Poboljšanje ivične vijčane veze u OSB i konvencionalnoj ploči iverici

Abstract

U ovom radu je predstavljen metod za poboljšanje vijčane veze u konvencionalnoj ploči iverici i ploči sa orijentisanim iverjem (OSB). Metod je zasnovan na predhodnom ubrizgavanju odgovarajućeg adheziva u vijčane otvore. Obe ispitivane ploče predstavljaju enterijerne ploče iste nominalne debljine od 18 mm. Ispitivanja su obavljena korišćenjem vijaka za ploče iverice sa navojem po celoj dužini tela vijka i prečnika od 5,0 mm. Vijci su uvrtani ivično u ispitne epruvete, pri čemu je dubina uvrtanja iznosila 30 mm za sva merenja sile izvlačenja. Prečnici vijčanog otvora iznosili su 2,5 mm i 3,0 mm. Odabrani PVAc lepak (tip 3) pomešan sa drvnim puniocem u količiini od 3-10% ubrizgavan je u vijčane otvore. Ispitivanja sile izvlačenja vijka su, takođe, rađena i posle demontaže vijka i naknadnog uvrtanja u cilju ispitivanja montažno-demontažnog karaktera vijčane veze. Ustanovljeno je da ubrizgavanje lepka u vijčane otvore i dodatak drvnog brašna imaju pozitivne efekte na silu ivičnog izvlačenja vijka u ispitivanim pločama.

This work presents the method for improvement of direct screw connection performance in conventional particleboard (PB) and oriented strand board (OSB). It is conceived on adhesive insertion into the pilot hole prior to embedment of the screw. The tests were carried out on the PB and OSB, both presenting interior boards and with the same nominal thickness of 18 mm. Particleboard screws of the 5 mm in diameter were inserted in the edge of the board. Pilot hole diameters were 2,5 mm and 3,0 mm and the depth of embedment was 30 mm for all tests. The chosen PVAc adhesive (type 3) with the addition of wood flour as consolidator in the range from 3-10% was inserted into pilot-hole. Tests were also obtained after consequent reassembly of the screw connection in order to examine the ratio of loss in withdrawal forces in such case. It was found that the insertion of PVAc adhesive into the pilot hole and the addition of wood flour have the positive effects on the screw withdrawal force in the tested boards.