ISO/TR 19032:2006
(Main)Plastics — Use of polyethylene reference specimens (PERS) for monitoring laboratory and outdoor weathering conditions
Plastics — Use of polyethylene reference specimens (PERS) for monitoring laboratory and outdoor weathering conditions
ISO/TR 19032:2006 describes a method that demonstrates the use of polyethylene reference specimens (PERS) for monitoring laboratory and outdoor conditions in weathering tests used for plastics.
Plastiques — Utilisation d'éprouvettes de référence en polyéthylène pour l'évaluation des conditions de vieillissement climatique
General Information
Relations
Standards Content (Sample)
TECHNICAL ISO/TR
REPORT 19032
First edition
2006-10-01
Plastics — Use of polyethylene reference
specimens (PERS) for monitoring
laboratory and outdoor weathering
conditions
Plastiques — Utilisation d'éprouvettes de référence en polyéthylène
pour l'évaluation des conditions de vieillissement climatique
Reference number
ISO/TR 19032:2006(E)
©
ISO 2006
---------------------- Page: 1 ----------------------
ISO/TR 19032:2006(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2006
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 permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2006 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/TR 19032:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope.1
2 Background information .1
3 Material.1
3.1 Preparation of PERS.1
4 Procedure.2
4.1 Method for measuring the carbonyl index of PERS.2
4.2 Round Robin Test of laboratory light-source exposure devices with PERS .3
4.2.1 Xenon-arc-lamp exposure.3
4.2.2 Open-flame carbon-arc-lamp exposure.3
4.2.3 Fluorescence lamp exposure.4
4.3 Outdoor exposure test of PERS.4
4.4 Consistency of laboratory light-source exposure devices .5
5 Results and discussion.6
5.1 Result of RRT of laboratory light-source exposure devices with PERS.6
5.1.1 Xenon-arc-lamp exposure.6
5.1.2 Open-flame carbon-arc-lamp exposure.10
5.1.3 Fluorescent lamp exposure.10
5.2 Characterizing the conditions of outdoor exposure test site .11
5.3 Examples of correlation between outdoor exposure test and laboratory light-source
exposure test using PERS.12
5.4 Control limit of particular laboratory light-source exposure apparatus.13
6 Conclusion.14
6.1 Results of RRT .14
6.2 Outdoor exposure of PERS .15
6.3 Correlation between outdoor and xenon-arc-lamp exposure for PERS .15
6.4 Consistency of laboratory light-source exposure devices .15
Bibliography .16
© ISO 2006 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/TR 19032:2006(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
In exceptional circumstances, when a technical committee has collected data of a different kind from that
which is normally published as an International Standard (“state of the art”, for example), it may decide by a
simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely
informative in nature and does not have to be reviewed until the data it provides are considered to be no
longer valid or useful.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/TR 19032 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 6, Ageing,
chemical and environmental resistance.
iv © ISO 2006 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/TR 19032:2006(E)
Introduction
The method described in this Technical Report demonstrates the use of polyethylene reference specimens
(hereafter called PERS) for monitoring conditions in weathering tests used for plastics. The PERS has double
bonds in its molecular structure, which are easily oxidized to produce carbonyl groups. The change in
carbonyl index of PERS is produced by the combined effects of ultraviolet (UV) and temperature. Therefore,
the carbonyl groups proportionally increase, depending on the received UV and temperature. Based on this
relationship, the effect of UV radiation and temperature on PERS can be expressed quantitatively. For
laboratory-accelerated exposures, PERS is also sensitive to changes in the chamber air temperature. The
effect of moisture was not determined in the study.
© ISO 2006 – All rights reserved v
---------------------- Page: 5 ----------------------
TECHNICAL REPORT ISO/TR 19032:2006(E)
Plastics — Use of polyethylene reference specimens (PERS) for
monitoring laboratory and outdoor weathering conditions
1 Scope
This Technical Report describes a method that demonstrates the use of polyethylene reference specimens
(PERS) for monitoring laboratory and outdoor conditions in weathering tests used for plastics.
2 Background information
Degradation of plastics in an outdoor environment is mainly influenced by the ultraviolet radiation received,
environmental temperature, moisture, etc. Especially in photo-oxidation induced from ultraviolet radiation,
temperature plays a very important role. Measuring the ultraviolet radiation during the exposure period is
useful for comparison of the result of the exposure test, but it is not enough to compare the exposure results.
Therefore, it is very important to find some index that can be used to evaluate the complex effect of received
ultraviolet radiation and environmental temperature. The PERS is used to characterize the level of combined
effect of ultraviolet radiation and temperature, and its characteristic proportionally increases depending on the
UV radiation and temperature received.
3 Material
PERS is high-density polyethylene polymerized using molybdenum dioxide as a catalyst, containing the trans-
form vinylene group. Other basic properties are as follows:
⎯ absorbance ratio of trans-form vinylene group to methylene group: 1,0 to 1,3;
⎯ melt flow rate (2,16 kg, 190 °C): 0,2 to 0,4 g/10 min;
3
⎯ density: 950 to 965 kg/m ;
⎯ thickness: (0,2 ± 0,02) mm.
3.1 Preparation of PERS
After kneading for 5 min the material between two rolls whose surfaces are heated at 150 °C to 170 °C, cut
into small pieces of 0,4 g to 0,5 g.
After pre-heating for 90 s in a compression moulding machine whose surface is heated at 160 °C to 180 °C,
compress the material for 60 s, cool in a compression moulding machine whose surface temperature is 30 °C
to 40 °C, for 60 s, and prepare the press sheet of the thickness mentioned above.
NOTE PERS can be obtained from the following organization:
Japan Weathering Test Center
1-3-7 Shibakoen Minatoku Tokyo Japan
© ISO 2006 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO/TR 19032:2006(E)
4 Procedure
4.1 Method for measuring the carbonyl index of PERS
An infrared (IR) spectrophotometer should be used as the measuring apparatus.
–1 –1
Measure the infrared absorption spectra after irradiation, in the range of 2 200 cm to 1 600 cm . In this
case, use for the scanning speed the same method as for a quantitative analysis.
The carbonyl index is determined in accordance with the following equation, based upon infrared absorbance
–1
spectra of exposed PERS. Absorbance at near 2 020 cm peak is employed as an internal standard to
–1
correct for sample film thickness, while absorbance at near 1 715 cm peak is used to indicate carbonyl
group content. A typical diagram of IR absorbance is shown in Figure 1.
A
1715
A =
r
A
2020
where
A is the absorbance ratio (carbonyl index);
r
–1
A is the absorbance at near 1 715 cm (I − I );
1 715 0
–1
A is the absorbance at near 2 020 cm (I − I );
2 020 0
I is the absorbance measured by the base-line method at individual wave number;
0
I is the absorbance at the peak of individual wave number.
Key
Y absorbance
−1
X wavenumber (cm )
−1
1 peak near 2 020 cm
−1
2 peak near 1 715 cm
Figure 1 — IR absorbance diagram showing base line and peak absorbance
2 © ISO 2006 – All rights reserved
---------------------- Page: 7 ----------------------
ISO/TR 19032:2006(E)
4.2 Round Robin Test of laboratory light-source exposure devices with PERS
It is well known that the degradation of plastics materials or products used outdoors will occur by the
combined effect of ultraviolet radiation and temperature, or other factors. It is also recognized that the
reproducibility in the laboratory light-source exposure test will vary with the change in ultraviolet spectrum
distributions and the chamber temperatures caused by deterioration of lamps and filters with operating time,
even if ultraviolet radiation and black standard temperature (BST) or black panel temperature (BPT) are under
constant conditions.
Since the PERS can quantitatively evaluate, as carbonyl index, the combined effect of UV radiation and
temperature, the carbonyl index obtained can reflect changes in a given environment.
In order to verify the repeatability and reproducibility of the specimens and exposure test, the Round Robin
Test (hereafter called RRT) using the PERS by laboratory light-source exposure devices in
ISO/TC 61/SC 6/WG 2 was conducted.
4.2.1 Xenon-arc-lamp exposure
[1]
The test conditions were according to ISO 4892-2 . The conditions are shown in Table 1. It was not
requested to control the chamber temperature, but participants were requested to report this temperature.
Each participant was provided with 4 sets of PERS that were mounted in 150 mm × 70 mm plastics holders.
One set of holders consists of 3 pieces of PERS.
Table 1 — Exposure conditions for xenon-arc lamp
Filter daylight filter
2 2
Irradiance
0,5 W/(m⋅nm) at 340 nm or 60 W/m (300 to 400 nm)
BST or BPT
(65 ± 3) °C for BST or (63 ± 3) °C for BPT
Chamber temperature Arbitrary
Water spray 102 min of light only followed by 18 min of light plus water spray
Humidity (50 ± 5) %
Period 24 h, 48 h, 72 h and 96 h
4.2.2 Open-flame carbon-arc-lamp exposure
[2]
The test conditions were according to ISO 4892-4 . The conditions are shown in Table 2. The chamber
temperature was not specified, but participants were requested to report this temperature.
Each participant was provided with 4 sets of PERS that were mounted in 150 mm × 70 mm plastics holders.
One set of holders consists of 3 pieces of PERS.
Table 2 — Exposure conditions for open-flame carbon-arc lamp
Filter Type 1 (Type 1 known as Corex 7058 filter)
BST or BPT
(65 ± 3) °C for BST or (63 ± 3) °C for BPT
Chamber temperature Arbitrary
Water spray 102 min light only followed by 18 min of light plus water spray
Humidity (50 ± 5) %
Period 24 h, 48 h, 72 h and 96 h
© ISO 2006 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO/TR 19032:2006(E)
4.2.3 Fluorescence lamp exposure
[3]
The test conditions were according to ISO 4892-3 . The conditions are shown in Table 3. Irradiance was not
specified at any intensity.
Each participant was provided with 4 sets of PERS that were mounted in 150 mm × 70 mm plastics holders.
One set of holders consists of 3 pieces of PERS.
Table 3 — Exposure conditions for fluorescent lamp
Lamp type UVA340
Irradiance Arbitrary
Mode Mode 1: 4 h of dry UV exposure followed by 4 h of condensation
BPT (63 ± 3) °C at UV exposure and (50 ± 3) °C at condensation
Period 8 h, 24 h, 32 h and 48 h
After each sample had been exposed for each exposure period, the carbonyl index was determined, based
upon the method described in 4.1.
4.3 Outdoor exposure test of PERS
The result of the outdoor exposure test varies, even if it is conducted in the same place, because of
differences due the seasonal climate changes. Although it is useful to measure the amount of ultraviolet
radiation for comparison of exposure tests, it is not enough in the comparison only to consider the amount of
ultraviolet radiation, because plastics are influenced not only by ultraviolet radiation but by temperature or by
moisture. Since PERS is influenced by the combined effect of ultraviolet radiation and temperature, PERS
were exposed in various places where the climate was different.
Six locations in different climates and different countries were selected: Sapporo, Choshi, Miyakojima (Japan),
Serpong, Bandung (Indonesia) and Phoenix (USA). Locations and exposure angles are shown in Table 4.
Table 4 — Locations and exposure angles
Exposure site Exposure angle Latitude
Sapporo (Japan) 45° South 43° 03' N
Choshi (Japan) 30° South 35° 43' N
Miyakojima (Japan) 20° South 24° 44' N
a
Serpong (Indonesia) 6° 15' S
5° South and north
Phoenix (USA) 34° South 33° 54' N
a
From November to February, the samples face south; and from March to October, they face north.
4 © ISO 2006 – All rights reserved
---------------------- Page: 9 ----------------------
ISO/TR 19032:2006(E)
[4]
The conditions of the outdoor exposure test are based on ISO 877 . Three pieces of PERS were exposed
for 1 month. By replacing exposed PERS with new ones, the exposure test was repeated in the following
months successively. The exposure test was repeated successively for more than 24 months.
The practical procedure of the outdoor exposure test is shown below.
1) The conditions of the outdoor exposure test are based on ISO 877.
2) Prepare a minimum of three PERS and expose them for 1 month. It is desirable to expose them at the
beginning of a calendar month, in order to evaluate the condition of the month.
3) By replacing exposed PERSs with new ones, the exposure test is repeated in the following months
successively.
4) The exposure test is repeated successively for at least 12 months.
5) The accumulated value of the carbonyl index for each month will be adopted for the index of combined
effect of UV radiation and temperature at the site of exposure.
4.4 Consistency of laboratory light-source exposure devices
It is recognized that changes in the characteristics of lamps and filters with time, and changes in the chamber
temperature of laboratory light-source exposure devices, influence the reproducibility and repeatability of test
results, even if the test is operated under constant conditions of ultraviolet radiation and BST or BPT.
Since the carbonyl index of a polyethylene reference specimen is proportional to the environment where
ultraviolet radiation and temperature are compounded, consistency of the exposure environment could be
monitored with this reference material.
In order to verify the correct operation of a particular xenon-arc-lamp device, the control limit was determined
by PERS.
The test conditions were according to ISO 4892-2. For different operating times of lamp and filters, exposure
was repeated three times.
The practical procedure was carried out as follows.
1) The conditions of the laboratory light-source exposure test are based on ISO 4892.
2) PERS should be irradiated for about 100 h. The number of PERSs should not be less than three.
3) Carbonyl indices are measured after removal from exposure.
4) Repeat 1) to 3), at three different times.
5) Calculate the standard deviation “S” of each exposure.
6) Calculate the repeatability standard deviation “S ”.
r
2
S
∑
S =
r
3
7) Calculate the control limit “CL” of this apparatus.
CL = total average value ± (2 × S )
r
© ISO 2006 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO/TR 19032:2006(E)
5 Results and discussion
5.1 Result of RRT of laboratory light-source exposure devices with PERS
5.1.1 Xenon-arc-lamp exposure
Fourteen devices from thirteen organizations of five nations, Japan, the USA, Germany, Switzerland, and
France, participated.
The test results are shown in Table 5.
Table 5 — Results of the round-robin test of xenon-arc-lamp
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.