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Over the last 20 years, Wisconsin’s family farms have grown into some very large operations. Forty and 50 cow farms have turned into 2,000 and 3,000 cow businesses. What used to be a once-a-day chore, milking, is now a 24-hour job with cows being milked three times a day and shifts of workers performing specific jobs on the farm. The traditional stanchion barn with one cow per stall is being rapidly replaced with free stall sheds with hundreds or thousands of cows being moved in and out all day long. That large number of cows in one place has created a problem with handling all the manure they generate.
Several types of scraper systems have been tried with varying results, but generally it was a steel bar scraper moving on a concrete floor which didn’t work too well. One of these systems was a steel automated scraper that was designed to move large amounts of manure to a slurry flume where it was flushed to a tank until it is ready to be distributed to the fields as fertilizer. It basically consisted of two steel bars in a V shape being pulled by a cable back and forth on a concrete floor. Each end of the bars had a steel guide that would ride against the wall on either side of the walkway. The floor had grooves in it to give the cows some traction while walking around. The cable pulling the scraper moved at about five or six feet per minute. The shed is 700-feet-long and the scraper is running 24 hours a day.
With a rough concrete floor, a heavy steel wiper and tons of manure, the wear on the components was tremendous. The whole scraper system would not last one year without having to be completely replaced. Dan Thiel of Badger Plastics and Supply, Inc. working with Cross Farms of Oshkosh, Wisconsin, had a better idea. Dan knew he needed a material that could take some abuse against the concrete, yet still wipe the floor to the customer’s satisfaction. His idea was to put a wiper made of a 75-85A durometer urethane molded onto a 10-gauge steel bar that could then be plug welded onto the bottom of the existing scrapers. The part was 3/4'' thick overall and was 4'' wide by 80'' long. The combination of urethane on a steel back would make for an easy change if needed, but still be soft enough to move the manure with no noise and hopefully no wear.
Next, Thiel tackled the steel guide ends that ride against each side of the walkway. He cut those ends off and machined a UHMW-PE guide that is bolted into the end of each arm of the scraper. These were rounded so that if they would wear on one side in the future they could be just turned around and used again on the other side. The whole system is being pulled by a cable and winch on each end of the 700-foot-long shed. Thiel also replaced the brass bushing with MD nylon ones that are press fit into the pulleys to help prevent wear on the pins they go around.
Cross Farms has 16 scrapers in service, all with the same set-up that Thiel has recommended, and couldn’t be happier with the results. The new system is going on its fourth year with no visible wear on any of the components. The cows are calm with much less noise and the floors are much cleaner making for a safer environment for them to walk. There are now different versions of these scrapers throughout the state. Most of them have some type of urethane wiper that Thiel developed.
This article was written by Larry Searl, Badger Plastics & Supply, Inc.
|In This Issue:
Urethane wiper improves
scraper systems used
in free stall barns
Urethane makes a dramatic difference over metal for a manure-moving automated scraper system.
Reaping the benefit of
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For manufacturers of plastic products and their distributors, there are many opportunities for plastics in agriculture applications. Perhaps the most visible and one of the most common are rotomolded tanks. As one travels the rural countryside, rotomolded tanks are often seen being used by ranchers and farmers. These tanks hold pesticides and herbicides which are applied to the crops that feed America and the world. Some also hold water for livestock watering or for small scale irrigation purposes.
Agriculture has branched out into the business of energy. Biofuel production continues to expand across the nation with 95 processing plants across the United States producing more than 3.9 billion gallons of ethanol in 2005. That is a 139 percent increase from the year 2000. Ethanol projections for 2006 are at 5 billion gallons. Ethanol is made from corn, sugar cane, sugar beets, grain sorghum, wheat, barley and potatoes.
The main consumption of ethanol is for displacement of fossil fuels as the United States tries to reduce its dependence on foreign oil. You may see fuel products like E10 percent unleaded, E85 ethanol, e-diesel or biodiesel at your local gas station. There is also an E85 avgas fuel (aviation fuel) which is just starting to be used in aviation. The consumption of these products for the use of manufacturing ethanol will continue to have a positive economic impact on rural America and throughout the nation. Thirteen percent of the U.S. corn production or 1.43 billion bushels of corn were used in the production of ethanol in 2005. Biodiesel is another product that is made from soybeans and is also increasing in production as a renewable fuel.
Are there plastics in ethanol plants? YES!
On the production side, rotomolded tanks are found holding chemicals used for the mix tanks, liquefaction process, saccharification process, boiler, cooling tower and clean in place (CIP) process. Also found are plastic tubing, valves and compression fittings used for chemical metering and transfer pumps used to adjust pH of the cooking tanks, waste water and process lines. There are quite a few corrosive atmospheric environments to be found in all ethanol plants where fiberglass grating, handrail, catwalks, ladders and corrosion resistant piping hangers are used.
Corrosive chemicals can be a large problem for a lot of these plants. Plastics offer a greater degree of chemical resistance to the corrosive environments found in these facilities. Plastics are a more economic alternative and much safer than metals in these corrosive environments. Chemical attacks on metal piping systems and tanks can cost these facilities large dollars in downtime and safety related injuries. In some operations, large PVC and/or CPVC ventilation is used to vent the mill and feed house process in the steep tanks. This is where acids are added to the corn, along with water, and hot corrosive gases rise to the top of the mixing vessel and are vented off used PVC or CPVC large diameter fabricated ventilation systems.
Sometimes CPVC or plastic-lined steel piping systems are used in the thick syrup transportation lines after the centrifuge grain recovery to the syrup holding tanks. This allows for better cleaning of those lines which are only used intermittently. These lines are also exposed to chemical attack during the CIP process.
Patricia Woertz, CEO and president of Archer Daniels Midland (ADM) said in a recent conference on ethanol, “It is not a question of whether a sustainable market for biofuels exists but rather how big that market will become.” Driving the demand are more than 5 million trucks and cars that are currently on the road in the United States today that are E85 capable, with plans to add more than one million more flex fuel vehicles (FFV) to the road in 2007.
Today there are 170,000 gas stations throughout the United States and 1,000 carry E85 ethanol at their pumps. There are plans to increase the number of gas stations carrying E85 to 2,000 stations in 2007. Wal-mart has agreed to start selling E85 at 383 of its retail locations in 2007. The U.S. government grants up to $30,000 to businesses and station owners who want to add E85 to their pumps. E85 ethanol’s cost today are approximately the same as unleaded, but when gas prices went to over $3 a gallon at the start of 2006, E85 was $1 less a gallon.
The Clean Air Act is the major driver for auto manufacturers to increase the number of FFV on the road today. Auto manufacturers are offering cash incentives to consumers who purchase these vehicles over the standard gas models.
This article was written by Larry Geer and Dean Majkrzak, Indelco Plastics Corporation.
The agricultural industry is made up of harvesting equipment in establishments — like farms, orchards, groves, greenhouses and nurseries — primarily engaged in growing crops, plants, vines or trees and their seeds. It is also made up of equipment used in the beef, poultry and dairy industries.
Agricultural applications are usually outdoors, which may decrease the use of plastic materials due to extreme temperature variations, moisture issues and UV conditions. However, environmental issues help when plastics replace steel, which will possibly rust over time and is much heavier. There are bearing and wear applications, as well as structural opportunities for panels and guards. Corrosion-resistant materials are used extensively in fluid flow applications.
Other opportunities for plastics include: rollers, guards, bushings, rail guides, bearings, wear and slide pads, hopper liners, process piping and tubing, chain guides, forming plates, jets and venturi nozzles for chemical sprayers, housing covers, site gages, laser targets, skid plates and skid shoes.
There are many agricultural application articles online at www.theiapdmagazine.com. Just check "agriculture" when you search the archives to find them. There are also many other free resources on the IAPD web site at www.iapd.org.
What do you know about plastics in the agriculture industry? Answers are at www.iapd.org/popquiz.html.
1. In agricultural applications, you must consider environmental issues. A material's water absorption is important because it measures the:
2. In any application, it is also important to consider all materials' strengths and weaknesses. Which of the following statements is NOT TRUE?
Your IAPD Distributor is your choice in finding the right material for your application. Go to www.iapd.org to find a distributor in your area. You can search by company name, location or product category.
The IAPD Magazine web site at www.theiapdmagazine.com allows you to search by material, trade name and fabrication process. You can also search for fabrication capabilities.
Designing with Plastics is published by the International Association of Plastics Distribution. While every effort has been made for accuracy, IAPD encourages you to verify information with a plastics distributor to ensure you select the correct plastic products to meet your needs.