Challenge

A corrugated packaging plant in central Florida experienced a market shift from heavyweight board to multiple board combinations. Its hot plate section could not quickly or accurately adjust temperatures for the different grades and overheating was causing the board to warp. The warping was slowing the converting process and reducing plant output. The degraded steam and control system could not control hot plate temperatures and had only manual control of shoe loading. The customer’s corrugator machine was older and ran below 1000 feet per minute. Improvements in quality and output were needed but the plant wanted to minimize its investment into an older system.

Solution

Kadant Johnson worked with the customer to find a solution that would improve board flatness and converting output while controlling cost. Kadant Johnson recommended a steam system rebuild with combined board temperature control (CBTC). The steam system upgrade included new steam traps, a low pressure condensate return, diverter valve stations, steam supply valves, exhaust valves, and temperature sensors. It was designed to quickly adjust to grade and speed changes.

Results

The CBTC controls the steam system and allows operators to set the grade of board before it runs. It optimizes hot plate steam pressure and shoe loading and allows operators to make manual temperature adjustments and uses machine learning to adjust future settings. When grades are changed, CBTC makes rapid and precise temperature changes to the board by adjusting the steam supply valves, exhaust valves, and shoe loading. The resulting flatter board is converted faster, increasing plant output. Fast and accurate temperature adjustments give the plant flexibility to run small batches across multiple grades to meet customer orders.

The corrugated packaging plant now makes flatter board, converts more product, runs smaller batches, and has increased plant output, at the fraction of the capital cost of a new double backer.

Combined Board Temperature Control - User Interface