This study investigates the utilization of spent coffee grounds (SCG), a major local agricultural by-product in the Philippines, as a sustainable, non-toxic pigment source for formulating a novel wax-based crayon medium. The goal is to optimize the formulation to achieve desirable mechanical strength, smooth application, and sufficient color saturation, thereby valorizing agricultural waste and directly contributing to SDG 12 (Responsible Consumption and Production) by significantly reducing waste and promoting sustainable material use.
SCG sourced from local Philippine coffee establishments was fully dried and milled into a fine pigment powder. Crayon prototypes were fabricated using a controlled melt-blend process, varying the ratios of pigment powder, paraffin wax (primary base), and refined coconut oil (binder/dispersant) across multiple trials. The resulting crayons were characterized by testing mechanical hardness, color intensity, and application performance (assessed for lay-down smoothness and adhesion on paper). The process itself aims to align with SDG 9 (Industry, Innovation, and Infrastructure) by demonstrating local technological innovation in materials science.
It is hypothesized that a formulation with a specific pigment-to-wax ratio (e.g., 1:10) will offer the optimal balance, yielding a durable crayon with rich sepia tones. High pigment loads are expected to increase color intensity but may negatively impact structural integrity and application smoothness. The development of a local, non- toxic pigment source also supports efforts towards SDG 13 (Climate Action) by offering a low-carbon alternative to imported, synthetic art materials.
This research aims to validate the potential of SCG as a valuable art material within the Philippine context, providing a scalable, non-toxic, and sustainable alternative to conventional synthetic crayons while serving as a model for local waste-to-resource innovation.