KENYA STANDARD                          DKS 2222:2009         
                            
 
 
 
 
 
 
 
 
 
 
 
Synthetic resin adhesives for plywood — -- 
-specification 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
©KEBS 2009        ……………. Edition 2009  
 
 
 
 
 
 
 DKS 2222:2009                                                                                                                  
 
ii                     © KEBS 2009 — All rights res erved  
TECHNICAL COMMITTEE REPRESENTATION 
 
The following organizations were represented on the  Technical Committee: 
 
1 Kenya Wood Products 
2 Timsales Limited  
3 University of Nairobi (Department of Architecture  and Building) 
4 Wood Products (k) ltd 
5 PG Bison 
6 J.K.U.A.T (Civil Engineering Department) 
7 Ministry of Roads (Materials Testing Laboratory) 
8 Kenya Bureau of Standards — Secretariat 
 
 
 
 
 
REVISION OF KENYA STANDARDS 
 
In order to keep abreast of progress in industry, K enya Standards shall be regularly reviewed. Suggest ions 
for improvements to published standards, addressed to the Managing Director, Kenya Bureau of Standards , 
are welcome. 
 
 
 
 
 
© Kenya Bureau of Standards, 2009 
  
Copyright. Users are reminded that by virtue of Sec tion 25 of the Copyright Act, Cap. 12 of 2001  of t he Laws of Kenya, copyright 
subsists in all Kenya Standards and except as provi ded under Section 26 of this Act, no Kenya Standard  produced by Kenya Bureau of 
Standards may be reproduced, stored in a retrieval system in any form or transmitted by any means with out prior permission in writing 
from the Managing Director. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
           
 
 
 
 
 KENYA STANDARD                                                     DKS 2222:2009        
  
 © KEBS 2009 — All rights reserved           iii  
 
 
 
 
 
 
 
 
Synthetic resin adhesives for plywood — -
Specification 
 
 
 
 
 
 
 
 
 
 
 
 
KENYA BUREAU OF STANDARDS (KEBS) 
 
Head Office:  P.O. Box 54974, Nairobi-00200, Tel.: (+254  020) 60 5490, 602350, Fax: (+254 020)  604031 
E-Mail: info@kebs.org,  Web:http://www.kebs.org   
 
Coast Region    Lake Region         Rift Valley Reg ion  
P.O. Box 99376, Mombasa-80100  P.O. Box 2949, Kisum u-40100       P.O. Box 2138, Nakuru-20100 
Tel.: (+254  041) 229563, 230939/40 Tel.: (+254 057 ) 23549, 22396       Tel.: (+254 051) 210553, 21055 5 
Fax: (+254  041) 229448   Fax: (+254 057) 21814         
 
 
 
 
 
 
 
 
 
 
 
 
 
 DKS 2222:2009                                                                                                                  
 
iv                     © KEBS 2009 — All rights res erved Foreword 
 
This Kenya Standard was prepared by the Plywood and  Boards Technical Committee under the guidance of 
the Standards Projects Committee, and it is in acco rdance with the procedures of the Kenya Bureau of 
Standards. 
 
Adhesive form one of the most important raw materia ls use in the plywood industry and wood working and   
joinery industry.  The selection of the adhesive an d its correct use are important factors controlling  the quality  
of the plywood or the joinery work produced.  The r aw materials for adhesive are not all found in this  country;  
a large quantity of raw materials and synthetic res in adhesives is imported.  In the context of this b ackground  
of the industry, it has been found necessary to lay  down performance excepted from the prepared glues.    
Such standards, it is believed, would guide further  development of the adhesives industry on sound lin es and  
lead towards the achievement of self sufficiency in  regard to the country’s requirements. 
 
 
During the preparation of this standard, reference was made to the following documents: 
 
IS 845: 1974  Specification synthetic resin adhesives for plywood  (phenolic and aminoplastic). 
 
Acknowledgement is hereby made for the assistance d erived from these sources. 
 
 
 KENYA STANDARD              DKS 2222:2009         
© KEBS 2009 — All rights reserved                     1  
 
Synthetic resin adhesives for plywood — specificati on 
 
1. Scope 
 
This standard prescribes the requirements for pheno lic and aminoplastic synthetic resin adhesives used  in  
the plywood industry. 
 
2. Terminology  
 
For the purpose of this standard, definition given in KS 02-93: 1984* and the following and the shall apply, 
 
2.1.1 Assembly time  
 
2.1.1.1 Open assembly time 
 
The time elapsing between the application of the ad hesive and assembly of joint components. 
 
2.1.1.2 Closed assembly time 
 
The time elapsing between the application of the ad hesive and assembly of joint components and the 
application of pressure. 
 
2.1.2 Adhesive 
 
2.1.2.1 Closed contact adhesive 
 
A non-gap –filling adhesive suitable for use only i n those joints where the surface to be joined may b e 
brought into close contact by means of adequate pre ssure, and where glue line exceeding 0.12 mm may be  
avoided with certainty. 
 
2.1.2.1.1 Gap filling adhesive 
 
An adhesive either for use in those joints where th e surface to be joined may or may not be in close o r  
continuous contact owing either to impossibility of  applying adequate pressure or to slight inaccuraci es in  
machining. 
 
2.1.3 Extender  
 
A substance added to the adhesive either to reduce the cost of gluing or to reduce penetration through  the 
veneers or both. 
 
2.1.4 Filler 
 
An inert substance, such as wood flour, added to al ter the characteristics, for example, reduce brittl eness or  
a synthetic resin sometimes loosely and incorrectly  use as interchangeable with “extender”. 
 
2.1.5. Fortifier  
 
A substance used primarily to increase the boil res istance and durability of hot area resins. 
 
2.1.6 Hardener  
 
A material used to promote the setting of the resin ; It may be either liquid or powder form.  It is an  essential  
part of the adhesive, the properties of which depen d upon using the resin hardener as directed. 
 
 
*Glossary of terms used in timber 
 
 
 DKS 2222:2009                    
                              © KEBS 2009 — All rig hts reserved 2  
2.1.7 Pot life  
 
The time between the mixing of the constituent part s of an adhesive and its reaching the age when it i s no  
longer usable. 
 
2.1.8 Self-life 
 
The period for which the adhesive or adhesive compo nents may be stored without affecting the suitabili ty for 
use in accordance with the standard. 
 
2.1.9 Spread of adhesive 
 
 The area of surface covered by 1kg of adhesive mix  prepared in accordance with the manufacturer’s 
instructions. 
 
2.1.10 Synthetic resin  
 
Amorphous organic materials produced by the polymer ization or condensation of one, two or less frequen tly,  
three relatively simple compounds.  The term is als o applied now days to chemically modified natural r esins.   
The properties of synthetic resins can vary widely depending upon their basic raw materials, propositi ons,  
and conditions for manufacture.  All synthetic resi ns are classified broadly as thermosetting or therm oplastic. 
 
2.1.10.1     A Phenolic synthetic resins 
 
 A phonenolic synthetic resin is derived form the r eaction of phenol with an aldehyde. 
 
2.1.10.2 Aminoplastic synthetic resin 
 
 An aminoplastic synthetic resin is derived from th e reaction of urea, thio-urea, melamine, or allied  
compounds. Or mixtures or theses compounds with for maldehyde. 
 
2.1.11 Synthetic resin adhesive 
 
A composition, substantially consisting of a synthe tic resin of either the phenolic or aminoplastic ty pe but   
including any hardening agent, fortifier, filler or  extender, which may be required to be added before  use  
according to the manufacturer’s instructions. 
 
3. Types 
 
Depending upon their degree of resistance, syntheti c resin adhesives for plywood shall be of the four types  
as specified in Table 1.  The characteristics of ea ch type shall be as given in Table 1.  For the guid eline of  
users in selection the grade of resins adhesive sat isfying the requirements for particular work, recom mended  
use of each type is also indicated. 
 
Table  1- Characteristics of different types of synthetic  resin adhesives 
 
 
Sl No.  Type glue shear  
strength  
in dry 
state 
(average Resistance 
to micro-
organisms 
 (fungi) Resistance to moisture Recommended Use 
    temperature of 
water under 
normal 
atmospheric 
pressure in 
which test  
pieces shall be 
immersed time of  
immersion of  
test piece average  
glue shear  
strength  
(1)  (2) (3) (4) (5) (6) (7) (8) 
i)  BWP(Boiling 
Waterproof) Kg 
135 Kg 
100  
100 0C H Kg Adhesives of the type have been proved 
to make joints highly resistant to 
weather, micro-organisms, cold and 
boiling water steam and dry heat.                      DKS 2222:2009         
 
 
© KEBS 2009 — All rights reserved         
     3 
 ii)  BWR(Boiling 
Resistance)  100 -do- 8 100 Joints made of this type adhesive w ill 
survive exposure to weather for only a 
few years.  They will withstand cold 
water indefinitely and boiling water for a 
limited period.  They are highly resistant 
to micro-organisms 
iii)  WWR  
(Warm Water 
Reisitance 100 80 70 ±20 0C 3 80 Joints made with these adhesives will 
withstand cold water for a long water for 
long period and hot water for a limited 
time, but fail in the boiling water test.  
They are resistant to attack by micro-
organisms 
iv)  CWR (Cold 
Water 
resistance) 70 35 27±2 0C 24 35 Joints made with these adhesives are 
resistance to cold water but not to 
alternating cycles of high and low 
humidity of wetting and drying.  They 
have moderated resistance to micro-
organisms. 
 
 
 
* The 72 hours may be the aggregate of shorter peri ods, the test pieces being left in cold water betwe en such period 
 
4. Keeping qualities  
 
The keeping qualities of adhesives shall be as foll ows: 
 
(a)  Liquid adhesives   
 
The adhesives shall comply with the requirements sp ecified under 6 after the resin and hardener  
have been stored in the original closed containers,  according to the manufacture’s instruction up to  
the date recommended by the manufacturer. 
 
(b) Film adhesives 
 
The film shall comply with the requirements specifi ed under 6 after it has been stored in accordance  
with the manufacturer’s written instructions up to the date recommended by the manufacturer. 
 
5.  Instructions for use 
 
5.1  The manufacturer shall furnish written instruction s detailing the manner in which each resin or  
recommended combination of resin(s), hardener(s), f iller, fortifier and extender shall be used.  The  
instructions shall give information in the manner i ndicated under 5.2 to 5.6, where applicable. 
 
5.2 Self-Life of adhesive or adhesive components 
 
The manufacturer shall specify the shelf-life of th e adhesive or adhesive components. 
 
5.3 Preparation for use  
 
The preparation of resin, hardener, fortifier, fill er and extender, methods of mixing, recommended typ es of 
mixing, apparatus and necessary precautions for any  kind shall be stated. 
 
5.4 Usable life of mixed adhesive or pot life  
 
The maximum time shall be stated during which the a dhesive maintained at temperatures of 15, 20 25, 30 ,  
40 and 45 0C would remain fit for use so as to comply with the  requirements of this standard. 
 
 
5.5 Application 
 
Guidance on the following points shall be given: 
 
 (a) Range of moisture content of wood, at the time  of gluing; DKS 2222:2009                    
                              © KEBS 2009 — All rig hts reserved 4  
 (b) Preparation of wood surfaces; 
 
(c) Method(s) of application, such as single or dou ble spread; 
 
 (d) Normal amounts of spread for single glue line;  
 
 (e) Maximum and minimum open and closed assembly t imes; 
 
 (f) Recommended range of pressures in kg/cm 2 ; 
 
 (g) Post-treatment of finished products; 
 
 (h) Cleaning of containers; and 
 
 (i) Tests. 
 
5.6 Setting times and conditions 
 
The recommended range of temperature to which the a dhesive in any glue line may be subjected and also  
the minimum and maximum times for which pressure sh all be maintained on flat panels at temperatures  
within the range shall be stated. 
 
6. Tests 
 
6.1 Sampling  
 
A representative sample shall be drawn from each ba tch of adhesive.  Such samples shall in each case b e  
tested separately, and not be bulked with other sam ples or otherwise averaged. 
 
6.2 Preparation of test pieces  
 
The test pieces shall be prepared according to the instructions given in Appendix A.  Veneers used for  the  
preparation of test pieces shall comply with the re quirement specified in A-1. 
 
6.3 Dry strength 
 
The average failing load of a set of six test  piec es, prepared in accordance with 6.2, when tested by  the  
method given in KS(Under development) # shall not be less than the values specified in Tab le 1. 
 
6.4 Resistance to water  
 
The resistance to water shall be such that a set of  six pieces prepared in accordance with 6.2, when t ested in  
accordance with Appendix B shall show average glue shear strength not less that the values specified i n  
Table 1. 
 
6.5 Resistance to micro-organism  
 
The resistance of adhesive to micro-organism shall be such that a six test pieces when tested in accor dance  
with KS (Under development) † after treatment in accordance.  
 
6.6 Acidity and alkalinity (pH) 
 
The pH of the adhesive when set shall be not less t han 2.0. The pH shall be determined by the method  
described in Appendix C. 
 
# Methods  of test of plywood part –Determination of glue shea r strength. 
† Methods  of test of plywood part- Mycological test  
 
 
                      DKS 2222:2009         
 
 
© KEBS 2009 — All rights reserved         
     5 
  
7 Retest 
 
In the even of failure to comply with any of the re quirements specified under 6.3 to 6.6 the batch of materials  
concerned shall be retested in respect of such requ irements.In the event of failure of retest, the bat ch shall  
be rejected. 
 
8 Marking 
 
Each container shall be legible and indelibly marke d with the following: 
 
 (a) Manufacturer’s name or distinguishing mark 
  
 (b) Description of material, 
  
 (c) Manufacturer’s reference number, 
 
(d) Batch number, 
 
 (e) Date of manufacturer, 
 
(f) The date beyond which the adhesive or adhesive components shall not be use when stored 
under conditions recommended by the manufacturer, 
   
 (g)  Reference to the manufacturer’s instructions for use, and 
 
 
 (h) The words “To be stored in a cool dry place”. 
 
 
 
Appendix A 
 
Methods of preparation of test pieces 
 
A 1 Veneers for test pieces 
 
A 1.1  Veneers shall be rotary cut canarium spp. 1.6 mm t hick with the growth rings approximately parallel  
to the face. 
 
A 1.2  The veneers shall be smooth cut on both faces, str aight grained and free from all defects, at least  
over the area that will form the middle 50 mm lengt h of the test pieces, and may be lightly sanded.   
Elsewhere the occurrence of slight defects, such as  small uplifts, small leaf knots and short grain ma y be  
disregarded.  The moisture content of the veneers s hall be 12.0 ± 2.5 percent for liquid adhesive and 12.0 ±  
2.0 percent for film adhesive, as may be recommende d by the manufacturer. 
 
A 2 Preparation of adhesive  
 
The adhesive shall be prepared and used according t o the instructions supplied by the manufacturer. 
 
A 3 Construction of test boards  
 
The test board shall be constructed by bonding toge ther three veneers of canarium spp. As specified in  A 1.   
The size of the board shall be such that all the te st pieces required for testing can be taken out of the same  
board leaving a margin of 25 mm on all the four edg es.  The grain of the core veneer shall be at right  angles  
to that of the two face veneers.  The prepared adhe sive face veneers, or as directed by the manufactur er,  
but care shall be taken in all cases to ensure that  the adhesive is uniformly spread and the surfaces are  
completely coated.  The veneers shall then be assem bled and loaded in a flat platen press within the t ime  
specified in the manufacturer’s instructions.  The pressing conditions shall be as recommended by the  DKS 2222:2009                    
                              © KEBS 2009 — All rig hts reserved 6 manufacturer.  Film glues shall be employed by simp le inter-leaving and in accordance with the  
manufacturer’s instructions. 
 
A 4 Conditions of test boards  
 
A 4.1   Immediately after removal from the press, the boa rds shall be given a special treatment (such as 
dipping in water) stipulated by the manufacturer.  The boards shall then be exposed at prevailing labo ratory 
atmospheric conditions in a manner to ensure a free  circulation of air around them for six to nine day s, or for 
such time as the manufacturer may direct, except in  the case of teat boards to be employed in the 
mycological test where the conditioning period shal l, in no case, be less than six days. 
 
A 5  Preparation of test pieces  
 
After conditioning of the test boards, six test pie ces as shown in Fig 1 shall be prepared for each of  the tests 
required, case being taken that the depth of the sa w-cut does not impinge upon the third ply.  The len gth of 
the test pieces shall be along the directions of th e grain of the outer plies.  
 
Appendix B 
 
Water resistance test 
 
B 1   Test pieces 
 
Six pieces shall be prepared by the method ad descr ibed in Appendix A. 
 
B 2 Procedure 
 
B 2.1  The test pieces shall be completely immersed in wa ter at the temperature and for the time  
appropriate to the type  (see Table 1) in such a ma nner that water shall have free access to all the s urfaces.  
While testing WWR and CWR adhesives, care shall be taken to ensure that water circulates freely around   
them.  At the conclusion of the specified time, the  test pieces shall be quickly transferred from the boiling  
water and submerged in cold water.  The pieces shal l then be plunged into water at 27 ± 2 OC and cooled.  
 
B 2.2  The test pieces, while still wet shall be subjecte d to shear strength test ad described in KS(Under 
development) # . 
 
 
Appendix C 
 
Determination of ph valve (hydrogen ion concentration) of liquid or p owdered resin 
adhesives  
C 1 Detail  
 
C 1.1  At least 100 g of the adhesives shall be prepared according to the manufacturer’s instructions.  If 
water is to be used in the mixing, only distilled w ater shall be used.  The mixture shall be stirred t horoughly,  
After stirring, about 20 ml of the mixed adhesive s hall be spread in a thin, even coat of 0.5 mm on a sheet of 
clean glass to cover an area approximately 15 x 25 cm.  The adhesive shall be cured at the temperature  and 
for the length of time recommended for gluing by th e manufacturer, after which the cured film shall be  peeled 
from the glass and ground in a clean mill or mortar  to a fineness so as to pass KS sieve 40 .  Immediately, 
after grinding, 2.0 g of the ground particles, accu rately weighed, shall be placed in a clean vial or small heat-
resisting glass flask and 10 ml of freshly boiled, cooled distilled water shall be added and thoroughl y stirred.  
The glass container shall be kept stoppered at all times except when pH value determinations are being  
made. The mixture shall be allowed to stand for 72 h at room temperatures after which time the mixture  shall 
be stirred and the pH value determined by means of a suitable pH meter.  The determination of pH value  
shall be repeated at intervals of 24 h until the di fference between the consecutive readings is not mo re than 
0.05 pH  unites.  The last reading taken shall be regarded a s the equilibrium film pH  value for the 
This standard covers requirements for materials, ma nufacture and performance of marine plywood suitabl e  
for the construction, repair and maintenance of mar ine and river craft, pontoons and the like the adhe sive.. 
 
 
# Methods  of test of plywood part –Determination of glue shea r strength.