Current Process
Biopsy needle notches are machined using milling, conventional abrasive grinding, or wire EDM.
Challenges
Exposing the material to high heat can affect the chemistry and mechanical properties of the material requiring manual secondary finishing operations. Setup and production are slow, requiring extensive mechanical adjustments. Frequent wheel dressing causes faster wearing, resulting in higher tooling costs.
Solution
Glebar’s Tridex SG-1645 NC/CNC and SG-2060 CNC Burr-Free Electrochemical Grinding (ECG) Machines
Electrolytic Grinding (ECG) provides fast, accurate, and burr-free results with no metallurgical damage and no distortion. Burr-free grinding eliminates the need for deburring or other secondary operations, improving productivity and reducing scrap.
Biopsy needle pointing can be completed using the PGS-100 ECG Point Grinding System. The PGS-100 can be easily added to the SG-1645 and SG-2060. It is a fully programmable pointing and material handling system with the ability to manufacture a wide variety of medical device points on tubing or solid wire using electrolytic grinding.
Almost all metals can be cut burr-free.
Increases throughput by notching multiple needles per cycle.
Less frequent wheel truing and dressing reduce tooling costs.
Maintains tight tolerances on complex grinds in high production environments.
Loading time can be reduced to almost zero using the optional pallet loader and 180-degree index table.
Secondary Processes
In addition to a well ground tip, biopsy and other needles benefit from processing with MicroBlasting technology.
Challenge: To improve bond adhesion of the overmold to the needle
Solution
Comco AccuFlo and ProCenter Plus MicroBlasting System
A textured surface has a greater surface area, the peaks and valleys of which provide more contact points for a stronger bond. However, only the small region of the overmold should be textured.
MicroBlasting with a sharp, cutting abrasive, like aluminum oxide or silicon carbide, quickly and efficiently textures the surface. Blasting properties can be controlled to match the specific surface requirements to best bond with a hub.
The AccuFlo provides a consistent stream of abrasive that can create a specified Ra finish with full coverage. Paired with either the Ring Nozzle or an automated platform, no masking is necessary due to the sharp delineation between the blasted/textured and unblasted region of <0.005″.
Challenge: Ultrasound uses high-frequency sound waves to create detailed images allowing a medical professional to see the cannula as it travels through the body. If the surface is shiny, specular reflection causes those waves to reflect in a singular direction that may miss the receiver, impeding proper imaging. To create an echogenic finish, by creating a series of satin bands along the needle shaft, diffuse reflection ensures some of the reflected energy finds its way back to the receiver for proper imaging.
Solution
Comco AccuFlo and ProCenter Plus MicroBlasting System with Ring Nozzle
Using glass bead with the Ring Nozzle is ideal for crating a series of band; the abrasive flows uniformly around the circumference imparting a satin finish. This not only eliminates the need to rotate the part during the blast, but also creates a sharp delineation on both ends of the band.
