Chipperpedia is your source for all things disc chipper, drum chipper, whole tree chipper, chain flails debarkers, and chip quality. But calling it DiscChipper-DrumChipper-FlailDebarker-Pedia just seemed to long, so Chipperpedia was born. Get the low-down on industry terminology, colloquialisms, and learn the ins-and-outs of Peterson’s industry-leading machines. Chipperpedia is your source for What You Need to Know.
Accept Chips (Accepts) are wood chips that fall within a specified length and thickness size range determined by the buyer or a contract. Accept Chips may also limit bark content to a specified range. A chip sample is often taken and put through a chip classifier to determine the quantity of accepts, overs (over thick & over length), and unders (fines, and pins) in a load.
Accept Chips are a customer specific tolerance based on their needs for file product.
For example: ABC CHIP requires 1″ (2.54 cm) chips with bark content of: 1% for pulp chips.
When sizing chips, you typically have acceptable chips, fines which fall below acceptable chips, and overs which are larger than accepts.
The chipper anvil is a stationary metal bar mounted to the chipper housing that supports the end of the logs as the chipper knife cuts through them. The anvil is adjustable to set a specified clearance between the knife point and the anvil.
Artificial Regeneration is the planting of tree seedlings or seeds after a timber harvest rather than relying on stump sprouts, seeds, and other forms of natural regeneration. Planting is usually one of the final steps after other site preparation activities designed to increase plantability, control competition from native vegetation, improve growth and increase seedling survival.
Babbitting is the process of bonding a molten, soft alloy metal (Babbitt metal) to a stronger metal. In the case of Babbitted chipper knives, Babbitt metal is added to the back end of a knife so that when it is installed it has the proper extension from the wear plate of the chipper disc giving you the desired chip size. Normally, a worn chipper knife is removed, re-ground and then Babbitted to restore the correct knife length.
Babbitt metal used for chipper knives is an alloy of tin, copper, antimony, and lead.
The Bark Pusher is a component of a Flail Debarker that pushes loose bark and limbs away from the machine on one side at ground level. Peterson uses a hydraulically powered reciprocating pusher to allow bark to drop down, and then be pushed into an easily removed pile.
Biomass is fuel that is developed from organic materials, a renewable and sustainable source of energy used to create electricity or other forms of power. Biomass can be created from sources such as forest residuals, waste wood (scrap wood), crops (such as corn stover), and other organically based waste residuals.
Peterson’s Chain Flail Debarker machines use links of hardened chain to debark large diameter logs. Peterson machines debark multiple logs at the same time, saving money every log. Flail Debarkers whip the logs with specialized chain to strip bark and small branches, delimbing trees before further processing.
A chip classifier is a mechanical device used to determine the distribution of chips across a length and thickness range. The most common classifiers use a series of trays with bar slots to sort on thickness and punch plate to sort on length. Classifiers help keep production on track, and contracts to size.
Chip quality is how chips compare to the required standard, although different applications have different specifications. Chip quality is something which is measurable by the predetermined contract size, and the output. Included in it’s measurement may be length, thickness, and bark content, moisture content, contamination, or meet additional standards such as those for playground chips.
Dialing a machine in to get the desired output chips with each specific feedstock takes skill and time. Knowing your application and using Peterson’s Chip Quality Index will greatly reduce the hassles associated with getting the perfect chip.
Peterson machines have customizable components that allow the end user to maximize their acceptable chips, minimize maintenance and exceed productivity standards. Chips for all applications, all sizes, and any variance can be cross referenced in the Chip Quality Index.
The Chip Quality Index (CQI) is the measurement which all chips are evaluated against post processing. The CQI is where money is made. By measuring chips against the CQI chip producers can determine value and potential profit based on consistency. To be sure you receive the highest consistency, and optimal chip for your application please consult the Peterson Chip Quality Index below.
The chip spout is the long hollow pipe connected to the chipper through which chips are ejected. The 5000H is built with one of two chip spout styles: the top-loading spout, and the shorter end loading spout.
Chip thickness is the measurement of how a chip is split. It is typically well correlated with chip length but not always. Thickness is the principal factor impacting paper pulping effectiveness (liquor or pulping chemical penetration, and time required in the digester penetration).
A Chip Van, also known as a chip trailer and bulk van, are an aluminum walled trailer designed to haul wood chips or biomass when coupled to a semi-truck. The trailer is either end loaded or top loaded. Made from lightweight aluminum to increase payload, and larger volume capacity, chip vans are typically used for infield chipping or transport.
Chip vans are available with a variety of features, multiple lengths, and axle configurations. It is common to include live floors that move material toward the tailgate.
The chipper disc houses the knife assembly on Peterson disc chippers. The chipper discs is available with traditional babbitted knives or with a Key Knife system and can be configured with 3, 4, or 5 pockets and several optional sheave sizes to make precise chips.
A Peterson Chipper Drum features durable AR450 steel wear surfaces, and come standard with one babbitted knife per pocket. Peterson Chipper drums have from 4 to 16-pocket available for chipping. The number of pockets directly relates to chip type and quality; more pockets make finer chips.
Peterson’s drum chipper grate system provides ultra-consistent chip sizing; twigs and small stems which can be difficult to size are easily fractured through our innovative system. The chipper grate is located next to the chipper drum and ensures that materials passing through the grate meet a specific size requirement.
Chips are the result of putting a tree through a cutting machine. Chips are larger, and courser than saw dust and typically have an intended outcome such as biomass, pellets, playground chips or paper pulp.
Clearcutting is the logging technique of removing all timber from an area. Clearcutting used in conjunction with sustainable forestry practices is a tool for even-aged timber management. A clearcut can both positively and negatively impact the land and can be used for a number of practices such as land clearing and right-of-way clearing.
A counter knife is a piece of sharpened steel that breaks chips into their desired lengths. Located behind, and similar in appearance to, the chipper knife. A counter knife cuts the chips into the proper lengths, where as a chipper knife cuts the chips to proper thickness. Counter knives can be sharpened when worn, or replaced when necessary. Always buy Peterson brand counter knives to ensure the best chip quality and accuracy.
Cribbing is the construction of beams of wood (cribs), stacked evenly to form a four-sided column that solidly supports and stabilizes the machine for either better performance due to uneven terrain or maintenance. Each row of cribs is typically laid 90 degrees from the previous.
Safety for all Peterson machinery operators is our highest concern. When employing cribbing methods, make sure to follow best practice safety measures.
Debarking is the mechanical removal of bark and small limbs from multiple logs at one time. Methods include rotating drums, chain flails, ring debarkers with adjustable tool steel arms, and high speed rotating heads. Drums and flails are the only methods suitable to debark multiple logs at one time.
Dirty Chips are produced from the entire tree, including the bark. The appearance of the high bark content gives dirty chips their name. A Dirty Chip may also be made from branch wood, leaves or needles, and roots.
Dirty chips are typically used in: biomass power, pellet or mulch applications.
A Disc Chipper is designed for high volume operations that require the ability to chip large diameter feedstock, or multiple smaller logs, simultaneously. Typically used in wood pulp chip applications in conjunction with flail debarkers.
Disposable Knives are smaller specialty knives that are single use. They typically have two usable edges and once both edges have dulled, the knives are discarded. Disposable knives may be preferred when chipping contaminated materials. Disposable knives may lower operating costs.
Peterson drum chippers are available in 4 to 16 pocket drum sizes depending on the machines application. Each drum can be configured to specific product output needs by changing certain options. Typically used for biomass, a Peterson Drum Chipper is the answer for high volume biomass producers.
To End Load is the process of blowing chips through the chip spout, into a closed top chip van from the rear of the chip van. Top loading uses a similar process to blow chips into an open top chip van.
Export Lifting Eyes are durable steel plates with a hole drilled in them for a crane hook which aid in loading the machines onto a boat for export. The Lifting Eyes are an optional feature for some equipment which attach to the front and rear of the machine and are capable of supporting it’s full weight.
A face plate is a wear part, and is a flat steel plate between chip pockets attached to the chipper disc. Wear is monitored over time and the face plates are replaced after a certain amount of wear is detected.
Feed rollers are high-torque, direct drive motors that pull the feedstock into the machine. Peterson chippers have both upper and lower feed rolls. The upper feed roll is sometimes referred to as a compression roll.
Fines are chips that fall below a minimum standard. Fines that exceed the relatively small required percentage of the total chip supply create real problems for pulp mills, such as plugged digester screens, excess chemical absorption, increased load to the recovery boiler, loss of fiber yield, diminished product quality, excessive heat in the chip pile resulting in chip degradation and higher dirt count. Fines are generally used to make wood pellets for fuel.
When sizing chips, you typically have acceptable chips, fines which fall below acceptable chips, and overs which are larger than accepts.
A Flail, also called a Chain Flail or Delimber/Debarker, is designed to removed bark and limbs from any type of tree. Flails whip away the unwanted outer layer of the tree using heavy duty chains attached to the flail drum. They are often used in tandem with a whole tree chipper to produce high quality clean chips which can even be done in-field.
Flail chain is heavy, hardened, specialty chain that attaches to a flail drum. The flail chain whips the log as the flail drum spins, debarking the log.
Peterson standard flail chain is 5/8″ (16mm) diameter wire, although different sizing and configurations are available depending on the desired output. Peterson flail chains can be customized depending on climate, species of wood, and desired bark content on output.
Flail Drums are specifically designed to be used in debarking application. The Flail Drum whips flail chains into the logs to debark them.
A high speed rotating drum that houses the flail shaft, and rods, used to retain the flail chains. The drum body is hardened to increase longevity and provide better wear resistance. Flail machines can be used to debark any species of wood, even species of eucalyptuses with the addition of eucalyptus rings. The flail drum is distinguished as an individual wear part. In appearance the part is: a tube with oval holes from which the chains protrude. The shaft, rods, chains, and end plates are separate parts.
The flail speed is the rotation speed of the flail chains in rotations per minute (rpm). Flail speed may be adjusted to reflect wood type, climate and other factors affecting bark removal. Flail direction can also be adjusted by the operator.
Gap is the diagonal measurement from the sharp edge of the chipper disc knife down to the nearest point on the face plate surface. This measurement is sized to correspond to chip size and desired length. Typically set to 1/16″ (1.5875 mm) smaller than the target chip length.
Hardwood trees are deciduous trees, loosing all their leaves annually. Hardwood trees tend to grow slower than softwood trees making their wood more dense. However, not all hardwood trees are harder than softwood trees.
A standard 40 ft (12.19 m) shipping container is 8′ 6″ (2.59 m) high on the exterior. A High Cube Container is a 40 ft (12.19 m) shipping container that is 1′ (0.31 m) higher than standard, or 9′ 6″ (2.9 m) on the exterior. Peterson’s 3310 Drum Chipper is uniquely designed to fit in a High Cube Container for easy overseas shipping and reduced transportation costs.
In-Field Chipping is the process of debarking and converting the feedstock to chips while on the logging site. This can lower transportation costs by eliminating the need to haul out whole trees from the job site as well as shorten the overall processing time considerably.
The Infeed (Hopper) is the primary opening used to insert feedstock into the machine. Also known as a hopper, it is the first thing to greet the feedstock as the feed rollers pull the feedstock into the machine.
Knife is the common term associated with a cutting face, or the sharpened planar surfaced used to separate wood into chips from the main body of the log. Different machines have different knife or blade types and the vast majority of knives and blades are customizable to individual climates, feedstock types, and workloads.
The knife extension is the distance between the blade, or edge of the knife and the surface of the drum or face of the disc. The knife extension at each pocket on the drum should be the same in order to maintain a consistent knife-to-anvil clearance.
Larger extensions cut longer, thicker chips, shorter extensions produce shorter, thinner chips. Knife extension can be adjusted to produce the desired chip type.
Indications that the knife extension is incorrect include:
Knife velocity measures the speed in feet per minute as a result of disc or drum diameter, engine rpm, and sheave dimensions. The best chip quality is produced in a range from 5500 to 6000 ft (1676.4 to 1828.8 m) per minute.
A Landing is a planned zone installed by the logging contractor to concentrate and deck the wood cut and skidded, sort stems by product and value, and load the trucks. Landings are often planned in advance and located to minimize site impacts such as erosion and to minimize the distances wood has to be skidded in the field.
A merchantable stem is a logged tree with saleable value. Trees must be of certain size for different applications–merchantable trees for pulp chips are different than lumber. Tree value is calculated by height of the tree and the diameter of the tree stem or trunk.
Microchips are very small cut chips produced from a disc chipper or drum chipper. Commonly specified at 60% to 70% 1/4″ (6.35 mm) minus chip length, these tiny chips are used primarily in pellet fuel and composite fuel markets.
The moisture content of both feedstock and chips is dependent on several factors including age of wood, species, and even seasonal weather.
Moisture content in feedstock affects how wood is chipped, and machine adjustments may need to be made to account for different levels.
Moisture content of chips is often important for the buyer. Biomass chip buyers concern is with combustibility–having the correct moisture content creates efficient fuel that doesn’t burn too fast or too slow. While paper and pulp chip buyers regard moisture content as a significant factor in pulp creation.
Natural regeneration relies on re-sprouting, stump sprouts, seeds or other natural occurrences to reforest a harvested area. Most hardwood species re-sprout vigorously from dormant buds near the stump or from the roots. Likewise pine seed can remain viable on the forest floor or years and germinate after a logging operation.
A Non-Merchantable Stem is a tree trunk too small to meet a pre-defined size and valuation category for a particular product (such as lumber) or customer. Previously wasted slash, these trees are now often harvested and utilized with microchipping or biomass.
Pins are a classification of undersized chip material which does not meet the chip quality specifications. Pins are long, thin pieces of wood resembling a toothpick or matchstick shape. Pins have shorter fibers and are therefore undesired for pulp. Most paper mills classify pins as material that passes through a 2mm bar slot and is retained on a 3mm round hole opening on a chip classifier.
Engineered wood chips or mulch designed specifically for outdoor play surfaces such as playgrounds. Chips should meet safety specifications for playground access and fall protection set by ADA (American Disabilities Act) and ASTM (American Society for Testing and Materials). Playground chips allow a springy surface with a tight enough surface to allow wheel chair access, yet still allowing water to pass through.
Peterson disc or drum chippers are an ideal tool for creating this type of material.
Pulp chips are cut for a paper or paperboard application. These are typically held to high chip quality standards for uniform sizing, and contamination control (bark and other contaminants). The most common form of pulping involves using chemicals in batch or continuous digesters. Other facilities use a thermo-mechanical form of separation, the pulp from the lining and other extractive.
Softwood trees are conifer trees, typically evergreen with needles. Softwood trees tend to grow faster than hardwood trees making their wood less dense–or soft. However, not all hardwood trees are harder than softwood trees.
Thinning is the removal of trees to achieve a desired spacing and number of remaining stems per acre. It is most commonly used in plantation forestry to prevent overcrowding and promote the health and growing speed of the remaining trees. After the trees are removed, the remaining trees have more space to grow, more soil nutrients, and more water per tree.
Trees that are removed are typically slower-growing, diseased, or poorly formed trees leaving the most vigorous, dominant trees to grow. It is a common forest management practice and the merchantable stems harvested are used to make fuel chips or pulp chips. Earlier thinning in younger non-merchantable stems is becoming a common practice. Stems cut in pre-commercial thinning are left in place to decompose.
It is a common practice used in agriculture as well as forest management.
Throughput is the amount of material that passes through a machine during a given amount of time. It is often measured in tons or tonnes per hour but can also be measured in cubic yards or meters per hour. Peterson calculates throughput values using the amount of material input to the machine.
A timber cruise is completed by a forester, determining the volume and value of merchantable stems on the property. This step allows land-owners to determine their next step, as well as provides opportunities for short- and long-term forest management. The person performing the timber cruise is often called a timber cruiser or just cruiser.
Twig Knockers are short nubs mounted on the outside edge of the chipper that help move small twigs and debris out of the chipper. They also function as clamps that help secure the wear plate to the chipper disc.
UHMW (Ultra-high-molecular-weight polyethylene) is an extremely tough plastic which is up to 15 times more resistant to abrasion than carbon steel. It has very low moisture absorption, is self-lubricating and allows for very little friction.
Peterson uses UHMW for wear liners in many of our machines to protect high-wear areas.
A Wear part is a part on a machine that is replaced as needed to maintain optimal performance. Wear parts are also often designed to allow for customization: flail chains, chipper knives, and counter knives.