-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
1/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
EXPERIMENT 2
Hardness Test
1.0 OBJECTIVE
1.1 To measure hardness of Ultra High Molecule Weight Polyetalline (UHMWPE)
samples using Shore (durometer) hardness test.
2.0 INTRODUCTION
Hardness is the property of a material that enales it to resist plastic deformation! usually y
penetration. Ho"e#er! the term hardness may also refer to resistance of ending! scratching!arasion or cutting. The hardness testing of plastics is most commonly measured y the Shore
($urometer) test or %oc&"ell hardness test. 'oth methods measure the resistance of the plastic
to"ard indentation. 'oth scales pro#ide an empirical hardness #alue that doesnt correlate to
other properties or fundamental characteristics.
n this e*periment! "e use the Shore (durometer) test to measure the hardness of the samples.
$urometer! li&e many other hardness tests! measures the depth of an indentation in the material
created y a gi#en force on a standardi+ed presser foot. This depth is dependent on the hardness
of the material! its #iscoelastic properties! the shape of the presser foot! and the duration of the
test. ,STM $--/ durometers allo"s for a measurement of the initial hardness! or the
indentation hardness after a gi#en period of time. The asic test re0uires applying the force in a
consistent manner! "ithout shoc&! and measuring the hardness (depth of the indentation). f a
timed hardness is desired! force is applied for the re0uired time and then read. The material under
test should e a minimum of . mm. 213
1 | P a g e
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
2/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
4igure 15 $iagram for durometer application
4igure -5 Type of durometer shore
The results otained from this test are a useful measure of relati#e resistance to indentation of
#arious grades of polymers. Ho"e#er! the Shore (durometer) hardness test does not ser#e "ell as
a predictor of other properties such as strength or resistance to scratches! arasion! or "ear! and
should not e used alone for product design specifications.
2 | P a g e
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
3/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
3.0 COMPONENTS AND EUIPMENT
6.1 Shore (durometer) hardness test
4igure 65 $urometer
6.- Ultra High Molecule Weight Polyethylene (UHMWPE) samples
4igure 5 The Sample of UHMWPE "ith /7 8n9 (pure)
3 | P a g e
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
4/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
4igure :5 The Sample of UHMWPE "ith 1-7 8n9
4igure 5 The Sample of UHMWPE "ith -:7 8n9
4igure ;5 The Sample of UHMWPE "ith 17
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
5/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
4igure =5 The Sample of UHMWPE "ith -7 5 The Sample of UHMWPE "ith 67
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
6/14
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
7/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
.6 The hardness reading "as read from the scale.
. ,STM $ --/ "as referred for more details.
".0 RESU#TS AND DISCUSSION
Tale 15 The hardness reading of different ratio of +inc o*ide and chitosan of UHWMPE samples and
their a#erage hardness.
Sa$%&es Rat'( )nO *
C+H11NO!, -
Read'n 1, N Read'n 2, N Read'n 3, N A/erae
Hardness HA, N
Sa$%&e 1 /5/ /.: :>.: -./ /.;
Sa$%&e 2 1-5/ 1./ 1.: 1.: 1.666666
Sa$%&e 3 -5/ :6./ :./ :./ :.666666
Sa$%&e ! 1-51 6./ :.: ./ .1;
Sa$%&e " 1-5- ./ -./ 6.: 6.1;
Sa$%&e + 1-51 :;./ :.: :./ ::.=66666
Tale -5 The con#ersion of a#erage hardness! H$ of different ratio of +inc o*ide and chitosan of
UHWMPE samples to the force.
Sa$%&es Rat'( )nO *
C+H11NO!, -
A/erae Hardness HA, N (re, 4 !!"HD , N
Sa$%&e 1 /5/ /.; ->>=.1:
Sa$%&e 2 1-5/ 1.666666 -;->1.=:
Sa$%&e 3 -5/ :.666666 -1;.=:Sa$%&e ! 1-51 .1; -=:::.:
Sa$%&e " 1-5- 6.1; -=11/.:
Sa$%&e + 1-51 ::.=66666 -=.6:
7 | P a g e
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
8/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
:.1 Plot graph hardness #s. load for all the samples tested. $iscuss.
1 2 3 4 5 64
5!
52
54
56
5
6!
62
64
66
The Graph of Average Hardness vs Ratio of Sample !"
Ratio of sample !"
Average Hardness #"
4igure 1-5 The graph of a#erage hardness (?) #s ratio of sample (7)
'ased on the graph at 4igure 1-! it sho"s that the trend for the graph of a#erage
hardness #s. ratio of sample UHWMPE is fluctuated. The highest #alue of a#erage
hardness elongs to sample "hich is contained 17 of chitosan and 1-7 of +inc o*ide
"ith .1;? and the lo"est #alue of a#erage hardness elongs to sample 6 that ha#e
-:7 of +inc o*ide "ith :.66?.
$ | P a g e
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
9/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
1 2 3 4 5 6
21!!!
22!!!
23!!!
24!!!
25!!!
26!!!
2"!!!
2!!!
2#!!!
The Graph of %or&e #" vs Ratio of Sample !"
Ratio of sample !"
%or&e #"
4igure 165 The graph of force (?) #s ratio of sample (7)
'ased on the graph at 4igure 16! it also sho"s that the trend for the graph of force #s.
ratio of sample UHWMPE is fluctuated. The #alue of force for e#ery samples is otained
y using a formula for shore $! 4@:H$. This graph also sho"s the t"o same samples
that ha#e highest and lo"est #alue of parameters state! force. The highest #alue of force
elongs to sample "hich is contained 17 of chitosan and 1-7 of +inc o*ide "ith
-=:::.:? and the lo"est #alue of a#erage hardness elongs to sample 6 that ha#e -:7
of +inc o*ide "ith -1;.=:?.
' | P a g e
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
10/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
21!!!22!!!23!!!24!!!25!!!26!!!
2"!!!2!!!2#!!!
The Graph of %or&e #" vs Average Hardness #"
Average Hardness #"
%or&e #"
4igure 15 The graph of force (?) #s a#erage hardness (?)
4igure 1 sho"s the graph of force (?) #s a#erage hardness (?). Ha#ing the same trend
"ith pre#iously t"o graphs! it sho"s fluctuated trend "ith the same samples that ha#e
highest and lo"est #alues of parameters stated. n this graph! the highest #alue force is-=:::.:? "ith respect to its a#erage hardness! .1;?. Mean"hile the #alue of the
lo"est is -1;.=:? "ith a#erage hardness of :.666?. ,s #alues of modulus of
elasticity and hardness arise! the #alues of force also arise ecause force is directly
proportional "ith a#erage hardness.
1( | P a g e
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
11/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
:.- Ho" to ma*imi+e the performance of durometer.
There are fe" aspects that "e can consider for ma*imi+ing the performance of
durometer5
:.-.1 ,lignment
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
12/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
:.-. Test Times
When comparing results it is important to use the same test times.
Some materials e*hiit a large degree of flo" after the full test load is
applied. , one or t"o second difference in ta&ing the reading can causesignificant #ariations.
:.-.: %ound Part TestingSmall round parts! li&e oArings! are particularly difficult to test.
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
13/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
:.6 Ho" to relate the durometer results "ith stiffness of tested material
$urometer is an indirect measure of the stiffness! or more correctly the modulus
of an elastomeric material. Modulus is a property of elastomers! analogous to the
same property of metals! "hich is the ratio of stress to strain in the elastomer at some
loading condition. Unli&e metals "hich is typically ha#e a linear stressAstrain cur#e
elo" their yield point! the stressAstrain relationship of elastomers is nonAlinear o#er a
range of loading condition and can e significantly influenced y amient
temperature. ,s a result! the modulus of an elastomer is highly dependent on the
conditions under "hich it is measured. This fact ma&es the understanding of
elastomers and their properties important in the understanding of the performance of
elastomeric #iration and shoc& isolators.n a relati#e sense! lo" durometer or hardness correlates to a lo" modulus or
stiffness. Similarly! as durometer increases so does modulus and #iceA#ersa. Ho"e#er!
the correlation et"een durometer and modulus is not directly proportional! douling
in durometer #alue does not e0uate to a douling in modulus.
solator stiffness is a direct function of elastomer modulus and part geometry. So!
as "ith the relationship et"een durometer and elastomer modulus! part stiffness
cannot e estimated for a &no"n durometer. Ho"e#er! part stiffness "ill increase in
durometer! part stiffness "ill decrease "ith a decrease of durometer too.
+.0 CONC#USION4rom the e*periment! "e can conclude that the Shore ($urometer) Hardness "hich is
used durometer "ith type of shore $ is used to determine the relati#e hardness of soft
materials! usually plastic or ruer. The hardness test measures the penetration of a specified
indentor into the samples under specified conditions of force and time. 'esides! "e also can
conclude that sample of Ultra High Molecule Weight Polyethylene "ith the presence of filler
+inc o*ide content increase "hen it has 1-7 +inc o*ide ut decrease "hen it ha#e -:7 +inc
o*ide. Mean"hile "hen chitosan content is added into the samples! it indicated rising in
graph ut fell "hen the content is increased.
5.0 REERENCES
213 http5CC""".ptc1.comC"hatDisDdurometer.htm
13 | P a g e
http://www.ptc1.com/what_is_durometer.htmhttp://www.ptc1.com/what_is_durometer.htm
-
8/19/2019 Polymer Properties: EXPERIMENT 2 Hardness Test
14/14
Polymer Properties (EBT 326) Exp. 2: Hardness Test
2-3 """.intes+t.huCP$4C/1CShoreDgeneralDcatalogue.pdf
263 http5CC""".usplastic.comC&no"ledgeaseCarticle.asp*content&ey@/=
23