New Materials for Large-Format Additive Applications

2022-07-02 03:11:45 By : Ms. Alice Lou

New materials for large-format additive manufacturing (LFAM) recently became available, including a biopolymer, a fire-retardant material and a translucent feedstock.

DIM 20-FR, from Massivit 3D, Lod, Israel, is the first flame-retardant, photopolymeric gel developed for 3D printing, according to the company. It complies with the highest standard for flame-retardant materials set by the Underwriter Laboratories, UL94-V0. The material is intended for end-use parts in the transportation industry where material safety is critical.

“The fire-retardant (material) is for people movers, any type of transportation that has those type of requirements, whether in Europe or in the U.S.,” said Mike Clark, composite sales manager for North America at Massivit 3D. “Even if it’s on the outside of a train, they don’t want something that’s highly combustible.”

So a customer with a legacy part that has no mold or who needs only one can 3D print the part with the fire-retardant material.

Another new material from Massivit 3D is Dimengel 300, which has high translucency. Clark sees its use largely for esthetics on prototypes where a designer might use it to simulate window glass or even a finished product with a lighting feature.

As with Massivit 3D’s existing portfolio of proprietary materials, DIM 20-FR and DIM 300 enable fast production of large, custom parts that cure on the fly, enabling ready-made solid objects straight off the printer. Dimengel facilitates the production of complex parts with little or no support structures required, according to the company.

Massivit 3D also tweaked the chemistry of its existing UV-cure material to make it water-breakable for use in a new 3D printing process used by the company’s Massivit 10000 model, also new.

Meanwhile, NatureWorks, Minnetonka, Minn., offers a new material from its Ingeo portfolio, IngeoD3700, specially designed for use in LFAM. It’s available in either pellet or filament form.

In LFAM, the higher rate and volume of polymer deposition can result in excessive warpage with materials such as ABS, or significant shrinkage as with some polyolefins or general-purpose PLA grades. This can result in costly failed prints as warping pulls the part away from the print bed or causes layer separation.

By controlling the polymer’s microstructure, the resulting amorphous PLA grade, Ingeo 3D700, has a low material shrink rate which is critical for reducing warpage, improving gap fill and adhesion and ensuring successful prints.

The new Ingeo 3D700 is already in use for metal casting. Using a direct resin-to-print process, TuoZhuo New Materials Technology Co., Ltd., Shanghai, prints sand casting molds that can be as tall as 1–2 m (3.3–6.6'). The 3D printed molds are increasingly used to replace the foundry’s traditional wood molds because they are faster to produce, more cost efficient, and easier to maintain. The wood molds eventally warp due to moisture.

“There is no warping or deformation when printing with an amorphous PLA grade like Ingeo 3D700,” stated Gabino Chen, project manager at TuoZhuo. “Using ABS, PETG or PA in prints of this size is difficult, which is why it’s important to use PLA and useful to have a PLA grade specifically designed for large format printing.”