Case Study

Repair and Refurbishment of Couch Roll Suction Box

Significant cost savings achieved with repair and refurbishment of couch roll suction box.



Pulp & paper, UK.


Application Date 

June 2007


Scope of Work 

The recycling plant had planned to scrap the couch roll suction box. The unit had not been used for over 10 years, and they were looking at replacing with a new stainless steel couch roll. Using our proven engineering and coating expertise, we were able to coat the existing unit for around 10% of the cost of a new suction box. The client uses advanced and sustainable methods to process recovered newspapers and magazines. Turnaround time was a crucial factor in winning the contract.



  • Corrocoat Corrofill VE
  • Polyglass PPV
  • Corroglass AR4
  • Corroglass AR4 Veilcoat


Coating System 

• Rebate and pre machine the flanges – mask off areas not requiring treatment

• Grit blast to ISO 8501-1, cleanliness standard SA 21/2 with a minimum surface profile of 50µm

• Repair holed area in vacuum chambers by welding in a 24” x 9” plate and applying laminate cloth, L600 and Corrofill VE to smooth out feathered edges

• Apply a single coat of Polyglass PPV as a holding primer

• Apply Corroglass AR4 to a minimum dft of 1.2 mm

• Thickness check and spark test to 16Kv HV – AC

• Apply a topcoat of Corroglass AR Veilcoat

• Lightly blast all bronze parts including seal strip holders

• On completion of coating application, the suction box was post cured at 60-80ºC for six hours to ensure full cure prior to entering into service.

• Following thickness and spark testing the suction box was assembled and returned to the client to complete final fit.

The unit is now fully operational and working efficiently without issues.



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