Recipient Organization
RYNEL, INC.
11 TWIN RIVERS DRIVE
WISCASSET,ME 04578
Performing Department
(N/A)
Non Technical Summary
The agricultural industry uses well over 600 million pounds of plastic in many forms such as greenhouse and mulch films, row covers, bale wraps, and pesticide and plant containers. A stabilized growing medium manufactured with a corn derivative in lieu of polyurethane would contribute to eliminating millions of tons of plastic from the environment and landfills. Stabilized plant propagation media are used throughout the agricultural industry for mechanized planting, to ease transplant and to increase efficiencies in greenhouses and nurseries. Rynel's Grow-Tech division manufactures a growing medium used by foresters and commercial growers to start seeds or cuttings, but it is only partially organic due to a polyurethane component. Grow-Tech's customers have requested a 100% organic and biodegradable product. This project will develop a fully biodegradable yet completely stabilized plant growing medium from corn-based polymer, which will result in a 100% biodegradable
propagation media for use in commercial forestry efforts, greenhouses and nurseries at a competitive price. Grow-Tech, the agricultural division of Rynel, Inc. manufactures a stabilized growing medium that is used by large paper companies in their reforestation nurseries, which increases transplant rates due to decreased transplant shock and reduces labor by utilizing mechanized tree planting systems. While Grow-Tech's current line of Rooting Sponger products has proven successful in commercial reforestation programs, it currently contains polyurethane, which does not biodegrade very quickly and readily.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
Rynel will prove that a 100% biodegradable stabilized media can be made from PLA. Expected outcomes from Phase I are at least two forms of a stabilized growing medium made from Polylactic Acid, chemical formulas and recipes, further knowledge of PLA properties including biodegradability and demonstrated tree growth in the medium We will produce two types of substrate: a non-woven and an open-celled foam. Experiments will include both forms and formulations and will take three team members including the PI, 420 hours to complete within the first three months. We will learn how to convert the raw PLA particles into the stabilized media format; and develop the green chemistry for modifying the properties of PLA to maximize its effectiveness for tree rooting and growth. The next objective is to characterize the biodegradation of the materials produced. These experiments will consist of exposing the media to extreme environmental conditions, including high temperature to
observe thermal degradation, high humidity to observe hydrolytic degradation and examination of the specimens under a microscope. In addition the growing media may be exposed to typical soil-based microbes and observed for bacterial degradation. This objective will take two team members 155 hours over the course of five months. We expect to meet or exceed our current product performance in terms of stability and ability to grow trees. We will determine which form encourages the best growth, how much water the medium will hold and for how long, and how easily the medium gives up water to the tree by planting trees in the media and observing them in in-house growing trials. More extensive growing trials will need to be done in Phase II given the six-month time frame in which the research will be conducted. However starting the types of trees most often used by our customers such as loblolly pine will allow us to determine if further refinements are necessary as we formulate the PLA
stabilized media. The growing trials are estimated to take two project team members 100 hours over the course of the last five months. Our PI will collaborate with a subcontractor over the course of the last three months of the project to scale up production of the samples selected for further Phase II development. Materials we will be sent to a facility that already has the equipment to deal with raw materials in the same form (pellets) as the PLA in order to demonstrate larger scale manufacturing feasibility and also to develop costing, timing and capacity data that can be used to determine what we will need for on-site production in Phase II. Rynel will come up with a manufacturing design and determine which equipment can be engineered in-house and which equipment must be purchased. Plans for equipment to be built in-house will be drafted. The PI and three team members including the Purchasing Manager will dedicate 164 hours over the course the final three months. Two members of
the sales and marketing team will conduct market research to determine the acceptance and adoption of the PLA plug. This will consist of 83 hours over the course of the entire project.
Project Methods
Work on the form and chemical composition with non-woven fibers will be carried out in the Rynel laboratory by Scott Kennedy, PI, and Dr. Herb Winicov. PLA pellets purchased from Cargill-Dow will be melted on a hotplate and extruded into fibers using a bench-top spinner. As of this time, Rynel/Grow-Tech has not produced an open-celled foam from PLA, so Mr. Kennedy and Dr. Winicov will consult with our subcontractor on how to best perform this sub-task. Existing laboratory equipment, such as a drying oven, heat & flame sources, a fume hood, water/humidity sources, and analytic tools will be used. PLA by itself does not have the optimum wetting and water retention properties that lead to superior rooting quality. At this time, we do know that some surfactants added to the PLA can significantly improve these properties. Therefore, Dr. Winicov will do a systematic search of the surfactant literature to identify those surfactants that conform to green origins and test
examples from each structural class. This will form the basis for a search for a cost effective optimal match. At the same time he and Mr. Kennedy will experiment combining PLA with other additives, including other environmentally-friendly polymers. We will perform proprietary QA tests, which were developed by Rynel to determine if its existing products are to customer specifications. These tests will determine whether or not we have the ideal formulation in terms of hydrophilicity (water absorption and retention). Surfactants and superabsorbers may be added to make the material attractive to water. Better aeration can be created by using blowing agents (surfactants and gases) to expand the material and make it more porous in structure. We will also test for both wet and dry tensile strength to make sure we have made a plug that is strong enough to sustain mechanized transplant. In order to determine if the plug biodegrades in an acceptable amount of time, Rynel technicians will
expose the media to extreme environmental conditions and observe how the media degrades, which can be measured by the time exposed and loss of mass and tensile strength. Changes to the physical composition of the plug can be seen by examining the specimens under a microscope. Chemical changes to the composition can be determined by measuring the pH and performing chemical analyses. High temperatures will cause thermal degradation. High humidity will cause hydrolytic degradation. In addition the growing media will be exposed to typical soil-based microbes and observed for bacterial degradation. We will also grow the seeds in our existing polyurethane-bound media side-by-side with PLA-based media to compare the performance of the PLA to our current product. Rynel will research and identify the requirements for manufacturing this product on a large scale in terms of handling procedures, equipment needed and projected costs. Much of this data will come out of our cooperation with our
subcontractor. Larger batches than can be produced in the lab will be run on a pilot line to see how the material behaves under manufacturing conditions.