Laminasi Kayu Sengon Sebagai Salah Satu Solusi Ketersediaan Kayu Untuk Bahan Bangunan

Abstracts. The supply of wood that is quite durable and of high quality has not been able to meet the needs of building construction at the present time, especially in the future. Sengon wood (Paraserianthes falcataria) is a fast-growing type of plant that has a large increase (volume of wood per hectare per year) which is around 28 - 48 m3 / ha / year. To fulfill various human objectives, the majority of Sengon wood can be collected from the age of 6 years. With the use of lamination technology, wood remnants can be utilized to be made into wooden blocks of various sizes and various shapes. Lamination can make the strength of Sengon wood higher than solid wood beams.The test is carried out by physical and mechanical tests as well as the Sengon wood laminated sliding block test. In testing physical and mechanical properties based on ISO 1975 regulations. Testing of physical properties of Sengon wood includes wood density test and moisture content test. Testing the mechanical properties of Sengon wood includes fiber parallel compressive strength test, fiber perpendicular compressive strength test, tensile strength test, shear strength test and flexural strength test. Testing of Sengon wood laminated sliding blocks to determine the strength of lamination has a variation of 30 MDGL, 40 MDGL and 50 MDGL slurry adhesives with 3 replications of each shear test.The average density of Sengon wood is 0.315 t / m3 and the average moisture content of Sengon wood is 13.539%. The average compressive strength of fibers is 26.85 MPa and the compressive strength of fibers is 9.62 MPa. The average tensile strength of Sengon wood is 61.48 MPa and the average shear strength of Sengon wood is 5.31 MPa. In testing the flexural strength of Sengon wood an average of 43.18 MPa. Testing of Sengon wood laminate sliding block for 30 / MDGL obtained an average of 0.05 kg / mm2. In the shear block 40 / MDGL obtained an average shear strength of 0.02 kg / mm2. For the 50 / MDGL laminate shear block an average shear strength of 0.08 kg / mm2 was obtained.

Shear Block Test Performance of Melunak and Mengkulang

This paper presented results of shear block test performance of tropical glued-laminated timber (glulam) from species of melunak and mengkulang. Glulam blocks were manufactured in accordance with MS758:2001. The shear block test for glue lines and the shear strength tests of melunak and mengkulang were conducted and evaluated in accordance with BS EN 14080:2013. Melunak and mengkulang produced average shear strength values of 10.62 N/mm2 and 8.19 N/mm2, respectively. In terms of wood and glue failure percentage, the results showed that melunak and mengkulang were mainly failed due to wood surface area and not due to the glue lamination in which both melunak and mengkulang showed a good bonding performance.

Characterization of PVAc Adhesive Penetration and its Effect on Wood Properties

Penetration of adhesive into the wood cell and lumens is an important factor that may enhance the durability of the adhesive bonds. In this study, the diffusion of adhesive polyvinyl acetate (PVAc) into the cell wall of various types of wood was evaluated making use of micro-CT. Compression shear block tests were also applied to examine the mechanical performance of the bond. In adhesive assemblies examined, cell walls at the immediate surface which were damaged during machine planning were full of adhesives. As the penetration of PVAc increased, the variation in the observed bind strengths was not substantial. Bonded with the same type of glue, black spruce appeared to have lower shear strength than Douglas fir and lodgepole pine. Moreover, gravity seemed to play a role in the glue penetration. During clamping and adhesive curing, the substrate on the lower of the shear block specimen had a deeper glue penetration. There are some correlations between glue penetration and glue line thickness measured using micro-CT.

Effect of grain angle on shear strength of Douglas-fir wood

The effect of grain angle (GA) on shear strength of Douglas-fir has been evaluated. Shear block specimens with a GA varying from 0 to 90° was loaded in the shear plane, resulting in failure mode transitioning from parallel to grain shear to rolling shear. As expected, shear strength decreased as the GA increased from 0° to 90°. A root-mean-square equation was found to be suitable to predict the relationship between GA and shear strength. Traditional Hankinson formula and the Tsai-Wu criteria were less effective with this regard.

Tack and shear strength of hybrid adhesive systems made of phenol-formaldehyde, dextrin and fish glue, and acrylic pressure-sensitive adhesive

The development of adhesives that have good initial adhesion (tack) that provides improved mat integrity during shape-forming of wood composites has been the subject of recent research. Hybrid adhesives were made based on thermosetting phenol-formaldehyde (PF), to which three tacky adhesives were added: high tack fish glue (FG), dextrin glue (DX) and a commercial acrylic, pressure-sensitive adhesive (PSA). Tacky adhesives were blended with PF at weight levels of 25%, 50% and 75%. The time-dependent tack development of the resulting hybrid adhesives was evaluated by means of a texture analyzer. The bond strength of adhesives was measured after curing by shear block test. PF/DX blends exhibited the highest tack during longer open times, while blends of PF and FG had low tack during shorter times. PF/PSA blends lost their bond strength completely after being heated at the curing temperature of PF. PF/FG blends did not show a significant decrease in bond strength compared to pure PF. The addition of DX had no effect on shear strength at ratios <75%.