ISO 12418-2:2012

INTERNATIONAL ISO
STANDARD 12418-2
First edition
2012-09-01
Plastics — Post-consumer poly(ethylene
terephthalate) (PET) bottle recyclates —
Part 2:
Preparation of test specimens and
determination of properties
Plastiques — Recyclats de bouteilles en poly(téréphtalate d’éthylène)
(PET) post-consommation —
Partie 2: Préparation des éprouvettes et détermination des propriétés
Reference number
©
ISO 2012
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ii © ISO 2012 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Characterization of PET recyclates . 1
4.1 Classification of characteristics . 1
4.2 Test methods . 1
Annex A (normative) Method for the determination of impurities in PET flakes . 3
Annex B (normative) Method for the determination of the bulk density of PET flakes . 5
Annex C (informative) Method for the determination of the melt volume-flow rate (MVR) of
PET recyclates . 7
Annex D (informative) Potentiometric method for the determination of the residual alkalinity of
PET recyclates . 9
Bibliography . 11
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.
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 12418-2 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9, Thermoplastic
materials.
ISO 12418 consists of the following parts, under the general title Plastics — Post-consumer poly(ethylene
terephthalate) (PET) bottle recyclates:
— Part 1: Designation system and basis for specifications
— Part 2: Preparation of test specimens and determination of properties
iv © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 12418-2:2012(E)
Plastics — Post-consumer poly(ethylene terephthalate) (PET)
bottle recyclates —
Part 2:
Preparation of test specimens and determination of properties
1 Scope
This part of ISO 12418 specifies the test methods to be used in determining the properties of post-consumer
poly(ethylene terephthalate) (PET) bottle recyclates.
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 472, Plastics — Vocabulary
ISO 1628-1, Plastics — Determination of the viscosity of polymers in dilute solution using capillary viscometers —
Part 1: General principles
ISO 1628-5, Plastics — Determination of the viscosity of polymers in dilute solution using capillary viscometers —
Part 5: Thermoplastic polyester (TP) homopolymers and copolymers
ISO 15270, Plastics — Guidelines for the recovery and recycling of plastics waste
ISO 15512:2008, Plastics — Determination of water content
EN 15348:2007, Plastics — Recycled plastics — Characterization of poly(ethylene terephthalate) (PET) recyclates
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472 and ISO 15270 apply.
4 Characterization of PET recyclates
4.1 Classification of characteristics
The characteristics of PET recyclates are classified into two types, given in Table 1, as follows:
— those which are required for all recyclates (i.e. mandatory characteristics);
— customer specifications (these are optional).
4.2 Test methods
The characteristics shall be determined using the test methods given in Table 1. A certificate of analysis,
including the test results for each batch of recyclate, the sampling method and the number of replicates, shall
be provided by the supplier to the purchaser on request.
NOTE The sampling method and the number of replicates are important in determining the quality of the material.
Quality levels can vary within the batch and from batch to batch, depending on the source of the recyclate.
Table 1 — Characterization of PET recyclates
Characteristics Unit Test method Notes
Mandatory items
Form Visual examination Flakes, pellets or powder
Colour Visual examination Natural or coloured
Maximum flake size mm Determined by the size of the screen
in the grinder
Maximum pellet size mm Determined by the die opening of
the pelletizer and measured by ruler
or callipers
Intrinsic viscosity (IV) dl/g ISO 1628-5 in combination Solvent shall be a mixture of phenol
with ISO 1628-1 and 1,1,2,2-tetrachloroethane (6:4)
(including its Amendment
ISO 1628-1:2009/Amd 1)
Contamination due to labels mg/kg Annex A Only for flakes
and other visible contaminants
Contamination due to mg/kg Annex A Only for flakes
poly(vinyl chloride)
Contamination due to poly- mg/kg Annex A Only for flakes
olefins, and including adhesive
Water content % ISO 15512:2008, method B
Bulk density kg/m Annex B
Optional items
Melt volume-flow rate (MVR) cm /10 min Annex C
Alkalinity pH Annex D Only for flakes
Filterability 10 MPa/h/cm EN 15348:2007, Annex F
Other tests may be carried out by agreement between the purchaser and the supplier. If they are, the results
of such tests shall be reported.
2 © ISO 2012 – All rights reserved

Annex A
(normative)
Method for the determination of impurities in PET flakes
A.1 General
This annex specifies a method for the determination of the content of the following impurities in flakes of
PET recyclates:
— pieces of label and other visible contaminants;
— poly (vinyl chloride) (PVC);
— polyolefins (POs), and including adhesive.
A.2 Principle
A weighed test portion of the recyclate is spread evenly over the bottom of a shallow tray.
The pieces of label and other visible contaminants are picked out using tweezers and weighed. The test
portion, still in the tray, is then placed in a forced air circulation oven at 220 °C for 1 h.
During this heat treatment, the PVC in the test portion becomes discoloured and can be detected visually. The
polyolefins in the test portion melt and turn yellow. The adhesive is also yellowed and might be indistinguishable
from the polyolefins.
A.3 Apparatus
A.3.1 Oven, with forced air circulation, capable of being maintained at 220 °C.
A.3.2 Technical balance, capable of weighing to the nearest 0,1 g.
A.3.3 Analytical balance, capable of weighing to the nearest 0,000 1 g.
A.3.4 Spatula, made of wood or metal.
A.3.5 Tweezers.
A.3.6 Tray, made of aluminium or enamelled ironware, with a bottom of surface area not less than 0,05 m .
A.4 Procedure
Weigh out, to the nearest 0,1 g, approximately 100 g of flakes and record the mass (m ). Spread the flakes
evenly over the bottom of the metal tray.
Stir the flakes slowly in the tray with a spatula and pick out the pieces of label and other visible contaminants
using tweezers. Continue this procedure for not less than 30 min. Weigh the pieces of label and other visible
contaminants picked out (m ), using an analytical balance.
Put the tray containing the remaining material into an oven, preheated to 220 °C, and leave it at that temperature
for 1 h. Remove the tray, allow to cool and inspect the material for not less than 30 min, as follows:
a) Pick out the black carbonized particles (PVC). Weigh the particles picked out (m ), using an analytical balance.
b) Pick out the yellowish particles (POs and adhesive). If they are stuck to PET flakes, separate them. Weigh
the particles picked out (m ), using an analytical balance.
A.5 Expression of results
A.5.1 The content of label and other visible contaminants, expressed in mg/kg, is given by the following formula:
m ×10
Content of label and other visible contaminants = (A.1)
m
where
m is the mass of label and other visible contaminants, in g;
m is the initial mass of the test portion, in g.
A.5.2 The PVC content, expressed in mg/kg, is given by the following formula:
m ×10
PVC content = (A.2)
m
where
m is the mass of the discoloured (black) particles, in g;
m is the initial mass of the test portion, in g.
A.5.3 The PO content (which will include any adhesive present), expressed in mg/kg, is given by the
following formula:
m ×10
PO content = (A.3)
m
where
m is the mass of the yellowish particles, in g;
m is the initial mass of the test portion, in g.
...