methods used to test explosive functions through lead cast.

 The standard is apt to test functions of pulverous, particle and pasty explosives. Liquid explosive function test is recommended to follow the standard as well.

2 Quoting Standards

 GB 6003  testing screen

 GB 7968  paper bag tissue

 GB 8031  industrial electrical detonator

 ZBG 89006  lead cast for explosive function test

 GJB 771.101 explosive function test method  accumulating density test

3 Theory

 Put explosive of certain quality and of certain density into the lead cast. Test its function by means of the volume expanded in the lead cast after explosion.

4 Testing Materials

4.1lead cast: following ZBG 89006

4.2quartz sand: windy-dried quartz sand filtered by Φ200×50/0.71-square hole top sieve and Φ200×50/0.40-square hole lower sieve, and keep the quartz sand, accumulating density 1.35~1.37g/cm³following GJB 771.101, on the lower sieve for further use.

4.3paper tube: from rolling a piece of paper bag tissue that follows GB 7968. Cut the tissue into a right-angled trapezium following map 1 and roll trapezium into a tube from the right-angled edge using a24mmdiameter rod. Then, form. the tube bottom showing 15~20mmrod folded innerwards.

4.4Round Cardboard with pores: from cutting cardboard following map 2.

  Specifications: thickness 1.75±0.25mm；

external diameter  23.75±0.25mm；

pore diameter  7.5±0.1mm.

4.5 No.8 instant electrical copper detonator: following GB 8031

4.6Testing Screen: following GB 6003, Φ200×50/0.40-square hole and Φ200×50/0.71-square hole.

5 Instruments or Equipment

a.      volume bottle: 250ml, 100ml for each, division value level 1;

b.     burette: 50ml, division value 0.1ml;

c.      scale: sensitivity0.001g;

d. glass thermometer: scope－30～＋50℃，division value1℃;－50～0℃，division1℃;

e.      initiator: optional

f.       brush: optional

g.      vernier caliper: division value0.02mm;

h.      experimental device: main components, lead cast, explosives and detonators following map3.

6 Sampling and Preparation

Get explosives 10.00±0.01g, and put them into the paper tube covered with cardboard with round pores; then, put the tube into a special copper model with inner diameter 24.5±0.1mm; and press the explosives into a explosive cylinder (density 1.00±0.03g/cm³) with pores in the center through a special copper punching pin (penetrating partof7.5mmdiameter,12mmhighin the center); and then, insert a detonator shell in the center after taking off the punching pin and exchange a electrical detonator when experimenting. At last, insert the pasty explosives directly into the detonator after being scaled in the cardboard.

Note: experiment with the density used permissible, but the density clarified in the result report.

7 Experimental Procedure

7.1test lead cast pore’ volume with volume bottle or burette using water as a medium, wipe off for further use.

7.2test temperature of lead cast pore; then, put the read-made explosive cylinder into the pore, and put it onto the bottom with a wooden stick carefully. At last fill the rest part of the lead cast inside with quartz sand (pour in freely without shake or tamping), and strike off the uneven part and set it off.

7.3brush the residue inside after exploding, and test lead cast pore’ volume following 7.1.

8 Calculation and Assessment of the Experimental Result

8.1formula of explosive function:

X=（V₂-V₁）（1+K）-22

X: explosive function (represented by the extended value of the lead pore), ml;

V₂: pore volume after explosion, ml;

V₁: pore volume before explosion, ml;

K: amendment temperature coefficient (see the following table);

22: function of electrical copper detonator at15℃,ml.

Amendment Temperature Coefficient Table

8.2test each sample twice, get the mean value to exact 1ml and the fault bit less than 20ml; experiment again if more than 20ml. Obtain the mean value of the smaller fault bit if the fault bit less than 20ml compared with the former results, and obtain the mean value of the within 20ml if more than 20ml. Find out the source of strange phenomenon happened, and test again.

Additional Information:

Proposed by Mechanical and Electrical Industry Department of the People’s Republic ofChina

Drafted by state-owned Qinyang Chemical Factory

Main draftsman: Zhang Bingyuan

The Standard WJ 301-65 is void since this standard was issued.