Edge glue clamp carrier glue line pressures based on pulling shims in the glue line

The objective of this study was to investigate how the glue line pressure i n edge gluing varied along the length of the glue line between the clamps f or different clamp spacings and clamp arrangements. It was hypothesised tha t it is possible to determine the pressure exerted on the glue line, at dif ferent positions, by measuring the force required to pull thin shims placed at different positions along the length of the glue line. According to the theory of friction the force required to pull a shim should be related to the coefficient of friction and the glue line pressure. The report describe s the preliminary investigations done to establish reliable methods of meas uring the coefficient of friction and assessment of the pressures at the gl ue line for the different parameters investigated. Using 30 year old radiat a pine clears, a strong relationship between glue line pressure and distanc e from clamp face to glue line and clamp spacing was found (r(2) = 0.90). A s the maximum clamp spacing to ensure a particular glue line pressure depen ds on the distance to the first glue line, a look-up table, based on a mini mum glue line pressure of 345 kPa (50 psi), was produced giving the maximum recommended clamp spacings for common clamp face to glue line widths.