PBF

Autoinjector housings are produced in very high volumes and must meet demanding requirements for dimensional accuracy, cleanliness, and consistency. Rising global demand for MED-PEN injection devices, especially those used for weight management therapies, has put significant pressure on mold makers to improve cooling performance and increase productivity.

ZAHORANSKY Automation & Molds, a major supplier of high-precision medical tooling, partnered with AddUp to investigate whether conformal cooling enabled by metal additive manufacturing could shorten cooling times and enhance temperature stability inside the mold. The project focused on improving thermal behavior, raising output, and validating corrosion-resistant AM tool steels for high-volume medical applications.

From Cooling Limits to High-Speed Autoinjector Production: Unlocking Cycle-Time Gains with AM Cooling

MATERIAL

Printdur HCT (1.2083 / PM420)

INDUSTRY

Tooling and Mold Making

CHALLENGE

Reduce cooling time and stabilize temperature distribution in autoinjector housing molds to support rapidly growing MED-PEN demand. The goal was to evaluate whether additively manufactured conformal cooling channels could outperform conventional cooling strategies and enable faster, more reliable production at high volumes.

KEY BENEFITS

• More than 30 percent reduction in cycle time
• Uniform mold temperature without hotspots
• Longer tool life through balanced heat distribution
• Higher output and more reliable processing for large production runs
• Smaller mold space requirements enabling more economical machine use

Shortened Cycle Times

Higher Output

Smaller Space Requirements

The Customer

ZAHORANSKY is among the leading manufacturers in tool and mold making.
The company is known for its innovative, high-precision tooling systems. Their solutions emphasize repeatability, reliability, and the ability to operate within automated, compact production environments.

As demand for autoinjector housings grows into the millions, ZAHORANSKY has been evaluating new processing strategies that can improve cooling efficiency and reduce cycle time. Conformal cooling produced using L-PBF technology has shown particular potential for delivering these performance gains while remaining compatible with the Z.SONIC turn tooling concept and modern medical molding platforms such as the Netstal Elion 1200 MED.

The Challenge

Producing autoinjector housings requires precise molding of sensitive features and the ability to maintain consistent temperatures throughout each cycle. With MED-PEN consumption rising, production volume requirements are pushing mold systems to their limits. In addition to molding the plastic housings themselves, ZAHORANSKY must also support the precise assembly of sensitive medical components within highly automated systems, which increases the importance of stable thermal behavior and consistent part quality.

ZAHORANSKY needed to determine whether additively produced conformal cooling could support:

• Faster cooling inside compact tool dimensions
• Improved thermal uniformity and the elimination of hotspots
• Higher output for large production runs
• Lower scrap rates through more stable temperature control
• Compatibility with the Z.SONIC turn system that transfers part of the cooling phase outside the tool

ZAHORANSKY’s Z.SONIC turn tooling concept uses a 180-degree rotation to transfer the molded part outside the cavity while the next injection cycle begins. This movement allows a significant portion of the remaining cooling time to take place outside the tool, reducing the in-mold cooling requirement and enabling faster cycle progression. In the current configuration, the system achieves an 8.5-second cycle time by combining internal cooling, external cooling, and continuous part rotation. To fully leverage this mechanism, ZAHORANSKY required even shorter internal cooling times, which became a key driver for exploring additive conformal cooling on the FormUp 350.

The Solution

AddUp and ZAHORANSKY first carried out a simulation-based evaluation to determine the potential performance gains. These early studies confirmed that a conformal cooling concept could significantly reduce cooling time and improve thermal stability. Based on these results, a fully three-dimensional cooling design was developed, incorporating a four-path parallel cooling circuit to ensure balanced flow and consistent temperature behavior inside the tool.

Because the cooling channels follow the exact contour of the cavity and core, heat can be removed precisely where it is generated. This leads to faster and more uniform cooling and supports stable, high-quality molding within a compact, automated production system.

This approach enables:

• Shorter cycle times
• Uniform temperature distribution throughout the insert
• Reduced distortion and more reliable dimensional control
• Stable processing during high-volume production

Conventional drilled or milled cooling channels cannot achieve such geometries and often require vacuum-brazed assemblies, which introduce limitations in thermal conductivity, increase the risk of leakage, and complicate repairs. Additive L-PBF manufacturing avoids these constraints by producing single-piece inserts with fully integrated freeform cooling channels.

For this project, five AM cavity inserts and twelve AM cores were manufactured on the AddUp FormUp 350 using a four-laser configuration. Total production time included 12 days of net printing and 5 days for design and auxiliary preparation. The selected material was a corrosion-resistant tool steel based on 1.2083 / PM420, ideal for injection molding and suitable for high-gloss Class 1 surface finishes.

After printing, the build was depowdered, heat-treated, and wire-cut from the platform. Final machining was completed at ZAHORANSKY to achieve the required tolerances and surface quality.

The Results

The additively cooled inserts and cores delivered significant and measurable improvements in cooling performance and tool stability.

Key findings:

• Cycle time reduction greater than 30 percent
  • Cooling time reduced to 9 seconds compared to more than 14 seconds previously
• Uniform mold temperature without hotspots
• Improved part quality and reduced scrap
• Longer tool life through balanced thermal behavior
• More reliable processing during large production runs

These results demonstrate that AM-based conformal cooling provides a clear performance advantage over traditional straight-line channels and supports stable, high-volume manufacturing of autoinjector housings within compact, automated production cells.

High-volume plastic components place strict demands on cooling performance, tool stability, and cycle time efficiency. For the Han-Eco plug, one of HARTING’s most widely used industrial connectors, thick wall sections and annual volumes exceeding one million units amplify these challenges. Even small improvements in cooling performance translate directly into significant productivity gains.

To explore these gains, HARTING Applied Technologies partnered with AddUp to evaluate whether conformal cooling produced through additive manufacturing could outperform traditional tooling methods. The project focused on reducing residual cooling time, eliminating thermal hotspots, and validating the use of corrosion-resistant AM tool steels for future series production. Early simulation work and prototype tooling confirmed that AM-enabled cooling could deliver measurable and repeatable benefits at industrial scale.

From Hotspots to High Output:
Accelerating Tooling Efficiency with Additive Cooling

MATERIAL

Printdur HCT (1.2083 / PM420)

INDUSTRY

Tooling and Mold Making

CHALLENGE

Reduce cycle time and eliminate thermal hotspots in a thick-walled plastic plug for annual production volumes over one million units, by replacing conventional mold cooling channels with an additively manufactured conformal-cooling solution.

KEY BENEFITS

• More than 25 percent reduction in cooling time
• Uniform tool temperature without hotspots
• Higher throughput and more stable production
• Lower scrap rates and improved part quality
• Scalable 3D cooling design for the full Han-Eco tool family

Shorten Cycle Times

Increased Production Rate

Scalable

The Customer

The HARTING Technology Group is a leading global supplier of industrial connection technology, supported by a high degree of in-house vertical integration. This includes a modern mold-making department that is continually exploring new ways to enhance HARTING products. In recent years, the company has gained valuable experience with advanced cooling concepts.

Building on this expertise, HARTING is now evaluating the feasibility of additive manufacturing as a standard process for selected series components.

Injection molding has been especially promising in these studies, as the use of conformal cooling can significantly improve part quality and increase tool productivity.

The Challenge

HARTING produces large volumes of plastic components for sectors such as energy, transportation, and mechanical engineering. With this level of demand, even small reductions in cycle time have a significant impact on overall production cost, making cooling performance a key driver of efficiency across the product family.

One example is the Han-Eco plug, one of the most important products in HARTING’s portfolio, and features relatively thick wall sections designed to meet strict functional requirements. These characteristics create a cooling challenge, particularly when annual volumes exceed one million units. Adopting an additive manufacturing approach to the cooling design enabled focus on several key objectives:

• Increasing production rates for plastic components
• Shortening cycle times
• Reducing required machine space
• Reducing overall manufacturing time
• Evaluating new corrosion-resistant AM tool steels

The Solution

The first step was to analyze and verify the potential for improvement using simulation combined with a conformal cooling concept. This early investigation is important for the Han-Eco product family because any lessons learned from additive manufacturing can be transferred to additional tools within the series.

Using the Siemens NX simulation environment, these studies could be run quickly during the early stages of tool development. Once the potential of additive manufacturing was confirmed, the cooling strategy was refined. This stage focused on designing a fully three-dimensional conformal cooling system that follows the contours of the cavities and surrounding tool surfaces. The cooling channels were optimized for flow performance through close collaboration between AddUp and HARTING. The final system uses a four-path parallel cooling circuit that ensures balanced flow and consistent thermal behavior.

Unlike conventional cooling channels that must be drilled or milled in straight lines, conformal cooling allows channels to follow the geometry of the mold. This removes heat exactly where it is generated and results in shorter cooling times, improved thermal uniformity, and better component quality.

This approach enables:

• Shorter cycle times
• More uniform temperature distribution throughout the mold
• Reduced warping and improved dimensional stability
• Stable and reliable processing at high output levels

Traditional manufacturing methods such as drilling or milling quickly reach their limits when handling complex geometry. To overcome this, toolmakers often join mold halves through vacuum brazing to create more intricate cooling paths. Although functional, this approach introduces several drawbacks such as restricted channel geometry, the inability to create true 3D contours, increased risk of leakage, lower thermal conductivity, and higher effort during repair.

With additive L-PBF technology on the AddUp FormUp 350, the entire insert can be produced as a single piece with fully integrated cooling channels. This capability reduces cycle times, decreases scrap rates, and significantly increases output per machine. These advantages are especially important for thick-walled components such as the Han-Eco connector.

Reduced Manufacturing Time: Inserts and Cores

The new AM inserts (two AS and DS units) and AM cores (four units) were produced on the AddUp FormUp 350 using a four-laser configuration. The chosen material was a corrosion-resistant, high-strength tool steel based on 1.2083 / PM420, which is well suited for injection molding and supports high-gloss polished surfaces (class 1). After printing, the parts were deburred, heat treated, and separated from the build platform. Final machining was completed at HARTING to achieve the required tolerances and surface finish.

The Results

Thermal performance was evaluated by recording temperature patterns on molded parts using a thermal imaging camera. Measurements were taken on parts produced with the conventional tool and with the additively manufactured tool under the same operating conditions.

After 15 seconds of residual cooling time, the additively cooled tool showed hotspot temperatures that were approximately 10 °C lower than those observed with the conventional tool. The thermal profile of the AM tool at 15 seconds matched the profile of the conventional tool at 20 seconds, confirming a meaningful acceleration in heat removal.

These findings demonstrate several clear improvements:

• Residual cooling time reduced by more than 25 percent, from 20 seconds to 15 seconds
• More uniform temperature distribution across the molded part, with hotspot regions significantly reduced
• Improved thermal stability that supports consistent quality at high output levels

The collaboration between AddUp and HARTING confirms that conformal cooling produced through L-PBF can resolve the limitations of straight-line cooling channels. By integrating fully three-dimensional cooling paths inside a single-piece mold insert, the process improves throughput, increases tool reliability, and provides a scalable model for other Han-Eco series tools.