Effects of temperature and moisture content of logs on size distribution of black spruce chips produced by a chipper-canter at two cutting widths

Abstract

Four matched groups of black spruce logs were processed with a chipper-canter at temperatures of 20, 0, -10, and -20 °C. Each log was transformed at two moisture contents (MC, green and air-dried) using two cutting widths (CW, 12.7 and 25.4 mm). Mean MC for each CW was assessed from a sample of the obtained chips. Knot characteristics were measured on the cant surfaces after log processing. Chip size was assessed by thickness (Domtar classifier) and width/length (Williams classifier). The results showed that the chip size was significantly affected by the CW and temperature, and in a lesser degree by the chip MC. The weighted mean chip thickness (WCT) increased with the CW. As temperature decreased below 0 °C, WCT and accepts decreased, while proportions of fines and pin chips increased. Chips obtained from green logs were thinner compared to air-dried logs when processed at the coldest temperature (minus 20 °C). The number and size of knots had an important impact on chip size, particularly on WCT. Multiple regressions were developed to predict WCT. Results showed the potential benefits of measuring log temperature and knot features to reduce chip thickness variation during fragmentation and thus improving chip size uniformity.

Effects of wood species on the energy requirements and size distribution of strands produced by a strander-canter

“…The physical properties of balsam fir, black spruce, and jack pine logs are shown in Table 2. In general, the means of MC and SG of all species used in this experiment were within the range of MC and SG reported in previous studies conducted in Eastern Canada (Hernández and Boulanger 1997;Hernández and Lessard 1997;Garrahan et al 2008;Elloumi et al 2021). Only the MC of jack pine sapwood (112%) was slightly lower than the MC reported in a previous study (124%) by Garrahan et al (2008).…”

Influence of storage time and log length on the distribution of wood chip size

“…Logs stocked for two weeks generated 1.7% more overthick than logs without a storage period (Table 6). Similar results were found by Elloumi et al (2021), in which conditions of lower moisture content resulted in thicker chips, especially at higher sub-zero temperature. The same behavior was observed by Watson and Stevenson (2007) in a study that analyzed the influence of wood moisture on the size of chips produced from both hardwood and softwood.…”

“…This indicates that moisture is influenced by several factors, and, over time, the interaction of these factors, such as variation in rainfall, wind, pile arrangement, results in greater variations in logs moisture. Elloumi et al (2021) concludes that the moisture content significantly affects the size distribution of chips. In contrast, log length, with a value p = 0.14 and F less than critical F, did not influence the moisture content of the chips (Table 3).…”

Quality of eucalyptus wood chips for bioenergy as a function of drying time and horizontal chipper settings

“…Initially, it was observed that Eucalyptus dunnii wood has a medium density, which is relevant for determining its energy potential, as evidenced by Ref. [ 13 ].…”

“…As emphasized by authors [ 1 ] in their research, efficient wood drying plays a vital role in controlling this variable, as it not only reduces the weight of the material but also increases the calorific value and energy efficiency, while minimizing emissions during energy conversion. The authors [ 13 ] highlighted in their research that wood logs with lower moisture content produce larger and thicker chips. This occurs because, according to Ref.…”