Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 2016

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Visual grading of small-diameter poplars for peeling use

Bayatkashkoli A., Sharefpour M., Shamsian M.

Drewno : prace naukowe, doniesienia, komunikaty

2016

vol. 59, nr 196

31--47

Small-diameter poplars (Populus euramericana, or Populus deltoids, or Populus nigra) are an important raw material resource for the wood and paper industry. Both manufacturers and governments are increasingly interested in obtaining this raw material from poplar plantations. A small-diameter poplar is between fifteen and thirty five centimetres in diameter at breast height. In this study, small-diameter poplars were graded visually for use in peeling. Traditional rules currently in use were applied when grading small-diameter poplars, and standard layer-sorting rules were used on the outputs from the peeling process. The field study has shown that standard sorting by layer doesn't correspond well when small-diameter poplars are sorted. For instance, the best small-diameter poplar is rarely classified as class A or B by standard layer sorting. In this research, small-diameter poplars are classified accurately using specific, alternative rules, and the grading scale ranges are presented. Some defects, such as knot and splits, have a strong influence on the quality of the final product, but often, existing standard-sorting methods do not reflect the degree to which the defects have affected the final product. A new method for classifying small-diameter poplars is presented, which groups the wood by its value in the final product.

Effects of inorganic nanoparticles on mechanical and morphological properties of wood flour-polypropylene nano composites

Ismaeilimoghadam S., Masoudifar M., Nosrati B., Shamsian M.

Drewno : prace naukowe, doniesienia, komunikaty

2016

vol. 59, nr 196

127--137

This research was conducted to examine the effect of SiO2 and TiO2 nanoparticles on the mechanical and morphological properties of wood flour-polypropylene nanocomposites. For this purpose, 60 (wt.%) wood flour was mixed with polypropylene. 4% maleic anhydride polypropylene was also used in all the compounds as a coupling agent. In addition, SiO2 and TiO2 nanoparticles were used as mineral fillers at 0, 1, 3 and 5%. The mixing process was performed inside an extruder and the test specimens were prepared by injection molding method. Bending and tensile tests were then performed on the specimens according to the ASTM standard. Scanning electron microscopy (SEM) was also used to show the distribution of nanoparticles over the composite substrate. The results showed that the composites containing nano-SiO2 had more favorable mechanical properties compared to those containing nano-TiO2. On the other hand, increasing the nanoparticles from 0 to 3% led to an increase in mechanical strength, however, the addition of more nano-fillers resulted in a significant decrease in mechanical strength. The results of SEM also showed a proper dispersion of nanoparticles at 1 and 3% levels, but using 5% nanoparticles caused the particles to aggregate on the composite substrate.