Effects of fire retardants on mechanical properties and water resistance of Pinus massoniana particleboard

Pinus massoniana Lamb. wood particleboards processed by inorganic and organic fire retardants of two densities were prepared by isocyanate and MUF resin. Variations of internal bonding strength (IB), modulus of rupture (MOR), modulus of elasticity (MOE) and thickness swelling rate (TS) of particleboard were observed. Results demonstrated decreasing of IB from 0.81 MPa to 0.42 MPa and 0.36 MPa, MOR from 17.3 MPa to 12.5 MPa and 12.3 MPa, MOE from 1840 MPa to 1328 MPa and 1117 MPa, and increasing of TS from 5.2% to 15.1% and 11.2%, respectively, for the treated MUF particleboards of density 0.65 g.cm-3. Similarly, decreasing of IB from 0.93 MPa to 0.66 MPa and 0.64 MPa, MOR from 16.2 MPa to 10.6 MPa and 12.1 MPa, MOE from 1246 MPa to 1573 MPa and 1466 MPa, and increasing of TS from 6.7% to 7.1% and 6.0%, respectively, when isocyanate adhesive was used. The similar changes were showed when the density of particleboard was 0.75 g.cm-3. Improving density of particleboard appropriately and decrease density difference between the surface to chip layers could make the profile density curve tend to be stable, which could get a relatively high mechanical strength and water resistance. Synergistic effects between isocyanate and fire retardants was confirmed. The particleboard prepared with isocyanate was obviously superior to that prepared with MUF resin in all performances.

Efficiency of chips removal during CNC machining of particleboard

The results of testing of chips extraction system efficiency during CNC milling of particleboards were presented in this paper. Experimental machining was performed using the 3-axis CNC router Weeke Venture 108M and a standard diamond tipped, newly sharpened shank-type router bit. As a material the market size (2200×1250×18 mm) laminated particleboards with density of 649 kg.m-3 were used. The efficiency of chips extracion system of the CNC machine depends on the mode of milling. For pocketing nearly 100 % of chips were removed succesfullywhile for through-milling it was only 87 %. The extraction system worked with very high effieiency regarding chips smaller than 0.1 mm. The chips extraction efficiency decreases for larger and havier chips.

Improving mechanical and physical properties of particleboard made from vine (Vitis vinifera L.) prunings by addition reinforcement materials

The main goal of this study was to improve mechanical and physical properties of particleboards made from vine (Vitis vinifera L.) prunings by addition of reinforcement materials. In Turkey, there are 462.000 hectare areas for vine cultivation. Annually, approximately 2.345.000 ton vine pruning parts residues are remained. Every season, large quantities of vine prunings are left as by-products in the fields, and unfortunately they are not utilized properly by the related industries. In this study, vine prunings and particles were used as raw material for three-layer flat pressed particleboards. Cord fabric fibre (CFF) (mixed), Cord fabric (CF) (sandwiched), plaster mesh (PM) (sandwiched), polyester fibre (PF) (sandwiched) were used as reinforcement materials. A commercial urea-formaldehyde (UF) resin was used as binder. Small size experimental panels (56x56x2 cm) were manufactured. Some physical properties (like, thickness swelling (TS), density, moisture content (MC) and mechanical properties (like, modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB) perpendicular screw-holding (PSH, ⊥), lateral screw-holding strengths (SHS, //), and tensile strength parallel to surface properties of panels were determined. The results indicated that some properties of the reinforced panels can give satisfactory values compared to control (non reinforcement) panels. Generally the reinforcement materials increased the mechanical properties of the particleboards. Such particleboards can meet the standards for isolation panels and interior-use.

The potential for using corn stalks as a raw material for production particleboard with industrial wood chips

In this study particleboards were manufactured from mixtures of corn stalks (Zea mays indurate Sturt.) and industrial woodchips at several ratios. The corn stalks and industrial wood particles were mixed at ratios 0, 25, 50, 75 and 100 % respectively. The suitability of corn stalks chips for particleboard production was examined. Urea formaldehyde resin was used as a binder in 3-layers particleboards. Produced panels were tested for certain mechanical and physical properties. The manufactured boards were tested according to EN standards. In addition, the chemical properties of corn stalks were evaluated. Experimental results indicated that increase in corn stalk chips in the mixture generally diminished the mechanical and physical properties.

An examination of the tool life and surface quality during drilling melamine faced chipboard

An analysis of the cutting process and tool wear during machining from metal materials has been the subject of many studies. On the other hand, the tool life when machining from wood materials has not received much attention. Optimisation of the cutting process consists of the appropriate selection of major processing parameters as the cutting depth, feed rate and cutting speed in order to ensure adequate machining accuracy at minimum cost, and appropriate process efficiency. Here, we present the results of experimental tests of wearing drills with carbide blades during processing of melamine faced chipboard (MFC). To evaluate the surface quality of the chipboard the maximum radius and area of delamination around the chipboard blind hole are adopted. These parameters are determined independently at the hole entry and exit. Statistical analysis of results using multifactor analysis of variance was carried out. The tool life of drills depends on many combinations of cutting parameters and the wear of the drill blade. In the drilling process, the value of the thrust force mainly depended on wear of tool flank and the feed rate. The cutting speed has little effect on the amount of thrust force and cutting torque.

Short note. Addition of propylamine as formaldehyde scavenger for urea formaldehyde-bonded particleboard

Rubberwood particleboard were produced using urea formaldehyde (UF) resin admixed with propylamine as formaldehyde scavenger. 1 % propylamine were incorporated into 8 %, 10 %, 12 %, 14 % and 16 % UF resins, respectively. The effectiveness of propylamine addition to reduce formaldehyde emission from particleboard was examined. Physical and mechanical properties were evaluated according to Japanese Industrial Standard (JIS). The results showed that addition of propylamine had reduced 33 to 65 % formaldehyde emission from particleboard made with different dosages of UF resin. However, the properties of the particleboard were adversely influenced by the addition of propylamine. Higher resin dosage (≥14 %) had counterbalanced the loss of strength and dimensional stability but accompanied by increased formaldehyde emission. As a conclusion, UF dosage of 14 % admixed with 1 % propylamine is the most ideal formulation to produce particleboard with low formaldehyde emission while maintaining the desired properties.

Effect of board density, resin percentage and pressing temprature on particleboard properties made from mixing of poplar wood slab, citrus branches and twigs of beech

In this study, construction conditions of homogenous particleboard manufactured from mixing of poplar wood (Populus alba) slab, citrus branches and beech (Fagus orientalis) twigs have been investigated. The density of particleboard at three levels of 0.65, 0.7 and 0.75 g.cm-3, the amounts of resin at two levels of 9 and 11% and the amounts of pressing temperature at two levels of 160 and 170° C were considered. Increasing the density from 0.65 to 0.75 led to an increase in MOR, MOE and IB. By increasing the density, water absorption of particleboard decreased but its thickness swelling increased. By increasing the resin percentage the mechanical properties of particleboard improved, although this improvement was not statistically significant. Furthermore, by increasing the resin percentage the dimensional stability of particleboard improved partially. Not only did increasing the pressing temperature have any significant effect on the improving of mechanical properties of the particleboard, but also it has even led to a decrease in IB. Increasing the pressing temperature reduced the water absorption of particleboard in the short term (2 hours) while this increase led to a further increase in the thickness swelling of particleboard.

Evaluation of corner joint strength of composite panels bonded with modified starch

The objective of this research was to evaluate the strength of corner joints of box shaped furniture made from eastern red cedar (Juniperus virginiana L.) and corn starch binder southern sample. Various types of corner joint techniques were evaluated (glued, glued and screwed, and glued with dowel corners). Eastern redcedar particle samples with corn starch and glutaraldehyde were used. Overlaid and non-overlaid particleboards along with sandwich panels were used at “L” type corner joints. Tension and compression strength moment values were measured. Particleboard panel joint mounted with dowel resulted in the highest tension strength moment values followed by the specimens having a sandwich-type configuration combined with a dowel. Particleboard and overlaid sandwich-type panels glued with polyvinyl acetate (PVAc) had the lowest strength values. It appears that composite panels manufactured with modified starch have the potential to be used for corner joints.

Efficiency of bark for reduction of formaldehyde emission from particleboards

Bark is much underutilized material. Most of the bark is used as fuel and for landscaping but there are still significant amounts of unused bark, hence creating a problem when disposed. Due to the aspects like colour, shape/size and ratio, and mechanical properties, bark is not a desired constituent for particleboard production. One of the possible uses of bark is related to its chemical compositions, specifically due to the phenolic-like components, bark can be used as formaldehyde scavenger.The aim of the paper is to present the usability of bark as particleboard formaldehyde scavenger. Single-layer particleboard made from wood particles spruce (Picea abies) and pine (Pinus sp.) bark mixture using urea-formaldehyde and melamine-urea formaldehyde as resin were tested for formaldehyde release. The formaldehyde release was determined by the Perforator method (EN 12460-5), gas analysis (EN 12460-3) and Flask method (EN 717-3). The experiment showed that the presence of bark lowers the formaldehyde release.