What is injection molding in eyewear?

Injection molding in eyewear is a manufacturing method that melts plastic pellets and injects them into a steel mold to form a frame in seconds. It delivers low cost, high consistency, and fast output, which makes it the standard choice for TR90, kids', sport, and budget frame programs. READSUN runs injection lines alongside its acetate and metal lines, so buyers can mix materials in one order.

How Injection Molding Works for Frames

1. Mold making: a steel mold is CNC-machined to the exact frame shape.
2. Melting: plastic pellets such as TR90 or PC are heated to a flowable state.
3. Injection: the melted plastic is forced into the mold under high pressure.
4. Cooling: the frame cools and hardens inside the mold, then is ejected.
5. Finishing: gates are trimmed, hinges fitted, and color or coating applied.

Pros and Cons at a Glance

Where Injection Molding Fits Your Line

Injection frames suit high-volume programs where price and repeatability matter most: children's collections, lightweight TR90 optical frames, and sport styles. Because the mold drives the shape, changes after tooling are costly, so lock the design before the mold is cut. Review the equipment behind both processes on our manufacturing capabilities page.

How READSUN Runs Injection Molding

Start from custom optical frames to see plastic models you can adapt, or work with the team through OEM & ODM eyewear services to plan tooling, sampling, and volume production in one schedule.

Considering injection-molded frames? Ask READSUN for a mold and sampling quote.