Perforated element in adhesive bond
Publication Date: 2015-Aug-21
The IP.com Prior Art Database
How to check a lap joint type bondline for voids in the adhesive in places where non-destructive testing (NDT) may be unsatisfactory (e.g. too much interference w. Infra-Red testing or lack of access to the bondline) and where intrusive/destructive methods may be laborious or undesirable.
One known void detection technique for detecting voids in an adhesive layer between two lap-joint bonded elements uses systematic drilling in a pattern (50mm/30mm) through the joint from the innermost flange. This method exposes possible voids, which become apparent through the drilled holes. Some of the voids may be such that respective drilled holes are connecting. When voids are identified they can be filled by injection of adhesive through the relevant drilled holes.
By perforating one face of two lap-joint bond elements, some of the adhesive applied between the bonding surfaces will spew out through the perforations when bonding pressure is applied to the bnond elements. This results in the creation of a reverse surface along the relevant bondline which is punctuated with adhesive spew points. Any absence of a spew point at any given perforation will signal a potential adhesive void between the bonded surfaces. Moreover, the relevant perforation provides a ready-made inspection access hole and a ready-made adhesive injection port if required. Inspection methods for checking holes with now spew may include endoscopy or blowing air into appare...