Editing Polypropylene (section)

==Applications==
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Polypropylene has a relatively slippery "low energy surface" that means that many common glues will not form adequate joints. Joining of polypropylene is often done using welding processes.
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[[Image:Mint box polypropylene lid.JPG|thumb|right|Polypropylene lid of a [[Tic Tac]] box, with a [[living hinge]] and the [[resin identification code]] under its flap]]

As polypropylene is resistant to fatigue, most plastic [[living hinge]]s, such as those on flip-top bottles, are made from this material. However, it is important to ensure that chain molecules are oriented across the hinge to maximise strength.

Polypropylene is used in the manufacturing of [[piping]] systems, both ones concerned with high purity and ones designed for strength and rigidity (e.g., those intended for use in potable plumbing, [[hydronic heating]] and cooling, and [[reclaimed water]]).<ref>{{citation | title=Specification for Pressure-rated Polypropylene (PP) Piping Systems | date=2017 | publisher=ASTM International | location=West Conshohocken, PA | doi=10.1520/f2389-17a}}</ref> This material is often chosen for its resistance to corrosion and chemical leaching, its resilience against most forms of physical damage, including impact and freezing, its environmental benefits, and its ability to be joined by [[heat fusion]] rather than gluing.<ref>[http://contractormag.com/news/green-pipe-mine-2345 Green pipe helps miners remove the black] Contractor Magazine, 10 January 2010</ref><ref>[http://www.achrnews.com/Articles/Feature_Article/BNP_GUID_9-5-2006_A_10000000000000690490 Contractor Retrofits His Business]. the News/ 2 November 2009.</ref><ref>[http://www.esmagazine.com/Articles/Case_In_Point/BNP_GUID_9-5-2006_A_10000000000000691766 What to do when the piping replacement needs a replacement?] Engineered Systems. 1 November 2009.</ref>

[[Image:Red Polypropylene Chair with Stainless Steel Structure.JPG|thumb|left|upright|A polypropylene chair]]

Many plastic items for medical or laboratory use can be made from polypropylene because it can withstand the heat in an [[autoclave]]. Its heat resistance also enables it to be used as the manufacturing material of consumer-grade [[kettle]]s{{Citation needed|date=February 2012|reason=A PP kettle could not be used on a stovetop}}. Food containers made from it will not melt in the dishwasher, and do not melt during industrial hot filling processes. For this reason, most plastic tubs for dairy products are polypropylene sealed with aluminum foil (both heat-resistant materials). After the product has cooled, the tubs are often given lids made of a less heat-resistant material, such as LDPE or polystyrene. Such containers provide a good hands-on example of the difference in modulus, since the rubbery (softer, more flexible) feeling of LDPE with respect to polypropylene of the same thickness is readily apparent. Rugged, translucent, reusable [[plastic container]]s made in a wide variety of shapes and sizes for consumers from various companies such as [[Rubbermaid]] and [[Sterilite]] are commonly made of polypropylene, although the lids are often made of somewhat more flexible LDPE so they can snap onto the container to close it. Polypropylene can also be made into disposable bottles to contain liquid, powdered, or similar consumer products, although HDPE and [[polyethylene terephthalate]] are commonly also used to make bottles. Plastic pails, car batteries, wastebaskets, pharmacy prescription bottles, cooler containers, dishes and pitchers are often made of polypropylene or HDPE, both of which commonly have rather similar appearance, feel, and properties at ambient temperature. An abundance of medical devices are made from PP.<ref>{{Cite journal|last1=Collinet|first1=Pierre|last2=Belot|first2=Franck|last3=Debodinance|first3=Philippe|last4=Duc|first4=Edouard Ha|last5=Lucot|first5=Jean-Philippe|last6=Cosson|first6=Michel|s2cid=2648056|date=2006-08-01|title=Transvaginal mesh technique for pelvic organ prolapse repair: mesh exposure management and risk factors |journal=International Urogynecology Journal|language=en|volume=17|issue=4|pages=315–320|doi=10.1007/s00192-005-0003-8|pmid=16228121|issn=0937-3462}}</ref>

[[File:PolypropyleneItemsForLaboratoryUse.jpg|thumb|Polypropylene items for laboratory use. Blue and orange closures are not made of polypropylene.]]

A common application for polypropylene is as biaxially oriented polypropylene (BOPP). These BOPP sheets are used to make a wide variety of materials including clear [[Plastic bag|bags]]. When polypropylene is biaxially oriented, it becomes crystal clear and serves as an excellent packaging material for artistic and retail products.

Polypropylene, highly colorfast, is widely used in manufacturing carpets, rugs and mats to be used at home.<ref>[http://www.fibersource.com/f-tutor/olefin.htm Rug fibers] {{Webarchive|url=https://web.archive.org/web/20100405073442/http://www.fibersource.com/f-tutor/olefin.htm |date=2010-04-05 }}. Fibersource.com. Retrieved on 2012-05-31.</ref>

Polypropylene is widely used in ropes, distinctive because they are light enough to float in water.<ref>[http://www.contractorsrope.com/braided-polypropylene-rope.html Braided Polypropylene Rope is Inexpensive and it Floats]. contractorrope.com. Retrieved on 2013-02-28.</ref> For equal mass and construction, polypropylene rope is similar in strength to polyester rope. Polypropylene costs less than most other synthetic fibers.

Polypropylene is also used as an alternative to [[polyvinyl chloride]] (PVC) as insulation for electrical cables for [[Low Smoke Zero Halogen|LSZH]] cable in low-ventilation environments, primarily tunnels. This is because it emits less smoke and no toxic halogens, which may lead to production of acid in high-temperature conditions.

Polypropylene is also used in particular roofing membranes as the waterproofing top layer of single-ply systems as opposed to modified-bit systems.

Polypropylene is most commonly used for plastic moldings, wherein it is injected into a mold while molten, forming complex shapes at relatively low cost and high volume; examples include bottle tops, bottles, and fittings.

It can also be produced in sheet form, widely used for the production of stationery folders, packaging, and storage boxes. The wide color range, durability, low cost, and resistance to dirt make it ideal as a protective cover for papers and other materials. It is used in [[Rubik's Cube]] stickers because of these characteristics.

The availability of sheet polypropylene has provided an opportunity for the use of the material by designers. The light-weight, durable, and colorful plastic makes an ideal medium for the creation of light shades, and a number of designs have been developed using interlocking sections to create elaborate designs.

Polypropylene fibres are used as a [[concrete]] additive to increase strength and reduce cracking and [[spalling]].<ref>{{cite journal|doi=10.14359/4439 |title= Properties of Polypropylene Fiber Reinforced Concrete|year=1993 |author1=Bayasi, Ziad |author2=Zeng, Jack |name-list-style=amp |journal=ACI Materials Journal|volume=90 |issue=6 |pages=605–610}}</ref> In some areas susceptible to earthquakes (e.g., California), PP fibers are added with soils to improve the soil's strength and damping when constructing the foundation of structures such as buildings, bridges, etc.<ref>{{cite journal|doi=10.1080/17486025.2015.1029013 |title=Effect of fibre inclusion on dynamic properties of clay |year=2015 |author1=Amir-Faryar, Behzad |author2=Aggour, M. Sherif |s2cid=128478509 |name-list-style=amp |journal=Geomechanics and Geoengineering|volume=11 |issue=2 |pages=1–10}}</ref>

===Clothing===
[[File:Textielmuseum-cabinet-03.jpg|thumb|Various polypropylene yarns and textiles]]
Polypropylene is a major polymer used in [[nonwovens]], with over 50% used{{Citation needed|date=March 2009}} for diapers or sanitary products where it is treated to absorb water (hydrophilic) rather than naturally repelling water (hydrophobic). Other non-woven uses include filters for air, gas, and liquids in which the fibers can be formed into sheets or webs that can be pleated to form cartridges or layers that filter in various efficiencies in the 0.5 to 30 [[micrometre]] range. Such applications occur in houses as water filters or in air-conditioning-type filters. The high surface-area and naturally oleophilic polypropylene nonwovens are ideal absorbers of oil spills with the familiar{{citation needed|date=June 2015}} floating barriers near oil spills on rivers.

Polypropylene, or 'polypro', has been used for the fabrication of cold-weather base layers, such as long-sleeve shirts or long underwear. Polypropylene is also used in warm-weather clothing, in which it transports sweat away from the skin. Polyester has replaced polypropylene in these applications in the U.S. military, such as in the [[Extended Cold Weather Clothing System|ECWCS]].<ref>[https://web.archive.org/web/20081217143906/http://peosoldier.army.mil/factsheets/SEQ_CIE_ECWCS.pdf Generation III Extended Cold Weather Clothing System (ECWCS)]. PM Soldier Equipment. October 2008</ref> Although polypropylene clothes are not easily flammable, they can melt, which may result in severe burns if the wearer is involved in an explosion or fire of any kind.<ref>[http://permanent.access.gpo.gov/lps11992/2002/fsmnov02.pdf USAF Flying Magazine. Safety. Nov. 2002]. access.gpo.gov</ref> Polypropylene undergarments are known for retaining body odors which are then difficult to remove. The current generation of polyester does not have this disadvantage.<ref>
Ellis, David. [https://web.archive.org/web/20100602092559/http://www.outdoorsnz.org.nz/cms_show_download.php?id=168 Get Real: The true story of performance next to skin fabrics]. outdoorsnz.org.nz
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===Medical===
Its most common medical use is in the synthetic, nonabsorbable [[surgical suture|suture]] [[Prolene]], manufactured by [[Ethicon Inc.]]

Polypropylene has been used in [[hernia]] and pelvic organ prolapse repair operations to protect the body from new hernias in the same location. A small patch of the material is placed over the spot of the hernia, below the skin, and is painless and rarely, if ever, rejected by the body. However, a polypropylene mesh will erode the tissue surrounding it over the uncertain period from days to years.

A notable application was as a transvaginal mesh, used to treat vaginal prolapse and concurrent urinary incontinence.<ref>{{Cite journal|last1=Collinet|first1=Pierre|last2=Belot|first2=Franck|last3=Debodinance|first3=Philippe|last4=Duc|first4=Edouard Ha|last5=Lucot|first5=Jean-Philippe|last6=Cosson|first6=Michel|s2cid=2648056|date=2006-08-01|title=Transvaginal mesh technique for pelvic organ prolapse repair: mesh exposure management and risk factors|journal=International Urogynecology Journal|language=en|volume=17|issue=4|pages=315–320|doi=10.1007/s00192-005-0003-8|pmid=16228121|issn=0937-3462}}</ref> Due to the above-mentioned propensity for polypropylene mesh to erode the tissue surrounding it, the FDA has issued several warnings on the use of polypropylene mesh medical kits for certain applications in pelvic organ prolapse, specifically when introduced in close proximity to the vaginal wall due to a continued increase in number of mesh-driven tissue erosions reported by patients over the past few years.<ref>[https://web.archive.org/web/20110717092929/http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm262435.htm UPDATE on Serious Complications Associated with Transvaginal Placement of Surgical Mesh for Pelvic Organ Prolapse: FDA Safety Communication], FDA, July 13, 2011</ref> On 3 January 2012, the FDA ordered 35 manufacturers of these mesh products to study the side effects of these devices.
Due to the outbreak of the [[COVID-19 pandemic]] in 2020, the demand for PP has increased significantly because it is a vital raw material for producing [[melt blowing|meltblown]] fabric, which is in turn the raw material for producing facial masks.