Product logo, QR code, serial number, production date and part specification marking are indispensable for consumer electronics, automotive plastic parts, home appliances and medical injection components. Compared with traditional pad printing, screen printing and hot stamping, laser marking has become the mainstream surface identification solution for modern injection molded parts, thanks to permanent wear resistance, zero consumables and flexible variable data printing.
In this blog, we make an in-depth systematic analysis of laser marking principles, applicable plastic materials, mold DFM design rules, equipment selection, defective troubleshooting and process comparison for injection molded products, helping mold engineers and production teams avoid mass production failures.
Have you ever looked at a plastic part and seen tiny bubbles inside, like air trapped in ice? You’re not alone. This is one of the most common headaches in injection molding.
But here’s the good news: bubbles are almost always fixable. The trick is to figure out what kind of bubble you're dealing with.
There are really only two main types. Think of them as Air Bubbles (trapped gas) and Vacuum Bubbles (shrinkage holes). Let’s break them down in plain English.
In the world of injection molding, most parts are 100% plastic. But sometimes, plastic alone isn't enough. You need the strength of metal, the conductivity of copper, or the hardness of steel — but you also need the design freedom, light weight, and corrosion resistance of plastic.
That's where Insert Molding comes in.
Insert molding is the process of placing a metal component — a nut, a terminal, a bracket, or even a complex machined part — into the mold cavity before injecting plastic. The plastic flows around the metal, solidifies, and creates a single hybrid part that combines the best of both materials.
In the world of injection molding, size changes everything. But there is an even bigger leap: moving from standard molds to the extremes.
On one end, you have Large Molds—20-ton monsters that produce car bumpers and refrigerator liners. On the other end, you have High-Precision Micro Molds—tiny blocks of steel that produce medical catheters and watch gears, often smaller than a grain of rice.
Having looked at both extremes, one thing becomes clear: Large mold making is "civil engineering." Micro mold making is "micro-surgery." They share almost nothing except the name.
Here is a practical three-way comparison.
Many mold buyers and new mold engineers confuse rotary thread mold with 2K overmold (soft rubber overmolding mold) and common fixed injection mold. Actually, plastic thread unscrewing mold is an independent rotary injection mold structure, specially designed for plastic parts with internal & external screw threads, no manual thread stripping, no obvious parting line on thread surface.
Unlike TPE overmold mold (double-color rotary mold for non-slip handle), thread rotary mold focuses on automatic thread demolding via gear rotary system, which is widely used in daily packaging, industrial plastic fittings and consumer plastic products.
