Sintered polyethylene

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Sintered polyethylene is a polyethylene powder that is formed into a solid without melting it. It can be produced using heat, pressure, or selective laser sintering. [1] It has applications as a coating on pipes and skis, and as a filter medium.

Contents

Applications

Pipes

Sintered polyethylene is applied to steel pipes to resist corrosion. Pipes are heated and then polyethylene powder coated, either electrostatically or through immersion. [2] [3]

Skis

Sintered polyethylene was introduced as a coating on skis in 1962. It is more durable, and less dense than solid, extruded polyethylene. Its porous structure allows the ski to absorb wax. [4] [5]

Filter medium

Sinter plate filter elements were developed in Germany [6] during the years of 1981 and 1982. These rigid filter elements are used in dust collectors and will produce clean gas values of 0.1 to 1.0 mg/m3 with emissions of 0.001 pounds per hour with a maximum of 0.0004 gr/ft3, even with dusts of D50 < 1 µm. The EPA defines high efficiency as removal of 0 to 5.0 µm particulates.

The filter element matrix consists of molded sintered polyethylene (PE) with a reinforced mounting header. An additional PTFE-coating gets into the pores of the PE-basic body and forms a micro-porous, non-sticking surface resulting in surface-loaded filtration. [7] This combined material is chemical resistant and unaffected by slight moisture. The rigid sinter plate filters have an extremely stable structure and can be recycled. The average useful life of a sinter plate filter element can exceed 10 years.

Sinter plate PE filter elements are environmentally compatible. They produce no toxic waste in themselves and can be washed off and reused. There is no contamination of material from filter fibers like fabric and cartridge media elements. Dust collector#Fabric Collectors

The rigidity of the matrix results in no wear from abrasive material. Cleaning is accomplished by on-line, low-pressure reverse air jet-pulse. [7] Standard elements will handle temperatures up to 158 °F with improved elements designed for up to 230 °F

The separation efficiency exceeds that required by the BIA-certificate regarding dust classification M.

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<span class="mw-page-title-main">Sintering</span> Process of forming and bonding material by heat or pressure

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<span class="mw-page-title-main">Powder metallurgy</span> Process of sintering metal powders

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<span class="mw-page-title-main">Selective laser sintering</span> 3D printing technique

Selective laser sintering (SLS) is an additive manufacturing (AM) technique that uses a laser as the power and heat source to sinter powdered material, aiming the laser automatically at points in space defined by a 3D model, binding the material together to create a solid structure. It is similar to selective laser melting; the two are instantiations of the same concept but differ in technical details. SLS is a relatively new technology that so far has mainly been used for rapid prototyping and for low-volume production of component parts. Production roles are expanding as the commercialization of AM technology improves.

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<span class="mw-page-title-main">Dust collector</span>

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<span class="mw-page-title-main">Agitated Nutsche Filter</span> Type of filter for liquid

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Plastic pipe is a tubular section, or hollow cylinder, made of plastic. It is usually, but not necessarily, of circular cross-section, used mainly to convey substances which can flow—liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipes are far stiffer per unit weight than solid members.

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<span class="mw-page-title-main">Ductile iron pipe</span>

Ductile iron pipe is pipe made of ductile cast iron commonly used for potable water transmission and distribution. This type of pipe is a direct development of earlier cast iron pipe, which it has superseded. The ductile iron used to manufacture the pipe is characterized by the spheroidal or nodular nature of the graphite within the iron. Typically, the pipe is manufactured using centrifugal casting in metal or resin lined moulds. Protective internal linings and external coatings are often applied to ductile iron pipes to inhibit corrosion: the standard internal lining is cement mortar and standard external coatings include bonded zinc, asphalt or water-based paint. In highly corrosive environments loose polyethylene sleeving (LPS) to encase the pipe may also be used. Life expectancy of unprotected ductile iron pipes depends on the corrosiveness of soil present and tends to be shorter where soil is highly corrosive. However, a lifespan in excess of 100 years has been estimated for ductile iron pipelines installed using "evolved laying practices", including use of properly installed LPS. Studies of ductile iron pipe's environmental impact have differing findings regarding emissions and energy consumed. Ductile iron pipe manufactured in the United States has been certified as a sustainable product by the Institute for Market Transformation to Sustainability.

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Laboratory funnels are funnels that have been made for use in the chemical laboratory. There are many different kinds of funnels that have been adapted for these specialized applications. Filter funnels, thistle funnels, and dropping funnels have stopcocks which allow the fluids to be added to a flask slowly. For solids, a powder funnel with a short and wide neck/stem is more appropriate as it prevents clogging.

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HDPE pipe is a type of flexible plastic pipe used for fluid and gas transfer and is often used to replace ageing concrete or steel mains pipelines. Made from the thermoplastic HDPE, its high level of impermeability and strong molecular bond make it suitable for high pressure pipelines. HDPE pipe is used across the globe for applications such as water mains, gas mains, sewer mains, slurry transfer lines, rural irrigation, fire system supply lines, electrical and communications conduit, and stormwater and drainage pipes.

References

  1. Bai, J.; Zhang, B.; Song, J.; Bi, G.; Wang, P.; Wei, J. (2016). "The effect of processing conditions on the mechanical properties of polyethylene produced by selective laser sintering". Polymer Testing. 52: 89–93. doi:10.1016/j.polymertesting.2016.04.004.
  2. Tim Burstall (1997). Bulk Water Pipelines. Thomas Telford. p. 18. ISBN   9780727726094.
  3. Mikael Braestrup; Jan B. Andersen; Lars Wahl Andersen; Mads B. Bryndum; Niels-J Rishøj Nielsen (2009). Design and Installation of Marine Pipelines. Wiley. p. 185. ISBN   9781405148740.
  4. Seth Masia (March 2004). "Milestone and Detours in Ski Design". Skiing Heritage: 21.
  5. George Thomas (1992). Performance Skiing; Training and Techniques to Make You a Better Alpine Skier. Stackpole Books. p. 169. ISBN   9780811730266.
  6. G.E. Klinzing; F. Rizk; R. Marcus; L.S. Leung (2013). Pneumatic Conveying of Solids; A Theoretical and Practical Approach. Springer Netherlands. p. 420. ISBN   9789401589819.
  7. 1 2 Huang, Mei; Yan, Cuiping; He, Chunhong; Tang, Cuiying; Yang, Fei; Li, Peng (2021). "The relationship between peak pressure and parameters of pulse-jet cleaning in a sintered plastic filter". Journal of the Air & Waste Management Association. 71 (9): 1055–1066. doi: 10.1080/10962247.2020.1860157 .