A vapor degreaser is a precise and efficient industrial cleaning equipment that relies on the selection of an appropriate solvent. The search for optimal solvent cleaners has intensified with the growing emphasis on sustainability and regulatory compliance. This article highlights the different types of solvents available, offering insights into their properties, applications, and the evolving paradigms driving solvent selection. Join us as we illuminate the paths towards enhanced cleaning efficacy, environmental stewardship, and operational excellence.
A Short Summary of Vapor Degreasing
Vapor degreasing is a highly effective cleaning and degreasing process that removes contaminants such as machining oils, cutting fluids, waxes, flux, and other substances in just a few seconds through “solvent cleaning”. This process is widely used in various industries, including electronics, aerospace, and metal fabrication, to clean metal and machined parts. Vapor degreasing offers comprehensive and fast cleaning capabilities without the need for rinsing and drying, making it an essential part of any manufacturing line. The process utilises non-flammable and non-hazardous solvents that can be recycled and reused, reducing operating costs.
Types of Solvents Used In A Vapor Degreaser
Many types of solvents can be used in a vapor degreaser. However, each type of solvent in vapor degreasing has its own distinct properties and characteristics. Below are brief descriptions of these different types of solvents, offering insight into their unique attributes and considerations for use in the cleaning process.
Chlorinated Solvents
Chlorinated solvent cleaners have been used for many years and have a higher boiling point than newer solvents. They are effective cleaners, non-flammable, and remain azeotropes. However, chlorinated solvents are classified as carcinogens and are heavily regulated regarding their shipment, use, emissions, and disposal. They are subject to NESHAP (National Emission Standards for Hazardous Air Pollutants) regulations. Despite this, many companies still use chlorinated solvents such as trichloroethylene (TCE), Methylene Chloride (MC), and Perchloroethylene (PERC).
Brominated Solvents
n-Propyl Bromide (nPB) is a brominated solvent cleaner commonly used as a replacement for chlorinated solvents. It is non-flammable and stays as an azeotrope. While it has a lower boiling point than some chlorinated solvents, such as TCE or PERC, it is also considered a probable carcinogen and is subject to regulation but with fewer restrictions compared to chlorinated solvents.
Fluorinated Solvents
Fluorinated solvent cleaners, such as HFEs (hydrofluoroethers) and HFCs (hydrofluorocarbons), are non-flammable and have low toxicity. Fluorinated solvents represent the newest generation of vapor degreasing solvents. These solvents typically have lower boiling points and are considered to have better health and safety profiles than chlorinated and brominated solvents. They are non-flammable and stay as azeotropes. Additionally, they are subject to fewer restrictions around shipment, use, emissions, and disposal.
Modified Alcohols
Modified Alcohols, such as isopropyl alcohol (IPA), are frequently employed in vapor degreasing processes due to several favourable characteristics. These solvents offer relatively low toxicity levels compared to chlorinated solvents, making them safer for workers and less harmful to the environment. Additionally, they exhibit good cleaning performance, effectively removing contaminants from parts during the degreasing process. However, despite their advantages, there are still some concerns regarding the health and environmental impacts of modified alcohols. While they are considered safer alternatives to chlorinated solvents, handling and disposing of them properly is essential to minimise any potential risks.
Hydrocarbon Solvents
Hydrocarbon solvent cleaners, including mineral spirits, petroleum ether, and Stoddard solvent, are sometimes used for vapor degreasing. They are generally less aggressive cleaners compared to chlorinated and fluorinated solvents but may be suitable for less demanding applications or for cleaning certain types of materials.
Mineral Spirits
Mineral spirits are a mixture of aliphatic and aromatic hydrocarbons, typically consisting of compounds such as hexane (C6H14), heptane (C7H16), and toluene (C7H8).
Petroleum Ether
Petroleum ether is a mixture of low-boiling aliphatic hydrocarbons. It is commonly used as a laboratory solvent and may contain various compounds such as pentane, hexane, and heptane.
Stoddard Solvent
Stoddard solvent cleaners, or mineral turpentine, is a mixture of aliphatic and aromatic hydrocarbons, including compounds such as hexane, heptane, and toluene.
Azeotropic Solvents
Azeotropic solvent blends, such as AK225, are designed to exhibit azeotropic behaviour, meaning they have specific compositions at which the vapor and liquid phases have the same composition and boil at a constant temperature. These blends are carefully formulated to achieve desired properties for vapor degreasing applications, including precise boiling points and cleaning capabilities. AK225, for example, is a blend of n-propyl bromide (nPB) and hydrofluorocarbons (HFCs). This combination allows for the optimisation of performance, safety, and environmental compliance.
What Are Azeotropes
An azeotrope is a mixture of two or more substances that behaves like a pure compound in certain proportions, meaning it maintains a constant boiling point and composition during distillation. In the context of vapor degreasing solvents, when it’s mentioned that a solvent “stays as an azeotrope,” it means that the mixture of solvents used in the degreasing process maintains this constant composition and boiling point, even as the solvent evaporates and condenses during the cleaning process. This property is desirable because it ensures consistent cleaning performance and simplifies solvent management.
ORAPI RECOMMENDS:
ORASOLV S1 is a multi-purpose, high-tech, biodegradable solvent that can replace chlorinated and ketonic solvents in some applications. It is guaranteed hydrocarbon-free.
Conclusion: Solvent Cleaners
Many types of solvents are utilised in a vapor degreaser. However, these vapor-degreasing solvents have evolved due to sustainability and regulatory constraints. Chlorinated solvents offer efficacy but have environmental concerns and strict regulations. Alternatives like brominated and fluorinated solvents offer better safety profiles. Modified alcohols, hydrocarbon solvents, and azeotropic blends are other options. Industries are searching for optimal solvents for cleaning efficacy and environmental stewardship. Orasolv S1-0543 Biodegradable Solvent is an eco-friendly solution that represents the industry’s commitment to operational excellence and environmental responsibility.
