Category: 3D Systems

Metal 3D Printed Conformally-Cooled Injection Mold Increases Production Rate by 30%

Large temperature variations in an injection molding cooling cycle can dramatically increase the risk of parts warping. When tests of a conventionally designed and manufactured injection molded automotive duct yielded temperature fluctuations of 132˚C throughout the process, B & J Specialty, Inc. recommended conformally-cooled mold inserts to its client for more even cooling. To achieve this, B & J Specialty engineers relied on 3D Systems’ Cimatron® software to design the molds and conform the internal cooling channels parallel to the part’s surface. To accurately deliver these complex internal channels, metal additive manufacturing on 3D Systems ProX® DMP 300 was used for production. The new conformally-cooled mold insert reduced temperature variation throughout cooling to 18˚C, and shrank cycle time on the mold from 1 minute to 40 seconds, an overall productivity improvement of 30%.

Jarod Rauch holds a 3d printed conformally cooling part in front of the DMP 300

The ProX® DMP 300 can hold tolerances of three or four thousandths of an inch according to Jarod Rauch.

Sub-Optimal Cooling Lines Lead to High Temperature Variations

Conformally-cooled molds take advantage of modern technology to solve an age-old problem. Many injection molded parts have curved surfaces, yet the drills used to create cooling channels only produce straight lines. In most cases this means it is impossible to match cooling lines to part geometry. Conventionally-produced straight cooling lines have to run beyond the outermost features of the part to avoid interfering with the cavity, which means that features closer to the part’s center are typically far from the nearest cooling line. This often results in significant temperature variations over the volume of the part at the start of the cooling process.

The automotive duct B & J Specialty redesigned for more efficient cooling features multiple irregular and curved surfaces. In the original mold design, straight cooling lines were drilled through a hub and stator block that were used to adjust the mold geometry to account for warpage. As is often the case with irregular shapes, several key features of the duct were distanced from the cooling lines due to the limitation of the straight channels. The resulting temperature variations generated various residual stresses that tended to bend the part as it cooled. In the past this problem was addressed by extending the cooling cycle to ensure the part was fully solidified before removing it from the mold and adjusting the inserts to account for any remaining warpage. The problem with this approach was that lengthening the cooling cycle reduced productivity and increased the cost of making the part.

Small image depicting 3d printed part - it has cooling line channels that are curved, conforming to the optimal shapes the part needs to cool

Metal 3D printed conformal cooling lines reduced temperature variation by 86% compared to conventional straight line channels.

Updating the Mold with Conformal Cooling Channels

According to Jarod Rauch, Information Technology and 3D Printing Manager at B & J Specialty, Inc., the automotive duct appeared to be a strong candidate for a modified conformal cooling design, which would help to improve final part quality, reduce scrap, and shrink the cooling cycle. B & J Specialty proposed this solution to their client, an automotive supplier, who agreed to test the new methodology. Provided with the CAD file of the original geometry, B & J engineers got to work using 3D Systems’ Cimatron Mold Design software. “Cimatron is pretty much a one-stop-shop software that allows us to have full CAD functionality for designing and gives us the option to roll right into build preparation from the same package.”

Rauch says B & J Specialty discovered Cimatron while researching metal 3D printers for conformal cooling applications. “We saw that 3D Systems provides a complete end-to-end solution including mold design software, build preparation software and 3D printers, and that’s what got me excited about this solution,” says Rauch. “3D Systems not only focuses on the machine, it also focuses on how engineers design for additive.”

An image of a digital 3d model with visualized indicators related to cooling performance

Integration between Cimatron and Moldex3D make it easy to simulate the injection molding cycle to evaluate designs digitally.

Working within Cimatron, B & J engineers removed the original straight cooling lines and replaced them with conformal ones that maintained a consistent distance from the part’s surface. Final mold production with metal 3D printing allowed the engineers to design complex channels with improved cross-sections and interface surfaces. These features help ensure turbulent flow, which further increases the amount of heat transferred from the mold to the coolant to assist in efficient cooling. The ability to cool molded parts more efficiently also helps ensure part quality by reducing the occurrence of part defects such as warping and sink marks. A direct path to higher quality parts saves time and money for both the tool builder and the mold operator by limiting the amount of corrections, trials and sampling required to achieve the desired results.

Setting Expectations with Accurate Simulation

B & J engineers then exported the mold file from Cimatron to Moldex3D, an injection molding simulation software for integrated cooling simulation. “The integration between Cimatron and Moldex3D make it easy to simulate the complete injection molding cycle and map temperatures across the mold and part to identify hot and cold spots, and simulate the effect of different cooling times,” says Rauch. The simulation also helps highlight areas where redesign may improve the overall cooling strategy before any investment is made in a physical part. Comparative simulations between the original mold design and the new design with conformal cooling lines showed a dramatic improvement in temperature distribution for the new part, reducing temperature variation by 86%.

3D Printing Mold Inserts with Conformal Cooling Lines

B & J engineers then used 3D Systems 3DXpert™ metal additive manufacturing software to prepare the mold insert designs for production. They imported the part data, optimized the geometry, calculated the scan-path, arranged the build platform, and sent the job to their in-house 3D Systems ProX DMP 300 metal 3D printer directly from the 3DXpert software.

The ProX DMP 300 directs a high precision laser to selectively build up metal powder particles in thin horizontal layers, one after the other using 3D Systems LaserForm® material. For this automotive duct mold, B & J Specialty used 3D Systems’ maraging steel material. “The ProX DMP 300 is ideal for producing conformal cooling lines because of its extraordinary accuracy,” Rauch said. “We can hold tolerances of three or four thousandths of an inch.” 3D Systems’ patented Direct Metal Printing (DMP) technology enables smaller material particles to generate the finest feature detail and thinnest wall thicknesses. A surface finish quality of up to 5 Ra μm (200 Ra micro inches) is achievable, and requires less post-processing.

Picture of happy engineer standing in front of DMP ProX 300

B & J Specialty has increased productivity throughput by 30% using conformal cooling channels delivered with direct metal 3D printing.

Substantial Gains in Productivity

When printing was complete, B & J Specialty scanned the inserts into 3D Systems Geomagic® Control X™ inspection and metrology software using a blue laser line 3D scanner and overlaid the mesh on the as-designed geometry to validate the metal 3D printed mold inserts. The inserts were shipped to the automotive supplier who installed them on its molding machine. “Benchmark testing demonstrated that the more even cooling provided by the conformal lines made it possible to reduce the cycle time and increase productivity throughput by 30%,” Rauch said. “The life of the mold is also expected to be substantially higher since the cycle time reductions provided by conformal cooling make it possible to reduce the injection pressure, which in turn reduces wear on the parting line and intricate details of the mold.”


PPI-Time Zero Prints High Value Reusable Packaging with ProJet® MJP 2500

Contract manufacturer PPI-Time Zero promises its customers performance, precision and integrity. As part of its process to deliver reliable, high quality components and products to military, aerospace, medical, controls and instrumentation markets, PPI-Time Zero does a lot of prototyping. According to Germ Orndorff, Senior Advanced Engineering Manager at PPI, prototyping plays an important role in confirming client expectations and streamlining communication among internal departments.

To drive its prototyping workflow, PPI-Time Zero uses a 3D Systems ProJet® MJP 2500 Plus that also serves a number of additional applications, including jigs, fixtures, and mold modeling, among others. Beyond these routine tasks, PPI-Time Zero has found a novel 3D printing application that saves the company an average of 40-50 hours per week using the engineering-grade VisiJet® ProFlex (M2G-DUR) material.

A sealable, watertight 3D printed cover ensures costly motors are not damaged during shipping or cleaning.

A sealable, watertight 3D printed cover ensures costly motors are not damaged during shipping or cleaning.

A need to protect high value motors

At PPI-Time Zero, a project is not complete until the order arrives safely in the hands of its customers. For the contract in question, PPI-Time Zero is responsible for manufacturing costly motors that must be shipped to a client in the defense, aerospace and security industry for final installation. According to Orndorff, these motors posed a two-fold challenge. The first was in finding an efficient way to protect the motor and gears from debris and fluids in the cleaning process; the second was in protecting them throughout shipping. Orndorff says that although incidents in transport were infrequent, the high cost of each motor and the quality standards of PPI warranted a solution that would preclude any mishaps. The solution to each challenge came from a single source with the introduction of VisiJet ProFlex to PPI-Time Zero’s material portfolio.

The automotive duct B & J Specialty redesigned for more efficient cooling features multiple irregular and curved surfaces. In the original mold design, straight cooling lines were drilled through a hub and stator block that were used to adjust the mold geometry to account for warpage. As is often the case with irregular shapes, several key features of the duct were distanced from the cooling lines due to the limitation of the straight channels. The resulting temperature variations generated various residual stresses that tended to bend the part as it cooled. In the past this problem was addressed by extending the cooling cycle to ensure the part was fully solidified before removing it from the mold and adjusting the inserts to account for any remaining warpage. The problem with this approach was that lengthening the cooling cycle reduced productivity and increased the cost of making the part.

The addition of VisiJet ProFlex solved two needs for PPI Time Zero, saving over 40-50 man hours a week.

The addition of VisiJet ProFlex solved two needs for PPI Time Zero, saving over 40-50 man hours a week.

Versatile 3D printing materials

In conjunction with high resolution and good surface finish, the ProJet MJP 2500 Plus offers PPI-Time Zero a versatile 3D printing solution in terms of material capability. As part of validating new materials for use, Orndorff prints a standard step gauge to verify tolerances and get a sense of material properties. When he did this with VisiJet ProFlex, his observations of the material gave him an idea for how he could bring greater efficiency into his team’s workflow. “The VisiJet ProFlex printed perfectly in terms of dimensions, and also demonstrated the ability to deform,” said Orndorff. “As it turns out, it filled a desperate need in our workflow for improving the cleaning and shipping of these motors, and we have resolved both issues with the same print.”

A time saving solution

Although PPI-Time Zero had a manual process to seal the motors from contaminants while cleaning, there was no previous solution to protect them from damage during shipping. Furthermore, the manual sealing process was time consuming, taking upwards of half an hour per motor. On a contract for 50,000 units, the man-hours added up quickly.

PPI Time Zero also uses VisiJet ProFlex for grips on handheld tools and devices.

With VisiJet ProFlex, Orndorff has been able to design and print a snap fit cover that can be assembled around the motor and sealed with a clamp to make it watertight for cleaning. Due to its low modulus, semi-rigid material properties, VisiJet ProFlex is dimensionally stable without being brittle, which also allows the cover to effectively protect the motors in transit. According to Orndorff, no cover is ever wasted: “The covers are sent back and we use them again in later cleanings and shipments, so these are good for repeat uses and are incredibly effective at ensuring the quality of our shipments.”

With this solution, PPI-Time Zero has found a way to cut significant time from its process as well as safeguard the arrival of its products. “We probably do 80 to 100 of these motors a day, so we have already felt the impact of this improvement,” says Orndorff.

PPI-Time Zero has also found VisiJet ProFlex to be excellent for grips on handheld tools and devices, and is expanding applicable use cases to bring more value to its workflow and customers.

 


Span Tech Develops Innovative Conveyor Systems with MultiJet 3D Printing

From manufacturing to e-commerce, effective conveyor systems make the pace of modern life possible. Founded in 1989, Span Tech is recognized as a global leader in unique and customizable conveyor systems that are used in a wide range of industries, from food and beverage production to packaging distribution, cosmetics, pharmaceuticals, and more. Span Tech has built and sustained its reputation through constant innovation and a dedicated team of engineers who are committed to introducing meaningful improvements to conveyor capabilities.

Span Tech 3D prints its conveyor prototypes in full size using the ProJet® MJP 2500 Plus.

Span Tech designs and manufactures modular conveyors made with durable plastic chain systems that can meet any size and motion requirement, from inclining, to curving, to helical. In the world of smoothly running high-speed switches, spirals and wedges, prototyping is key for cost-effective development. Always on the lookout for innovative solutions to keep ideas and test systems flowing, Span Tech owner Bud Layne has made 3D printing part of his company’s development process for the past several years. To further increase its in-house capability, Span Tech decided to purchase a 3D Systems ProJet® MJP 2500 Plus and VisiJet® Armor (M2G-CL) and VisiJet® M2R-BK materials. Since installation, Span Tech has used these 3D printed parts to validate designs within a test system to introduce faster and more frequent design cycles, increase innovation, and boost confidence in final tooling investments.

Printing true-to-CAD models in robust materials allows Span Tech to print and test new conveyor assemblies quickly.

Confidence in final molding investment

Before purchasing its MJP system, Span Tech prototyped using a small desktop 3D printer, occasional one-off 3D printed parts, and traditional machining, but Layne wanted his engineers to have access to a faster and more robust in-house solution to enable more thorough and cost-effective development. The accuracy and material properties of the ProJet MJP 2500 Plus and VisiJet materials answered those requirements and fit seamlessly into Span Tech’s workflow.

Span Tech’s final conveyor systems are an injection-molded plastic assembly of eleven to twelve parts, depending on the component’s placement within the system. In order to prototype these parts, Span Tech R&D Engineer Scott Barbour prints them in full size on the ProJet MJP 2500 Plus and assembles them just like the final product, with functional features such as snap fits, sliding connectors, and integrated metal pieces including shafts and bearings. Taking advantage of the ProJet’s build platform and accuracy, Span Tech is able to print parts ranging from the largest, which are roughly six inches by four inches, to the smallest, which are less than half an inch in diameter and only a few millimeters thick. (The ProJet MJP 2500 Plus has a build platform of 11.6 x 8.3 x 5.6 in (294 x 211 x 144 mm) and offers resolution of 800 x 900 x 790 DPI, 32µ layers.)

“With the ProJet 2500 we can go through trial and error before we invest in tooling so we don’t have to spend time and money updating the mold,” says Barbour. “The molds for each of these eleven or twelve parts cost thousands of dollars apiece, so getting the part design right before making the molds is a big cost saver.”

Materials that match functional requirements

A big motivation behind Span Tech’s purchase of the ProJet MJP 2500 Plus was to expand in-house material options. According to Barbour, the previous 3D printing solution Span Tech used did not offer the right material properties and produced parts that were brittle and grew fragile over time. With the ProJet MJP printer, Span Tech now uses two different VisiJet materials, capitalizing on the strengths of each to achieve the optimal properties required for its prototypes. These prototypes use both VisiJet Armor (M2G-CL), a tough, ABS-like clear performance plastic, and VisiJet M2R-BK, a high modulus, rigid black plastic.

“VisiJetArmor is a lot stronger than the material we used to use, and it doesn’t break and isn’t brittle,” says Barbour. He also says the rigid black material is durable and good for weight bearing: “All the VisiJet parts print out true to the CAD models and we are able to run them through our test system to evaluate the feasibility of our designs,” Barbour says.

Accelerating development cycles with real world feedback

Most recently, Span Tech has been using its ProJet to develop a new guide rail system. According to Barbour, the printer has been invaluable in accelerating design iterations and enabling the company to deliver consistent improvements. The Span Tech bracket is designed to move and can both collapse and extend. To prototype these brackets, Barbour prints each part separately and assembles them to get a sense of how the final product will fit together. When anticipated clearances are not viable once prototyped, updating the design is a simple matter of tweaking the CAD model in SOLIDWORKS® and printing it again. “We’ve gone through several cycles where we’ll set everything up and decide something needs to change, so we update each CAD file, print them out and try again,” says Barbour. For the guide rail system, Barbour says he has printed twenty or thirty test parts to perfect the final performance.

3D Sprint® software facilitates a streamlined and optimized transition from file to 3D print.

Smooth workflow keeps development in motion

Span Tech reports an easy transition from CAD file to 3D printed part and a more streamlined post-processing operation than previously experienced. Every 3D Systems’ plastic printer comes with 3D Sprint® software for plastic additive manufacturing, which Barbour says is simple to learn and navigate: “3D Sprint is intuitive and easy to use. I was able to figure it out before anyone even had time to show me, and we were able to train our intern on it in no time at all.”

Once parts have been printed, post-processing with the ProJet Finisher takes about an hour of hands-off time to melt the support material, followed by about 20 minutes in the ultrasonic cleaner with oil. The ProJet Finisher is a post-processing accessory offered by 3D Systems that alleviates the need for manual scrubbing of parts. According to Barbour, using oil delivers VisiJet Armor parts that are almost crystal clear, and VisiJet M2R-BK parts that are richly black. “I just take them out of the ultrasonic cleaner and wipe them off with paper towels and am good to go,” says Barbour.

Looking for future opportunities

The success Span Tech has had in prototyping its conveyor system assemblies has gotten the company thinking about other opportunities for 3D printing for its product lineup. “Once you get used to working with this capability, you start designing things that would work better for you, but that are only possible with 3D printing,” says Barbour. Although Span Tech is not yet using 3D printing for production, it is interested in expanding the range of its 3D printed applications to extend the time and cost savings it has experienced in prototyping.