Şeref Kurt

Combustion Properties of Oak (Quercus robur L.) Laminated Veneer Lumbers Bonded With PVAc, PF Adhesives and Impregnated With Some Fire-Retardants

In this study, the effects of impregnation materials — di-ammonium phosphate, aluminium sulphate, potassium carbonate, calcium chloride, zinc chloride — on combustion properties of 3-ply laminated veneer lumbers (LVL) produced from oak (Quercus robur L.) bound by phenol-formaldehyde (PF), or poly(vinyl acetate) (PVAc) have been investigated. The pressure–vacuum method was used for the impregnation process. Combustion test was performed according to the procedure of ASTM-E 69 standards. According to the test results, zinc chloride was found to be the most successful fire retardant chemical in LVL with PF adhesive. Since zinc chloride diminishes combustion, it is possible to advise the use of LVL produced from oak with PF adhesive and impregnated with zinc chloride as a fire retardant building material where required.

The effect of edge banding thickness of white oak bonded with different adhesives on withdrawal strengths of beech dowels in composite materials

Dowel joints are widely used in furniture frame construction as a load-bearing connection structure, as well as a simple locator for parts. Joints constructed with dowels were subjected to withdrawal, bending, shear, and tensile forces. The aim of this study was to determine the withdrawal strengths of 6, 8, 10 mm diameter beech dowels embedded into matching holes drilled into the edges of medium-density fiberboard (MDF) and particleboard (PB) with solid wood edge banding of white oak with 5, 10 and 15 mm thickness, bonded with hot-melt, poly(vinyl acetate) (PVAc) and Desmodur-VTKA (D-VTKA), a polyurethane-based one-component adhesive. The effects of edge banding thickness, dowel dimension, type of composite material and type of adhesive used for edge banding on the withdrawal strength were determined. According to the interaction results from the Duncan test the highest withdrawal strength (7.019 N/mm2) was obtained in beech dowels with 6 mm diameter for MDF with solid wood edge banding of white oak with 10 mm thickness bonded with the hot-melt adhesive. Should the dowels be subjected to withdrawal, it is advised that a beech dowel should be used for MDF with solid oak edge banding with 10 mm thickness bonded with a hot-melt adhesive in furniture production and decoration applications.

Bonding strength of oak with different adhesives after humid-water-heat tests

Composite materials manufactured from wood with different adhesives are being used increasingly in the construction of furniture frames and buildings. In this study, it is aimed to describe the effects of adhesives (PVAc, VTKA and UF) on white oak cut tangentially and radially impregnated with Protim WR 230, CCA, and Celcure AC 500 and exposed to humid-water-heat resistance and heating and cooling tests. Impregnation chemicals have decreased the bonding strength, and control samples gave higher bonding strength value. According to the control samples, it can be said that humid-resistance test, water-resistance test, heat-resistance test have decreased the bonding strength. As a result of the tests, white oak cut tangentially and impregnated with Protim WR 230 and bonded with VTKA adhesive can be used as a material in damp condition where the strength is required.

Effect of dowels and adhesive types on withdrawal strength in particleboard and MDF

Composite materials and wooden dowels are being used increasingly in the construction of furniture frames and inner decoration. However, there is little information available concerning the withdrawal strength of various fasteners and in particular, dowels in these materials. The aim of this study was to determine the withdrawal strengths of 6, 8, and 10 mm diameter dowels produced from different wood species bonded parallel or vertical to the surfaces of a medium-density fiberboard (MDF) or particleboard with poly vinylacetate or Desmodur (D-VTKA). According to TS 4539 standard, the effect of dowel species, direction of withdrawal, board type and the type of adhesive on the withdrawal strength were determined. The highest (8.35 N/mm2) withdrawal strength was obtained for oak dowels bonded with D-VTKA adhesive vertically to the surface of MDF. This value is higher than the predictive expression that allows designers to estimate the withdrawal strength of dowels.

Determination of Static Fatigue Performance of Upholstery Foams

In this study, change of hardness value of polyurethane foam used in furniture upholster was investigated. The dimension of test samples was determined that based on the surface of one seat 45x45x10 cm. The change of hardness value of test samples was determined after testing of fatigue performance applied to7000 times at 50, 70, 90 and 120 kg. Density value of test samples was determined. Result shown that the high density foam was affected less then low density foam during the fatique performance.

Bond Strength-Disbonding Behavior and Dimensional Stability of Walnut and Poplar Impregnated with Some Chemicals and Bonded with PVAc, VTKA and Urea Formaldehyde

The aim of this study, is to describe the effects of adhesives (PVAc-Desmodur VTKA and Urea formaldehyde) on wooden materials (walnut and poplar) cut tangentially and radially impregnated with Protim Solignum, CCA and Celcure AC 500 and exposed to: humid–water–heat resistance; heating; and cooling tests. All these tests show a decreased in bonding strength. The conclusion is that poplar wood cut tangentially and impregnated with CCA, bonded with D-VTKA adhesive can be used as a material in damp conditions where good bond strength is required.