Do you prefer a nice, smooth flow, or a head-on crash?

With injection molding, the flow of molten plastic often has to split and converge around features in the product (for example a screw or fitting), creating either meld or knit lines. Like water flowing around a rock in a river, splitting and then merging again.

When two flow fronts remerge after being split by a feature in the part design, these are known as Meld Lines. Imagine merging onto a freeway after work; everyone is going the same direction, trying to avoid damage and the transition is smooth.

Knit Lines on the other hand, form when two flow fronts meet head-on, like a collision at a four-way stop. They don't merge well, resulting in weaker joints. Without additional cavity geometry to flow through, pressurizing this area is difficult, making knit lines less robust.

When put like this, it's probably obvious that meld lines are stronger than knit lines because the flow can continue and pressurize the area, enhancing strength.

However, getting this right is not just based on luck.

At ADIS Tachov s.r.o. we're experts in injection molding, offering innovative solutions to ensure your designs achieve the desired outcome without stress or risk of weakness or problems.

With over two decades of experience we provide precise, cost-effective, and high-quality injection-molded components, and best of all, we can advise on the best approach and design to optimize the strength and quality of your parts without you having to do the hard work!

Ready for the nice, smooth route? Get in touch!