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    PN-EN 310 Wood-based panels – Determination of modulus of elasticity in bending and of bending strength

    The standard describe the method in determination of modulus of elasticity in bending and bending strength wood-based panels. The test relay on weight down of the sample, which is supported at two points. The weight down point is in the middle length of the sample. There is also shown the method how to calculate results.
    Appropriate requirements are put in EN-636.

    EN 313-1 Plywood – Classification and terminology
    Part 1: Classification

    The standard concerns the plywood classification

    1. in regard of general appearance:
    • – in regard of construction
    • – in regard of form and shape
    1. in regard of main properties:
    • – in regard of durability
    • – in regard of mechanical properties
    • – in regard of surface appearance
    • – in regard of surface finish
    1. in regard of condition of the plywood use.

     

    EN 313-2 Plywood – Classification and terminology
    Part 2: Terminology

    The standard concerns general terminology of the plywood, in particular concerning plywood’s construction, surface appearance, wood defects, processing defects. The terms are written in different languages.

    EN 314-1 Plywood – Bonding quality
    Part 1: Test method

    The standard concerns the test method of determination of bonding quality (strength of the glue joint) in plywood, wood-based panels and LVL.
    In the standard determined shape and dimensions of the samples, equipment and described preparation treatments of the samples according to condition of the plywood use.
    Appropriate requirements are described in EN 314-2.

     

    EN 314-2 Plywood – Bonding quality
    Part 2: Requirements

    The standard concern requirements concerning class of the plywood bonding quality according to condition of the plywood use. Bonding quality is divided onto three classes according to resistant to humidity.

    EN 315 Plywood – Tolerances of dimensions

    In the standard there are tolerance of the plywood dimensions (length, width, thickness) edge straightness and squareness.
    According to the standard:

    1. Tolerance of length and width

    – Tolerance to nominal dimension: ± 3,5 mm.

    1. Thickness tolerance
    Nominal thickness (t)

     

    mm

    No sanding boards Boards after sanding
    Thickness tolerance in one board

    mm

    Tolerances to nominal thickness

    mm

    Thickness tolerance in one board

    mm

    Tolerances to nominal thickness

    mm

    ≥3

     

    ≤12

     

    1,0 +(0,8 + 0,03 t)

     

    -(0,4 + 0,03 t)

    0,6 +(0,2 + 0,03 t)

     

    -(0,4 + 0,03 t)

    >12

     

    ≤25

     

    1,5 +(0,8 + 0,03 t)

     

    -(0,4 + 0,03 t)

    0,6 +(0,2 + 0,03 t)

     

    -(0,4 + 0,03 t)

    >25

     

    ≤30

     

    1,5 +(0,8 + 0,03 t)

     

    -(0,4 + 0,03 t)

    0,8 +(0,0 + 0,05 t)

     

    -(0,4 + 0,03 t)

    >30

     

     

    1,5 +(0,8 + 0,03 t)

     

    -(0,4 + 0,03 t)

    0,8 +(0,0 + 0,03 t)

     

    -(0,4 + 0,03 t)

    EN 635-1 Plywood – Classification by surface appearance
    Part 1: General

    The standard concern the general rules of classification plywood due to the appearance of the surface of both the amount and dimensions of natural features of the wood and defects which occur during production process. In standard there is no information about the plywood whit cladding.
    The plywood’s class is specify on the basis of surface appearance.
    The plywood’s class first specify the right side of the plywood, then the left side, e.g. class II/III.

     

    EN 635-2 Plywood – Classification by surface appearance
    Part 2: Hardwood

    The standard concerns properties and dimension with tolerance of the characteristic features of the wood and defects which occur during production process, which allows visual assessment of plywood to the appropriate class. In standard there is no information about the plywood whit cladding.

     

    EN 635-3 Plywood – Classification by surface appearance
    Part 3: Softwood

    The standard concerns properties and dimension with tolerance of the characteristic features of the wood and defects which occur during production process, which allows visual assessment of plywood to the appropriate class. In standard there is no information about the plywood whit cladding.

    EN 636 Plywood – Specifications

    The standard specifies the requirements for plywood for both general purpose use (non structural-application) and structural application in dry (1), humid (2) or exterior (3) conditions. It also gives a classification system based on the bending properties (tables).
    According to the standard:

    1. Plywood for use in dry conditions (EN 636-1)

    Plywood to be used in dry conditions characterised by a moisture content in the material corresponding to a temperature of 20°C and a relative humidity of the surrounding air only exceeding 65% for a few weeks per year. These conditions correspond with class 1.

    Requirements for plywood for use in dry conditions:

    • – Bonding quality – shall comply with the requirements of bonding class 1 of EN 314-2
    • – Biological durability – plywood shall be appropriate for prevailing climatic conditions characteristic for class 1.of hazard of biological attack of EN 335-3
    1. Plywood for use in humid conditions (EN 636-2)

    Plywood to be used in dry conditions characterised by a moisture content in the material corresponding to a temperature of 20°C and a relative humidity of the surrounding air only exceeding 85% for a few weeks per year. These conditions correspond with class 2.

    NOTE! This plywood is appropriate for protected external applications (e.g. behind cladding or under roof coverings), but is also capable of resisting weather exposure for short periods (e.g. when exposed during the construction). It is also suitable for interior situations where the service moisture condition is raised above humidity of dry conditions.

    Requirements for plywood for use in semi-waterproof conditions:

    • – Bonding quality – shall comply with the requirements of bonding class 2 of EN 314-2
    • – Biological durability – plywood shall be appropriate for prevailing climatic conditions characteristic for class 2.of hazard of biological attack of EN 335-3
    1. Plywood for use in exterior conditions (EN 636-3)

    Plywood to be used in climatic conditions leading to higher moisture contents than in service class 2. These conditions correspond with class 3.

    NOTE! Plywood is capable of withstanding exposure to weathering conditions and liquid water, or water vapour in a damp but ventilated location. In that class biological durability could be bring down by making appropriate protection or/and if the plywood will be properly coated by chemical agents on surface and edges, and if plywood is properly used and maintain.

    Requirements for plywood for use in exterior conditions:

    • – Bonding quality – shall comply with the requirements of bonding class 3 of EN 314-2
    • – Biological durability – plywood shall be appropriate for prevailing climatic conditions characteristic for class 3.of hazard of biological attack of EN 335-3

    According to that standard all types of plywood can be classified independent of wood species, number of plies and thickness of plies based on bending properties, which show table 1 and 2.

    Table 1 – bending strength classes for plywood

    Bending strength
    Class Lower limit value [N/mm2]
    fm 0,5 F 3 5
    F 5 8
    F 10 15
    F 15 23
    F 20 30
    F 25 38
    F 30 45
    F 40 60
    F 50 75
    F 60 90
    F 70 105
    F 80 120
    Table 2 – bending modulus classes for plywood

    Bending modulus
    Class Lower limit value [N/mm2]
    Em 0,5 E 5 500
    E 10 1000
    E 15 1500
    E 20 2000
    E 25 2500
    E 30 3000
    E 40 4000
    E 50 5000
    E 60 6000
    E 70 7000
    E 80 8000
    E 90 9000
    E 100 10000
    E 120 12000
    E 140 14000

    EN 717-2 Wood-based panels – Determination of formaldehyde release
    Part 2: Formaldehyde release by the gas analysis method

    The standard specifies determination of formaldehyde release by the gas analysis method. In that method the sample of determined dimensions is putted
    to closed chamber, in which parameters are defined. Emitted formaldehyde from the sample is mixed with air in chamber. The air goes constantly into bottle with water. The formaldehyde is absorbed by the water.
    After 4 hours testing, concentration of formaldehyde in water is determined photometrically. Formaldehyde release is evaluate on the basis of the concentration in water, time and the sample’s dimensions. The result is expressed in mg/m2h.
    For plywood which is used in external conditions there is no need to determined formaldehyde release. Plywood used in interior conditions should be tested
    and classified to one class: E1 or E2.

    Table 1 – Class of formaldehyde (according to EN 636)

    Class E1 Class E2
    Initial type testing Test method EN 717-1 or EN 717-1
    Requirement Release ≤ 0,124 mg/m3 of air Release > 0,124 mg/m3 of air
    Test method ————- or EN 717-2
    Requirement ————- Release > 3,5 mg/m2h to ≤ 8 mg/m2h

    or > 5 mg/m2h to ≤ 12 mg/m2h

    within 3 days after production

    Factory production control Test method EN 717-2 EN 717-2
    Requirement Release ≤ 3,5 mg/m2h

    or ≤ 5 mg/m2h

    within 3 days after production

    Release > 3,5 mg/m2h to ≤ 8 mg/m2h

    or > 5 mg/m2h to ≤ 12 mg/m2h

    within 3 days after production

    EN 13986 Wood-based panels for use in construction – Characteristics, evaluation of conformity and marking

    The standard defines the performance characteristics required by wood-based panels (including plywood) for use in construction applications, important properties and testing method of determination. A series of tables lists the relevant performance characteristics for load bearing (structural) and non-structural applications in the three service environments – dry, humid and exterior. Information is also given covering evaluation of conformity and marking.
    Marking and accompanying information can be placed onto panel, or on a label firmly affixed to each pane, or on the packaging containing the panels and on accompanying trade documentation.

    Independent from above marking, information should consist:

    – name (logo) or identifying mark of the manufacturer,
    – reference to this standard and technical class,
    – indication of use; “S” – for structural applications; “G” – for non-structural applications
    – formaldehyde class or marking “only for external use”,
    – nominal thickness of the panel in millimeter,
    – class of modulus of elasticity in bending and of bending strength,
    – number of the certificate of conformity and of the notified certification body (if there is),
    – number of the patch or week and year production.