Accelerated Prototyping to Accelerated Production

To get new products to market faster by lowering the time and cost of prototypes, Rodriguez started working with 3D printers several years ago.

Although 3D printers were excellent at producing design prototypes, early attempts to 3D print mould tooling lacked durability. When the 3D printed moulds were used in blow moulding machines, they could produce only about 100 bottles before the mould began to fail. This prompted Rodriguez and his team to explore using a hybrid approach, combining parts of a conventional metal mould with 3D printed inserts.

This hybrid model – which PepsiCo patented in late 2020 – involves using a universal metal outer mould shell that fits into most commercial blow moulding machines. PepsiCo then explored using additive manufacturing to print only the essential internal parts of the mould that yield the final product’s geometry.

Exploring the 3D Printed Solution

Working with Chicago-based additive manufacturing technology distributor Dynamism, the PepsiCo team explored industrial 3D printing solutions that could meet their requirements for both size and materials.

“Our relationship with PepsiCo began years ago with desktop 3D printers for their design prototyping,” says Dynamism CEO Douglas Krone. “When their needs turned to industrial applications, we introduced them to 3D printers designed for production industrial parts.”

Between 2020 and 2022, Rodriguez conducted proof-of-concept trials with a pilot-plant-scale blow moulder at a third party, running bottles at a rate of 600 to 800 bottles per hour, with a single hybrid mould. The modular mould set concept was a success, but the durability of the materials was still a challenge.

“When tackling a solution for mould tool generation using additive manufacturing, we were focused on identifying a material that would withstand the blow moulding conditions typically found in our production environment,” says Rodriguez. “In blow mould heat set applications, it is common in the industry to heat the moulds to a temperature of about 140ºC. It was also important the material be able to withstand a blow pressure of 40 bars.”

The only viable material solution at the time Rodriguez started his research about three years ago was cyanate esther, he says. “Since then, the major material suppliers, such as Henkel Loctite and BASF, accelerated their material development for additive manufacturing applications.”

Henkel introduced its XPEEK147 material about a year ago, which provided several advantages cyanate esther, according to Rodriguez. The team applied a backing of dental stone to the printed inserts to give the mould cavities the compressive strength needed for blow moulding pressure. It then used a modified, lab-scale Blowscan stretch blow moulding machine from Northern Ireland-based Blow Moulding Technologies to produce the actual test bottles.

PepsiCo has been producing bottles on a daily basis using its hybrid tooling approach for the past few months, says Rodriguez. “Time and cost are obviously important, but more important is to have the flexibility to run through a number of different design iterations at a record pace so that we can evaluate performance in all of the downstream activities. That really is what helps us to accelerate.”

These downstream activities include confirming how the bottle will perform on PepsiCo’s packaging lines, in vending machines, and throughout its distribution network.

The blow moulding trials at PepsiCo’s R&D centre provided the data that showed the samples from the 3D printed mould were comparable to samples from a metal mould.

Rodriguez has 3D printed moulds on the Carbon M2 printer, the Stratasys J55, and the Markforged X5, to validate that the mould-tool concept is printer agnostic, but ultimately chose the Nexa3D NXE 400 and its xPEEK147 material from Henkel Loctite for the 3D printed tool inserts.

The NXE 400 is large enough to print several mould parts at the same time, plus it’s fast, which speeds up the iteration and production process.