Composite Wood Article Density Gradient Additive Cost
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high cost of additives in wood composites due to their widespread incorporation across the entire composite component, and the susceptibility of laminated wood composites to delamination and negative market perception.
Innovation Solution
A non-laminated composite article with a matrix and filler material embedded, featuring a density gradient and varying filler-to-matrix ratio across its thickness, where additives are limited to specific regions for protection, and a method of forming this article using dual extruders in an extrusion process to create regions with different compositional makeups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additives are incorporated throughout the entire wood composite component, then protection against discoloration, mildew, and ultraviolet light exposure is provided, but the cost of additives increases significantly
Solution Approach 1:
The patent applies local quality by creating a cap layer with a different composition than the substrate layer. The cap layer contains a higher concentration of additives (pigments and stabilizers) specifically at the surface regions where protection is most needed, while the substrate layer contains fewer additives. This localized distribution of additives provides effective protection against discoloration, mildew, and ultraviolet light while reducing the overall quantity and cost of additives required.
2Quantity of substance
If a thin cap layer with additives is added to protect the substrate layer, then the amount and cost of additives is reduced, but the distinct cap layer becomes susceptible to delamination and negative market perception
Solution Approach 1:
The patent merges the cap layer and substrate layer into a single integrated composite article with a continuous filler material distribution. The filler material presents a density gradient that transitions smoothly from the substrate layer to the cap layer, eliminating the distinct interface between layers. This merging approach maintains the protective function of surface additives while preventing delamination and avoiding the negative market perception associated with laminated structures.
3Quantity of substance
If a laminated structure with distinct cap layer and substrate layer is used, then additive cost is reduced, but the structure becomes susceptible to delamination
Solution Approach 1:
The patent applies parameter changes by creating a density gradient in the filler material distribution across the composite article. The filler material density transitions continuously from the substrate layer to the cap layer, changing the physical parameter of density rather than maintaining a sharp interface. This gradual parameter change eliminates the distinct boundary that causes delamination in laminated structures, while still allowing the cap layer to contain concentrated additives for protection.
Data Source
AI summary
A composite article includes a matrix having first and second opposing surfaces defining a transverse dimension and a filler material embedded in the matrix. The filler material presents a density gradient in the transverse dimension wherein a minimum filler density is at the first surface. In one embodiment, the composite article is a non-laminated article defining first and second regions wherein the first region encompasses the first surface. The first region has a filler-to-matrix ratio that varies along the transverse dimension, the filler-to-matrix ratio being at a minimum at the first surface. The first region can include one or more additives. A method for forming a composite article includes injecting first and second compositions into a die head at different points so as to produce a partially mixed composition that is discharged from the die head. The second composition contains less filler material than the first composition.