operation_pretreat

Process No. 1
Warm Water Washing (Preparatory Washing)

Temperature: 50 +/- 3 *
Time: 0.5 minute
Pretreatment Process First Stage
This washing process (preparatory washing) is for removing any oil or dust at this stage using a warm water spray to prevent contamination of the degreasing agent used in the next process as much as possible.

Process No. 2
Preparatory Degreasing

Temperature: 50 +/- 3 *
Page 5
Free Alkalinity: 7 to 14 po
Time: 1 minute
Spray the heated alkali-degreasing agent to raise the oil attached to the surface.

Process No. 3
Degreasing

Temperature: 50 +/- 3 *
Free Alkalinity: 7 to 14 po
Time: 1.5 minutes
Spray the heated alkali-degreasing agent again to further raise any remaining oil attached to the surface.

Process No. 4
Water Washing 1

Time: 0.5 minute
Rinse the oil lifted using the alkali-degreasing agent away using a water spray.

Process No. 5
Water Washing 2

Contamination Degree: 1 po or less
Water Supply: 400L/hrs or more
Time: 0.5 minute
Risen the oil further away using the water spray.
If any alkali-degreasing agent remains, it would not be good for the acid washing agent in the next process. Check the degree of contamination and manage it so that the water is kept clean.

Process No. 6
Acid Washing

Free Acidity: 17 to 32 po
Conductivity: 60 to 100ms/cm
Oxidation-Reduction Potential (ORP Value): 400 to 800 mv
Temperature: 40 +/- 2 *
Time: 3 minutes
Dip the product in a huge bath tab in a building filled with heated acid agent (mainly sulfuric acid) (Dipping). Any dirt (impurities) that could not be removed with the alkali agent is removed with the acid agent like peeling off film (Etching).

Process No. 7
Water Washing 3

Time: 0.5 minutes
Rinse away any remaining acid agent with the water spray

Process No. 8
Water Washing 4

Time: 0.5 minute
Further rinse away any remaining acid agent by means of spraying water cleaner than in Process No. 7.

Process No. 9
Water Washing 5

Conductivity: 0.24ms/cm or less
Water Supply: 320L/hrs or more
Time: 0.5 minute
Pure water is replenished. Rinse the product by means of spraying water cleaner than in Process No. 8. If any acid agent were left, it would not be good for the forming agent in the next process.　Measure the water in the purpose-built bath tab and manage the conductivity so that it is 024ms (milisiemens)/cm or less.

Procedure No. 10
Chemical Conversion Coating (Non-Chrome)

RP Value: 4 to 8 po, A Value － RP Value: 0.5 to 2.0 po
Temperature: 40 +/- 2 *, pH: 3.2 to 3.8, Time: 1 minute
Conductivity: 0.4 to 1.5 ms/cm
Spray heated forming agent (zirconium phosphate) to form a film. Either too thick or too thin a film affects the performance after the coating. Liquid management is important.

Procedure No. 11
Water Washing 6

Time: 0.5 minute
Rinse away the excessive forming agent with water spray to stop the chemical reaction.
If any excess of forming agent remains, a chemical reaction would cause the film to be too thick, which causes an adverse effect on the coating performance.

Procedure No. 12
Water Washing 7

Time: 0.5 minute
Rinse the product again with the spray of the water cleaner than in Water Washing 6

Procedure No. 13
Water Washing 8

Conductivity: 5μs/cm or less
Water Supply: 500L/hrs or more
Time: 0.5 minute
Rinse the product again with the spray of the water cleaner than in Water Washing 7.
Measure the conductivity and manage the conductivity so that it is 5μs (microsiemens)/cm or less to keep the water clean.

Procedure No. 14
Pure Water Mist

Conductivity: 0.5μs/cm or less
Time: 0.2 minute
Spray pure water to finish the water washing. The pure water is created in the pure water unit. The conductivity is managed so that it is 0.5μs (microsiemens)/cm or less.

Procedure No. 15
Air Blow

Time: 0.2 minute
Perform the preparatory water removal with air blowing to reduce the moisture in the next process (post-treatment and water removal and drying).

Procedure No. 16
Post-processing

Total Alkalinity: 1.5 to 2.5 po
Conductivity: 30 to 100μs/cm
Time: 0.2 minute
Apply the post-treatment agent (silane coupling agent) with the mist spray. It creates an excellent adherence effect in the powder coating system. With this, an effect corresponding to chrome film can be obtained.

Procedure No. 17
Water Removal and Drying

Set Temperature: 120*
Time: 15 minutes
Remove the moisture from the product with heated air. Manage it so that there is no moisture left on the product.