In a meeting of the Working Group related to standards on plywood and resin adhesives, hosted by BIS on 28th June, 2024 under the chair of Dr M P Singh, Director, IWST and Chairman CED 20 along with all the members, the recommendations of the working group concerned with various specifications such as IS 303 - Plywood for General Purposes, IS 710 – Marine Plywood and IS 4990 – Shuttering Plywood are discussed at length to explore the effective means of QCO implementation.
As per IWST, IS 303 can be revised based on strength limits stating direct MoR /MoE Values in steps of 5 / 500 N/mm2 for less than 60 /6000 N/mm2 and in steps of 10/1000N/mm2 after words for better understanding.
Similarly Higher values than above can be classified accordingly in steps of 10/1000N/mm2 for MoR/ MoE. For given plywood, the four classes shall be given according to the Strength in length direction/ strength in width direction/modulus in length direction/modulus in width direction.
On the basis of the surfaces of the Plywood IS 303 can be classified into A type, B type and C type, BIS has compiled a list of quality requirements for permissible surface defects in various types of IS 303.
According to working group, a suitable note will be added in IS 303: 2024 to clarify that the plywood upto and including 4 mm used solely as the base for Veneered Decorative Plywood shall conform to the requirements specified in IS 1328.
Comments from Russian Plywood manufacturers reveal that IS 303, veneers from non-durable species and sapwood of all species when used for plywood manufacturer must be treated with a boric acid or borax based compound. Russian producers of wood products decontaminate produced and exported plywood by heat treatment in accordance with international standards on phytosanitary measures.
Indian plywood manufacturers often use veneers from plantation species, which are not highly durable under Indian climatic conditions. Therefore, these industries have long adopted a simple chemical treatment using a composition of boric acid and borax, which is considered eco-friendly.
Working group requested BIS to ask for any data or studies from the representative of the Russian Plywood Industry to share related to the efficacy of their heat treatment process or other type of treatments processes they followed for borer and termite protection of Plywood under Indian tropical conditions.
As per the recommendations of Working Group no changes are required in Indian Standard on Plywood for concrete shuttering works. However, the study for repetition cycle is already going on under IWST.
Comments from FIPPI suggested that Plywood sheets (less than 4mm) not covered in any of the BIS plywood specification. Indian Plywood companies have been importing certain quality of less than 4 mm thick plywood sheets across the globe, for some specialized application / end use. These thin sheets of plywood less than 4 mm are not covered in any of the BIS specification.
Concrete Shuttering Plywood made in the country is by MSME Plywood may not be compliant with BIS standard IS 4990 but it fully serves the purpose of concreting in most of the applications requiring only 5-7 repetitions. What is important is that the bonding must be waterproof and that Plywood does not delaminate.
Working group suggests that whole Sheet of Plywood is scrubbed by removing each layer of Veneers underneath the two faces to see, if it really compliant or not and the mechanical failing load of face veneers of 0.18mm or core veneers having finger joints is also tested to see if it is feasible to produce BIS compliant plywood using the plantation wood.
Birch Plywood is entirely different Plywood and should not be lumped with Indian made Plywood under any standard because, it is not made in India, it cannot be made in India even if Birch logs are imported, because the kind of equipments used in manufacture are simply not there and prohibitive in cost.
In the end, the working group requested BIS Secretariat to prepare a draft Amendment No.-1 to IS 303: 2024 and process the draft amendment as per decision taken in the last (32nd) meeting of the Sectional Committee, CED 20 with approval of the Chairman, CED 20.