Solvent degreasing

Last updated

Solvent degreasing is a process used to prepare a part for further operations such as electroplating or painting. Typically it uses petroleum, chlorine, dry ice or alcohol based solvents to dissolve the machining fluids and other contaminants that might be on the part. [1]

Contents

Process

To begin with, a cleaning agent is applied directly to the surface by spraying, brushing, blasting or wiping. This process removes oil, grease, dirt, loose particles, and any other contaminants that may exist on the surface of the material.

Characteristics include: cleans almost all electronic assemblies, electrical components, and almost all metals. Parts are usually dried at an elevated temperature, however usually not below room temperature. However if you're cleaning by dry ice blasting objects are left dry and clean. Almost any size or shape of a part can be cleaned.

Spraying

The most common cold solvent operation, this is usually used in small maintenance degreasers using a petroleum or mineral solvent. Usually to remove the bulk of the material, and prepare it for the cleaning tank. Although if the part does not need to be perfectly clean, then the operation can be ended after spraying. Spraying can also be used as a prequel other degreasing operations such as vapor degreasing which gives a better clean.

Immersion

The part is immersed in a tank of solvent and usually agitated like a washing machine for clothes to get all of the contaminant off. It is then hung on a rack over the tank to allow drying. [2] This is not to be confused with pickling, during which the part would be soaked in the bath for an extended period of time. This operation covers a relatively short period and doesn't clean as deeply as pickling.

Soaking is typically the most common application of this process. The material is left to soak until all the dirt or contaminates are removed from the surface. However, the work piece may also be sprayed or have solvent directly wiped on it. These two applications are typically used for spot cleaning

Due to the ability of the solvent to reach in all places, virtually all parts of any shape or size can be cleaned using solvent degreasing. The only restriction lies in the size of equipment available. Solvent degreasing equipment is available in a wide variety of sizes and shapes and mainly consists of a submersion tank. However, some degreasing equipment has a circulation and filtering system or some sort of elevation mechanism.

Design considerations

Benefits

Challenges

Related Research Articles

Dry cleaning is any cleaning process for clothing and textiles using a solvent other than water.

Cleaning Activity that purifies people, animals and objects of dirt and other particles

Cleaning is the process of removing unwanted substances, such as dirt, infectious agents, and other impurities, from an object or environment. Cleaning occurs in many different contexts, and uses many different methods. Several occupations are devoted to cleaning.

Environmental remediation Removal of pollution from soil, groundwater etc.

Environmental remediation deals with the removal of pollution or contaminants from environmental media such as soil, groundwater, sediment, or surface water. Remedial action is generally subject to an array of regulatory requirements, and may also be based on assessments of human health and ecological risks where no legislative standards exist, or where standards are advisory.

Dye penetrant inspection (DP), also called liquid penetrate inspection (LPI) or penetrant testing (PT), is a widely applied and low-cost inspection method used to check surface-breaking defects in all non-porous materials. The penetrant may be applied to all non-ferrous materials and ferrous materials, although for ferrous components magnetic-particle inspection is often used instead for its subsurface detection capability. LPI is used to detect casting, forging and welding surface defects such as hairline cracks, surface porosity, leaks in new products, and fatigue cracks on in-service components.

Flue-gas desulfurization

Flue-gas desulfurization (FGD) is a set of technologies used to remove sulfur dioxide from exhaust flue gases of fossil-fuel power plants, and from the emissions of other sulfur oxide emitting processes such as waste incineration.

Industrial wastewater treatment Processes used for treating wastewater that is produced by industries as an undesirable by-product

Industrial wastewater treatment describes the processes used for treating wastewater that is produced by industries as an undesirable by-product. After treatment, the treated industrial wastewater may be reused or released to a sanitary sewer or to a surface water in the environment. Some industrial facilities generate wastewater that can be treated in sewage treatment plants. Most industrial processes, such as petroleum refineries, chemical and petrochemical plants have their own specialized facilities to treat their wastewaters so that the pollutant concentrations in the treated wastewater comply with the regulations regarding disposal of wastewaters into sewers or into rivers, lakes or oceans. This applies to industries that generate wastewater with high concentrations of organic matter, toxic pollutants or nutrients such as ammonia. Some industries install a pre-treatment system to remove some pollutants, and then discharge the partially treated wastewater to the municipal sewer system.

Cosmoline is the genericized trademark for a common class of brown, wax-like petroleum-based corrosion inhibitors, typically conforming to United States Military Standard MIL-C-11796C Class 3. They are viscous when freshly applied, have a slight fluorescence, and solidify over time with exposure to air.

Ultrasonic cleaning

Ultrasonic cleaning is a process that uses ultrasound to agitate a fluid. The ultrasound can be used with just water, but use of a solvent appropriate for the object to be cleaned and the type of soiling present enhances the effect. Cleaning normally lasts between three and six minutes, but can also exceed 20 minutes, depending on which object has to be cleaned.

Carpet cleaning Process of removing dirt and stains from carpets

Carpet cleaning is performed to remove stains, dirt, and allergens from carpets. Common methods include hot water extraction, dry-cleaning, and vacuuming.

Low-temperature thermal desorption (LTTD), also known as low-temperature thermal volatilization, thermal stripping, and soil roasting, is an ex-situ remedial technology that uses heat to physically separate petroleum hydrocarbons from excavated soils. Thermal desorbers are designed to heat soils to temperatures sufficient to cause constituents to volatilize and desorb from the soil. Although they are not designed to decompose organic constituents, thermal desorbers can, depending upon the specific organics present and the temperature of the desorber system, cause some organic constituents to completely or partially decompose. The vaporized hydrocarbons are generally treated in a secondary treatment unit prior to discharge to the atmosphere. Afterburners and oxidizers destroy the organic constituents. Condensers and carbon adsorption units trap organic compounds for subsequent treatment or disposal.

Parts cleaning is essential to many industrial processes, as a prelude to surface finishing or to protect sensitive components. Electroplating is particularly sensitive to part cleanliness, since molecular layers of oil can prevent adhesion of the coating. ASTM B322 is a standard guide for cleaning metals prior to electroplating. Cleaning processes include solvent cleaning, hot alkaline detergent cleaning, electrocleaning, and acid etch. The most common industrial test for cleanliness is the waterbreak test, in which the surface is thoroughly rinsed and held vertical. A quantitative measurement for this parameter is contact angle. Hydrophobic contaminants such as oils cause the water to bead and break up, allowing the water to drain rapidly. Perfectly clean metal surfaces are hydrophilic and will retain an unbroken sheet of water that does not bead up or drain off. ASTM F22 describes a version of this test. This test does not detect hydrophilic contaminants, but the electroplating process can displace these easily since the solutions are water-based. Surfactants such as soap reduce the sensitivity of the test, so these must be thoroughly rinsed off.

Dry-ice blasting

Dry-ice blasting is a form of carbon dioxide cleaning, where dry ice, the solid form of carbon dioxide, is accelerated in a pressurized air stream and directed at a surface in order to clean it.

Abrasive blasting

Abrasive blasting, more commonly known as sandblasting, is the operation of forcibly propelling a stream of abrasive material against a surface under high pressure to smooth a rough surface, roughen a smooth surface, shape a surface or remove surface contaminants. A pressurised fluid, typically compressed air, or a centrifugal wheel is used to propel the blasting material. The first abrasive blasting process was patented by Benjamin Chew Tilghman on 18 October 1870.

Adhesive bonding describes a wafer bonding technique with applying an intermediate layer to connect substrates of different types of materials. Those connections produced can be soluble or insoluble. The commercially available adhesive can be organic or inorganic and is deposited on one or both substrate surfaces. Adhesives, especially the well-established SU-8, and benzocyclobutene (BCB), are specialized for MEMS or electronic component production.

Cleaning agent Substance used to remove dirt or other contaminants

Cleaning agents or hard-surface cleaners are substances used to remove dirt, including dust, stains, bad smells, and clutter on surfaces. Purposes of cleaning agents include health, beauty, removing offensive odor, and avoiding the spread of dirt and contaminants to oneself and others. Some cleaning agents can kill bacteria and clean at the same time. Others, called degreasers, contain organic solvents to help dissolve oils and fats.

Vapor degreasing is a surface finishing process. It involves solvents in vapor form to cleanse the workpiece in preparation for further finishing operations.

Parts washer

A parts washer is a piece of equipment used to remove contaminants or debris, such as dirt, grime, carbon, oil, grease, metal chips, cutting fluids, mold release agents, ink, paint, and corrosion from workpieces. Parts washers are used in new manufacturing and remanufacturing processes; they are designed to clean, degrease and dry bulk loads of small or large parts in preparation for assembly, inspection, surface treatment, packaging and distribution. Parts washers may be as simple as the manual "sink-on-a-drum" common to many auto repair shops, or they may be very complex, multi-stage units with pass-through parts handling systems. Parts washers are essential in maintenance, repair and remanufacturing operations as well, from cleaning fasteners, nuts, bolts and screws to diesel engine blocks and related parts, rail bearings, wind turbine gears boxes and automotive assemblies.

Pemaco is a former chemical mixing company and facility located on the Los Angeles River in Maywood, a small city in southeastern Los Angeles County, California.

Spray (liquid drop) Dynamic collection of drops dispersed in a gas

A spray is a dynamic collection of drops dispersed in a gas. The process of forming a spray is known as atomization. A spray nozzle is the device used to generate a spray. The two main uses of sprays are to distribute material over a cross-section and to generate liquid surface area. There are thousands of applications in which sprays allow material to be used most efficiently. The spray characteristics required must be understood in order to select the most appropriate technology, optimal device and size.

Air sparging, also known as in situ air stripping and in situ volatilization is an in situ remediation technique, used for the treatment of saturated soils and groundwater contaminated by volatile organic compounds (VOCs) like petroleum hydrocarbons which is a widespread problem for the ground water and soil health. The vapor extraction has manifested itself into becoming very successful and practical when it comes to disposing of VOCs. It was used as a new development when it came to saturated zone remediation when using air sparging. Being that the act of it was to inject a hydrocarbon-free gaseous medium into the ground where contamination was found. When it comes to situ air sparging it became an intricate phase process that was proven to be successful in Europe since the 1980s. Currently, there have been further development into bettering the engineering design and process of air sparging.

References

  1. Kalpakjian, Serope, Schmid, Steven R. (2006). Manufacturing Engineering and Technology. 5th ed. Upper Saddle River, NJ: Pearson Prentice Hall. 1079.
  2. US EPA. (1995). Solvent Degreasing. Available: http://www.epa.gov/ttn/chief/ap42/ch04/final/c4s06.pdf . Last accessed 19 April 2008.

See also