Recipient Organization
INNOVASEA SYSTEMS INC
35 FRANKLIN ST
AUGUSTA,ME 04330
Performing Department
(N/A)
Non Technical Summary
The purpose of this USDA SBIR Phase I project is to determine the feasibility of a novel wood fiber based composite material for structural elements of marine structures, particularly the structural frame of the aquaculture pens manufactured by InnovaSea Systems.InnovaSea has been manufacturing and marketing the Aquapod spherical geodesic fish pens since 2006 and has learned much in the years since we began, steadily improving the product design and construction. An aquaculture structure operates in the marine environment, one of the most demanding of environments, one in which most affordable materials succumb to environmental degradation quickly. It could be argued that the marine environment, especially in a stationary year round use such as an aquaculture net pen, is the most demanding of all.InnovaSea has spent years searching for structural materials that provide greater strength and stiffness at an affordable price. The Aquapod cages are currently constructed using fiberglass-reinforced High Density Polyethylene (HDPE) plastic for the primary structural plastic lumber. This is the primary commercially available plastic lumber available in the market presently that approaches the structural properties required. The HDPE plastic lumber has a number of merits, but it is difficult to fasten, cannot be coated, and has relatively low strength and stiffness. Using this material, InnovaSea has increased the size of the cage with successive models until we now seem to be near a structural limit of the HDPE materials.We have searched for a better product, reasonably priced, already produced and sold in the market. Price is an issue as the large volume of structural material in Aquapods contributes to our price being near the top end of the market for net pens. We need to use commodity type products and the more exotic but costly materials such as carbon fiber are simply not an option. It appears that we are using the best commercially available plastic lumber already, so we need to consider new materials not yet on the market.SMA-WPC is a thermoplastic composite made by combining engineering plastic SMA (styrene maleic anhydride copolymer) and wood fiber. SMA-WPC plastic lumber shows significant promise as a replacement for the HDPE plastic lumber.The purpose of this Phase 1 project is to test the SMA-WPC in the marine environment, making a side-by-side comparison with other materials. We will use a combination of laboratory testing and field exposure test in the ocean environment. We expect to confirm the durability of the material in the ocean so that we can take advantage of it's known superiority in structural properties.SMA-WPC is not yet a commercial product but InnovaSea will be working with the University of Maine (UMaine) researchers who have developed the production process in their laboratory using their commercial scale production system. If the material properties can be proven for this marine application, it can be brought to commercial production either by InnovaSea or under contract with another company.Changing from HDPE plastic lumber to SMA-WPC would improve the Aquapod structural strength and make it relatively insensitive to heat issues. Using SMA-WPC would enable the company to develop new and superior methods of fastening and fabrication of panels thus enabling the company to increase the durability, size and commercial viability of the Aquapod product line.While InnovaSea has identified the need for this material, it will also be applicable to many other marine structures and projects. The development of a reasonable-cost inert and impervious wood fiber based lumber for use in dynamic marine environments opens up a realm of potential uses in marine applications. The information derived from this project would allow the evaluation of suitability for those projects.
Animal Health Component
50%
Research Effort Categories
Basic
(N/A)
Applied
50%
Developmental
50%
Goals / Objectives
The goal of this USDA SBIR Phase I project is to advance the state of knowledge of a new wood fiber based composite material for structural elements of marine structures, and in particular the Aquapod geodesic fish pens. SMA-WPC is a thermoplastic composite material made by a special process of combining the engineering plastic SMA (styrene maleic anhydride copolymer) and wood fiber. SMA-WPC plastic lumber shows significant promise as a replacement for wood composites and other types of plastic lumber, and the project will study the feasibility of using it in aquaculture and other marine structures.The Phase I Objectives are:Determine the appropriateness of SMA-WPC material in marine settings.Test the effects of prolonged and intermittent submersion and outdoor exposure on the durability and strength of the material with testing in the laboratory and under marine field exposure.Compare the SMA-WPC material to the existing HDPE materials now used in both these settings.Determine design properties for use in the engineering design and analysis of Aquapod structural elements.Test alternative connection designs and fabrication techniques using SMA-WPC.Identify the cost/benefit of SMA-WPC composite material versus other plastic lumber. Identify material cost and production related issues enabling an economic comparisonwith existing materials and fabrication methods for the Aquapod.
Project Methods
Task Organization of the Project:Final design of the test programDetermine formulations to be tested- laboratory manufacturing trialsProportions of polymer vs fibersFoaming and other agentsTwo types of wood fibersNatural wood fibersStora Enso ThermoWood fibers (A special process that treats the wood cellular structure and which is expected to improve properties of interest in the marine environment)Fabrication trials and creation of test specimens and test frames and assembliesLaboratory tests of new composite lumber samples,independent of the exposure tests. Test results will characterize the "before" properties for exposure specimens. Samples of currently used HDPE lumber types will be tested for comparison.Exposure tests in the Atlantic Ocean at a Maine coastal site will be the primary test samples, A secondary location for simultaneous exposure tests but less extensive monitoring will be at a commercial fish farm in the Sea of Cortez. This will enable us to expose the SMA-WPC to two distinct marine environments and temperature regimes. These tests would make use of the natural environment to stress the material. The samples would be observed monthly and examined for deterioration or change. Observation would include microscopic examinations of samples retrieved during visits.Laboratory tests on field specimens. A portion of the specimens will be retested, "after" specific lengths of exposure, for changes in density, strength, elastic modulus, surface hardness and fastener strength. (These tests will take place within the allowed period of the grant, but plans to continue with longer term exposure after the grant ends, with periodic follow-up will occur.)Cost analysis to develop cost of production and deployment comparisons with existing materialsFinal ReportProperties of particular interest to us for use in aquaculture structures:Testing protocols and definitions will generally follow the ASTM standards for evaluation of wood composite materials, selected as appropriate to derive marine related data of interest. The main test procedures are incorporated by reference in ASTM D7031"Standard Guide for Evaluating Mechanical and Physical Properties of Wood Plastic Composite Products." The following is a list of the specific properties to be researched.Structural PropertiesDensityStiffnessDuctility, overloading capability, brittlenessStrength for rupture in tension and bending,Dynamic loading and stress reversals, fatigueDimensional stabilityHardnessDurabilityChanges in the above properties with temperature and time of exposure, ( Thestructurewill be expected to survive many years of use before repairs or rehabilitation.)Behavior with submergence -water infiltration into the pores, with prolonged deep immersion, changes in density and integrityUV resistanceBehavior with intermittent drying and wettingFreeze-thaw resistanceReaction with associated materials such as steel coated mesh, galvanized steel parts, copper and aluminum, in a seawater environmentBiofouling - surface properties, treatability with anti-fouling coatings, support or resistance to growthIn addition, research will include studies of activities and aspects that affect the cost of production:Methods of extrusion, molding, etc.Cutting and machining performanceUniformity of properties within and between batchesConnection methods by fasteners, welding and adhesivesPenetration and holding of staplesWhile the Phase 1 grant final report will be a milestone, if the material shows successful performance up to that point, the intent of the company is that the exposure tests will continue for a longer term. The grant period is fairly short and will likely miss a full winter season of exposure, so longer term exposure and monitoring is necessary.