AS 6669:2016 Plywood—Formwork
4.3 BONDING
The bonding between plies shall be a Type A or Type B bond and shall comply with the following requirements:
(a) The adhesive used in the manufacture of the formwork plywood shall be of a type complying with AS 2754.1.
(b) The bond between the plies shall continue over the whole area of the sheet other than in bonds coincident with permitted imperfections.
(c) When tested in accordance with AS/NZS 2098.2 for Type A or Type B bond, the gluelines in a single test piece, prepared from each sample, shall have a bond quality in any single glueline of not less than 2 and an average of not less than 5 when assessed in accordance with AS/NZS 2098.2. If the initial test piece fails these requirements, a second test piece shall be taken from the same sample and tested in accordance with AS/NZS 2098.2. The average bond quality for the initial and second test piece shall have a minimum, in any single glueline, of not less than 2 and an average of all gluelines not less than 5 when assessed in accordance with
AS/NZS 2098.2.
4.4.1 Construction
The veneer arrangement within the formwork plywood assembly shall comply with the following requirements:
(a) The construction shall be balanced in regard to all properties affecting panel stability.
(b) Sheets shall be free from any ferrous material such as clips and staples.
(c) All veneers within each sheet shall be of quality D or better, unless stress grades or characteristic strength and stiffness values are assigned in accordance with the in-grade test method defined in Clause 5.3. Where Clause 5.3 is used to assign stress grades or characteristic strength and stiffness values, the specification shall include a specific minimum veneer quality as defined in Clause 2.5.
4.4.2 Standard constructions
The standard constructions for formwork plywood shall be as given in Table 4.1. The veneer thicknesses detailed in the standard constructions are the assumed actual dry veneer thicknesses in the finished formwork plywood. These assumed actual veneer thicknesses in the finished panel shall be used to compute the section properties in Appendix B for standard construction.