摘要：

Improved safety is achieved in blasting fuse manufacture by utilizing unincorporated black powder confined within the core of the fuse by fibrillated polypropylene yarn. The unincorporated black powder is produced by premixing the sulfur and charcoal components and separately pregrinding the mixture and the alkali metal nitrate to a particle size of about 45 microns or less. The preground material is then blended immediately prior to its formation into the powder train of the fuse and is enclosed by a number of ribbon-like fibrillated polypropylene yarns which directly contact the powder core and by a number of additional superimposed protective layers. The resultant fuse exhibits uniform cross sectional size and a controlled uniform burning rate.

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