Chemical resistance
Encyclopedia
The chemical resistance of a material
or surface
can be determined in compliance with ISO 2812 Paints and varnishes – Determination of resistance to liquids – Part 1: Immersion in liquids other than water (ISO 2812-1:2007); German Version EN ISO 2812-1:2007 or Part 4: Spotting methods (ISO 2812-4:2007); German Version EN ISO 2812-4:2007. With these methods, a material or surface is exposed to the relevant chemical for a longer, defined period of time and the relevant area then inspected microscopically
. Possible changes which could occur include:
On completion of the defined test period, any residues of test liquid are removed and the material surface assessed and analyzed for visible alterations in accordance with DIN EN ISO 4628-1 to -5. To ascertain a possible regeneration
time, the assessment is made once immediately after removal of the test liquid and again one hour later. In compliance with DIN EN ISO 4628-1, the following criteria are grouped into Classes 0 to 5: amount of damage (N), size of damage (N) and intensity of alteration (I). Any other changes observed are also noted. The assessment is made as shown below:
“Blistering, N2-S2” or “Discoloration, I1”
Any increase in the concentration of the test liquid on a surface due to drying in the real cleanroom
environment must also be taken into consideration.
The test procedure proves whether a material or surface is “resistant”, “partially resistant” or “not resistant” to a specific chemical over a defined period of time.
Material
Material is anything made of matter, constituted of one or more substances. Wood, cement, hydrogen, air and water are all examples of materials. Sometimes the term "material" is used more narrowly to refer to substances or components with certain physical properties that are used as inputs to...
or surface
Surface
In mathematics, specifically in topology, a surface is a two-dimensional topological manifold. The most familiar examples are those that arise as the boundaries of solid objects in ordinary three-dimensional Euclidean space R3 — for example, the surface of a ball...
can be determined in compliance with ISO 2812 Paints and varnishes – Determination of resistance to liquids – Part 1: Immersion in liquids other than water (ISO 2812-1:2007); German Version EN ISO 2812-1:2007 or Part 4: Spotting methods (ISO 2812-4:2007); German Version EN ISO 2812-4:2007. With these methods, a material or surface is exposed to the relevant chemical for a longer, defined period of time and the relevant area then inspected microscopically
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
. Possible changes which could occur include:
- Discoloration
- Alteration in the degree of shine
- Softening
- Swelling
- Detachment of coatings
- BlisteringBlisteringBlistering, founded in 1998, is an international online magazine dedicated to heavy metal and hard rock music. Its editor-in-chief is David E. Gehlke, an American music journalist who has written for About.com, Metal Maniacs, and Throat Culture...
On completion of the defined test period, any residues of test liquid are removed and the material surface assessed and analyzed for visible alterations in accordance with DIN EN ISO 4628-1 to -5. To ascertain a possible regeneration
Regeneration
-In biology:* Regeneration , the ability to recreate lost or damaged tissues, organs and limbs* Bush regeneration, an ecological technique practiced in Australia-In music:* Regeneration , a 1977 album by Roy Orbison...
time, the assessment is made once immediately after removal of the test liquid and again one hour later. In compliance with DIN EN ISO 4628-1, the following criteria are grouped into Classes 0 to 5: amount of damage (N), size of damage (N) and intensity of alteration (I). Any other changes observed are also noted. The assessment is made as shown below:
“Blistering, N2-S2” or “Discoloration, I1”
Any increase in the concentration of the test liquid on a surface due to drying in the real cleanroom
Cleanroom
A cleanroom is an environment, typically used in manufacturing or scientific research, that has a low level of environmental pollutants such as dust, airborne microbes, aerosol particles and chemical vapors. More accurately, a cleanroom has a controlled level of contamination that is specified by...
environment must also be taken into consideration.
The test procedure proves whether a material or surface is “resistant”, “partially resistant” or “not resistant” to a specific chemical over a defined period of time.