To help you make the best decision for your mill, we put together a short guide to log debarkers. 

1. Drum Debarker

Drum debarkers are an older technology developed for processing large volumes of lumber. It is an on-mass system, meaning operators feed multiple logs into the debarker and debark them simultaneously.  

Drum debarkers are composed of a large, rotating cylinder (the drum), the inside surface of which is equipped with ridges (“rifters,” “staves,” or “lifters”). As the drum rotates, the rifters lift the logs and cause them to tumble against one another. As bark comes off the logs, it exits the debarker through slits in the drum.

Drum debarkers are not mechanical debarkers, meaning the machine itself does not debark the logs. Friction produced as the logs tumble against each other does the debarking. The rifters may occasionally remove some bark, but they are not designed to cut.

We suggest producers consider the Drum debarkers for large-volume debarking.

DRUM DEBARKER ADVANTAGES

High capacity

Producers can feed in and discharge multiple logs

Produces a smooth surface finish in a wet process

DRUM DEBARKER DISADVANTAGES

Does not process small-diameter logs well

Does not do well with species that have stringy or difficult-to-remove bark

High costs and long downtimes for maintenance

Inconvenient for shipping

2. Roller Debarker (Rotary Debarker)

Roller debarkers debark logs using friction and mechanical means. Like drum debarkers, they are an on-mass system and can debark multiple logs at the same time.

Roller debarkers look similar to drum debarkers, but they operate differently. Like drum debarkers, they have a large tube through which the logs travel. This tube, however, is fixed; it is merely sidewalls and a cover. (Smaller roller debarkers may have open tops.) Inside the debarker are a series of rollers equipped with abraders. These abraders act like small hammers that “kick” logs as they pass through, forcing them to move up the side of the debarker until they reach the top and tumble back onto the pile of logs inside the debarker. While this is occurring, all the logs are tumbling against one another. The abraders also cut the log surface to start peeling the bark.

Like drum debarkers, the logs can be kept inside the debarker by closing a gate on the output side of the machine. If the roller debarker has a floor, bark leaves the debarker through slits. If the debarker has an open floor design, bark exits between abraders, which are designed to work as a screen.

ROLLER DEBARKER ADVANTAGES

Can debark logs with both small and large diameters

Can debark frozen logs

Can debark species with difficult-to-remove bark

Minimal fiber loss

High bark removal percentage

Reasonable capital costs

Less power required than drum debarkers

Variety of sizes available

Convenient for shipping

ROLLER DEBARKER DISADVANTAGES

Lower capacity than drum debarker

Won’t produce as smooth of surfaces as a rosserhead debarker