DRAFT UGANDA STANDARD  
  DUS 202 -3 
First Edition  
2015-mm-dd 
 
 
 Reference number  
DUS 202 -3: 2015 
© UNBS 201 5  
  
Flexible Polyurethane Foams  — Part 3: Reconstituted  foams  — 
Specification  
 DUS 202 -3: 2015 
ii © UNBS 201 5 – All rights reserved  
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. User s are 
responsible for its correct application  
© UNBS 200 7  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and microfil m, without prior written 
permission from UNBS.  
Requests for permission to reproduce this document should be addressed to  
The Executive Director  
Uganda National Bureau of Standards  
P.O. Box 6329  
Kampala  
Uganda  
Tel: 256 41 4 505 995  
Fax: 256 41 4 286 123  
E-mail: unbs@infocom.co.ug  
Web: www.unbs.go.ug  DUS 202 -3:201 5 
© UNBS 201 5 – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ................................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4  Requirements  ................................ ................................ ................................ ................................ .........  2 
4.1  General  ................................ ................................ ................................ ................................ ...................  2 
4.2  Class of foam  ................................ ................................ ................................ ................................ .........  2 
4.3  Density and hardness  ................................ ................................ ................................ ...........................  2 
4.3.1  Density  ................................ ................................ ................................ ................................ ....................  2 
4.3.2  Hardness  ................................ ................................ ................................ ................................ ................  2 
4.4  Flammability  ................................ ................................ ................................ ................................ ...........  3 
4.5  Other physical properties  ................................ ................................ ................................ .....................  3 
4.6  Shape and dimensions  ................................ ................................ ................................ .........................  4 
5. Marking  ................................ ................................ ................................ ................................ ...................  4 
6  Sampling and compliance criteria  ................................ ................................ ................................ ....... 4 
6.1 Sampling  ................................ ................................ ................................ ................................ ................  4 
6.2  Compliance criteria  ................................ ................................ ................................ ...............................  5 
7  Inspection and methods of test  ................................ ................................ ................................ ...........  5 
7.1  Inspection  ................................ ................................ ................................ ................................ ...............  5 
7.2  Conditioning  ................................ ................................ ................................ ................................ ..........  5 
7.3  Dimensions  ................................ ................................ ................................ ................................ ............  5 
7.4  Methods of test  ................................ ................................ ................................ ................................ ...... 5 
Appendix A (normative)  title ................................ ................................ ................................ .............................  7 
Bibliography  ................................ ................................ ................................ ................................ ........................  8 
 DUS 202 -3: 2015 
iv © UNBS 201 5 – All rights reserved  
 Foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal  under the Ministry of Tourism, Trade and 
Industry established under Cap 327 , of the Laws of Uganda.  UNBS is mandated to co -ordinate the 
elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point  for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT/SPS Agreements of the World Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of representatives of 
consumers, traders, academicians, manufacturers, government and other stakeholders.  
Draft Uganda Standards adopted by the Technical Committee are  widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
Committee membership  
 DRAFT UGANDA STANDARD  DUS 202 -3: 2015 
 
© UNBS 2015– All rights  reserved  1 
 Flexible Polyurethane Foam  — Part 3: Reconstituted Foam  — 
Specification  
1 Scope  
This draft Uganda standard specifies  requirements  and methods of sampling and test  for seven classes 
(based on density) of  reconstituted flexible polyurethane foams, in the form of blocks, slabs, sheets, or other 
shapes cut from  these.  
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 la test edition of the referenced 
document (including any amendments) applies.  
FDUS ISO 1798, Flexible cellular polymeric materials — Determination of tensile strength and elongation at 
break  
FDUS ISO 1856, Flexible cellular polymeric materials — Determinatio n of compression set  
FDUS ISO 1923, Cellular plastics and rubbers — Determination of linear dimensions  
FDUS ISO 23529, Rubber – General procedures for preparing and conditioning test pieces for physical test 
methods.  
FDUS ISO 2439:2008, Flexible cellular p olymeric materials — Determination of hardness (indentation 
technique)  
FDUS ISO 2440, Flexible and rigid cellular polymeric materials — accelerated ageing tests  
FDUS ISO 3385, Flexible cellular polymeric materials — Determination of fatigue by constant -load pounding  
ISO 8067:2008 F lexible cellular polymeric materials -- Determination of tear strength  
FDUS ISO 8307, Flexible cellular polymeric materials — Determination of resilience by ball rebound  
US ISO 845, Cellular plastics and rubbers — Determination of  apparent density  
3 Terms and definitions  
For the purposes of this standard, the following te rms and definitions shall apply.  
3.1 
acceptable  
acceptable to the authority administering this standard, or to the parties concluding the purchase  contract, as 
relevant  DUS 202 -3: 2015 
2 © UNBS  2015 – All rights reserved  
 3.2 
Block/log/bun/loaf/slabstock  
mass of polyurethane foam formed by a free -rising foam process, in its original form, before  conversion  
3.3 
lot 
not less than 10 and not more than 1 200 sleeping mats or mattresses of the same type and  nominal 
dimen sions, from one manufacturer, submitted at any one time for inspection and testing  
3.4 
polyurethane foam  
cellular material produced by the reaction of a polyol with an organic polyisocyanate in the presence  of water 
and that may include catalysts, surface -active agents, auxiliary blowing agents, fillers,  plasticizers, colourants, 
and any other additives that do not adversely affect the properties of the  foam   
3.5 
reconstituted foam  
a composite material that consists of chips  of flexible polyurethane foam of the polyether ( requirements in US 
202-1) or the  polyes ter type  ( requirements in US 202 -4) or of a mixture of these types) held together by 
means of a suitable binder . 
4  Requirements  
4.1  General  
The foam shall be a reconstituted foam, shall be non -toxic, and shall be free from objectionable  odour. The 
chip structure shall be acceptably uniform, and the largest dimension of any void  between the chips shall not 
exceed 3 mm except in the case of foams of classes 56 and 64 where  the largest dimension of any  void shall 
not exceed 6 mm. In the cases of trimmed blocks, slabs,  sheets, and shapes cut from any of these, the 
surfaces shall be smooth and free from cuts and  tears.  
4.2  Class of foam  
The class of foam shall be one of the following  and the manufacturer  shall declare as such under clause 5 . 
Class 56, 64, 80, 96, 117, 145, or 160.  
4.3  Density and hardness  
4.3.1  Density  
The density of a foam, determined in accordance with 7.4, shall be within the appropriate limits  given in 
columns 2 and 3 of table 1.  
4.3.2  Hardness  
The hardness factor of a foam, determined in accordance with 7.4, shall be as follows:  
a) Class 56, class 64, class 80, and class 96 foams. Within the limits given in columns 5 and 6 of  table 1 
appropriate to the class of foam and to one of the nominal values given in column 4 and  specified by 
the purchaser.  
b) Class 117, class 145, and class 160 foams. At least equal to the appropriate minimum given in  
column 5 of table 1.  DUS 202-3: 201 5 
© UNBS  2015 – All rights reserved  3 
 Table 1 — Density and hardness factor  
1 2 3 4 5 6 
Class  Density, kg/m3 Hard ness factor  
Nominal  Actual  
Min. Max.  Min. Max.  
56 - 56 (10 7 14 
   (17 14 21 
64 56 72 (19 14 24 
   (30 25 35 
80 72 88 (30 25 35 
   (40 35 45 
96 88 104 (45 38 52 
   (51 42 60 
117 104 130 52 52 - 
145 130 160 63 63 - 
160 160 - 77 77 - 
4.4  Flammability  
When a foam is tested in accordance with 7.4, 
a) no specimen shall burn for 3 min or more, and  
b) no specimen shall burn beyond the gauge line.  
4.5  Other physical properties  
When tested in accordance with the relevant methods referred to in 7.4, a foam shall comply with  the 
requirements given in table 2 appropriate to the class of foam specified by the purchaser.  
Table 2 — Other physical properties  
1 2 3 4 5 6 7 8 
Property  Class  
56 64 80 96 117 145 160 
Compression set , %, max . 25 20 15 15 12 - - 
a) Tensile properties , kPa, min  
  1) original  40 40 45 45 45 45 45 
2) after heat aging  40 40 45 45 45 45 45 
3) after humid aging  40 40 45 45 45 45 45 
b) elongation at break, kPa, min  
1) original  50 90 90 90 75 50 50 
2) after heat aging  50 90 90 90 75 50 50 
3) after humid aging  50 90 90 90 75 50 50 
Tear resistance , N/mm of width, min.  0.09 0.26 0.35 0.35 0.35 0.26 0.26 DUS 202 -3: 2015 
4 © UNBS  2015 – All rights reserved  
 Fatigue resistance  
a) Retention of hardness factor  - 80 82.5 82.5 85 - - 
b) Loss in height  - 5 4 4 3 - - 
 
4.6  Shape and dimensions  
The foam shall be supplied in the form of blocks, trimmed blocks, slabs, or sheets cut from trimmed  blocks, or 
other sha pes cut from any of these forms . The size of  blocks (nominal dimensions and the tolerances on 
those) shall be as specified by the purcha ser or as required by the market . In the cases of trimmed blocks, 
slabs, sheets, and other shapes, the actual dimensions  measured in accordance with 7.3, shall not  differ from 
the nominal values  declared  by more than the appropriate tolerances given in tab le 3. 
Table 3 — Tolerances on dimensions (other than of blocks)  
1 2 3 
Magnitude of dimension, D, mm Tolerance  
mm( unless otherwise specified)  
Length  width  Thickness  
D ≤ 25  N/A N/A 0                                               +3 
25 < D ≤ 150  0                +6.5  0                +6.5  0                                            +4.8  
151 < D ≤ 300  0               +12.5  0               +12.5  0………………………………+6.5  
301 < D ≤ 600  0                 +20  0                 +20  0………………………………+12.5  
601 < D ≤ 1000  0                 +30  0                 +30  0………………………………..+20  
1001 < D ≤ 1500  0                 +30  0                 +30   
1501 < D ≤ 2000  0                 +40  0                 +40  
D > 2000  0                 +45  0                 +45    
5. Marking  
The following shall appear in legible and indelible  permanent  marking on  an end or on a sleeping surface near 
an end of the foam of the mattress and shall be visible t o the purchaser.  
a) Trade n ame and address of Manufacturer  or importer  or distributor , 
b) lot or batch number , 
c) dimensions of the mattress  or foam  
d) class and grade  
e) Country of origin  
6  Sampling  and compliance criteria  
6.1 Sampling  
The following sampling procedur e shall be applied in determining whether a lot complies with the 
requirements of the specification. The samples so taken shall be deemed to represent the lot.  DUS 202-3: 201 5 
© UNBS  2015 – All rights reserved  5 
 Take at random from the lot the number of samp les shown in Column 2 of Table 4  relative to the a ppropriate 
lot size shown in Column 1. Each sample shall consist of the following:  
a) For inspe ction ― A complete piece.  
b) For testing ― Pieces of total volume of at least 0.01 m3. 
Table 4 — Sampling  
Size of lot, L, m3 Number of samples  
L ≤ 8  2 
8 < L ≤ 15  3 
15 < L ≤ 25  5 
25 < L ≤ 50  8 
50 < L ≤ 100  13 
 
6.2  Compliance criteria  
The lot shall be d eemed to comply with the specification if after inspection and testing of the samples taken in 
accordance with Clause 5, no defective is found.  
7  Inspection and methods of test  
7.1  Inspection  
Visually examine and measure (using the method referred to in 7.3) the samples taken for  inspection (see 6.1) 
for compliance with the requirements of 4.1, 4.6, and section 5. 
7.2  Conditioning  
Before testing , prepare and  condition all specimens as in ISO 23529 .  
7.3  Dimensions  
The dimensions shall be measured in acc ordance with ISO 1923 . 
7.4  Methods of test  
Use the relevant methods given in  Table 5  
Table 5: properties and methods of test  
Property  Test method s 
Density  US  ISO 845  
Hardness  factor   ISO 2439:2008, 7.3 method A  
Flammability  Annex A  
Compression set  ISO 1856  
Tensile strength and elongation at break  ISO 1793  DUS 202 -3: 2015 
6 © UNBS  2015 – All rights reserved  
 Fatigue resistance  ISO 3385  
Tear resistance  ISO 8067  
 DUS 202-3: 201 5 
© UNBS  2015 – All rights reserved  7 
 Appendix A 
(normative)  
 
Flammability  
A.1  Apparatus  
An apparatus as shown schematically in Figure G.1 and consisting of a heat -resistant gl ass tube (chimney) in 
which a test specimen can be mounted, the base of the tube being connected to metered supplies of oxygen 
and nitrogen. The glass tube shall have a diameter of at least 75 mm and a height of at least 450 mm, and 
shall have at its base a bed of glass beads (or other inert particles) that will mix and distribute the incoming 
gases. The tube shall also contain a clamp that is capable of holding a test specimen (vertically) that the top of 
the specimen is at least 100 mm below the top of th e tube.  
The oxygen and nitrogen used shall be of commercial grade (or better) and shall be supplied to the base of 
the glass tube through individual metering devices that enable the volumetric flow of each gas to be measured 
with an accuracy of 1 % or bett er. 
A.2  Test specimens  
From the appropriate slab ( see 5.1b)) cut five specimens each of size 12.5 mm + 0.5 mm x 12.5 mm + 0.5 mm 
x 130 mm and draw a gauge line across each specimen 75 mm from the end that is to be positioned 
uppermost in the apparatus.  
A.3  Procedure  
Clamp a test specimen in the holder of the apparatus so that it is held vertically in the centre of the glass 
chimney. Open the valves of the gas cylinders and adjust the flow so that the oxygen content of the gas 
mixture is 20 % + 0.2 % and t hat the flow rate up the glass chimney (as calculated from the volumetric flow 
rate divided by the cross -sectional area of the chimney) is 40 % + 10 % mm/s. Allow the gas to flow for at 
least 30 s and then, using a small gas flame at the end of a tube, ign ite the test specimen so that the whole of 
the upper surface is burning. Note whether the specimen burns for 3 min or longer and if not, whether or not 
the specimen has burned to below the 75 mm gauge line. Repeat the test with the remaining four specimens . 
 
Figure A.1 — General arrangement of flammability test apparatus  
 DUS 202 -3: 2015 
8 © UNBS  2015 – All rights reserved  
 Bibliography  
[1] SANS 642:2010 Reconstituted flexible polyurethane foams  
 DUS 202-3: 201 5 
© UNBS 2015– All rights  reserved  9 
 Certification marking  
Products that conform to Uganda standards may be marked with Uganda National Bureau of Sta ndards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is governed by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licensed under the certification mark scheme oper ated by 
the Uganda National Bureau of Standards and in conjunction with the relevant Uganda Standard. The 
presence of this mark on a product or in relation to a product is an assurance that the goods comply with the 
requirements of that standard under a sy stem of supervision, control and testing in accordance with the 
certification mark scheme of the Uganda National Bureau of Standards. UNBS marked products are 
continually checked by UNBS for conformity to that standard.  
Further particulars of the terms an d conditions of licensing may be obtained from the Director, Uganda 
National Bureau of Standards.  
 
 DUS 202-3: 2015   
 
ICS nn.nnn.nn  
Price based on nn pages  
© UNBS 2015– All rights reserved