Reference number  
DRS 377: 2017  
© RBS yyyy 
© RSB 2017  
 
 RWANDA 
STANDARD  DRS 
377 
 
Nth edition  
2017 -mm-dd 
 
Paper  towels  — Specification  
  DRS 377: 2017  
©RSB 2017  All rights reserved                  ii 
 
 In order to match with technological development and to keep continuous progress in industries, 
Standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
 
 
© RSB2017  
All rights reserved. Unless otherwise specified,  no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reproduce this document should be addressed to  
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
Tel. +250 252 586103/ 582945  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  DRS 377: 2017  
iii                 ©RSB2017  All rights reserved  
 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 Requirements  ................................ ................................ ................................ ................................ ....... 54 
4.1 Material  ................................ ................................ ................................ .....Error! Bookmark not defined. 4 
4.2 Physical req uirements  ................................ ................................ ................................ ..........................  5 
4.3 Dimensions  ................................ ................................ ................................ ................................ ..........  65 
5 Packing  ................................ ................................ ................................ ................................ ...................  6 
5.1 Wrapping  ................................ ................................ ................................ ................................ ................  6 
5.1.1  Packets  ................................ ................................ ................................ ................................ ...................  6 
5.1.2  Rolls  ................................ ................................ ................................ ................................ ........................  6 
5.2 Containers  ................................ ................................ ................................ ................................ ............  76 
6 Labelling  ................................ ................................ ................................ ...Error! Bookmark not defined. 6 
6.1 Packets and wrappers ................................ ................................ ................................ .........................  76 
6.2 6.2 Bulk packs  ................................ ................................ ................................ ................................ ........  7 
7 Inspection and methods of test  ................................ ................................ ................................ ...........  7 
7.1 Inspection  ................................ ................................ ................................ .Error! Bookmark not defined. 7 
7.2.Sampling  ................................ ................................ ................................ ......... Error! Bookmark not defined. 7 
Annex  A (normative)  Determination of Dimensions  ................................ ................................ ....................  98 
A.1 Conditioning  ................................ ................................ ................................ ................................ ........  98 
Annex  B (normative)  Determination of Softness  ................................ ................................ .......................  109 
Annex  C (normative)  Determination of Total water absorption  ................................ ..............................  1110 
Annex  D (normative)  Determination of Rate of water absorption  ................................ ..........................  1211 
Annex  E (normative)  Assessment of perforation  ................................ ................................ .....................  1312 
 DRS 377: 2017  
©RSB 2017  All rights reserved                  iv 
 
 Foreword  
Rwanda Standard s are prepared by Technical Committees and approved  by Rwanda Standards Board (RSB) 
Board of Directors in  accordance with the procedures of RSB,  in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare  national standards. Final Draft Rwanda Standards 
adopted by Technical committees are ratified by members of RSB Board of Directors for publication and 
gazettment as Rwanda Standards.  
DRS 377 was prepared by Technical Committee RSB/TC 024, Chemicals and co nsumer products ,  
In the preparation of this standard, reference was made to the following standard s: 
SANS 1887 -1:2008, Tissue paper – Part 1: General requirements  
SANS 1887 -2:2008, Tissue paper – Part 4: Paper towels.  
The assistance de rived from the above source is hereby acknowledged with thanks.  
Committee membership  
The following organizations were represented on the Technical Committee on Chemicals and consumer 
products (RSB/TC 024) in the preparation of this standard.  
Paragraph of participants  
Rwanda St andards Board (RSB) – Secretariat  
 
 
 DRS 377: 2017  
1                 ©RSB2017  All rights reserved  
 
 Paper towels  — Specification  
1 Scope  
This draft standard covers paper towels,  in rolls and in sheets (single ply and double ply), suitable for general 
and industrial purposes.  
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.  
ISO 2470, Paper, board and pulps – Measurement of diffuse blue reflectance factor (ISO  
brightness).  
3 Terms and definitions  
For the purposes of  this standard, the following terms and definitions apply:  
3.1 
acceptable  
acceptable to the authority administering this document or to the parties concluding the purchase  contract, as 
relevant  
3.2 
break -up 
disintegration of the tissue specimen into small pieces approximately 10 mm × 10 mm  
3.3 
crêpe paper  
paper that has been subjected to crêping  
3.4 
crêping  
operation of crinkling in order to increase its stretch and softness   
©RSB 2017  All rights reserved                  2 
 
 3.5 
cross direction , CD 
that direction in the plain of a paper at right angles to t he machine direction  
3.6 
defective  
corrugated board container, bulk package, wrapper, holder, a roll, sheet or a set of test pieces,  whose 
average properties have been determined, and that fails in one more respects to comply with  the relevant 
requirements   
3.7 
embossed paper  
paper of which raised or depressed design has been produced generally by pressure from an  engraved roll or 
plate  
 
3.8 
grammage  
mass of a unit area of paper or board determined by the standard method of test  
 NOTE Grammageis expressed in grams per square metre.  
 
3.9 
grammage, actual  
average  grammage obtained on a sample of paper under specified test conditions and which should normally 
be within ± 5 % of the nominal grammage  
 
3.10 
grammage, nominal  
designated  grammage of paper, used for  reference purposes  
 DRS 377: 2017  
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 3.11 
hole 
opening, of which the largest dimension exceeds 4 mm, in the paper  
3.12 
inversion  
from an initial vertical position, one complete inversion is accomplished by rotation of the cylinderabout 
horizontal axis through 180° and back to the initial starting position in a time of 1 sec 
3.13 
lot 
aggregate of paper or board of a single kind of sp ecified characteristics produced under conditionsthat are 
presumed uniform, and available for sampling at one time  
NOTE A lot comprises one or more nominally identical units. Where the material to be tested has alreadybeen 
incorporated into a manufactured article (for example a packing case), the lot is the aggregate of sucharticles of a single 
kind, of specified characteristics.  
3.14 
machine direction  
MD 
that direction in a paper or a board corresponding to the direction of travel of the web on the paper  or board 
machine  
3.15 
non-wet strength tissue product  
product that has not had any wet strength enhancing material added during manufacturing  
3.16 
sample  
aggregate of all the specimens taken from the lot to provide information on the average quality of  the lot and 
possibly serve as basis for a decision on the lot  
3.17 
sheet  
area of paper or board taken from the selected units   
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 3.18 
single ply  
sheet material manufactured on a tissue machine or after converting as a part of a single or multiply  tissue 
product  
3.19 
specimen  
area of paper or board cut to given dimensions, from the sheets or manufactured articles  
3.20 
test piece  
piece of paper or board on which the measurement is carried out in accordance with stipulations ofthe method 
of test  
3.21 
tissue paper  
wet- or dry -crêped or uncrêped (single ply) sheet material, manufactured on any kind of tissuepaper machine, 
mainly based on cellulosic fibre pulps  
3.22 
tissue product  
tissue paper in its converted form, single or multi -ply, embossed or not embossed, laminat ed or notlaminated 
as required for its intended use  
3.23 
unit 
component of a lot which may be in the form of a reel, a bale, a bundle, a parcel, the contents of a packing 
case, a pallet load, etc.  
3.24 
sheet  
single paper towel in a packet of towels or a portion of paper towel between consecutive perforations on a 
perforated roll  DRS 377: 2017  
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 4 Requirements  
4.1 General requirements  
The paper  from which paper towels are made  shall have a crêped or a crêped  and embossed textur e 
 
Paper  shall also:  
a) be white, unless otherwise specified by the purchaser  
b) be manufactured from processed cellulose fibres, present a neat, well  finished appearance and be free of 
all imperfections or defects (or both) which might affect appearance, normal life, or serviceabi lity. 
c) be clean, and be reasonably free from visible wood splinters, specks, holes, tears, wrinkles, abrasive 
particles, or other imperfections.  
d) have no disagreeable odour, either wet or dry.  
e) be uniform in colour and trimmed with clean smooth edges.  
f) be eith er a roll (see 4.2) or individually folded (see 4.3), as required by the purchaser  
4.2 Specific  requirements  
4.2.1 The paper towels shall be single - or double -ply, as specified by the purchaser and shall comply with the 
appropriate requirements for physical pr operties as per Table 1. 
Table 1 — Physical requirements for paper for Paper towels . 
Parameter  Requirement  
Test Method  
Single ply  Double ply  
BasisWeight g/m2, min. 43 43 ISO 536.  
Rate of absorption ofwater , s, Max 50a 5a Annex D  
Totalabsorptionof water  %, min.  180 250 Annex C  
Tensile 
strength 
N/m, min.  Wet CD 23 23 
ISO 3781.  
ISO 1924 -2. MD 50 50 
Dry CD 160 160 
MD 350 350 
Softness mN, max  300 300 Annex B  
pH value, permissible range  4.4 - 10.0 4.4 - 10.0 ISO 6588  
aRate of absorption of 0.02 mL  of water.  
C Denotes nominal and minimum values respectively.  
 
  
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 4.2.2 When tested in accordance with Annex E , every sheet of a perforated roll shall be severed along  the 
perforation and the tear shall be manifestly due to the perforation only.  
4.2.3 Paper towels shall be supplied in packets or in rolls or as specified by the purchaser  
4.2.4 When the towels are supplied in rolls, the rolls shall be perforated or unperforated, as  specified by the 
purchaser .The quality of perforations shall compl y with the  requirements of 4.2.2.  
4.2.5 When packets of folded towels are supplied, the folds shall be regular, the edges clean cut,  and 
towels presented in such  a way that they can be taken from a suitable dispensing cabinet  without sticking or 
other undue difficulty.  
4.3 Dimensions  
4.3.1 The length and width of the sheets shall be as specified on the packaging.  
4.3.2 The number of sheets per packet and per perforated roll, shall  
a) unless otherwise specified by the purchaser, be in accordance with acceptable  commercial practice,  
b) not be less than 2 % nor exceed 4 % of the quantity marked on the packet or perforated roll in no  more 
than one sample roll per ten.  
4.3.3  The length of an unperforated roll shall not be less than ± 2% of the length specified by the  purchaser 
and if not specified, then as in accordance with acceptable commercial  practice.  In the case of rolls, the 
quantity of sheets or the roll length (as relevant) shall be such that (unless  the number of sheets or the roll 
length  specified by the pur chaser renders it  impossible) the diameter of a roll does not exceed 125 mm  when 
determined as per annex A . 
5 Packing  
5.1 Wrapping  
5.1.1  Packets  
Single paper towels shall be supplied in packets that, unless a special type of packet as specified by  the 
purchaser are normal to acceptable commercial practice.  
5.1.2  Rolls  
Unless otherwise specified by the purchaser each roll of paper towels shall becompletely covered by a 
wrapper . 
 DRS 377: 2017  
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 5.2 Containers  
Packets and rolls shall be packed in acceptable corrugated board containers or bulk packages  and the 
quantity per container shall be as specified by the purchaser. Only  packets or rolls of the same grade, ply, 
texture, colour (unless packing together of packets of  different colours is required by the purchaser), and 
number and size of she ets (or, in the case of  unperforated rolls, roll width and length) shall be packed together 
in a bulk container.  
6 Labeling  
6.1 Packets and wrappers  
The following information shall appear in legible and indelible marking on each packet and wrapper:  
a) name of the product;  
b) name or trademark of the manufacturer or both;  
c) description of  the product i.e. paper towels ; 
d) number and  size of sheets or roll length as relevant ; 
e) ply of the paper; and  
f) unless the colour is apparent to the purchaser , the colour.  
6.2 Bulk packs  
The fol lowing information shall appear in legible and indelible marking on each bulk container:  
a) information required in terms of 6.1.(a) to 6.1.(e);  
b) colour(s) of the paper towels; and  
c) number of packets or rolls.  
7 Sampling  
Use the sampling procedures given in Table 3 and to determine whether a lot complies with the relevant 
requirement of this draft standard, and deem the samples so taken to represent the lot for the respective 
properties .  
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 Table 3 — Sampling  
 
 
DRS 377: 2017  
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 Annex  A 
(normative)  
 
Determination of Dimensions  
A.1 Conditioning  
Precondition and condition all tissue paper and tissue products under test in accordance with ISO 187, using 
the conditioning atmosphere designated, 23°C ± 1 °C  and 50% ± 2 %  RH, and carry out the tests given in 5.2 
in an atmosphere maintained  at these conditions. Also during conditioning, ensure that test pieces and test 
sheets are laid flat instead of being suspended, as in the latter case their properties to be tested might be 
affected.  
A.2 Dimensions  
Measure, to the nearest 1 mm without stretching the sample, and, when relevant, count the sheets  in each 
packet or roll drawn in accordance with B.2 for compliance with the appropriate  requirements of 4.3. 
Determine the width and length of sheets on two sheets taken at random from  each packet  or roll.  
Record the results of the checks in respect of each requirement.  
 
   
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 Annex  B 
(normative)  
 
Determination of Softness  
B.1 General  
From the sample, cut ten pairs of test specimens.  
B.2 Apparatus  
Suitable instrument , that measures the combination of resistance due t o the surface friction and  flexural 
rigidity of sheet material when forced by a blade through a slot that has parallel edges and a  width of 6,35 
mm, and that has been calibrated in accordance with the manufacturer's instructions. In the case of paper 
towel s, use a slot width of 10 mm.  
B.3 Procedure  
 
Take two test specimens and place one of the specimens centrally over the slot with its machine direction 
parallel to the slot opening.  
Start the blade mechanism.  
Take the maximum reading registered on the gauge.  
Repeat the test on the second test specimen but with the cross direction  parallel to the slot opening.  
Calculation  
Calculate and report to three significant figures the average of all the readings in millinewtons as the softness 
of the paper. Check for co mpliance with Table 1. 
 
Test each pair of specimens in this way, testing the specimens from one sheet from one side and those cut 
from the other sheet from the opposite side of the paper.  
 
 
 
 
 
 
 
 
 
 
 
 DRS 377: 2017  
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 Annex  C 
(normative)  
 
Determination of Total water absorption  
C.1 Test specimens  
From the sample, cut ten test specimens and condition them as per A.1 above..  
C.2 Apparatus  
Balance , that has a sensitivity of 1 mg (or better).  
Drainage strip , that consists of a piece of wet towel -paper of size 3 mm × 40 mm.  
C.3 Procedure  
Determine the mass of a test specimen and submerge it in distilled water for 2 min.  
Remove, press onto one corner of the test specimen a drainage strip so that the longitudinal axis of the strip 
forms a continuation of the diagonal of the test specimen, a nd then suspend the assembly by diagonally 
opposite corner over water in a vessel that has a tight -fitting cover.  
Close the vessel, allow the test specimen to drain for 30 min, then remove it, discard the drainage strip, place 
the test specimen in a tared  weighing bottle, and determine its mass.  
Test each specimen in this way, and from the results.  
 
Calculation  
calculate and record the average total absorption (i.e. the percentage increase in mass based on the original 
dry mass) for each packet/roll and f or the sample.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
©RSB 2017  All rights reserved                  12 
 
 Annex  D 
(normative)  
 
Determination  of Rate of water absorption  
D.1 Test specimens  
From the sample, cut ten test specimens and condition them as per A.1  
Test half of the test specimens from one side of the paper and the other half from the other side.  
D.2 Apparatus  
Water applicator,  that consists of a micrometer syringe or a suitable pipette that can  deliver accurately 0,01 
mL or 0,02 mL  of water  
 
Stopwatch . 
 
D.3 Procedure  
Place a test specimen on the rim of a beaker that has a diameter of approximately 50 mm.  
Fill the syringe with distilled water at 23 °C ± 1 °C  and ensure that trapped air bubbles are removed.  
Hold the syringe at an angle of about 30° to the horizontal with the tip nearly in contact with the paper, and 
allow the required millilitres of water to flow onto the test specimen.  
Keep the tip of the syringe in the drop of water until delivery is compl ete.  
Measure with the stopwatch the rate of absorption, in seconds, from the instant the water touches the test 
specimen until the drop of water is completely absorbed, as indicated by no further reflection of light from it 
when viewed at an angle.  
Carry  out five tests on each side of the paper.  
Calculation  
Calculate and report to three significant figures the average water absorption rate in seconds. Check for 
compliance with Table 1. 
NOTE 2 For paper towels, disposable and paper -towel rolls for centre -feed devices 0,02 mL  of water should be allowed to 
flow onto  the test specimen.  DRS 377: 2017  
13                 ©RSB2017  All rights reserved  
 
 Annex  E 
(normative)  
 
Assessment of  perforation  
E.1 Test specimen  
Use all the perforated rolls drawn in accordance with Table 3  
E.2 Procedure  
At a position chosen at random on the roll under test, detach a sheet by holding it between thumb  and 
forefinger at its perforated end and exerting a steady pull at an angle of about 10° to the edge  of the roll.  
Carry out the test on five consecutive sheets in each roll.  
Examine the torn ends for compliance with 4.2.2.  
 DRS  377: 2017  
ICS 85.080 
 
©RSB 2017 All right s reserved