ISO/PRF 4216

INTERNATIONAL ISO
STANDARD 4216
First edition
Thermosetting resin and UV curable
resin — Determination of shrinkage
by continuous measurement method
PROOF/ÉPREUVE
Reference number
ISO 4216:2021(E)
ISO 2021
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ISO 4216:2021(E)
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© ISO 2021

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Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Principle ........................................................................................................................................................................................................................ 1

5 Test methods and test conditions ....................................................................................................................................................... 3

5.1 Test methods ............................................................................................................................................................................................. 3

5.2 Test conditions ........................................................................................................................................................................................ 3

6 Number of measurements .......................................................................................................................................................................... 3

7 Apparatus ..................................................................................................................................................................................................................... 4

7.1 Apparatus configuration ................................................................................................................................................................. 4

7.2 Sample container .................................................................................................................................................................................. 5

7.3 Displacement gauge (thickness meter) ............................................................................................................................. 6

7.4 UV irradiation device ......................................................................................................................................................................... 6

7.5 Heating/cooling device .................................................................................................................................................................... 6

7.6 Data processing unit ......... .................................................................................................................................................................. 6

8 Curing method ........................................................................................................................................................................................................ 6

8.1 UV curable resin curing method .............................................................................................................................................. 6

8.2 Thermosetting resin curing method .................................................................................................................................... 6

9 Measurement procedure .............................................................................................................................................................................. 6

10 Expression of results ........................................................................................................................................................................................ 7

10.1 Volumetric shrinkage ........................................................................................................................................................................ 7

10.2 Curing shrinkage ................................................................................................................................................................................... 7

11 Test report ................................................................................................................................................................................................................... 8

Annex A (informative) Influencing factors on measurement ..................................................................................................... 9

Annex B (informative) Examples of measurement result ............................................................................................................10

Annex C (informative) Example of measurement report .............................................................................................................13

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This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 12,

Any feedback or questions on this document should be directed to the user’s national standards body. A

The use of resin first requires curing it under specific conditions that vary depending on the product

specification. During this curing process, chemical reactions occur and volatiles evaporate, and so the

resin shrinks. This can cause defects, strength reduction, and the deformation of the finished parts or

The conventional method which measures the shrinkage of resin based on specific gravity requires

long measurement time and an amount of resin about a few cubic centimetres. This sample size is

larger than what is actually used in many applications such as the epoxy encapsulation compounds

for integrated circuits, resin coating or adhesive for electronic devices. In order to improve the quality

control and further promote the technical advancement of high precision production, a convenient and

A totally new measurement method has been developed to meet this demand, allowing to measure

curing shrinkage continuously with just a trace amount of resin. Moreover, since measurements are

taken continuously, the curing behaviour of resin such as thermal expansion and thermal contraction

SAFETY STATEMENT — Persons using this document should be familiar with normal laboratory

practice, if applicable. This document does not purport to address all of the safety concerns, if

any, associated with its use. It is the responsibility of the user to establish appropriate safety

This document specifies the continuous measurement method of shrinkage for thermosetting resin

The following documents are 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.

For the purposes of this document, the terms and definitions given in ISO 472 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

ratio of the change in resin volume due to curing process to the resin volume before curing

Cure the resin inside a sample container and continuously measure the changes of sample thickness.

Since the horizontal cross-sectional area of resin sample remains constant due to the sidewalls of

the sample container, the changes in sample volume are proportional to the changes in the sample

thickness. Therefore, shrinkage of resin is calculated from the changes in sample thickness, as shown in

In addition to the determination of the curing shrinkage, this continuous measurement technique

also allows to see the volumetric changing behaviour of a resin at the time it is being irradiated by UV,

NOTE 1 Typically, upon irradiation by UV rays, UV curable resins expand immediately then contract as curing

proceeds (see Figure 1). However, some types of UV curable resin exhibit fast reactions wherein shrinkage starts

NOTE 2 When a thermosetting resin undergoes heating, thermal expansion occurs due to the increase in the

resin temperature. This expansion continues as the temperature rises. When the curing temperature is reached,

the curing begins and the resin starts to contract. This shrinkage continues until the resin is fully cured and

The test methods are classified according to the curing conditions applied to the resin. There are

three different types of curing condition: UV curing, thermal curing, and a combination of UV and

Conduct measurements in the standard laboratory atmosphere of 23 °C ± 2 °C (73,4 °F ± 3,6 °F) and

50 % ± 5 % relative humidity, unless otherwise specified in the experiment conditions.

An apparatus for measuring the curing shrinkage of resin by this method is a system that consists of

different units. Primarily, it includes a sample container, displacement gauge, UV irradiation device,

heating/cooling device, etc. Figure 3 shows an example of an apparatus configuration compatible with

a UV curable resin, and Figure 4 shows an example of an apparatus configuration corresponding to a

A sample container of accurately known volume and dimensions shall be used. To ensure an accurate

measurement, container material should be used which does not cause either the detachment of resin

from the bottom after curing or absorb the sample via the wall surfaces. Moreover, in order to calculate

easily the container capacity/volume, the sample container should have a smooth bottom surface and