Reinforcement of Cellulose Nonwovens with Thermoplastics Lattices
Lead:
WEAV3D
Partners:
Volkswagen Group of America, University of Tennessee, Knoxville (UT)
Cost share:
IACMI: 69%
Industry: 31%
Duration:
October 2024 — June 2025
Problem statement
UT and VW had previously developed a novel paper composite material using existing recycled paper feedstock commonly available but discovered significant forming issues with complex parts. Therefore, they involved WEAV3D to tackle the challenge of proving how this composite could be used to form complex parts and parts with deep draw, with the ultimate goal to lower material emissions in vehicles.
Project goals:
- Develop a method using WEAV3D composite lattice materials to eliminate tearing of paper composite during forming of complex shapes
- Characterize the effect of adding lattice to the flexural properties and water uptake of the paper composite
Technical approach:
WEAV3D’s composite lattice materials, produced from thermoplastic unidirectional (UD) tapes, have been previously validated in compression molding processes and were selected to control elongation and stresses within the paper composite during forming. WEAV3D produced lattices from both glass/PP and flax/PP unidirectional tapes, which were combined with paper composite materials in 3 geometries: flat panels (at UT), complex surrogate part geometry (at WEAV3D), and a full-scale part geometry (at VW’s supplier, Antolin). Flat panels and full-scale parts were characterized for mechanical properties and water uptake, while the surrogate parts and full-scale parts were characterized for formability.
Deliverables & Outcomes:
16 full-scale paper composite parts were molded: 3 control, 3 with glass/PP lattices, and 10 with flax/PP lattices. Parts with properly located lattices exhibited no through-tearing of the paper composite, validating the hypothesis that UD tapes can improve paper composite formability. Water uptake, which is frequently a concern for natural fiber composites, was observed to be materially the same in control as with flax fiber lattices, while glass lattices demonstrated a significant decrease in water uptake as glass is not hydrophilic.
Recognition:
SPE ACCE – Part nominated for Most Innovative Part Award, SPE ACCE and SPE TPO – conference presentations
Potential Impact:
- Enhanced formability of low melt strength thermoplastic materials (applicable beyond paper composites)
- Expanded use of natural fiber in complex automotive parts