Pulp and paper chips are primarily manufactured (cut, chipped) by disc chippers (either stationary or in-field) after some form of debarking. They are sometimes referred to as “clean chips”. Chips will be pulped either chemically (continuous or batch digesters) or using a Thermo-Mechanical Process (TMP). Pulp chips are made from softwood and hardwood trees but are segregated at paper mills and processed separately. Fiber requirements for different paper types determine whether softwood or hardwood is used exclusively or if a blend of softwood and hardwood fiber is required.
The Peterson Advantage
Common sources for pulp and paper chips include mill wood yard chips, in-field clean (flail) chips, sawmill residual chips. In-field clean chipping with a Peterson system has many advantages over a conventional round wood harvest where wood is cut and transported to a central site for debarking and chipping. These advantages spanning the total supply chain and include:
- Increased yield vs round wood
In-field chipping results in an increase in harvested and delivered tons per acres up to 30% in hardwood and up to 15% in softwood. Whole trees are fed into the in-field chipping system versus being topped and limbed for road transport of round wood. As a result, the upper stems and large limbs are debarked and chipped providing for more yield per acre. Additionally, in-field crews can harvest and chip stems smaller than those typically utilized in round wood logging and blend these stems into the feed going into the in-field clean chipper. This results in more revenue per acre for the land- and timber owner and also reduces the frequency of moves over the course of a year. This is a significant revenue advantage for timber owners and provides a competitive advantage for in-field chippers competing to buy timber against round wood crews.
- In-field chipping results in a much cleaner site after logging.
More wood is utilized (limbs, large tops and small stems chipped versus being left on site) as the land is being harvested and left clear of debris. This is a proven public relations advantage for the logging companies and the purchasing mills as neighbors report viewing these harvests as clean and less “wasteful”. It can be a buying advantage as many landowners want the clean site left from in-field chip harvesting. Additionally savvy landowners can often negotiate lower reforestation costs as tree planting crews will accept lower rates for in-field chip harvested sites.
- Increased transport payload
Efficient chip loading and well-designed chip vans make it possible to realize increased payloads up to 3 tons per load with chips versus round wood (conventional 25 ton round wood loads)
- Customer mills receive a more ready to use fiber per load.
With round wood, 8 to 12% of the wood purchased is lost at the mill site to debarking. With in-field clean chipping this bark is left in the woods and you only buy usable pulp and paper chips for your process.
Pulp and paper chips must meet mill-specific requirements for length, thickness and overall size distribution. In addition to sizing, they must also meet mill requirements for allowable bark and contamination (dirt, rot or decayed wood, fire char, and other inorganic material such as plastics and metal). Mill chip specifications need to provide specific details on their definitions of “accepts” or “rejects” and details on allowable bark percentage and contamination.
Peterson’s line of in-field clean chippers feature adaptive control systems making it easy to monitor and adjust all systems and setting necessary to optimize chip quality.
DISC CHIPPER KNIVES & COUNTER KNIVES
Peterson offers several different Chipper Disc Knife options for our 3-pocket and 4-pocket chipper discs for maximum production and consistent chip quality. Whatever your pulp and paper chip needs, Peterson Sales consultants can recommend a system that fits your requirements.