Norland Photoengraving Glue is a liquid protein solution of high molecular weight which has extreme attraction to clean metal surfaces. This makes it the ideal material for plating release in electroplating.
Norland Photoengraving Glue is completely water soluble, but when a clean metal master is dipped into a dilute solution of this protein, a monomolecular layer of glue attaches itself to the metal surface. This cannot be removed with ordinary rinsing and provides the correct amount of release without destroying the adhesion or electrical contact which is necessary for precision plating operations.
Advantages of Norland Photoengraving Glue are:
Eliminates blistering - Forms a uniform layer on the metal surface that follows all the contours. This provides uniform adhesion as well as release.
No build up of organics - Only a tightly bonded thin layer goes into the plating bath.
No build up on master - Norland Photoengraving Glue is removed completely from the master by commercial caustic cleaners.
A dilute solution of photoengraving glue is made by stirring one quart of glue into 20 gallons of water. This is the plating release solution.
Clean the master to be plated in a commercial caustic cleaner such as Stauffer 500 or Kemper Passivator Cleaner. Follow manufacturers directions. Rinse in water spray for 30 seconds and dip into plating release solution for 15 seconds. Rinse again with water for 5 to 10 seconds and place in plating bath.
After plating the master and negative are separated by starting at one edge and peeling the two pieces apart.
The important point to remember is the master must be freshly cleaned so that the glue molecules can attach to all the active metal sites. Do not touch plating surface after treatment and do not allow surface to become dry.
For best results the solution should be made up fresh every day. Since it is a protein solution it is subject to bacteria attack in the diluted form.
Photoengraving glue is the technical term for fish gelatin. This is obtained from the skin of cod fish. It received its name over the years of use in the graphic arts industry as a coating for metal.
Fish gelatin is different from animal gelatin in that a water solution of fish gelatin is liquid at room temperature, whereas a water solution of animal gelatin is a solid (gel). Animal gelatin is available in liquid form but this has been broken down or chemically modified.
Norland Photoengraving Glue is pure fish gelatin
with an average molecular weight of 50,000. It is manufactured
in our own plant in Nova Scotia, Canada and we control it to give
consistent results from batch to batch.