NF grade - meets or exceeds requirements of the National Formulary (NF).For food, drug, or medicinal use in addition to most laboratory purposes. USP grade - meets or exceeds requirements of the United States Pharmacopeia (USP).This grade is specified for food, drug, or medicinal use and other applications that require strict quality specifications and purity over 95%. ACS / reagent grade - meets or exceeds purity standards set by the American Chemical Society (ACS).The following are typical grade designations of isopropyl alcohol, their respective specifications, and their operating procedures: This video shows the comparative evaporation rate of 50% pure IPA, 99.8% pure IPA, and 100% pure acetone. In the case of electrical contact cleaning, the faster evaporation time helps ensure that the flammable solvent is gone before energizing the equipment. That is one of the reasons 70% pure isopropyl alcohol is commonly used for degreasing and SMT stencil cleaning. Slowing down the dry time often improves the cleaning effectiveness. When breaking down and removing thick, gummy, or baked-on materials, more dwell or soak time is required. Technicians tend to prefer a fast dry time so that they can clean the electronics and bring them back into service as quickly as possible. For example, isopropyl alcohol is often used as a flux remover to remove flux residues from around solder joints. This can be an advantage or disadvantage depending on the application. The dry time is greatly increased as the percentage of water in the alcohol solution is increased. РІР‚СљWater spotsРІР‚Сњ are particularly problematic when cleaning mirrors, lenses, and other optics. This causes the solvent to bead up more as it dries rather than wet or sheet, which can lead to spotting. The more water isopropyl alcohol contains, the greater the surface tension. Whether an IPA has 0.2% or 50% water has little effect on the look and smell of the material, but greatly impacts surface tension (its ability to wet) and the dry time. Water can be removed to form purer grades of isopropyl alcohol, resulting in what is called РІР‚СљanhydrousРІР‚Сњ isopropyl alcohol. When you see on the label РІР‚Сљ70% isopropyl alcoholРІР‚Сњ, it refers to amount of alcohol in relation to the amount of dissolved water РІР‚вЂњ i.e. Isopropyl alcohol is hydrophilic, so it readily accepts water into an azeotropic solution. Isopropyl alcohol is available in a large number of varieties and grades, which are generally differentiated by the amount of water in the solution and trace amounts of other chemicals or nonvolatile materials.

This video shows an extreme example of acetone on polycarbonate, which causes it to fog, soften, and even scratch from contact with the plastic dropper. In the case of seals or gaskets, this incompatibility will cause parts to swell, shrink, or become brittle. When a solvent is not compatible with a substrate, it may cause crazing (micro-cracks) or soften the material. The following are a list of common materials used in PCB assembly and their respective compatibility ratings: Material As with any chemical product used, component compatibility must be determined on a non-critical area prior to use. Isopropyl alcohol is generally compatible with most materials used in electronics. Material compatibility of Isopropyl Alcohol Maintenance cleaning with isopropyl alcohol is common for removing caked-on and burnt-on flux from SMT reflow ovens, wave soldering fingers, selective soldering nozzles, pallets, and anywhere else flux tends to collect in automated soldering processes. IPA is also used to remove solder paste or adhesive from SMT stencils. It is also readily miscible in water, which makes it an effective drying agent.Р”Р‡or electronic printed circuit board (PCB) assembly, you will find isopropyl alcohol being used either to clean flux residues from recently soldered circuit boards, or in PCB repair and rework. It dissolves a wide range of both polar and nonpolar soils, and is often used to dissolve and remove light oils, fingerprints, cutting fluids, flux residues, carbon deposits, and mold release. Isopropyl alcohol (CAS #67-63-0) is also referred to as IPA, isopropanol, 2-propanol, and even rubbing alcohol (more on that later). It is universally used for cleaning and as a main constituent of fluxes, but how much do you really know about isopropyl alcohol? A variety of chemicals can be found throughout the electronic assembly and repair process, but no solvent appears more commonly than isopropyl alcohol.

Iso alcohol