Philippine National Standard Dpns 1562:2001

DPNS 1562:2000

DPNS 1562:2001

ICS 97.140

School furniture – Specification

DPNS 1562:2001

PHILIPPINE NATIONAL STANDARD DPNS 1562:2001

School furniture - Specification

1 Scope

This standard specifies the requirements for desk, tablet-arm chair, table and chair used in the classroom in all educational level.

2 References

The titles of the standards publications referred to in this standard are listed in the inside back cover.

3Definitions

For the purpose of this standard, the following definitions apply:

3.1

adhesive

a substance capable of holding materials together by surface attachment. It is a general term and includes cements, mucilage, and paste, as well as glue.

3.2

bark

the layer of a tree outside the cambium.

3.3

board

lumber less than 50mm in nominal thickness. Boards less than 150mm in width may be classified as strips.

3.4

boxed heart

the term used when the pith falls entirely within the four faces of a piece of wood anywhere in its length. Also called boxed pitch.

3.5

decay

decomposition of wood substance by fungi, resulting in softening, loss of strength and weight, and often in change of texture and color.

3.6

defect

any irregularity or imperfection in wood that reduces the volume of sound wood or lowers its durability, strength or utility value.

3.7

desk

a table, frame and case that has a sloping or horizontal surface especially for writing and reading and is often provided with drawers, compartments and pigeon holes

3.8

dimension

lumber from nominal 50mm through 100mm thick and 50mm or more wider.

3.9

end check

a seasoning check occuring on the end of a board

3.10

equilibrium moisture content (EMC)

a moisture content at which wood either gains or loses moisture to the surrounding air.

3.11

fiber board

a board generic term inclusive of sheet material of widely varying densities manufactured of refined or partially refined wood (or other vegetable) fibers. Binding agents and other materials may be added to increase strength, resistance to moisture, fire, or decay, or to improve some other property.

3.12

honeycombing

checks, often not visible at the surface, that occur in the interior of a piece of wood, usually along the wood rays.

3.13

knot

that portion of a branch or limb which has been surrounded by subsequent growth of the wood of the stem. The shape of the knot as it appears on a cut surface depends on the angle of the cut relative to the long axis of the knot.

3.14

laminated wood

an assembly made by bonding layers of veneer or lumber with an adhesive so that the grain of all laminations is essentially parallel

3.15

lumber

the product of the sawmill and planning mill usually not further manufactured other than by sawing, resawing, passing lengthwise through a standard planing machine, crosscutting to length, and matching.

3.16

moisture content

the amount of water contained in the wood, usually expressed as a percentage of the mass of oven-dry wood.

3.17

particle board

a generic term or a panel manufactured from lignocellulosic materials-commonly wood-essentially in the form of particles (as distinct from fibers). These materials are bonded together with synthetic resin or other suitable binder, under heat and pressure, by a process wherein the interparticle bonds are created wholly by the added binder.

3.18

plywood

a composite panel or board made up of cross-banded layers of veneer only or veneer in combination with a core of lumber or of particleboard bonded with an adhesive. Generally the grain of one or more plies is roughly at right angles to the other plies, and almost always a odd number of plies are used.

3.19

pitch

the small, soft core occuring near the center of a tree trunk, branch, twig, or log.

3.20

sapwood

the living wood of pale color near the outside of the log. Under most conditions the sapwood is more susceptible to decay than heartwood.

3.21

sound knot

a knot that is solid across its face, at least as hard as the surrounding wood, and shows no indication of decay.

3.22

split

a lengthwise separation of the wood, due to the tearing apart of the wood cells.

3.23

surface check

a check occuring on the surface of a piece of wood, usually on the tangential face not extending through the piece.

3.24

tablet arm-chair

a chair with one arm that is broadened to serve as a writing surface

3.25

timber

lumber 125mm or more in least dimension.

3.26

veneer

a thin layer or sheet of wood.

3.27

wane

bark or lack of wood.

3.28

warp

any variation from a true plane surface. It includes bow, crook, cup and twist

4 Requirements

4.1 Materials

4.1.1 Solid wood

a)Dimensions and tolerances of solid wood shall be in accordance with PNS 173.

b)Classification and grades of sawn lumber shall be in accordance with PNS 194.

4.1.1.1Moisture content

All solid wood used for school furniture used in the local market, shall have a moisture content of not more than 16 percent for room temperature and 12 percent for air-conditioned room.

All solid wood used for school furniture used for export shall be dried to a moisture content range of 6-12 percent at the time of shipment, depending upon the equilibrium moisture content (EMC) of the importing countries.

To ensure that the moisture content is between 12% to 16% a calibrated electric moisture meter shall be use or the method specified in ISO 3130.

4.1.1.2Defects and imperfections

Defects and imperfections that are permitted or not permitted for sawn wood for furniture production shall be in accordance with table 1. Defects of wood other than specified in table 1 shall be in accordance with PNS 194.

DPNS 1562:2001

Table 1 - Permissible defects for school furniture

Possible defects and imperfections that are permitted and not permitted
Components
Defects / Leg / Rail / Seat / Splat/Backrest / Top/Tablet / Support/Stretcher

Bark or Wane

/ Not Permitted / Not Permitted /