<p>DRAFT PHILIPPINE NATIONAL STANDARD DPNS 166:2002</p><p>Foreword</p><p>This Philippine National Standard specification for corrugating medium was prepared by the Technical Committee on Paper, Board and Pulps of the Bureau of Product Standards, BPS/TC 21.</p><p>This standard is revised to include two classes of corrugating medium presently available in the market.</p><p>All units in this standard are expressed in SI units. DRAFT PHILIPPINE NATIONAL STANDARD DPNS 166:2002 Paper, board and pulps, Corrugating medium - Specification</p><p>1 Scope</p><p>This standard specifies the requirements for corrugating medium used in forming the fluted portions of the corrugated fibreboard.</p><p>2 References The titles of the standard publications referred to in this standard are listed on the inside back cover.</p><p>3 Definitions</p><p>For the purpose of this standard, the following terms and definitions apply:</p><p>3.1 corrugated fibreboard a board consisting of one or more sheets of fluted paper stuck to a flat sheet of paper or between several sheets. It can be single face, single wall, double wall, or triple wall</p><p>3.2 corrugating medium fluting medium a paper used in forming the fluted portion of the corrugated fibreboard also known as fluting medium</p><p>3.3 concora medium test (CMT) a measure of the crushing resistance of a laboratory fluted strip of corrugating medium</p><p>3.4 flute or corrugation the configuration of the undulations in fluted paper</p><p>3.5 grammage the mass of a unit area of paper or board expressed in grams per square metre</p><p>3.6 pulp the fibrous material, generally of natural vegetable origin, made ready for use in further manufacturing processes</p><p>3.7 recycled fibre secondary fibre any fibrous material that has already undergone a manufacturing process and is being recycled as the raw material for another manufactured product DPNS 166:2002 3.8 ring crush resistance the compressive force sustained by the specimen held in ring form in a special jig. It correlates with edgewise compressive strength which is a principal element in determining the box compression strength</p><p>3.9 thickness (of a single sheet of corrugated fibreboard) the distance between two plane parallel surfaces of a micrometer between which a test piece is subjected to the specified pressure</p><p>4 Classification</p><p>Corrugating medium shall be classified based on physical properties:</p><p>Class A </p><p>Class B </p><p>5 Requirements</p><p>5.1 Material</p><p>Corrugating medium shall be made of pulp and/or recycled fibre.</p><p>5.2 Physical Properties</p><p>Corrugating medium shall conform to the physical property requirements specified in table 1.</p><p>Table 1 - Physical properties</p><p>Requirement Property Class Class Class Class Class Class Test A B A B A B A B A B A B method Grammage, g/m² Tol.: ±5% 115 125 150 160 175 185 PNS ISO 536 Thickness, mm Tol.: ±0.03 mm 0.20 0.23 0.26 0.28 0.31 0.33 PNS ISO 534 Concora medium test (CMT), N, 210 190 256 228 290 268 310 284 340 310 360 330 PNS 326 TAPPI T 809 min. Ring crush resist- ance*, kN/m, 0.9 0.7 1.0 0.8 1.2 1.0 1.3 1.1 1.4 1.3 1.6 1.4 PNS 1268 TAPPI T 818 min., CD 0 0 5 0 6 5 4 5 9 0 0 0 * Test result from PNS 1268 (TAPPI T 818) which uses deflecting beam tester maybe different from TAPPI T 822 which uses rigid support.</p><p>5.3 Form</p><p>The roll shall not be less than 1000 mm diameter with a maximum of two splices that are properly marked.</p><p>2 DPNS 166:2002 5.4 Workmanship</p><p>The corrugating medium shall be free from imperfections which may affect its appearance and serviceability.</p><p>6 Sampling</p><p>Sampling of corrugating medium for testing shall be made in accordance with PNS ISO 186.</p><p>7 Test Methods</p><p>Test methods shall be as specified in Table 1.</p><p>8 Marking and labeling</p><p>Every roll shall be stamped, as near to the center as possible, with the following:</p><p>8.1 Name of commodity, "Corrugating medium"</p><p>8.2 Grammage and Class</p><p>8.3 Manufacturer's name and/or trademark and address</p><p>8.4 "Made in the Philippines" or Country of origin (if imported) </p><p>8.5 Size and mass of roll</p><p>8.6 Length of roll</p><p>8.7 Direction of unwind</p><p>3 References DPNS 166:2002</p><p>The following standards contain provisions, which through reference in the text form part of this national standard. At the time of publication of this PNS, the editions indicated were valid:</p><p>PNS 326:2001 - Flat crush of corrugating medium (CMT Test) (TAPPI T 809 om-93) </p><p>PNS 1268:2000 - Ring crush of paperboard (TAPPI T 818 om-87)</p><p>PNS ISO 186:2000 - Paper and board - Sampling to determine average quality (ISO published 1994)</p><p>PNS ISO 534:2001 - Paper and board - Determination of the thickness of (ISO published 1988) single sheets (and method of calculation of the apparent density of board)</p><p>PNS ISO 536:2000 - Paper and board - Determination of grammage (ISO published 1995</p>