Let us talk about cooling. The temperature control in the mold is pivotal for achieving high-quality products within tight timelines. Numerous factors contribute to this, ranging from temperature control units, coolant types, mold probes and working temperatures to cooling current outputs, flow patterns, careful planning of duct and product spacing, pipe selection, connecting accessories, and more.
One technology that has reshaped the landscape in the past decade is the 3D printing of cooling channels, professionally known as Conformal Cooling. While it was once a costly tool limited to a select few in the industry, it has now become a standard consideration in our mold planning. Rarely do we encounter new molds that do not incorporate Conformal Cooling.
Beryllium Copper, once a staple, is now set aside.
Ronen Raveh, the manager of the mold department at Rion, emphasizes, “Working with Conformal Cooling facilitates the production of products with intricate geometry and sensitive materials. The technology streamlines complex cooling designs, and the configuration of channels, along with their proximity to the product’s surface, enables more efficient cooling compared to traditional methods. Previously, in challenging scenarios where cooling sensitive areas in the mold proved difficult, we combined Beryllium Copper inserts for their heat conductivity. However, the drawbacks included reduced mechanical strength, increased wear, and health hazards in the metal processing. The expertise gained in Conformal Cooling allowed us to have efficient cooling without the Beryllium copper disadvantages. The tangible benefits include improved product quality, meeting tighter tolerances, and cycle time savings, occasionally up to 50%.
Here are several recommendations for working with Conformal Cooling:
- Given the technology’s still-high cost, hybrid inserts are common. These inserts consist of a machined core with 3D-printed sections in relevant areas. It is crucial to ensure that the expansion coefficient of the printed part closely matches that of the core. Ideally, both the core and printed insert should be of the same alloy. The recommended steel for the core is 2709, an excellent but limited-availability option. As an alternative, H13/2343 steel can be used, offering similar performance at a better cost and availability.
- To achieve suitable steel hardness, mold’s printed inserts undergo thermal treatment using Aging technology.
- Flow losses and pressure drops can impair cooling effectiveness. Changes in the channel’s cross-sectional area are beneficial but should be approached cautiously, ensuring that turbulent flow is maintained.
- Preliminary tests and flow simulations are crucial, particularly when dealing with coolants at temperatures above 60 degrees. These are essential to spot pockets of trapped water. Such pockets are cavitation-prone and can lead to insert cracks.
- Proper maintenance is paramount for printed cooling ducts. After the injection is done, actively drying the channels is recommended, surpassing mere water drainage. Prolonged standing water can result in residues, and due to the intricate geometry of printed channels, standard cleaning methods such as acid treatment or ultrasonic cleaning may be challenging. Additionally, utilizing filtration systems to minimize contamination and precipitation risk is advised.
Conformal Cooling technology has seamlessly integrated into the routine workflow for many of the new molds we produce at Rion. We also apply it to older molds in need of duplication. The synergy between the knowledge and experience we have accumulated and our collaboration with excellent suppliers consistently yields superior results. For solutions that enhance process efficiency and quality in challenging products, please reach out to us, and we will be delighted to assist.