By: Kevin Kauth
There are numerous differences between the many types of emulsions available. The three main types of emulsions are diazo, dual cure, and photopolymer.
Diazo based emulsion is a two part product consisting of unsensitized emulsion which gets sensitized when diazo is added in. Once sensitized it has a pot life of approximately 4 to 6 weeks. Diazo emulsion can be water resistant OR solvent resistant but not both. It has medium exposure latitude and can be affected by humidity.
Dual cure emulsion is a two part product consisting of a pre-sensitized emulsion which gets sensitized when diazo is added in. Essentially there is one curing system in the bucket and when you add diazo (a secondary curing system) you end up with two curing systems in the bucket, hence dual cure. Once sensitized it has a pot life of approximately 4 to 6 weeks. Depending on formulation, dual cures can be water resistant, solvent resistant, or even both at times. Dual cures are by far the most user friendly emulsion available and have a wide range of exposure latitude.
Photopolymer emulsion is a one-part ready to use product that does not require sensitizing. Since it does not need to be sensitized it has a much longer shelf life, approximately 2 years if stored properly. Photopolymers can be water resistant, solvent resistant, or even both at times. Photopolymers are fast exposing and have a very narrow exposure latitude.
Kevin Kauth is Chromaline’s Technical Sales Representative for the Midwest region. Kevin has a strong background in screen printing and graphic arts. Prior to Chromaline, Kevin was employed at SEFAR where he was an Applications Specialist in their Technical Service and Marketing Department. At SEFAR, he interfaced with clients doing technical training and process control and improvement. He also has a strong digital background and can assist with outputting high-quality artwork for photopositives and photonegatives.
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