EN 314-1:2004

SLOVENSKI STANDARD
01-marec-2005
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SIST EN 314-1:1996
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Plywood - Bonding quality - Part 1: Test methods
Sperrholz - Qualität der Verklebung - Teil 1: Prüfverfahren
Contreplaqué - Qualité du collage - Partie 1: Méthodes d'essai
Ta slovenski standard je istoveten z: EN 314-1:2004
ICS:
79.060.10 Vezan les Plywood
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 314-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2004
ICS 79.060.10 Supersedes EN 314-1:1993
English version
Plywood - Bonding quality - Part 1: Test methods
Contreplaqué - Qualité du collage - Partie 1: Méthodes Sperrholz - Qualität der Verklebung - Teil 1: Prüfverfahren
d'essai
This European Standard was approved by CEN on 14 October 2004.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 314-1:2004: E
worldwide for CEN national Members.

Contents
page
Foreword.3
1 Scope .4
2 Normative references .4
3 Test pieces .4
3.1 Sampling.4
3.2 Shape and sizes.4
4 Apparatus .8
4.1 Physical test.8
4.2 Shear test.8
5 Pre-treatments.8
5.1 Sequence of pre-treatment .8
5.2 Choice of pre-treatment .8
5.3 Positioning of test pieces .8
6 Procedure .9
6.1 Determination of behaviour of bonding by shear test.9
6.2 Determination of the percentage of apparent cohesive wood failure.9
7 Expression of results .9
8 Test report .10
Annex A (normative)  Determination of the percentage of apparent cohesive wood failure by
comparison.11
Annex B (informative)  Guidelines for the evaluation of glue bond of insulating core plywood .14
Bibliography .20

Foreword
This document (EN 314-1:2004) has been prepared by Technical Committee CEN/TC 112 “Wood based
panels”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by June 2005, and conflicting national standards shall be withdrawn at
the latest by June 2005.
This document supersedes EN 314-1:1993.
In the revised version the following modifications have been made as compared to EN 314-1:1993:
— the standard contains not only test methods for veneer plywood but also for blockboard and laminboard;
— the normative annex A "Determination of the percentage of apparent cohesive wood failure by
comparison" has been extended;
— a new informative annex B "Guidelines for the evaluation of glue bond of insulating core plywood" has
been added.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and United Kingdom.
1 Scope
This document specifies methods for determining the bonding quality of veneer plywood, blockboard and
laminboard by shear testing.
The relevant requirements are specified in EN 314-2.
This document is suitable for insulating core plywood as defined in Annex B.
Annex A is normative. Annex B is informative.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 314-2, Plywood — Bonding quality — Part 2: Requirements
EN 326-1, Wood-based panels — Sampling, cutting and inspection — Part 1: Sampling and cutting of test
pieces and expression of test results.
3 Test pieces
3.1 Sampling
Sampling shall be according to EN 326-1.
Test pieces shall be without any manufacturing defects or characteristics inherent in wood (see EN 635-1) in
the testing area.
3.2 Shape and sizes
The test pieces of veneer plywood shall be prepared as shown in Figure 1.
Each test piece shall be cut so that the grain direction of the layer between the gluelines under test is
perpendicular to the length of the test piece.
The test pieces have to be prepared and the nicking is made to allow the examination of each glueline of the
panel.
The saw cuts shall extend into the layer between the gluelines under test, as shown in Figure 1.
Full panel thickness test pieces may be used for veneer plywood with 3 to 9 layers.
For panels of more than 9 layers, excess layers may be removed by planing, cutting or sanding.
Similar procedure can be used for determining the bonding quality of blockboard and laminboard (Figure 2) or
thin faces veneered plywood (Figure 3). The saw cuts shall extend into one of the layers between the
gluelines under test between face layers and core layers, as shown in Figures 2 and 3.
NOTE For insulating core plywood, see Annex B.
Key
b (25 ± 0,5) mm (shear width of test piece)
b 2,5 mm to 4 mm (saw cut width)
l (25 ± 0,5) mm (shear length)
l 50 mm min (distance between clamps)
along the grain direction
Figure 1 — Test piece example for a 7 ply veneer plywood
Key
1 Face
2 Back face
3 Part 1
4 Part 2
5 Faces of part 1 and part 2, the same set-up shall be made for the back face of part 1 and part 2
6 Glueline not subject to the shear test
7 Saw cuts throughout the face layers
b (25 ± 0,5) mm (shear width)
b (2,5 to 4) mm (saw cut width)
l (25 ± 0,5) mm (shear length)
l 50 mm min (distance between clamps)
along the grain direction
Figure 2 — Composite test piece for blockboard and laminboard
Key
1 Face
2 Back face
3 Part 1
4 Part 2
5 Faces of part 1 and part 2, the same set-up shall be made for the back face of part 1 and part 2
6 Glueline not subject to the shear test
b (25 ± 0,5) mm (shear width)
b (2,5 to 4) mm (saw cut width)
l (25 ± 0,5) mm (shear length)
l 50 mm min (distance between clamps)
along the grain direction
Figure 3 — Composite test piece for thin face plywood panel
4 Apparatus
4.1 Physical test
 Thermostatically controlled water-bath suitable for immersing test pieces and capable of maintaining a
temperature of (20 ± 3) °C.
 Boiling tank enabling the test piece to be immersed in boiling water.
 Ventilated drying oven capable of maintaining a temperature of (60 ± 3) °C at all points.
 Measuring instrument of lengths with an accuracy of 0,1 mm.
 A lens with a magnification of 10.
4.2 Shear test
A tensile testing machine with suitable serrated grips capable of operating continuously and measuring the
applied load to an accuracy of ± 1 %.
5 Pre-treatments
5.1 Sequence of pre-treatment
5.1.1 Immersion for 24 h in water at (20 ± 3) °C.
5.1.2 Immersion for 6 h in boiling water followed by cooling in water at (20 ± 3) °C, for at least 1 h.
5.1.3 Immersion for 4 h in boiling water, then drying in the ventilated drying oven for 16 h to 20 h at (60 ±
3) °C, then immersion in boiling water for 4 h, followed by cooling in water at (20 ± 3) °C for at least 1 h.
5.1.4 Immersion for (72 ± 1) h in boiling water, followed by cooling in water at (20 ± 3) °C for at least 1 h.
5.2 Choice of pre-treatment
EN 314-2 gives information on pre-treatments for particular plywood types.
5.3 Positioning of test pieces
The test pieces shall be placed, well separated, in a suitable rack or wire basket. During soaking, each test
piece shall remain completely immersed in water.
6 Procedure
6.1 Determination of behaviour of bonding by shear test
 Before the water treatment, the length and width of the shear area shall be measured to an accuracy of
0,1 mm and recorded.
 The shear test shall be carried out on wet test pieces from which a wiping can be realized.
 The shear test pieces shall be arranged in the centre of the clamping devices in such a way that the load
can be transmitted from the testing machine, via the ends of the test pieces, to the shear area without any
transverse loads. If slipping occurs it is only allowed in the initial stage of the loading. This clamping is
made on faces.
 The load shall be applied at a constant rate of motion so that rupture occurs within (30 ± 10) s.
 The breaking load shall be determined to an accuracy of 1 %. The shear strength shall be calculated in
Newton per square millimetre (N/mm ) according to clause 7.
 After the shear test, the apparent cohesive wood failure shall be determined according to 6.2.
6.2 Determination of the percentage of apparent cohesive wood failure
The failure should normally occur in the wood, or in the glue-lines between the saw cuts, i.e. within the shear
test area. When failure occurs outside the test area, or if by cross-grain breaking within 50 % or more of the
surface of a face veneer, the result shall be rejected and the test shall be repeated with a shear length of
25 mm by using the procedure for plywood with faces made of thin veneers in Figure 3.
With the exception of results from test pieces containing tape, the results of failures arising from the presence
of strength reducing defects shall be excluded. Test pieces with such defects should normally be identified
and replaced during the cutting operation. If the number of test pieces rejected exceeds 20 %, it will be
necessary to resample. If the resampling is also rejected on this basis, then the batch shall be rejected.
The test pieces shall be allowed to dry before the determination of apparent cohesive wood failure.
The apparent cohesive wood failure percentage shall be recorded by use of the written guidelines and
comparison with the pictures in Annex A (determination of apparent cohesive wood failure percentage, if
possible by 5 % increment from 0 % to 100 %).
7 Expression of results
The shear strength f of each test piece in Newtons per square millimetre (N/mm ) is calculated from the
v
following equation:
F
f =
v
l1 × b1
where
F is the failing force of the test piece, in Newton;
l is the length of the shear area in millimetres;
b is the width of the share area
...