Thesis (M.E.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (p. 132-135). Also available via the World Wide Web.

The hardwood sawmill industry is faced with a decreasing availability of high quality timber, and declining log quality. Ways to improve the technology are needed so that this lower quality resource can be better utilized. The hydraulic linear positioner is one such new technology. The objective of this research is to quantitatively determine the impact of hydraulic linear positioners on the production efficiency of hardwood sawmills by an analysis of: 1) lumber grade yields; 2) log value; 3) sawing time; and 4) sawing variation attributed to the linear positioners, using Factory Grade No. 2 red oak logs sawn into lumber by full-infinite taper and conventional sawing patterns. The results of this study indicate: 1) Hydraulic linear positioners in a hardwood sawmill can improve the production efficiency by a little over one percent (the positioners alone), and by up to 11 percent when including the contribution of the hardware and software with the positioners. 2) Selecting the opening face and using the full-infinite taper setout capabilities of the positioners did not improve the lumber grade yield from the logs used in this study. 3) Opening face selection and taper setout increase sawing time and thereby reduce the log value when based upon a $/log/operating minute. Such practices can reduce the production efficiency by up to $17 per log per operating minute. / Master of Science

The primary objective of this study was to improve residue chip quality at high production southern pine Sawmills. A general economic analysis suggested that improving sawmill residue chip quality could be beneficial to both pulp and sawmills. Studies were conducted at several sawmills to determine methods of improving residue chip quality. The first study examined the composition of material entering a residue chipper. Trim ends and oversize chips contributed the most pieces, but only 10% of the residue weight. Two-foot trim blocks accounted for the remaining material, 90% by weight. A number of these pieces resulted from slashing entire boards or cutting longer trim lengths into 2-foot pieces to clear them from the mill. Two studies were conducted to examine the possibility of leaving trim in longer lengths to improve piece orientation and stability. Both studies found significant improvements in chip quality, the over-thick chips decreased while the percentage of acceptable chips increased. Chip quality improved with each incremental increase in trim length, but increasing trim length to four feet alone accounted for 50% of the overall improvements. Four-foot trim lengths would generate an additional 4-5 tons of acceptable chips per day for the sawmill. Feed conveyor loading was found to affect chip quality. Highest chip quality was achieved when the feed conveyor was half-full, with two or three pieces entering simultaneously. An overloaded conveyor produced higher percentages of large chips, whereas chipping single pieces increased the percentage of smaller chips. The effect of seasonal temperatures on pin chip and fine production at southern pine and hardwood chip mills was examined as a secondary objective. The pin chip and fine content at the hardwood mills increased as temperatures decreased, but variability in species and inventory obscured the relationship. Southern pine chip mills experienced 4-5% increases in the pin chip and fine content during the winter months. Pin chips and fines increased 1% for every 10°F drop in temperature. / Master of Science

Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: For wood manufacturers around the world, the single biggest cost factor is known to be its raw material. Thus maximum utilisation, specifically volume recovery of this raw material, is of key importance for the industry. The wood products industry consists of several interrelated manufacturing steps for converting trees into logs and logs into finished lumber. At most primary and secondary wood processors the different manufacturing steps are optimised in isolation or based on operator experience. This can lead to suboptimal decisions and a substantial waste of raw material. The objective of this study was to determine the optimal machine settings for two interrelated operations, namely the sawing and ripping operations which have traditionally been optimised individually. A model, having two decision variables, was developed which aims to satisfy market demand at a minimal cost. The first decision was how to saw the log supply into different thicknesses by choosing specific sawing patterns. The second was to decide on a rip saw’s settings, namely part priority values, which determines how the products from the primary sawing operation are ripped into products of a certain thickness and width. The techniques used to determine the machine settings included static simulation with the SIMSAW software to represent the sawing operation and mixed integer programming to model the ripping operation. A metaheuristic, namely the Population Based Incremental Learning algorithm, was the link between the two operations and determined the optimal settings for the combined process. The model’s objective function was formulated to minimise the cost of production. This cost included the raw material waste cost and the over or under production cost. The over production cost was estimated to include the stock keeping costs. The under production cost was estimated as the buy-in cost of purchasing the under supplied products from another wood supplier. The model performed well against current decision software available in South Africa, namely the Sawmill Production Planning System package, which combines simulation (SIMSAW) and mixed integer programming techniques to maximise profit. The model added further value in modelling and determining the ripping priority settings in addition to the primary sawing patterns. / AFRIKAANSE OPSOMMING: Die grootste enkele koste vir houtprodukvervaardigers wêreldwyd is dié van hulle roumateriaal. Die maksimale gebruik van rou materiaal, of volume herwinning, is dus van primêre belang vir hierdie industrie. Die vervaardigingsproses in die houtprodukte-industrie bestaan uit ‘n verskeidenheid interafhanklike stappe om bome na stompe te verwerk en stompe na eindprodukte. By meeste primêre -en sekondêre houtvervaardigers word die verskillende vervaardigingsstappe in isolasie ge-optimeer. Hierdie praktyk lei tot sub-optimale besluite en ‘n vermorsing van roumateriale. Die doelwit van hierdie studie was om die optimale masjienverstellings vir twee interafhanklike prosesse, die primêre -en kloofsaag prosesse, te bepaal. Tradisioneel word hierdie twee prosesse individueel optimeer. ‘n Model met twee besluitnemingsveranderlikes is ontwikkel wat poog om die markaanvraag te bevredig teen ‘n minimum koste. Die eerste besluit was watter saagpatroon gekies moet word om die stompe in die regte dikte produkte te saag. Die tweede besluit was wat die kloofsaagstellings, ook bekend as prioriteitswaardes, moet wees sodat die regte wydte produkte gesaag word. Die tegnieke wat gebruik is sluit statiese simulasie met SIMSAW sagteware in om die primêre saagproses te modelleer en gemengde heelgetalprogammering (“mixed integer programming”) om die kloofsaagproses te modelleer. ‘n Metaheuristiek genaamd die “Population Based Incremental Learning” algoritme,was die skakel tussen die twee operasies om die optimale masjienstellings vir die proses te bepaal. Die model se doelfunksie was geformuleer om die koste van produksie te minimeer. Hierdie koste sluit die roumateriaal afvalkoste en die kostes van oor -en onderproduksie in. Die oorproduksiekoste was ‘n skatting van die voorraadkostes. Die onderproduksiekoste was ‘n skatting van die koste om voorraad van ‘n ander verskaffer aan te koop. Die model het goed opgeweeg teen die beskikbare besluitnemingssagteware in Suid Afrika, die “Sawmill Production Planning System”, wat ‘n kombinasie van SIMSAW en ‘n gemengde heelgetalprogrammeringstegniek is. Die model het verder waarde toegevoeg deur die kloofsaag se prioriteitswaardes te modelleer saam met die primêre saagpatrone.

Thesis (MBA)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Northern Timbers Sawmill (NTS), a hardwood sawmill in Tzaneen and part of Merensky Timber (Pty) Ltd, wished to determine their customers’ expectations and perceptions of the products and services offered. In order to assist NTS with this it was decided to develop a customer satisfaction survey that would be a tool for NTS to use to accurately and consistently measure and monitor the satisfaction of their customers with their products and services over time. A thorough literature study was done followed by primary research that included semi-structured interviews and a quantitative survey. Semi-structured interviews were performed on a randomly selected sample of customers from two primary segments, namely wet-off-saw and kiln dried timber. Based on the feedback from the interviews it was decided that the standard SERVQUAL model was the most appropriate framework to use as part of the development of the survey. An additional product quality and related aspects section was also included. The Cronbach alpha results of the SERVQUAL survey was 0.75 and 0.87, for expectations and perceptions, respectively, indicating a high internal correlation and consistency and indicating that the survey provided reliable results. The internal consistency was also confirmed by high Cronbach alpha results for each individual dimension. The primary components of satisfaction that were measured were expectations and perceptions (or performance). The customer satisfaction index for NTS was 89.87 per cent, which was fairly similar to the product satisfaction of 91 per cent attained from the product quality related section. The most important priorities for improvement identified were “Employees in Northern Timbers tell you exactly when services will be performed”, “Employees in Northern Timbers give prompt service to you” and “When Northern Timbers promises to do something by a certain time, they do so.” The effort NTS has made in ensuring that they stack, wrap and paint the select grade timber bundles contributed to the visibility and one of the highest mean scores in the survey of 5.63 out of 6. The fact that customers can contact the production team at the sawmill directly holds advantages for the customers and this was also confirmed by the survey producing the joint highest mean score of 5.63. It is also clear that there is very little interest and value for NTS in selling the FSC timber at a premium or offering pre-planed timber at a premium. The survey will be done twice a year – once during May or June, and once during October or November.

S3 (Softwood Sawmill Simulator) is a sawmill simulation system for modeling the operations of Pacific Northwest softwood lumber mills. S3 consists of three main parts. The first part is the framework for construction of the sawmill layout. The second part focuses on individual machine centers, their process and down times, and their interconnections. The third part consists of databases for raw material and final products. S3 inputs process logic from external data files. All parts are integrated in an object-oriented framework. The system was developed using the object-oriented environment, Actor. All data input and output are through database files in dBASE IV format. S3 can model a sawmill represented by the machine center and connection types defined in S3. The size of the model is controlled by the Actor programming environment. The construction of a sawmill model is demonstrated. / Graduation date: 1993

Stormwater runoff from log yards in different BC regions can affect aquatic habitats to varying degrees given differences in weather, water quality and tree species. The objective of this thesis was to compare runoff quality and total runoff loadings from a coastal and interior log yard. Chemical analyses, toxicity tests and treatments were conducted. Data were compared to criteria, statistically compared between sites and assessed for seasonal trends. Export coefficients (ECs) were compared between sites. Relationships between toxicological and chemical variables were explored statistically. Runoff toxicity was similar between sites and fairly low. LC50s for 48-hour Ceriodaphnia dubia tests ranged from 32.95 to > 100 and 58.70 to > 100 for coastal and interior runoff, respectively. Microtox ®.5 minute EC50s ranged from 27.12 to > 100 for coastal runoff and 22.22 to > 100 for interior runoff. Several metals and dehydroabietic acid (DHA) exceeded criteria in runoff from both sites. Biochemical oxygen demand, alkalinity, pH and metals were significantly higher (p < 0.05) at the interior site. Sodium and conductivity were higher at the coastal site. No seasonal differences in runoff quality were observed. Therefore, acute effects would occur during periods of high runoff, during autumn at the coastal site and late winter at the interior site. The unpaved interior site generated less runoff per square meter due to ground infiltration. ECs were comparable to the paved coastal site. Exceptions to this include tannins and lignin (11 fold higher at the coastal site) and DHA (9 fold higher at the interior site). C. dubia toxicity was partially associated with TSS for both sites. Tannins and lignins were correlated (r² =0.91) with C. dubia toxicity for coastal runoff. Tannin and lignin concentrations ranged from 45 to 263 mg/L and 43 to 75 mg/L in coastal and interior samples, respectively. Since results suggest that TSS is partially responsible for toxicity, and since contaminants are often bound to TSS, source control and treatment options for TSS should be implemented.

Lic.-avh. Luleå : Luleå tekniska univ., 2005.

No description available.

Orientador: Claudio Angeli Sansígolo / Banca: Elias Taylor Durgante Severo / Banca: Ademilson Coneglian / Resumo: Madeira é um material que vem sendo largamente utilizado pela humanidade ao longo da história. No Brasil que é um país rico em florestas nativas, ocorre por inúmeras vezes a exploração desenfreada desses recursos. O Cambará (Qualea albiflora Warm.) está entre as espécies de grande interesse do setor madeireiro por ser uma matéria prima de baixo custo e de alta durabilidade tornando a espécie visada pelos empresários desse setor. Com isto o presente trabalho tem como objetivo avaliar o rendimento de uma serraria beneficiando esta espécie como produto final de vigamento de várias medidas, procurando identificar os parâmetros significativos que devem ser levados em consideração no momento de seu beneficiamento. Em 895 árvores abatidas de Cambará apresentando amplitude de comprimento entre 2,50 e 8,00 metros e variação de diâmetro de 33 a 80 centímetros, oriundos de manejo florestal na região de Alta Floresta-MT sendo analisados os parâmetros intimamente relacionados com o rendimento que são o diâmetro, comprimento, número de toras beneficiadas ao longo do dia e quantidade em m³ de toras beneficiadas. Após o beneficiamento, foram avaliados os resultados diários referentes ao total de vigamentos, bem como seu rendimento diário percentual. O rendimento das toras de Cambará foi de 48,90%. Esse valor está de acordo com a literatura para os produtos analisados e para a amplitude de rendimento considerada normal para madeiras de folhosas (45-55%). A serraria não apresentou linearidade nos seus rendimentos, o que pode onerar os custos de produção e manutenção de seus maquinários. Por esse motivo, é importante salientar que não se deve analisar apenas o rendimento das toras como fator limitante do sucesso de uma empresa madeireira, haja vista que o cálculo desse parâmetro é feito por meio de proporção entre o total de madeira serrada e o total do metro cúbico de tora / Abstract: Wood is material that has been widely used by humanity throughout history. In Brazil it is a country rich in native forests, occurs by unbridled exploitation of these countless times. The Cambará (Qualea albiflora Warm.) is among the species of great interest of the wood sector by being a low-cost raw material and high durability making the species targeted by entrepreneurs in this sector. The present work aims to evaluate the performance of a sawmill benefiting this species as the end product of framework of several measures, seeking to identify significant parameters that must be taken into consideration at the time of their processing. In 895 trees felled to cambará showing extent of length between 8.00 and 2.50 meters and variation of diameter of 33 to 80 cm from forest management in the region of Alta Floresta-MT, being analyzed parameters closely related income that are the diameter, length, number of logs benefited throughout the day and quantity in m³ of logs. After processing, the results were evaluated for the daily total of frames, as well as your daily income percentage. The yield of logs of Cambará was 48.90%. This value is consistent with the literature for the products examined and for the breadth of income considered normal for wood of hardwoods (45-55%). Despite this, the sawmill does not present a linearity in their income, which may charge the costs of production and maintenance of their machines. For this reason, it is important to stress that one should not look at only the yield of logs as a limiting factor of the success of a logging company, given that the calculation of this parameter is done by means of the ratio of the total of lumber and the total cubic meter of logs / Mestre