DRAFT UGANDA STANDARD  
  DUS 2239  
First  Edition  
2020 -02-03 
 
 
 Reference number  
DUS 2239 : 2020 
© UNBS 2020   
  
Plastic Closures — Specification  
 DUS 2239 : 2020   
ii © UNBS 2020  – 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. Users are 
responsible for its correct applica tion 
© UNBS 2020   
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 microfilm, 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 4 333 2 50/1/2/3  
Fax: +256 41 4 286 123  
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  DUS 2239 :2020  
© UNBS 2020  – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 Classification of plasti c closures  ................................ ................................ ................................ ........  2 
5 Raw materials  ................................ ................................ ................................ ................................ ........  5 
6 Geometrical and dimensional accuracy ................................ ................................ ..............................  6 
7 Application torque  ................................ ................................ ................................ ................................ . 8 
8 Finish  ................................ ................................ ................................ ................................ ......................  9 
9 Marking  ................................ ................................ ................................ ................................ ...................  9 
10 Storage  ................................ ................................ ................................ ................................ ...................  9 
Annex  A (informative)  Examples of typical plastic closures  ................................ ................................ ...... 10 
A.1 Example for typical carbonated soft drink cap  ................................ ................................ ................  10 
A.2 Example for typical still product cap  ................................ ................................ ................................ . 11 
A.3 Example for typical Hotfill cap  ................................ ................................ ................................ ...........  12 
 DUS 2239 : 2020   
iv © UNBS 2020  – All rights reserved  
 Foreword  
Uganda National Bureau of Standa rds (UNBS) is a parastatal under the Ministry of Trade , Industry and 
Cooperatives established under Cap 327 , of the Laws of Uganda , as amended .  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  Agreement  of the World Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out throu gh Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of key stakeholders 
including government, academia, consumer groups, private sector and other interested parties.  
Draft Uganda S tandards 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 Nation al Standards Council.  
The committee responsible for this document is Technical Committee UNBS /TC 19, Packaging and packaging 
products . DUS 2239 :2020  
© UNBS 2020  – All rights reserved  v 
 Introduction  
The raw material used for packaging in beverage machinery industry is critical for the efficiency of the 
packaging lines and the quality of the product.  
This Uganda standard is developed to:  
a) give manufacturer and users a reference tool to help them carry out the operation s  
b) determine the specification of each of the elements and the relevant interfaces  
c) give all  actors in this business sector a reference document for the establishment of technical 
documents and quality control procedures  
d) facilitate diagnosis in case of malfunctions  DRAFT UGANDA STANDARD  DUS 2239 : 2020  
 
© UNBS 2020  – All rights reserved  1 
 Plastic closures  — Specification  
1 Scope  
This Uganda standard covers g eometrical and dimensional accuracy , physical properties , storage and 
handling conditions , processing and application  of plastic closures for sealing of still product, carbonated 
drinks and hot fill.  
2 Normative references  
The following referenced documents referred to in the text in such a way that some or all of their content 
constitutes requirements 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.   
US 1659, Materials in contact with food - Requirements for packaging materials  
3 Terms and definitions   
No terms and definitions are listed in this document.  
ISO and IEC maintain terminological databases for use in standardization at the follow ing addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
3.1  
cap 
closure used to seal a bottle  
3.2  
application torque  
torque force measured in Nm required to screw a closure onto a contain er 
3.3  
removal torque  
torque force measured in Nm required to unscrew a closure from a container  
3.4  
one piece  cap 
Cap without a liner  
3.5  
two piece  cap 
Cap with a liner  
3.6  
liner 
Disc of paper, cork, foam, plastic etc. retained in a closure to provide  a flexible barrier between a closure and 
the sealing surface of the container  DUS 2239 : 2020   
2 © UNBS 2020  – All rights reserved  
 3.7  
tamper -evident band  
band at the bottom of the closure that breaks away and stays on the neck finish the first time the cap is 
removed from the bottle.  
4 Classification of p lastic closures  
4.1 Depending on the filled product  i.e. still product, carbonated drinks and hot fill , plastic closures are 
classified as follows ; 
a) flat cap (one piece) , 
b) flat cap (two piece) ,and 
c) sport caps  DUS 2239 : 2020  
© UNBS 2020  – All rights reserved  3 
 d)  
a) Flat cap (one piece)  b) Flat cap (two 
piece)  c) Sport caps  
 
 
 
Figure 1 — Typical plastic closures in each class  
4.2 Tamper evident bands are classified as follows depending on their  design  
a) Slitted  
A straight band that is created by cutting a thin interrupted slit in the skirt of  the cap during production.  
 
b) Moulded  
A band that is formed by a gap that was moulded in the skirt of the cap and held to the closures by moulded 
bridges.  
 
c) Straight band  
A band that has the same diameter as the rest of the closure.  
 
d) Offset band  
A band th at has a greater diameter than the rest of the closure.  DUS 2239 : 2020   
4 © UNBS 2020  – All rights reserved  
 
 
e) Recessed  
A band that has a smaller diameter than the rest of the closure.  
 
f) Ratcheted band  
An offset moulded band that features hooks on the inside that fits in grooves on the bead at the base of th e 
neck of the bottle. The system is designed so that the band can move freely when screwing the closure but 
will be blocked when unscrewing the cap, breaking the band.  
 
g) Beaded band  
A band that has a continuous bead moulded inside of it to hold it on the b ottle’s neck once the band has been 
broken.  
 
h) Hooked band  
A band that has an interrupted bead moulded inside of it to hold it on the bottle’s neck once the band has 
been broken.  DUS 2239 : 2020  
© UNBS 2020  – All rights reserved  5 
 
 
i) Folded band  
A band that is folded inward to form its retaining feature.  
 
j) Tear band  
A band that needs to be torn off prior to removing the closure. It typically features a pull tab and a tear line to 
facilitate its removal.  
 
Note:  Every cap is considered as part of a system consisting of  cap, bottle / neck  and product and its des igned for a 
specific bottle neck.  
5 Raw materials  
5.1 Plastic closures shall be made from polyethylene or polypropylene, which conform to the requirements 
of US  1659.  
5.2 Additives such as colorants and a nti-stat maybe added to the material in such proport ions that do not 
affect the performance and safety of the closures.  
5.3 Plastic closures may be provided with either peelable (adhesive) or non -peelable (cohesive) liners.  DUS 2239 : 2020   
6 © UNBS 2020  – All rights reserved  
 6 Geometrical and dimensional accuracy  
Tolerances of the following dimensions given in figure 3 shall be as indicated in Table 1.DRAFT UGANDA STANDARD  DUS 2239 : 2020  
 
© UNBS 2020  – All rights reserved  7 
 Outside diameter (D and d)  Inner Diameter (Di)  Overall Height (H)  
 
 
 
Figure 2 — Dimensions of plastic closures  DRAFT UGANDA STANDARD  DUS 2239 : 2020  
 
© UNBS 2020  – All rights reserved  8 
 Criteria  Symbol  Unit  Tolerance  
Top knurl Diameter  D  mm  ±0.30 
Inner plug Diameter  Di  mm  ±0.15  
Overall Height  H  mm  ±0.30 
Ovality  O  mm   
Height of centre of gravity  Hs  mm   
Size of protrusion sprue  A  mm   
Number of knurls  nK  #   
Number of threads  nT  #   
Number of temper band bridges  nB  #   
Full Thread extension angle  at  °   
Thread pitch  mm   
Weight  W  g   
Ambient temperature  (aT)  °C   
Shelf life time  (sT)  months   
Application angle  aa  °   
Capping top load  ctl  N   
Application torque  at  Nmm    
Removal torque after applicati on 
(zero hours)  rt0  Nmm   
Removal torque after 1 hour  rt1  Nmm   
Removal torque after 24 hrs  rt24  Nmm   
Temper band breaking removal 
torque  BT  Nmm   
Temper band breaking strength  BS  N   
7 Application torque  
Application torque of plastic closures s hall be as given in Table 2 below  
Table 2—Application torque values  
Closure size  
mm Application torque  
Nm 
15 0.68-2.04 
20 0.90-2.72 
24 1.13-4.06 
28 1.36-4.52 
29 1.47-4.60 
33 1.69-5.64 
38 1.92-5.64 
48 2.15-6.40 DUS 2239 : 2020  
© UNBS 2020  – All rights reserved  9 
 Note  Immediate removal torque (IRT) i s approximately 50% of the application torque value  
8 Finish  
There shall be no moulding burrs protruding beyond the geometry of the closure or other protruding non -
specified sprues.  
9 Marking  
9.1 Plastic closures shall be legibly and indelibly marked with manufacturer’s name and/or trademark.  
9.2 The bulk package shall be labelled with the following information : 
a) manufacturer’s name and/or trademark  and physical address ; 
b) batch number ; 
c) country of origin ; 
d) grammage of the caps;  
e) closure size in milimeters ; and  
f) date of manufacture  
10 Storage  
10.1 To ensure optimal performance, the following shall be followed during storage and handling of plastic 
closures.  
10.1.1 Plastic closures shall be stored in dust -free low humidity conditions.  
10.1.2 Direct UV radiation, ext raneous odours or taints shall be avoided during storage of plastic closures.  DUS 2239 : 2020   
10 © UNBS 2020  – All rights reserved  
 Annex  A 
(informative)  
 
Examples of typical plastic closures  
A.1 Example for typical carbonated soft drink  cap 
 Dimension 
name  Symbol  
 Top knurl 
diameter  D 
External sealing 
diameter  De 
Inner plug 
diameter  Di 
Outer max 
diameter  D out max  
Height  H 
Slitting height  Hs 
Top panel 
thickness  t 
 DUS 2239 : 2020  
© UNBS 2020  – All rights reserved  11 
 A.2 Example for typical still product cap  
 Dimension 
name  Symbol  
 Top knurl 
diameter  D 
External sealing 
diameter  De 
Inner plu g 
diameter  Di 
Outer max 
diameter  D out max  
Height  H 
Slitting height  Hs 
Top panel 
thickness  t 
 DUS 2239 : 2020   
12 © UNBS 2020  – All rights reserved  
 A.3 Example for typical Hotfill cap  
 Dimension 
name  Symbol  
 Top knurl 
diameter  D 
External sealing 
diameter  De 
Inner plug 
diameter  Di 
Outer max 
diameter  D out max  
Height  H 
Slitting height  Hs 
Top panel 
thickness  t 
 
 DUS 2239 : 2020  
© UNBS 2020  – All rights reserved  13 
 Certification marking  
Products that conform to Uganda standards may be marked with Uganda National Bureau of Standards 
(UNBS) Certification Mark shown in the figure below.  
The u se 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 operated 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 system 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 and conditions of licensing may be obtained from the Director, Ugand a 
National Bureau of Standards.  
 
 DUS 2239 : 2020    
 
ICS 55.10  
Price based on nn pages  
© UNBS 2020 – All rights reserved