High-performance polymer for meltable fuse plugs

PTI Tech is an integrated precision injection molder of advanced polymers, metals (MIM), and ceramics (CIM) supporting the defense sector for more than 30 years.

Problem

155mm projectiles are large caliber artillery munitions requiring careful handling. During handling, the projectiles are hoisted by a legacy investment-cast, all metal lifting plug. However, these lifting plugs allow pressure inside the projectiles to build up to dangerous levels when the munition is exposed to elevated temperatures. This internal high pressure creates the potential for unintended detonation and for sympathetic detonation of neighboring munitions, putting personnel and material at risk.

Solution

PTI Tech formulated a lifting plug consisting of a high-performance polymer with mechanical properties able to handle 120 lb 155mm projectiles, but which softens enough at elevated temperatures to allow the excessive pressure within the projectile to dislodge the threaded plug. By passively venting the extra pressure, the potential for unintended detonation is mitigated. The finished product – incorporating the molded glass-filled ionomer, a machined washer, and multiple screws and gaskets – is assembled at PTI Tech’s Clifton, New Jersey, facility, leveraging automation to ensure quality and conformance to pricing targets. PTI Tech has successfully manufactured and shipped more than 250,000 units – with zero reported failures – since being awarded the prime contract in 2013. Displaying exceptional performance on this effort, PTI Tech was awarded an Eagle Note from Picatinny Arsenal. In February 2025, PTI Tech was awarded a five-year contract by the Army Contracting Command-New Jersey (ACC-NJ), Picatinny Arsenal, to manufacture and deliver the Meltable Fuze Plug (MFP).

PTI Tech
https://pti.tech