For over 25 years, polyvinylidene fluoride (PVDF) has been thematerial of choice for UPW (Ultra Pure Water) system because thequalities of this fluoropolymer ensure purity and long-termperformance. PVDF is inherently pure, unlike other polymers PVDFcontains no additives, fillers, pigments, or fire retardants whichcan leach out. PVDF offers exceptional chemical and thermalresistance, standing up to aggressive chemicals withoutdegradation. PVDF provides exceptional surface smoothness toprevent bacterial and biofilm growth. Other piping materialshistorically used in UPW piping system such as stainlesssteel, polyvinyl chloride (PVC); and polypropylene (PP) cancompromise purity. Over time, chemical attack and corrosion canresult in the oxidation or iron (rouging), stess cracking, or biofilmadhesion.PVDF UHP Packaging Fitting Packaging
Ultra Pure WaterCertain grades of PVDF are listed by the US FDA, National Sanitation Foundation (NSF)for use in food (NSF 51) and potable water (NSF 61). While water is not commonlyconsidered highly corrosive, there is an increasing desire for water systems to lastnearly indefinitely. With the concern for bacteria, bioterrorism, chlorine content ofwater and UV exposure for many years of service life, a material like PVDF offers agreater opportunity for long-system life even if the system parameters change overtime.PVDF Meets this standards :
Pharmaceutical and BiotechnologyThe life sciences field uses a multitude of chemicalcombinations, such as bromine, iodine, chlorine, acids andalcohols, just to name a few. Simply reading theingredients on a medicine box will give you the awarenessof the processing challenges this industry faces.This challenge is coupled with FDA regulations, USP Class6 requirements and process water purification targets.PVDF meets all of these requirements and has the addedadvantage over common plastics because it can berepeatedly steam cleaned at up to 30 psi.Plastics are gaining increased use in the pharmaceuticalindustry due to the fact that they do not rust whenexposed to cleaning agents and do not rouge over time inwater exposure. PVDF and PVDF copolymers are listed inthe ASME Bioprocessing Equipment (ASME-BPE)standards as a common material selected by designers forbiotech system design. Piping, flexibletubing, tanks, membranes and pumps are all commonapplications for PVDF in this industry.
Food, Diary and BeverageIn general, foods are not corrosive, but consumable foods like sauces and fruits can havepH ranges between 2.0 and 3.5.5 This can be a very aggressive environment over time.PVDF components are often machined and used in the processing of cranberry, hotsauces, alcoholic beverages, lime juices and a few other relatively common foods. Theabrasion resistance of PVDF and its ability to be sterilized with various chemicals andsteam also adds to the attractiveness of this material for food, dairy and beverageapplications.
Semiconductor ProcessingPerhaps the biggest industrial use for PVDF isin the semiconductor industry. PVDF hasmany properties desired for this industrythat are not always a requirement in generalchemical applications.Flame and smoke resistant compliance Project Reportoutlined by Factory Mutual (FM) 4910 plusUnderwriters Laboratories (UL 2360) andSEMI F57 high purity standards are specialrequirements in the manufacture of highpurity piping systems and acid etchingequipment used in the process of preparingsilicone wafers.The combination of chemical resistance, highpurity and superior strength of PVDFcompared to other high quality materials hasmade it a standard material of constructionin areas of a semiconductor facility.
Nuclear IndustryThe nuclear reclamation industry has interesting challenges. First, a series of harshchemicals are used in the glove boxes manufactured to purify the radioactive ores. Whilemany materials handle the chemicals like hydrochloric acid and nitric acid used to purifyplutonium and uranium, the contact surfaces of the glove box must also handle theradioactivity associated with this process. After several years of testing and years of fieldexperience, PVDF has been found to be the most radiation-resistant polymer capable oflong life in nuclear glove box design and waste holding equipment.The corrosion caused by hydrochloric acid in the traditional stainless steelined gloveboxes wouldhave added unwanted impurities, especially iron, which would not separate from the plutonium.PVDF has a number of applications including : solid sheet lining the interior ofgloveboxes, brackets, pipe supports, vacuum traps, flanges and end plates for glasscolumns, piping used in solution transfers between gloveboxes, pumps, valve and flowmeters.Commonly, the chemicals used in the recovery operations are hydrochloric acid, oxalic acid, nitricacid, potassium hydroxyde, hydroxylamine hydrochloride and sodium nitrite.Most of these chemicals are stored within the glovebox in slab tanks constructed of PVDF. Thisdesign allows for greater storage volume within the glovebox, without sacrificing limited workspace. PVDF can handle a wide range of acids and chlorides routinely found in nuclearprocessing. It can handled elevated temperatures up to 275°F (135°C) or more withoutsignificant loss of physical and mechanical properties.