Engineered from the ocean floor up.
Coffee Kelp BioMulch is the product of materials science, agricultural engineering, and a deep commitment to closing the loop on two of agriculture's most overlooked waste streams.
Patent Pending
Twin-screw extrusion: the process that makes it possible.
Our core innovation is a twin-screw extrusion process that co-processes spent coffee grounds and kelp-derived biopolymers into a continuous, uniform film. Unlike single-screw systems, twin-screw extrusion delivers the shear forces and residence-time control needed to fully disperse hydrophilic coffee particles within a hydrophobic biopolymer matrix — without delamination or brittleness.
Feedstock preparation
Spent coffee grounds are dried to <8% moisture and milled to a consistent particle size (80–120 µm). Kelp biomass is processed into a sodium alginate concentrate, then blended with PHA (polyhydroxyalkanoate) pellets at a 3:7 ratio.
Co-extrusion
The blended feedstock enters a co-rotating twin-screw extruder at 165–180°C. Screw geometry is optimized for distributive mixing, ensuring uniform coffee particle dispersion and preventing agglomeration that would create weak points in the final film.
Film formation
The melt exits through a flat-die head and is drawn down to a target thickness of 25–40 µm via a chill-roll system. Thickness uniformity is maintained within ±2 µm across the web width.
Surface treatment
A corona discharge treatment improves surface energy for downstream printing and labeling. No chemical coatings are applied — the film's functional properties derive entirely from its biocomposite formulation.
Biocomposite Materials
Two waste streams. One high-performance film.
The mechanical and agronomic performance of Coffee Kelp BioMulch emerges from the synergistic interaction of its two primary feedstocks.
Functional filler & soil amendment
Spent Coffee Grounds
Coffee grounds contribute cellulosic reinforcement to the polymer matrix, improving tensile strength and reducing elongation at break. Upon soil incorporation, they release nitrogen, potassium, and phosphorus — functioning as a slow-release fertilizer.
Matrix binder & moisture regulator
Kelp-Derived Biopolymers
Sodium alginate from brown kelp (Macrocystis pyrifera) forms the continuous phase of the biocomposite. Its hygroscopic nature creates a moisture-buffering effect at the soil surface, reducing evaporative loss while the film remains intact.
Mechanical Properties
Tested to perform in the field.
Prototype films have been characterized under ASTM D882 (tensile), ASTM D1003 (haze/clarity), and ISO 14855 (biodegradation). Key results from our most recent formulation batch:
Development Roadmap
From lab to field.
Formulation development
Identified optimal coffee:kelp:PHA ratios and extrusion parameters for film-grade output.
Mechanical characterization
ASTM tensile, elongation, and tear resistance testing on prototype films.
Greenhouse trials
Controlled trials measuring weed suppression, soil moisture retention, and crop yield vs. LDPE and bare soil.
Field pilot program
Partner farms in the Pacific Northwest for real-world mechanical laying and multi-season performance data.
Scale-up & commercialization
Transition from pilot-scale extruder (50 kg/hr) to commercial-scale line (500+ kg/hr) with co-manufacturing partners.
Interested in the science?
We welcome research collaborations, field trial partnerships, and technical inquiries from agronomists, universities, and agricultural institutions.