IRRIGATION PIPE

Shipments of concrete pipe in 1990 had a value of > 1.6 billion dollars. Much of this piping was for storm and sanitary sewers, culverts, and irrigation piping. Pressure piping sales were close to 300 million. There are a large number of manufacturers of concrete pipe since much of the pipe is produced reasonably close to the point of use. 

Polyethylene is an inexpensive thermoplastic that can be molded into almost any shape, extruded into fiber or filament, and blown or precipitated into film or foil. Polyethylene products include packaging (largest market), bottles, irrigation pipes, film, sheets, and insulation materials. 

HDPE is important for producing bottles and hollow objects by blow molding. Approximately 64% of all plastic bottles are made from HDPE. Injection molding is used to produce solid objects. Another important market for HDPE is irrigation pipes. Pipes made from HDPE... 

Polyvinyl chloride (PVC) is one of the most widely used thermoplastics. It can be extruded into sheets and film and blow molded into bottles. It is used in many common items such as garden hoses, shower curtains, irrigation pipes, and paint formulations. 

Rating combustion gases from combined cycle plants to use in vegetable crops in greenhouses, in applications in irrigation pipes to prevent clogging and to balance the pH in nutrient solutions. 

In many countries, women and children often play an important part in agriculture. Irrigation is a most difficult task inasmuch as conventional pipe is quite heavy. Lightweight irrigation pipe of bagasse or straw will find a ready market due to the fact that it is gender-sensitive. 

Q Chlorine gas Is used to manufacture polyvinyl chloride products such as these irrigation pipes. Q Sodium hydroxide Is the key ingredient in drain cleaners. 

Antioxidant for natural and synthetic rubber, tires, automotive and appliance molded goods, polyamides and carbon black filled olefin formulations for use in geomembranes, wire and cable jacketing, and irrigation piping. 

LDPE/LLDPE agricultural waste, e.g., irrigation pipes monolayer trash bags Leaversuch, 1993... 

Irrigation pipe. Pata from Rapacki, S. R., J. Vinyl Additive TechnoL, 4,1,12-21,1998.]... 

Irrigation pipe with foamed layer. [Data from Dorm, C, us Patent 4,577,998, Mar... 

Irrigation pipes Salt water disposal pipes Underground water pipe Oil well tubes Ladders... 

Irrigation pipes are conventionally made from non biodegradable petroleum-based plastics such as poly(ethylene) or poly(propylene) (PP). As a result, conventional irrigation pipes that are discarded are generally not readily recycled into the environment and add to pollution stress of the environment. In addition, because petroleum is a non-renewable raw material, it is expected that raw material costs for producing irrigation pipes from petroleum-based plastics will increase (7). 

However, recently a biodegradable irrigation pipe formed from a renewable material has been described (7). The biodegradable irrigation pipe is formed having a pipe wall with a plurality of layers. The layers may be fabricated from a core layer sandwiched between inner and outer protective layers. 

The core layer provides body and mechanical strength to the irrigation pipe and is formed from a biodegradable material, which degrades relatively quickly when exposed to degrading elements... 

T. Yankovitz and A. Schweitzer, Biodegradable irrigation pipe, US Patent 7 862 873, assigned to Netafim, Ltd. (Tel Aviv, IL), January 4,... 

Exfoliation is commonly experienced on exposure of susceptible aluminum alloys to marine atmospheres. Simulation in the laboratory is accomplished by controlled intermittent spray with 5% NaCl containing added acetic acid to pH 3 at 35-50°C (95-120°F) [28]. In practice, severe exfoliation corrosion has been experienced in water irrigation piping constructed of type 6061 alloy [29]. The cause in this instance was ascribed to pipe fabrication methods and presence of excess amounts of impurity elements (e.g., Fe, Cu, and Mn). 

Johnson, J., Delta Recycles Irrigation Pipe in 4 States, Plastics News, Oct. 13, 2003. 

The situation in Southern Europe is better than in the north. There is increasing demand for irrigation pipe in Southern Emope. There is scope for the renewal of old sewerage pipes across the whole continent, but public expenditure remains constrained. There are also large markets in the developing world for irrigation and water pipe. 

Plastics are also based primarily on carbon. Plastics or polymers are based on linking small molecules chemically to form long chains. The main bonds are carbon to carbon. It is also possible to make plastics in which the bonds are not just along the chains, but across the chains. This crosslinking, as it is called, produces firmer, harder plastics. Polyethylene is a softer plastic. Some grades of PVC, such as in irrigation pipe, are harder. 

Generally, non-pressurized pipes contain carbon black (CB) as a pigment. However, CB may have a negative effect on the thermo-oxidation of polyolefins. The influence of CB on the long term thermal behavior of irrigation pipes (for vineyards in Cap Province, South Africa) based on LLDPE/LDPE recyclate is shown in Figure 21. 

Several applications based on biodegradable plastics that end up directly in soil after their useful life are under development and experiencing rapid market growth. Examples are mulch films, strings, hooks and clips, slow release pheromone dispensers and drip irrigation pipes. Furthermore, mature industrial compost, obtained from a feedstock that includes biodegradable polymers, also ends up in soil because of its application as a soil improver. 

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