USA – “Shocking development”: Projectile Taser cartridge made with 56 micromolded parts, 20 molds, and on-target collaboration (2011-02-15)

Published on March 7 2011 by admin

[[GlobalShock: an article from the technical review “Plastics Today” (focusing in plastics moldings) on ICON’s supply of plastics to TASER Inc. for the new XREP cartridges: “It packs twice as much power and has four times the range of standard Taser guns,” says ICON President. “The XREP projectile generates NMI for 20 continuous seconds, according to Taser. As the chassis falls away, six “Cholla” electrodes automatically deploy to deliver the NMI effect of a greater body mass.”]]

Plastics Review, By Clare Goldsberry

A partnership that dates back to 1997 between Icon Injection Molding Inc. (Phoenix, AZ) and Taser International has now brought the Taser XREP (Extended Range Electronic Projectile) cartridge into the hands of law enforcement/corrections personnel, professional security personnel, the military, and consumers (for personal protection). When Taser International came to Icon with its newest law enforcement device, Icon’s engineering team began looking at ways to design and manufacture this unique and challenging product.

Icon Taser XREP cartridge
The XREP from Taser International was challenging from a design standpoint, as the shotgun-sized shell casing holds several dozen electronic and plastic components.

What it is
The Taser XREP cartridge is the size of a shotgun shell, loaded with Taser components that shoot a wireless charge. “It packs twice as much power and has four times the range of standard Taser guns,” says Icon president and co-owner Danny Kleitsch. This self-contained wireless electronic control device (ECD) deploys from a standard 12-gauge pump-action shotgun, and is the most technologically advanced projectile ever deployed in this manner, according to Taser. It delivers a neuro muscular incapacitation (NMI) bio-effect similar to Taser’s other well-known devices, such as the handheld Taser X26 ECD.

Taser asserts it can be delivered to a maximum effective range of 100 ft (30.48m), combining the bio-effect with blunt force impact. The battery supply is fully integrated into the chassis and provides the power to drive the XREP projectile engine. The nose assembly of the projectile contains forward-facing barbed electrodes, and on impact, the electrodes attach to the body of the target. The energy from the impact breaks a series of fracture pins that release the main chassis of the XREP projectile, which remains connected to the nose by a nonconductive tether.

The XREP projectile generates NMI for 20 continuous seconds, according to Taser. As the chassis falls away, six “Cholla” electrodes automatically deploy to deliver the NMI effect of a greater body mass.

How Icon made it
Due to the small size of the XREP cartridge, and because the number of components it contains (23 injection molded parts) are extremely small with very tight tolerances and are packed closely together, Icon had to design and build extremely precise molds with tight tolerances. The XREP flight stabilizer fins had to have very thin walls (0.011 inch).

One of the molds Icon built for the XREP project was a six-cavity tool that required the company to purchase a high-speed Nissei injection molding machine-an NEX15 with upgrades including a 19.7-in/sec injection velocity capacity with no accumulator. The press was fitted with automation for part removal.

Mark Hanchett, mechanical engineer with Taser’s R&D department, says that the very thin walls of the parts presented a challenge in material selection. “We had to deal with materials that normally don’t flow well through these thin walls . . . [by] heating the material to higher temperatures,” Hanchett explains.

Icon and Taser worked closely with Icon’s material suppliers, and for many of the parts chose Lexan EXL from Sabic Innovative Plastics, an experimental grade of polycarbonate (PC) with very high impact modifier content. A custom LNP Teflon-filled PC was chosen for the XREP’s flight stabilizer fins, with a shot size of 0.0276g each. The shell base is a multicomponent part that includes Lexan EXL PC molded over a metal injection molded (MIM) ring for improved mechanical properties when fired and ejected.

Because many of the 56 mechanical components that comprise the XREP are technically micromolded parts, the intricate detail of the parts presented the biggest challenges. “There is one molded component that mates with 15 other components, but that component is the size of a dime,” says Hanchett, “and all of these components must be contained in a product that is the size of a standard 12-gauge shotgun shell.”

The molder/moldmaker designed and built 20 molds for the Taser XREP cartridge and performed R&D on the preproduction tools to ensure they would run consistently, Hanchett says. “Icon researched the materials and performed Moldflow analysis on part designs and hot runner manifolds to ensure consistent quality.”

Icon specializes in micromolding, insert molding, overmolding, and multimaterial molding, and operates 16 presses from 15-500 tons clamping force. Additionally, the company provides product design and development assistance, mold design, manufacturing, and a variety of secondary operations including assembly, pad printing, sonic welding, and heatstaking. —Clare Goldsberry

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