How does wall thickness affect the injection molding process?

At Fleur Plastics, we love plastics, but even more, we love perfection. Every detail in the injection molding process makes a difference, and wall thickness is one of the most important. Whether it’s about product strength, production speed, or shape stability after cooling, wall thickness plays a role everywhere.

In this blog, we explain why wall thickness has such a big impact on the injection molding process and how we at Fleur Plastics manage it to deliver top-quality products.

What is wall thickness and why is it important?

The wall thickness of a plastic part is simply the distance between the inside and outside of a product’s wall. During design and production, it’s a crucial parameter. A well-considered wall thickness prevents issues like warping, air traps, and uneven shrinkage.

We collaborate at every stage of the process—from mold design to final production, to ensure wall thickness is always optimally matched to both the product’s function and the customer’s specific requirements.

Impact on mechanical strength

A thicker wall can increase a product’s mechanical strength. Think of parts that must withstand heavy loads or impacts, these require greater wall thickness.

However, thicker is not always better. Too thick walls can cause internal stresses or uneven shrinkage. That’s why we analyze the right balance between strength and stability for each application. Thanks to our experience as injection molding technicians, we know exactly which technical choices lead to durable final products.

Thicker walls mean longer cooling times

During injection molding, plastic is injected at high pressure into a mold. Once inside, the material must cool before it can be removed. The thicker the wall, the more heat the material retains, and the longer it takes to cool sufficiently.

Longer cooling times translate into longer cycle times. And the longer the cycle time, the fewer products can be produced per hour. In short, thicker walls lead to a less efficient production process and higher costs.

That’s why we always critically assess wall thickness. Sometimes, clever rib structures or other technical solutions can make a product strong enough without increasing wall thickness. This way, we combine technical creativity with production efficiency.

Wall thickness variations often cause unwanted shrinkage and deformation

A less visible but very important effect of wall thickness is shrinkage. Plastics shrink as they cool. With uneven wall thicknesses, this shrinkage can be uneven, leading to warping or dimensional inaccuracies in the final product.

Therefore, we strive for as consistent a wall thickness as possible within a product. Where this isn’t feasible, we compensate with technical adjustments in the mold or process. This guarantees dimensionally stable products that meet all tolerances.

Wall thickness determines quality

By considering wall thickness early on, many problems can be avoided, such as unwanted warping, longer production times, or parts that don’t fit. Wall thickness influences the entire process, from the initial design sketch to final delivery.

At Fleur Plastics, we help customers make these choices consciously. Whether you already have a design or are just starting product development, it’s always worthwhile to discuss details like wall thickness. Together, we look at the product’s function, material, production volume, and desired tolerances. This combination of collaboration, advice, and production makes us a reliable partner for high-level injection molding work.

Feel free to contact us, we’re happy to think along and find solutions that are technically sound and practically feasible.