Micro molding, the process of injection molding micro-sized, precision plastic components, is not new, but Westfall’s approach to the concept is changing the game. We are the only injection molding company to have its own micro molding machine, the M3, which we acquired in December 2018 as part of our purchase of Ontario, Canada-based Mold Hotrunner Solutions Inc. (MHS).

The ISOKOR Micro Molding Method

Since then, our experts have continued to refine the process, named ISOKOR, which is designed to eliminate the use of cold runners and thereby greatly reduce scrap, slash cycle times, and boost overall production efficiency. This is vitally important since conventional micro molding with cold runners often uses expensive, highly specialized materials, such as bio-absorbable/resorbable resins that increasingly are taking the place of metals. We’ve been successfully designing and molding parts from polyetheretherketone (PEEK), polyoxymethylene (POM), and polylactic acid (PLA) bioresins, among others.

Using traditional cold-runner micro molding techniques can result in 90 percent or so of such materials ending up as scrap, leading to an incredible amount of added cost and unnecessary waste. ISOKOR’s direct gating process solves this problem. 

Our M3 machine, which is designed for both prototype and high-volume production, boasts numerous innovative features that separate it from the pack. It has magnetic clamps that offer ultimate mold safety with a resolution of 10 microns able to detect a hair in the mold parting line. It features secure data connectivity via the OPC machine protocol to cloud-based Industry 4.0 solutions, and a free-fall cycle time of 2.5 seconds. The machine also has an integrated robot inside the machine that does part separation. The M3 is an all-electric, pneumatic machine designed to run in clean rooms.

Micro molding machines are defined by how small a micro part they can mold (in weight) while retaining the polymer properties and a consistent part quality. The true micro molding challenge is melt residence. The ultimate solution is a direct-gated micro part without cold-runner waste that weighs less than 10 milligrams. Our M3-D08 machine, for example, features eight direct valve gates that can produce up to 100 million micro parts per year without waste. The micro capability is in the process, the quality and quantity, not in machine size. 

Injection Molding for Medical Devices and Uses

The market for less invasive medical devices continues to grow rapidly. The market segments seeing some of the highest growth rates include drug delivery and management, general surgery, ear/nose/throat (ENT), orthopedic implants, reconstructive surgery, and wound closure. For medical OEMs to succeed, they need to lean on companies such as Westfall whose experts have decades of experience in both micro molding and in the fabrication of micro molds. Our in-house equipment and capabilities include polymer characterization, design, CT scanners and automation expertise, which together provide our clients with a level of confidence that their project will be successful. 

Micro molded parts often weigh just 0.001 to 0.4 grams, and their dimensions generally have tolerance bands of +/-.001” or less. These tiny medical parts are so small that you could put 1,000 pieces on your fingernail. The part may use a novel resin and its ability to fill a given geometry consistently may not be fully understood in the macro molding world. Additionally, the part may have delicate features or finishes that would require special handling and packaging.

Our ISOKOR process allows for better control of the injection process. The cavities are filled and pressurized in milliseconds, thereby improving shot-to-shot consistency, improving cavity replication, and reducing quality issues such as short shots, sink marks and voids. 

Additionally, the direct-gating approach reduces cycle times by 50-75 percent by eliminating the need to wait an additional 4-10 seconds for the cold runner to cool below its ejection temperature. The micro molder also does not have to wait for the cold runner to fill and pack during each cycle.

The result: much faster production, virtually no waste, lower energy usage, cost savings on expensive materials, and high-quality end parts. 

Westfall is unquestionably the new industry leader in micro –– specifically, micro-injection molding. We have essentially “skipped” a generation by taking this technology and to an entirely new level. 

Join us on this exciting journey, as we do big things with micro parts.