Journa l of Scient ifi c & Industri al Research

Vol. 62, May 2003, pp 462-467

Usage of Polyester Textile Wastes in Composites

Te lem Gok Sadikoglu* and Cagri Shikim

Istanbul Techni ca l University, Mechani cal Engineering Faculty, Department of Textile Engineering, Istanbul, Turkey

and

Canan Gamze Guleryu z and Barlas Eryurek

Istanbul Techn ical University, Mec hani cal Engineering Faculty, Department of Mechanical Engineering, Istanbul , Turkey

Recei ved: 13 June 2002; accepted: 03 March 2003

A composi te material is prod uced by using pol yester textil e wastes as reiriforcement material and mainly urea formald ehyde as mat ri x material. This co mposite is used in banks , tables, shelves , and pots. The bending strength and absorpt ion properti es of the textil e rcinforced composite arc in ves tigated and ~.ompared with fibreboard and med ium density fibreboard whi ch are alternative materi als for the same end-uses' .. The polyester wastes such as, yarns, woven, and knitted fabrics cut at random dimensions are used as reinfo rcement material. Matrix material is prepared by mixing urea formaldehyd e res in , ammoni um sulphate, and nour in a weight ra ti o of 100:5: 10 co nsecutively. The bendi ng strength of the textil e rein forced composite is less than the fibreboard and the medium density 1ibreboard , but it absorbs less water. It seems that the properti es of the tex tile reinforced composite can be improved by considering the test results obtained.

Introduction

Textile re info rced compos ites have various applications in engi neering sciences in less expensive mate rials, Since 1970, textil e re inforced composites grew attention wh ich led to many g lobal researches. As a result , in the past 30 y great attention has been g iven to textil e re inforced composites. The main reasons for whi ch be ing that they are light and rigid , pe rforming well under complex thermo-mec hanical loads, having hi gh strength/weight rat io or modulu s/weight rati o, having low expans ion and good damping c haracteristics.

Three dimens ional tex til e prepregs and composites have been useful in developing new fibre and matri x production techniques . As a result of these de ve lopments text ile reinforced composites have been an important alte rnative for the traditio!la l eng ineered mate rial s in ae rospace and automot ive ind ustri es l

.5

1n this sllldy, a composi te has been prod uced and tested by us ing polyeste r textile wastes such as ya rns , wove n and kni tt ed fabr ics. This textile rei nfo rced cOlllposi te is used in banks, tables , shel ves,

.,. ;\uthor 1'01' correspondence

pots, e tc. The absorpt ion and strengt h properties of the composite have been in vestigated and compared with fibreboard and med ium de nsity fibreboard (MDF), which are a lte rnative material s for the same end-uses.

Experimental Procedure

Materials

U rea formaldehyde res in, ammonium sulph ate and flour have been used for the matri x mate rial. Hundred per cent polyeste r (PET) tex til e wastes , such as yarns and woven and knitted fabri cs, cut at random dimensions were used as re info rcement mate rial. In samples Band D packing bands were used. Material s and their properties are given on T ab le I. Fibreboard (Samp le E) and medium dens ity fibreboard (Sample F) were also tested for comparison.

PI"cparation of the Matedals

Mat ri x mate rial was prepared by mi xing urea forma ldehyde resi n, ammonium sulphate and fl our in a weigh t rat io of 100:5: 10 consecLltively. PET wastes we re sunk in th is m ixture first and we re immersed thoroughly by the matrix mater ial. Afte r excess resin was removed from texti les by sq ueezing, they were

SADIK OG LU el a t.: USE OF POLYESTER TEXTILE WASTES 463

Tab le 1- Material properti es

Material Tex tile rein forcement co ntent code

Texti le rein rorcement material ratio by weight (per ce nt)

Matrix materi al ra ti o by weight (per cent)

Density. p (g:/c m")

A PET woven fabri c and yarn waste 30 70 0,97

B PET woven fnb ri c and yarn waste wi th 30 70 0.97 package IX1I1ds

r PET Kni tted fabric waste 35 '-" 65 O)'iS<J

D PET K!lilted fabr ic waste wi th p,lckage h~ln ds 35 65 O.<J4

E Fiberhoard 0.60

F Medium density fiberboa rd 0,64

Table 2 - Dimensions of bend in g test samples

Materia l code A B

Di mensions (mm) 279x23x24 27Sx20x24

laid in a mould (the in side d imens ions: 305 mm x 126 mm x 20 mm). The lid of the mould was cl osed and 700 N pressure was appli ed on it. The compos ite was

dri ed in an oven at 75 °C fo r 2 h. After 2 h, the sample was kep t outs ide the laboratory for I d to become harde r. In samples B and 0 , f i ve pacb ge bands were p laced at the bo ttom of the compos ite para ll e l in the longitudina l directi on.

Tes ts

lJending Tests

After product ion of compos ites the p lates were mac hine-cut into f ive pi eces through the ir 125 mm long edges. T he dimensions of th e sampl es are given in Table 2. T hree sam ples were tested for each mate ria l type . Three-poin t-bending test was carri ed out , as shown in F igure I. T he tests were conducted in a DARTEC servo-hydraulic uni versal tensile test f rame with a ramp rate of 0, I mm's and he di ameter of the bend ing supports be ing 30 mm.

Wa ter Ahsorptioll Test

T he sampl es we re weighed afte r being conditi oned for 24 h . They were pl aced in a tank full of wate r. A we ight that prevented them fro m fl oating was placed over them. T he samples were weighed aga in after I , 3, 6, and 24 h, Sampl e E and F were weighed onl y afte r I and 24 h,

c D E F

276x20x2 1 278x2 1x23 281x36x lSl 27lJx]l)xlx

F

L=l21nun

Figure 1- Three-paint-bending tes ting ap parat us

Results and Discussion

Bending Strength Test Results

Bending strength (J was calculated by us ing the fo ll owing formul a :

M (J =-- · h

J ' where M = bending moment (M = F . L), I =

moment of ine rtia, h = max imum di stance from neutra l ax is in sampl e c ross-sect ion, F = max imum load on the iinear porti o n of load-defl ect ion curve, and L = hal f span length . Bendi ng stre ngths of the samples are li sted in T abl e 3.

Us ing linear elas ti c ana lys is , modu lus of e lasti ci ty values (Table 4) can be obta ined as fo ll ows:

464 J SCI IND RES VOL 62 MAY 2003

E = (2L)' ( dF ),

32B (~) ' d8 2

where L = half span length (L = 12 1 mm), B = width of the specimen, h = he ight of the specimen,

F = load applied in e las ti c region, 8 = load point

defl ecti on, dPld8 = slope of the linear portion of the load-def lection curve.

T oughness va lues were calcul ated as "Work to P roportiona l Limit per Unit Volume7

" f rom Load­Deflection curve as shown in Tabl e 5.

Wa ter Absorption Tes t Results

Water absorption percentages (W AP) by weight were calcul ated according to the fo rmula g iven be low:

Water absorption percentage = Last weight (after I ,3,6,24h) - Init ial we ight

x 100 Init ial we ight

T he tes t results are li sted in T able 6.

Discussion

W hen average bend ing strengths are taken into account , it can be seen that Sample E and F have higher va lues than the tex ti Ie-re inforced composi te sa mpl es (Figure 2 and 3) .

Interest ing ly, Sampl e A, whi ch is composed of woven fab ric and yarn wastes, has got a higher bend ing strength than Samp le B, which is composed of woven fabr ic and ya rn wastes with package bands . Sim il arly, Sample C , which is composed of kn itted fabr ic wastes, has hi gher bending strength than

Sample D , which is composed of knitted fabric wastes with package bands . Thi s can be attributed to the band's behav iour as a di scontinuity that creates a defect when a bending moment is appli ed.

Tab le 3- Three-point-bendi ng tes t results

Materi al Average bending Specific bend ing code strength, strength, al p

a (MPa) (MPa/g.e lll·' )

A 7.18 7. 38

B 5.97 6 .. 07

C 6.39 7.46

0 6. 17 6.54

E 8.26 13.56

F 10.44 16.24

Table 4 - Mod ulus of Elasti ci ty va lues

Materi al Average mod ulu s of Specific modulus, E/p code elasticity, E (M Pa) (MPa/g.clll·')

A 573 587

B 624 635

C 433 504

0 6 14 652

E 1085 1779

F 2072 3224

Table 5- Toughness val ues

Material A ve mge toughness, Spec ific tou ghness, code (N m/nr\) (N Illlll/g.cn'-')

A 5053 699

B 3 11:::4 34 1

C 5360 (lS I

0 3766 461

E 3502 9~l)

r: 201:"1 ~O.1-

Table 6- Weight of salllp ies and water absorption percentages by weight

Ma terial coLic A 13 C 0 E F

Ini ti .l l weight (g) 115.03 12(1.17 114.6R 12(1.94 2~.54 20.t-:O

Weight I h (g) 12305 136.10 127.60 134.35 45.1 ~ 23.27

Weight.\ h (g) 123.93 1378l) 12S00 135.0S

Weight (l h (g) 12~. 62 13~.60 129.67 136.13

Wcight 2.+ !J (g) 132 .53 141.40 12SJ.()~ iJ(,2 i 4S .04 17(, ::'

WAP I h (PCI' cCllt ) 7.75 7.S7 11 .27 5K3

\V AP 3 il (per cellt) 10.35 l)2l) 124 (1.30

WAP () II (pu cent ) I J. X I ()~:i 1.107 7.2.1-

\\ ' 1\1' ::'-1 h ,,!lc r cent) 15 .21 12.D7 13 .OS ..... ~ ( ' ' . . 1d

SADIKOGLU et al. : USE OF POLYESTER TEXTILE WASTES 465

oS 12 , ----------------, g> 10 +--------------'--.

~ IV 8 (/) a. 6 g> ~ 4 -g 2 ~ 0 +-,"--''-,--=''"'--,-JL....;;;.J'-,---'''''-'---,-JL.-J'-,---'-'-''-'---j

A B c o E F

Material Type

Figure 2-Bending strength chart by material type

A B C 0

Material Type

E F

Figure 3- Specitic bending strength by material type

If we compare the modulus of elasticity values (Table 4, Figure 4 and 5), Sample A and C are less rigid than Sample Band 0, nevertheless Sample B and 0 have the same rigidity . It is obvious that the rigidity is gained by the reinforcement effect of the package bands. Package bands decrease the strength of the composite material, but at the same time increase the elasticity modulus. Elasticity modulus values of textile composites are less than fibreboard and MOP. If the toughness values are checked (Table 5, Figure 6), Sample A and C have higher toughness values. It can be said that the package bands decreased the toughness.

It is seen from water absorption results that Sample E absorbs maximum water (68,33 per cent) after 24 h (Table 6 and Figure 7) . Sample F is the second highest absorbent material with a W AP of 32,79 per cent after 24 h. The textile reinforced composite samples have less WAP values than fibreboard and MDF.

Sample A and B have higher WAP values compared with Sample C and O. Sample A and Bare composed of yarns and woven fabrics and Sample C and 0 are composed of knitted fabrics only. Because of the presence of the yarns in Sample A and B the

t:: 'u 2500 ,-----"-----------.~-----, :;;; :g 2000 ~-------

ii:i ~ 1500 -j--------------[ ; .... a. ~ ! 1000 -j-----------l--;-J--l :::I :i 500 J-I...."., __ I<"' I----==---I "0 ~ O+-' .......... '-r-&.:.. ........ T-'---'--,--J--'-T-'---'--,---'-'--'-l

A B c o E F

Material Type

Figure 4- Modulus of elasticity by material type

~ 3500 ,----------------,

~ 3000 -j--------------L;1\. "0,.....

w"? 2500 +---------------lMiit ,nE .= ci. 2000 +---------- -----liI ::I ...... og ~ 1500 +----------- 1 :E:E ~ '-' 1000

'2 500 -'-'.~--' Co Ul

A B c o Specimen

E

Figure 5-Specific modulus by material type

F

1200 T ············· ··········· ................................ .. .... ......... .. .. ..... .................. ........ . .................... .... .. ... ... ................................... ,

~- ~ 1000 t-------------,-...,------i

~ & 800 -1--------- ------1

:l '" ~ E 600

!E ~ 400 ~~

~ 200

A B c D E

Material Type

Figure 6- Specific toughness by material type

c:~ 80 ~ Qj e-~ 60 ons~ CIl CII ;;:: 40 .0 OJ ~ « ........

nloC ... c: 20 CII CII ..... nI 0

:s: Qj 0 a.

A B C 0 E

Material Type

F

Figure 7- Water absorption percentages by weight after 24 h for the material s

466 1 SCI IND RES VOL 62 MAY 2003

Table 7 - Comparison Index values for the tested materials

Material Average bending strength, Density, p (g/cm') code (J (MPu)

A 7.18 0,97

B 5.97 0,97

C 6. 39 0,85

D 6.17 0.94

E 8.26 0.60

F 10.44 0,64

absorbency may be high, but this cannot be taken for granted . The initial absorbency test for yarns, woven fabric, and knitted fabric before producing the composite should have been done.

If we compare Sample A with B and Sample C with D, it is seen that the composites with bands have lower WAP values. The bands cause less water absorption, because they are very rigid and non­absorbent materials. Sample A and B have similar densities, but Sample C has a lower density than D. The reason for the W AP value for Sample C to be much higher than Sample D (13,08 » 7.3 - after 24 h) may be this dens ity difference. Sample A has highe r W AP value than B, but the difference is not as much as with Sample C and D (15.21 > 12.07, after 24 h) .

For Sample A and B, at the end of I h, the samples absorb approximately half of the water that is absorbed at the end of 24 h. For C and D, at the end of I h, the samples absorb approximately 80 per cent of the water that is absorbed at the end of 24 h. This may be due to the absorbency of textile materials used, again .

As a result, W AP values for texti le reinforced composites are lower than fibreboard and MDF up to great extent. This may be advantageous for their end­uses that expose to water. For example, banks, tables in the parks, pots, etc. The strength of the wetted materials should also have been taken into account, but unfortunately the wetted materials have not been tested.

The most important properties of a texti le composite are strength, density , and water absorption. The tested materials were examined by a Comparison Index (Cl), introduced by us, further. CI can be expressed as:

CI = (5

p . W24

Water absorption per cent in Comparison Index, 24 h CI (MPa/ g.cnf')

0. 1521 48.5

0.1207 50.3

0.1308 57.0

0.7300 89.6

0.6833 19.8

0. 3279 49.5

>< 100 (I)

"0 .= 80 s:: 60 0 I/) 'C 40 C1l a. 20 E 0 0 u

A B C 0 E F

Material Type

Figure 8- Comparison Index vs . material lype

where (j" is bending strength in MPa, p is density in g/cm3 and W24 is the water absorption per cent by weight of the composite in 24 h. High Comparison Index values indicates a better composite for chosen properties . According to the CI results, Sample D, which is the texti le reinforced composite composed of knitted fabric wastes and package bands, gave the best result and Sample E the fibreboard, gave the worst resu lt. Generall y the texti Ie reinforced composites have similar Comparison Index values with MDF (Table 7 and Figure 8).

Conclusions

The new textile-reinforced composite absorbs less water than fibreboard and MDF. The specific bending strength of the new composite is less than fiberboard and MDF. But the CI values are much better than fibreboard and similar to MDF. It seems that the properties of the new composite can be improved by considering the above results. The bending strength test after water absorption should be done and this value should be used as strength value in the CI calculations in the future works. Also some additive tests for evaluating its performance, such as thermal conductivity, flammability, resistance to sun

SADIKOGLU et al.: USE OF POLYESTER TEXTILE WASTES 467

light, effect of textile materials (fibre, yarn, fabric properties) could prove to be useful.

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(Woodhead Publishing Limited, Cambridge, England) 2000 [ISBN I 855733854].

2 Sierakowski R L.& Chaturvedi S K, DYllamic loading alld characterizatioll of fib er-reinforced composites (Wiley Intersicence Publication) 1997.

3 Mall H, Composite - a modern material using woven fabric , NOllwovens-llld Text, 2 (200 I), 55-58.

4 Shishoo R, Future developments in fibres, yarns and fabric s for technical applications, NOllwovens-lnd Text, 3 (200 I), 24-29.

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