Flexural Analysis of High-Density Polyethylene as a

Shipbuilding Materials

Kharis Abdullah

, I Putu Arta Wibawa, Sumardiono, Abdul Gafur, Eriek Wahyu Restu Widodo

and Zaini Aris Musthofa

Shipbuilding Institute of Polytechnics Surabaya, Surabaya, Indonesia

Keywords: HDPE, Ship, Flexural Strength.

Abstract: Ships are transportation at sea for the community which made from materials, such as wood, steel, and others.

Along with the development of technology, the use of durable and recyclable materials has become a new

concern so that other alternative materials are still needed as the basic materials for shipbuilding. HDPE can

be used as an alternative material due to its characteristics of durability and recyclable. It was necessary to

know in advance the mechanical properties of HDPE due to its strength. One of its mechanical properties is

the flexural strength. Therefore, research was conducted on the analysis of the mechanical properties of HDPE

through flexural strength testing. This research was conducted to determine the flexural strength and flexural

modulus of the three brands of HDPE to be applied as a basic material for shipbuilding by referring to the

Turk Loydu acceptability standard. The HDPE material is processed into test specimens and flexural strength

testing was carried out. The analysis data obtained in the form of flexural strength and flexural modulus of

HDPE AGRU of 24.44 and 372.35 MPa, local HDPE of 58.16 and 648.54 MPa, and HDPE ROCHLING of

61 and 650.15 MPa. Based on the analysis, it can be concluded that HDPE ROCHLING had the greatest

strength and flexural modulus. Meanwhile, HDPE that could be used as the basic material for shipbuilding

based on flexural strength, namely local HDPE and ROCHLING HDPE.

1 INTRODUCTION

Ships are a common transportation which used by the

community for inter-island goods distribution

activities and fishing at sea. The materials that are

usually used in shipbuilding, such as wood, steel,

aluminium, fiberglass. Nowadays, 90% of fishing

boats in Indonesia were made from wood (Huwae and

Santoso, 2016). Along with the development of

technology, the use of materials that are durable,

environmentally friendly, and recyclable has become

a new concern for society. The ships production

might be used for a long period of time. Therefore,

other alternative materials are still needed that could

be applied as basic materials for shipbuilding.

HDPE (high density polyethylene) could be an

alternative base material for shipbuilding due to its

characteristics, the durability against aging and

corrosion, and recyclable (Siswandi, 2016). Used-

HDPE’s ships would not become waste because it

https://orcid.org/0000-0001-7859-4783

https://orcid.org/0000-0002-4424-0351

recyclable into other derivative products. Therefore,

shipbuilding which made from HDPE has begun to be

widely implemented.

Of course, before being applied as a structural

material for ships, it is necessary to know in advance

about the characteristics of HDPE. One of the

characteristics that need to be known is the resistance

of the material to deformation due to loading or the

influence of perpendicular forces. Regarding the level

of material resistance due to loading, it is closely

related to the flexural strength of a material. The

flexural strength of HDPE material can be revealed

through a destructive test, namely a bending test.

The flexural strength testing of a material is the

best way to determine the strength and ductility of a

material. In this test, the upper cross section of the test

specimen will experience compressive stress due to

loading and the back will experience tensile stress

(Siswanto, 2021). Therefore, to determine the flexural

strength of HDPE and determine whether the material

Abdullah, K., Arta Wibawa, I., Sumardiono, ., Gafur, A., Restu Widodo, E. and Aris Musthofa, Z.

Flexural Analysis of High-Density Polyethylene as a Shipbuilding Materials.

DOI: 10.5220/0011769500003575

In Proceedings of the 5th International Conference on Applied Science and Technology on Engineering Science (iCAST-ES 2022), pages 331-333

ISBN: 978-989-758-619-4; ISSN: 2975-8246

331

can be applied as a basic material for shipbuilding, the

authors make a solution by testing the flexural

strength to reveal the mechanical properties of HDPE

material.

2 EXPERIMENTS

The material which used in this research was HDPE

sheets with three different brands (HDPE AGRU,

Local, ROCHLING). The manufacture of test

specimens is carried out through stages, making

moulds, attaching the mould to the material, forming

and cutting, re-checking dimensions, cleaning, and

coding the test specimens. The mould was attached to

the material whose dimensions have been designed

according to the ASTM D-790 standard. The

dimensions of the test specimens that have been

regulated in ASTM D-790 for material thickness over

3.2 mm are 127 mm x 12.7 mm x 3.2 mm (ASTM,

2003). The shape of the test specimen has also been

adjusted to the ASTM D-790 standard can be seen in

Figure 1 below:

Figure 1: Testing specimen according of ASTM D-790.

After the test specimen was made, the flexural

strength testing was carried out using a universal

testing machine (UTM) with the SHIMADZU UH-

600kNI brand with a testing speed of 2.7 mm/min.

The processing of the test results was carried out after

the testing process was completed to bring up the

value of the mechanical properties after the flexural

strength test, flexural strength, and flexural modulus.

3 RESULTS

The fishing boats or pompong boats made of HDPE

could be used as a substitute for wood-based

materials, this research was carried out only on the

design side of fishing boats, without calculating the

size of the construction (Jamal, 2017). Similar study

in 2021 on tourist boats made of HDPE, where in

determining the construction size of HDPE ships

using the rules from DNVGL-ST-0342 (Fitria, 2021).

Based on these two studies, this research was focused

on knowing the mechanical properties of HDPE

material before it was applied and calculated as ship

construction.

Based on the characterization carried out with the

flexural testing machine, the mechanical properties

data after the flexural test were obtained in the form

of flexural strength, flexural strain and flexural

modulus as shown in Table 1.

Table 1: Flexural strength of HDPE materials.

No. Merk

Flexural Strength

(MPa)

1 AGRU HDPE 24.44

2 Local HDPE 58.62

3 ROCHLING HDPE 61.00

Figure 2: Flexural strength of HDPE.

Based on Table 1, shown that the test results

produced the flexural strength values of the three

HDPE brands. HDPE ROCHLING had the largest

flexural strength value, which was 61.00 MPa.

Meanwhile, HDPE AGRU had the smallest flexural

strength, which was 24.44 MPa. There were previous

studies that discuss the flexural strength of HDPE

materials. Looking at the research conducted by

Fetrissa in 2017 on the effect of the addition of

LLDPE on the mechanical properties of HDPE, the

flexural strength value of HDPE was 17.69 MPa.

Based on this, the bending strength values of the three

HDPE brands studied were above the flexural

strength values of other HDPE studies. After knowing

the value of flexural strength, it would be referred to

one of the accepted standards for mechanical

properties of HDPE material for shipbuilding, namely

Turk Lyodu for Polyethylene Crafts. The criteria and

minimum acceptance set by Turk Lyodu on the

mechanical properties of HDPE material could be

seen in Table 2.

iCAST-ES 2022 - International Conference on Applied Science and Technology on Engineering Science

332

Table 2: Acceptance standard of HDPE in Türk Loydu

Tentative Rules for Polyethylene Crafts.

No. Property

Properties of

HDPE

Unit

1 Flexural Strength Min. 40 MPa

(Source: Turk Lyodu, 2014)

The results of the acceptance of the mechanical

properties of HDPE material after the flexural test

resulted in the conclusion that the Local HDPE and

HDPE ROCHLING met the standard values of the

Turk Lyodu acceptability for the mechanical

properties after the flexural strength test, it was

flexural strength. Meanwhile, Local HDPE did not

meet the acceptability standard due to the flexural

strength value was below the acceptability standard.

In addition, the mechanical properties after

bending testing in the form of flexural modulus can

be seen as shown in Table 3.

Table 3: Flexural modulus of HDPE.

No. Merk

Flexural Modulus

(MPa)

1 AGRU HDPE 372.38

2 Local HDPE 648.54

3 ROCHLING HDPE 650.15

The results of the flexural strength test resulted in

the flexural modulus of the three HDPE brands.

HDPE ROCHLING has the largest flexural strength

value, which is 650.15 MPa. Meanwhile, HDPE

AGRU has the smallest flexural strength, which is

372.38 MPa. The research conducted by Ahmed in

2019 on the comparison of the physical and

mechanical properties of HDPE and PP materials

resulted in a bending modulus of HDPE material of

450 MPa (Awad, 2019). The results above were not

accepted according to the standard which was

minimum of flexural modulus of HDPE was less than

750 MPa.

The results of the acceptance of the mechanical

properties of HDPE material after the bending test, it

is concluded that there was no HDPE brand that meets

the Turk Lyodu acceptability standard value for the

mechanical properties after the flexural strength test,

the flexural modulus. The three brands of HDPE

cannot be implemented as a basic material for

shipbuilding based on the mechanical properties of

the flexural modulus

4 CONCLUSIONS

Based on the flexural strength testing that has been

carried out, each of the highest mechanical properties

of HDPE material was obtained, it was the flexural

strength of 61 MPa and the flexural modulus of 650,

15 MPa (HDPE ROCHLING). Based on the accepted

standard of mechanical properties of HDPE material

regulated by Turk Lyodu, HDPE ROCHLING and

Local HDPE materials can be used as basic materials

for shipbuilding based on the acceptability of

mechanical properties of flexural strength.

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