Case Study: Couch roll suction box

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

Industry

Pulp & paper.

Application Date

June 2007 (completed in three weeks).

Scope Of Work

• 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 AR Veilcoat
• Lightly blast all bronze parts including seal strip holders

Post cure

On completion of coating application, the suction box
was post cured at 140-176 °F for six hours to ensure
full cure prior to entering into service.

History

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.

Coating system

Aylesford Newsprint uses advanced and sustainable
methods to process recovered newspapers and
magazines. Turnaround time was a crucial factor in
winning the contract. 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.

Photographs

Left: Couch roll delivered.
Middle: Interior division plates coated.
Right: Fully coated and tested.