{"id":163228,"date":"2021-04-20T11:51:32","date_gmt":"2021-04-20T03:51:32","guid":{"rendered":"http:\/\/facfox.com\/docs\/?post_type=kb&p=163228"},"modified":"2021-04-19T15:13:01","modified_gmt":"2021-04-19T07:13:01","slug":"know-your-materials-epu","status":"publish","type":"kb","link":"https:\/\/facfox.com\/docs\/kb\/know-your-materials-epu","title":{"rendered":"Know Your Materials: EPU"},"content":{"rendered":"

Elastomeric polyurethane (EPU) is a family of rubber-like materials developed by Carbon\u00ae<\/sup> for digital light synthesis (DLS). Similar to other elastomeric materials, EPU has a non-linear material response with a very high elongation to failure. This highly elastic material is suited for applications that require impact resistance or vibration isolation.<\/p>\n

Carbon\u00ae<\/sup> offers two different grades of EPU: EPU 40 and EPU 41. Although they have many commonalities, EPU 41 is slightly stiffer than EPU 40 and therefore has more shape rigidity, even under constant cyclic loading. However, the stiffer EPU 41 has a much lower elongation to failure, which means it\u2019s more prone to fracture at higher strain. Both EPU 40 and 41 are perfect materials for the integration of a compliant lattice structure, where the structure can be optimized or locally tailored for your given application requirements.<\/p>\n

MECHANICAL SPECIFICATIONS FOR CARBON\u00ae<\/sup> EPU 40 AND 41<\/h2>\n

EPU 40 mechanical specifications<\/strong><\/h3>\n

Ultimate tensile strength: 7.7 MPa
\nElongation at break: > 250%
\nTear strength: 23 kN\/m
\nStress at 50%: 1.9 MPa
\nStress at 100%: 3.0 MPa<\/p>\n

Read the Carbon\u00ae<\/sup> EPU 40 technical datasheet<\/a> for more details.<\/p>\n

EPU 41 mechanical specifications<\/strong><\/h3>\n

Ultimate tensile strength: 6.2 MPa
\nElongation at break: > 130 %
\nTear strength: 20 kN\/m
\nStress at 50%: 2.7 MPa
\nStress at 100%: 4.7 MPa<\/p>\n

Read the Carbon\u00ae<\/sup> EPU 41 technical datasheet<\/a> for more details.<\/p>\n

\n

Why use EPU 40 vs. EPU 41<\/h2>\n

The most obvious difference between EPU 40 and 41 is the natural coloring; EPU 40 is a standard black while EPU 41 is a distinctive linen green. Both EPU 40 and 41 can replace traditional elastic materials while providing good energy dissipation and compliance. Although the two are fairly similar, the details of your application might make one material advantageous over the other.<\/p>\n

EPU 40<\/strong><\/h3>\n

<\/p>\n

EPU 40 is Carbon\u00ae<\/sup>\u2019s original EPU material. The lower stiffness provides a more compliant structure that is well suited for applications that require dampening, energy dissipation and shock absorbance. Additionally, the high elongation to failure means that it can recover from very large deformations.<\/p>\n

However, due to the natural black coloring, parts printed with EPU 40 limits the color aesthetic options. We recommend EPU 41 if your part needs to be dyed a color other than black.<\/p>\n

EPU 41<\/strong><\/h3>\n

<\/p>\n

EPU 41 is Carbon\u00ae<\/sup>\u2019s latest addition to its EPU family. It\u2019s a production-grade elastomeric material with higher rigidity and resilience (energy return) than EPU 40. EPU 41\u2019s rigidity allows you to push the limits on part complexity because parts can be made from more intricate structures like lattices.<\/p>\n

Generally speaking, parts printed with EPU 41 have a smoother surface finish and require less post-processing, making them ready for customer-facing applications.<\/p>\n

\n
\n
\n

Popular applications<\/h2>\n

EPU materials lend themselves well for applications that demand abrasion resistance, tear strength, chemical resistance and temperature compatibility.<\/p>\n

Combined with the unique ability of both EPU 40 and 41 to create functional lattice structures, they can accommodate designs for demanding applications such as:<\/p>\n