The primary characteristics of PBXs (Plastic Bonded Explosives) are low vulnerability, high
performance, and superior aging, compared to the conventional explosives, i.e. TNT, Comp B,
Octol and so on.
Chugoku Kayaku, Chuka, has been engaged in the study of PBXs for 22 years. In 1980,
Chuka licensed production technology for PBXN - 4. We proceeded to press the PBXN - 4 molding
powder and processed it with a lathe. We discovered that the performance and safety of PBXs
were excellent. In 1983, Chuka initiated a study of castable PBXs using PBXN - 105 as a baseline.
We also licensed the production of PBXN - 3, PBXN - 5 and PBXN - 301. Assisting in our development
and study efforts was the fact that Chuka had the extensive experience in the production and
quality control of HMX, RDX, and HNS (Hexamitrostilbene), which were the primary ingredients
in PBXs. The development of PBXs has progressed smoothly. In order to differerentiate Chuka's
developed PBXs from others, we devised a naming convention. Chuka's PBXs were referred to
as PBXK - C1106, PBXK - P1205 or PBXK - E6201. K stands for the initial letter of Chuka's president,
Mr, Kozu. C means castable, P pressable, and E extrudable, respectively. The first digit of four
figures means the main explosive that is comprised in the PBX; l is HMX, 2 RDX, 3 CL - 20
(Hexanitrohexaazaisowurtzitan), 5 NTO (3 - nitro - 1,2,4 - triazol - 5 - one), 6 PETN. The Second
digit is the type of binder systems ; I is energetic binder, 2 insert binder. The third and fourth
digits are consecutive numbers relating to the order of development.
In this paper, we will present our three developmental results of 2 PBXs as well as a combined
composition study. The first composition is a low vulnerability PBX that consists of NTO,
HMX, and binder. Shock sensitivity test, fast cook - off test, and other various tests were conducted.
The results were ascertained safety performance. The second PBX studied consists of CL - 20
and binder. This PBX has a high performance for metal acceleration. Detonation velocity for
this PBX is about 8700 m s-1. Since this PBX has a high flowability, loading it in complex
shaped charge warheads is very easy. The third presented result is an aging study of 6 types of
PBXs. In terms of aging theory for PBXs, we have identified no prevailing mechanism. We
think that the real age exploration is the best way for confirming the aging phenomena. Since
1995, we have been conducting a variety of evaluation tests for the aged PBXs. These tests
included detonation velocity, under water explosion, card gap sensitivity, friction sensitivity,
drop hammer sensitivity, DTA (Dimerential Thermal Analysis), TG (Thermal - gravinetry), tensile
parameters test,vacuum stability test and nondestructive testing. Most studied PBXs of good
aging performance were confirmed.