The adhesion properties of wood preserved with natural preservatives

Wood preservation technology has been using synthetic preservatives for a long time. However, some disadvantages have been recorded such as quality degradation of environment, killing more non target wood destroying organism. Since environment quality requirement has been up lifted, then general wood processing and wood preservation paradigm has to change from utilization of synthetic to natural wood preservatives. The new natural wood preservatives have their own properties and influence differently on wood adhesion. Wood adhesive based products such as plywood, lamination, particleboard and fiberboard use wood waste consisting of all kind of processes wood such as naturally preserved wood. The objective of this research is to know the effect of naturally wood preservatives on wood adhesion properties. This research was conducted by wood adhesion block method. The fast growing teak plantation wood was chosen since this type of teak wood was claimed as low grade of wood quality. This type of wood has high portion of sapwood which is susceptible to wood destroying organism. The source of natural, local wood preservatives are gadung tubers, pulai bark and kumis kucing leaves. The wood adhesive used was bio-industrial PVAc in the form of glue paste. Extraction procedure of natural wood preservatives followed ASTM D1110-1984. The procured naturally extracts was processed to obtain extract concentration 1.00 gram per liter concentration. Wood preservative application used padding method on the wood surface by 0; 1; 2 and 3 application times. Each padding layer processed was applied after the former one was air dried. Wood adhesion test followed block type with 40#/MSGL glue spread and cold press system. Compression shear test of block samples followed British Standard (1957). This adhesion test method was chosen since the method has proven as efficient and effective adhesion test in the laboratory. The research results showed that interaction factor of natural wood preservative and padding application did not affect to the adhesion strength. This adhesion strength was affected by single factor of natural wood preservative and padding application. The highest adhesion strength of 94.29 kg.cm-2 was resulted by pulai bark followed by gadung tubers (80.61 kg.cm-2) and kumis kucing leaves (55.31 kg.cm-2). Padding application exerted a negative correlation to adhesion strength. Higher padding application number of natural preservative on the wood surface, lower adhesion strength. The reduction of adhesion strength of 1; 2 and 3 padding application resulted 20; 42 and 66 % for gadung tubers. Pulai bark extract reduced 24; 30 and 57 % while kumis kucing leaves lowered 22; 37 and 75 % consecutively.

Bonding ability of sengon wood treated with natural extracts

Wood preservation technology has been using a lot of synthetic preservatives for a long time. However, some disadvantages have been recorded such as environment quality degradation and killing more untargeted wood destroying organism than targeted one. Recently environment quality maintenance has been required causing a significant change in general wood processing technology and wood preservation paradigm. In terms of wood preservatives has changed from synthetic to natural wood preservatives application. Sengon is the fast growing wood species chosen in Indonesia to fulfill national and international wood demand. Unfortunately this wood species is class V of wood durability and has to be treated with preservatives. Glued wood products such as plywood, lamination, particleboard and fiberboard use low durability wood such as sengon. The objective of this research is to know the adhesion strength of sengon wood after treatment with the natural preservatives. This research was conducted by wood adhesion block method. The fast growing sengon plantation wood was chosen since this type of sengon wood was classified as low grade of wood quality (Class V). This type of wood had high portion of sapwood which was susceptible to wood destroying organism and absence of natural preservatives. The sources of natural wood preservative chosen were gadung tubers, pulai bark and kumis kucing leaves, while the extraction methods were hot water and alcohol toluene. The wood adhesive used was bio-industrial PVAc. Extraction procedure of natural wood preservatives followed ASTM D1110-1984 and D-1107-1996-2013. The procured naturally extracts was processed to obtain extract concentration 1 gram per liter. Wood preservative application used padding method on the wood surface by 0; 1; 2 and 3 application times. Each padding method was processed was applied after the former one was air dried. Wood adhesion test followed block type with with 196.gm-2 glue spread and cold press system. Compression shear test of block samples followed British Standard (1957). The research results showed that adhesion strength was highly significantly affected by single factor of padding application. Padding application exerted a negative correlation to adhesion strength. Increased natural preservatives treatment (padding application) on the wood surface resulted lower adhesion strength. The average sengon wood adhesion strength of control, 1; 2 and 3 padding application were 5.10; 3.00; 2.22 and 1.05 MPa respectively. The average wood failure were 69.20; 66.71; 62.12 and 45.83% respectively.

Effect of pressing temperatures on bonding properties of sucrose-citric acid for nipa palm fronds particleboard

The objective of this study was to investigate the properties of nipa front particleboard bonded using the combination of sucrose and citric acid, and the effect of different pressing temperature. The results showed that the adding citric acid to sucrose and increasing pressing temperature increased the physical and mechanical properties of the nipa fronds particleboards. FTIR analysis results indicated that the peak intensity of C=O ester group and C–O–C hemiacetal group increased and the hydroxyl OH groups decreased with increasing pressing temperature and addition of citric acid, which indicated that crosslinking between sucrose and citric acid occurred. TG-DTA analysis confirm that increasing pressing temperature and addition of citric acid to sucrose increasing thermal stability of nipa fronds particleboards, which is suspected caused by the polycondensation reaction between sucrose and citric acid.