Detonating cord
A detonating cord (also: detonating fuse , detonating fuse , Knallzündschnur ; engl. : Detonating fuse , detonating cord ) is comprised of a plastic or fabric covered core of up.With the explosive explosives . When ignited, it detonates along its entire length at the detonation speed of the explosive it contains - in contrast to the non-explosive fuse , which burns more slowly.
As a rule, PETN is used as an explosive, but there are also detonating cords with a filling of hexogen or octogen as well as fulminate cords, detonating cords made of paraffin with a core made of mercury fulminate .
properties
Detonating cords are available with different cargo weights. The most common cargo weights are 5 g / m, 12 g / m, 20 g / m, 40 g / m and 100 g / m. Due to the explosives used as cargo, detonating cords have a very explosive behavior, similar to military explosives.
| Chemical composition | |
|---|---|
| Explosive components |
|
| Physical Properties | |
| Density in g / cm³ | 1.7 |
| Oxygen balance in% | -10 |
| Explosion heat in kJ / kg | about 6000 |
| Steam volume in l / kg | 800 |
| Specific energy in l · MPa / kg | 1200 |
| Detonation speed in m / s | from 6500 to 7200 |
| Explosion temperature in K | unknown |
| Property comparison | |
| Explosiveness | high |
| Ignition sensitivity | high |
| Steam volume | low |
| price | medium |
| Credentials: | |
application
While detonating cords with a charge weight of 5 g / m are used to connect tube ignition systems, detonating cords with a slightly higher charge weight of 12 g / m or 20 g / m are mostly used to connect several explosive charges , which are carried out simultaneously or in a small amount , but should detonate at a well-defined time interval. When buildings are blown up, the collapse behavior can be controlled. This type of ignition of explosive charges is also known as pilot fire.
The larger detonating cord types with 40 g / m and 100 g / m are often used as explosive charges themselves, especially where linear charges are necessary.
Frequent areas of application are:
- Pilot lighting of conventional explosive charges
- Triggering of explosions in the large borehole area to detonate ANFO explosives (quarry)
- Charges created or brought into the borehole in the event of building blasts
- Metal blasts (instead of cutting charges )
- Wood blasting (e.g. from trees to erect vehicle barriers or to remove storm wood in dangerous locations)
- Blowing up mast holes
- The cabin roof was blown up in front of the ejection seat exit
Trade names
Detonating cords are sold under the following trade names:
- Dynacord from Orica , Troisdorf
- Sprewacord from sprewa Sprengmittel , Nördlingen
- Nitrocord from Westspreng , Finnentrop
- Octocord and Hexacord from Dynawell, Troisdorf
Web links
- Safety data sheet according to regulation (EG) 1907/2006 (REACH) detonating cord (accessed on April 20, 2020)
- Basics of blasting service (accessed April 20, 2020)
- Maxam (accessed April 20, 2020)
- Unusual blasting procedures (accessed April 20, 2020)
- TEXTBOOK FOR THE STATE RECOGNIZED SPECIAL COURSE IN PYROTECHNICS (accessed April 20, 2020)
Individual evidence
- ↑ Orica GmbH (Ed.): Datasheet Dynacord . Troisdorf ( orica-germany.com ).
- ^ Josef Köhler, Rudolf Meyer: Explosivstoffe . Wiley-VCH, ISBN 978-3-527-28864-9 .
- ↑ Closed cabin roof with detonating cords ( memento from April 10, 2017 in the Internet Archive ).