PepsiCo Inc. is using additive manufacturing in addition to blow molding to develop beverage bottles faster at a reduced cost.
The Purchase, N.Y.-based company patented technology in late 2020 for a blow molding process that uses 3D printed mold inserts instead of metal tooling to create new bottle designs.
The hybrid technology compresses the time it takes to develop prototype tooling from four weeks to 48 hours and slashes costs from as much as $10,000 to $350 per mold set, according to Max Rodriguez, senior manager of global packaging R&D in the advanced engineering and design unit of PepsiCo's Valhalla, N.Y., research center.
"Time and cost are obviously important," Rodriguez said in a case study. "But more important is to have the ability 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."
For their research, Rodriguez's team 3D printed the internal parts of the mold, which determine the final bottle's geometry, but continued to use a universal metal outer mold shell, which fits into most commercial blow molding machines.
The researchers produced their test bottles with a modified lab-scale stretch blow molding machine built by Belfast, Northern Ireland-based Blow Moulding Technologies (BMT).
PepsiCo took delivery of the reengineered BLOWscan-brand machine earlier this year and its researchers have been producing bottles on a daily basis using its hybrid tooling approach for the past few months.
The results show complementary technologies like molding and 3D printing can open up new capabilities.
Meanwhile, conventional metal tooling for blow molding bottles starts with a CAD file of the package design and then it can take up to four weeks to machine a metal tool plus another two weeks to get a trial unit to do the actual blow molding.
Depending on its complexity, a single metal tool set can cost up $10,000, Rodriguez said.
The time and expense has prompted many research and development teams to turn to 3D printing to shorten the process. However, shortcomings still exist. For example, it takes up to three days to print a single blow molding tool from a material like digital ABS using 3D printer equipment that costs some $250,000.
Also, the resulting tool lacks durability and can only produce about 100 bottles before the mold begins to fail.
To overcome the challenges, PepsiCo researchers turned to 3D printer maker Nexa3D in Ventura, Calif., for a hybrid approach that combines parts of a conventional metal mold with 3D printed inserts.
Founded in 2016, Nexa3D makes a range of 3D printing products from desktop printers to industrial additive manufacturing systems.
PepsiCo researchers used Nexa3D's NXE 400 printer and a material called xPEEK147 by Henkel Loctite to 3D print the internal parts of the mold while keeping a universal metal outer mold shell.
To give the mold cavities the compressive strength needed for blow molding up to 40-bar pressure, the team applied a backing of dental stone to the printed inserts.
These hybrid-made molds then were successfully used with the BMT machine to produce more than 10,000 bottles before failure. The cost was up to a 96 percent reduction compared to traditional metal tooling.
A complete mold set can be made in 12 hours, with eight hours of 3D printing time and four hours of curing, according to the case study.
This approach "also facilitates our capability of validating our virtual tools because we are now able to pair them up with physical results," Rodriguez said, adding it will assist PepsiCo in its material characterization work, performance analysis and physical testing.
"Through the use of these capabilities, we expect our development cycle to improve by 30 percent," Rodriguez said.