Stratasys has filed a patent that targets a surprising bottleneck in PolyJet 3D printing: the need to run hot just to keep materials jettable.
Most 3D inkjet photopolymers are engineered to behave like “ink” only when warmed, because printheads demand low viscosity and rapid UV cure without nozzle clogging. In practice, that typically means heating the jetting system and materials into the 50C to 90C range. That’s workable on industrial machines, but it complicates everything else: energy use, thermal stability in the head, odor control, and any hope of printing temperature sensitive materials.
Their newly published patent application describes modeling material formulation systems designed to stay within inkjet friendly viscosity at much lower temperatures. The core claim is this: build each formulation from two or more curable components whose average molecular weight is no more than 500 g/mol, and tune the mix so viscosity is no more than 50 cPs at 35C.
A Chemistry Lever With System Level Consequences
The patent describes the problem in language PolyJet users will recognize: low viscosity, controlled surface tension, and fast UV curing are non negotiable if you want reliable droplet formation and clean nozzles. The new aspect here is a systematic approach to keeping viscosity down at 30C to 40C without giving up the mechanical and thermal properties customers expect.
To do that, the formulations mix hydrophobic and hydrophilic curable materials, including mono functional and multi functional components, plus optional “reactive diluents” with very low room temperature viscosity.
The document specifically lists typical PolyJet style performance targets: rigid families comparable to Vero, elastomeric families comparable to Tango and Agilus, and even Digital ABS style core shell strategies where one formulation emphasizes heat deflection temperature (HDT) and another emphasizes Izod impact resistance. UV photoinitiators, surfactants, inhibitors, pigments, and fillers are all part of the toolkit.
The Stratasys examples suggest their team was trying to preserve “digital materials” flexibility: voxel level blending of multiple base formulations to create gradients and composites. That matters because PolyJet’s competitive edge is not just resolution, but programmable multi material behavior at the voxel scale.
What It Could Change For PolyJet Users
If these formulations behave in real printers the way the patent suggests, the biggest benefit is not a new headline material, but a new operating envelope. Lower jetting temperatures could reduce warm up time, simplify thermal management, and potentially improve consistency by shrinking thermal gradients in the printhead and build area. It also opens the door to applications that are uncomfortable at 70C, such as printing around embedded components, more volatile additives, or temperature sensitive molecules (the patent specifically mentions biomolecules as a motivation).
The data tables in the document show why Stratasys is pursuing this: example formulations report viscosities around the mid teens cPs at 35C while maintaining HDT and impact numbers in the neighborhood of existing rigid and Digital ABS style materials, and elastomeric examples showing elongation above 290% with far lower viscosity than existing elastomeric formulations. That combination hints at reduced “human touch time” as well, because less heating can mean fewer temperature related print failures, fewer material handling constraints, and less time babysitting machine readiness.
Still, this is a patent, not a product announcement. The text is thin on the operational details that matter in production: shelf life in cartridges, long term stability under recirculation, odor and VOC behavior at room temperature, and whether lower temperature jetting changes cure depth, interlayer bonding, or matte versus glossy surface behavior in support contact zones.
If Stratasys commercializes any of this, it could become an enabling platform change rather than a single material SKU: PolyJet that behaves a bit more like an office safe appliance while keeping industrial grade multi material capability. What will their brand name be for this approach?
Via WIPO PATENTSCOPE
