Development of hybrid glue formulations and determination of performance properties in particleboard

In this study, it was aimed to produce biobased glues by utilizing the bark obtained from red pine woods used for board production in the wood panel industry and used as waste. Biobased glues were mixed with commercial urea formaldehyde (UF) glue at certain ratios and 16 mm thickness particle boards were produced. Red pine (Pinus brutia) bark used in the study was obtained from Kastamonu Entegre Ağaç San. (KEAS) Balıkesir facilities and used in the extraction process for biobased glue. UF, paraffin, hardener and wood chips used in particleboard production were obtained from KEAS Gebze facilities. The tar material, which is waste and creates disposal costs, was obtained from the KEAS Gebze plant after the electrostatic filter. In order to incorporate the tar material into the glue at certain ratios, its solubility in solvents such as toluene, acetone and ethonol was investigated. p-toluene sulfonic acid (PTSA), hexamethylenetetetramine (HMTA), furfuryl alcohol (FA), glutaraldehyde (GA) chemicals were used for modification of glue formulations. Characterization studies such as pH, viscosity, solids determination, surface tension, lap shear, FTIR, SEM, TGA, DSC, XRD were carried out to measure the adhesive performance. Physical and mechanical tests were carried out to measure the performance of the produced boards. In addition from these tests, in order to test the combustion performance of tannin glued boards, combustion tests were carried out according to TS EN ISO 11925-2 standard with the test setup in Bursa Technical University (BTU) laboratories. As a result of the test, it was observed that the addition of tannin in the glue did not have a significant effect on the combustion properties of the boards. For formaldehyde determination of the boards produced with hybrid glues, a test was carried out according to the perfarator method. The solid content of tannin glue produced after extraction was measured as 40%. Extraction efficiency was determined as 26.34% and stiasny number as 72.41. In order to calculate the inorganic matter content in the biobased glue, ash was determined and found to be 4.46% on average. Hybrid glue formulations were created by adding 5-10-20% of tannin glue into UF glue and 1-3-5% of tar material into UF glue. When the glue tests and the test values of the produced boards were analyzed, the closest physical and mechanical results to UF glue were obtained from TUF and TUG boards. The tensile test results of the boards produced with UF glue were 0.88 N/mm2, 0.80 N/mm2 for TUF boards produced with FA, and 0.78 N/mm2 for TUG boards produced with GA. The lowest formaldehyde test value was obtained with 100% tannin glue. It was observed that the formaldehyde test values decreased as the tannin content in the glue formulations increased. Difficulties were encountered in the dissolution of tar material and its homogeneous distribution in the glue. Low values were obtained in the performance properties of the boards produced using tar material. It was revealed that tar is not suitable to be used as an additive material in glue formulations. It was determined that the physical and mechanical values of the boards decreased slightly as the tannin participation rate increased, but they provided P2 class test values.