5-7 OCTOBERISFR2011

157

TOLEDO (SPAIN)

ADDITION OF CRUSHED PARTICLES FROM RECYCLED TIRE (GTR) TO
RECLAIMED RUBBER (NRR)
J. E. Crespo1, A. Nadal1, M. A. Selles1, R. Navarro1, S. Sánchez-Caballero2
1 Materials Technology Institute, Universitat Politècnica de Valencia (Spain)
2 Design Institute for Manufacturing, Universitat Politècnica de València (Spain)

e-mail:jocream@dimm.upv.esAbstract
The habit of excessive consumption of so-called first world generates lots of waste, a waste of greatest concern for its large
size and because it can not easily be recycled is tires, since the mass production of these and the difficulties to manage is
one of the most serious environmental problems in recent years throughout the world. Although it is non-hazardous waste,
have features that drive the best way to manage your treatment. Thus, a tire qualities is that it takes more than 100 years todecompose and the other is its high heat capacity, making it difficult for fire fighting, another important feature is its chemical
stability (low biodegradability) by which has not been considered as hazardous waste.
This paper seeks to improve the mechanical properties of recycled rubber from waste tires (GTR) through the addition ofreclaimed rubber (NRR), with this is to obtain a final material with better mechanical properties and can be used in different
applications depending characteristics obtained.
The aim is to get a new material made from recycled materials so you can enter the market, getting to work with theenvironment by a utility to used tires, a material that currently poses a serious problem because of the huge accumulations
that have taken place and the risk of fire and pollution that goes with it in storage.

Keywords: reclaimed rubber, elastic properties and mechanical properties

1. Introduction

2. Materials and Equipment

The habit of excessive consumption of so-called firstworld generates lots of waste, a waste of greatest
concern for its large size and because it can not easily berecycled is tires, since the mass production of these andthe difficulties to manage is one of the most serious
environmental problems in recent years throughout theworld.
Although it is non-hazardous waste, has features thatdrive the best way to manage your treatment. Thus, a tirequalities is that it takes more than 100 years todecompose and the other is its high heat capacity,
making it difficult for fire fighting, another importantfeature is its chemical stability (low biodegradability) by
which has not been considered as hazardous waste.
Clean way to dispose of unserviceable tires is noteasy. One method to eliminate the direct burning waste
is causing great environmental and health problems. Also
many of these tires stored in dumps, landfills often havelarge causing great visual impact, in addition to causing
stability problems for partial chemical degradation theysuffer. Another problem of landfills is that the reefs areaccumulations of tires where the proliferation of rodents,
insects and other pests is an additional problem.
The objective to be met with this work, is to seek adisposal of these wastes, this will seek to improve theirmechanical properties by mixing different types of waste
and reduce the problems caused by this.

For materials used in the preparation of work havebeen:
- Elastomeric residue from the shredding of used tires
called GTR (Ground Tire Rubber) of 250 μm- Sheets of reclaimed rubber, which has been added
sulphur for vulcanization accelerator.
For fabrication and characterization of the material, wehave used the following equipment:- The sintering process is performed by a press
Robima SA (Valencia, Spain) with hot Dupra S.L(Castalla, Spain).
- Vulcanizing composition was performed using hotrollers Dupra S.L (Castalla, Spain) model CM120.
- Traction machine model ELIB 50 W (SAE Iberstest,Madrid), with which we have obtained the following
parameters: strength and elongation.
- Shore hardness machine, used to determine theresistance of the material to be penetrated by apenetrator type scale Shore A.

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3. Results and Discussion
Obtained more favorable results, according to theoptimization of processing variables of reclaimed rubber(10000 Kg pressures sintering with a time of 6 minutes
and a temperature of 150º C), will be a new study by therollers sintering and hot dishes in which to study theeffect of the addition of elastomeric residue (GTR) to therubber composition (NRR).

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6th International Symposium on Feedstock Recycling of Polymeric Materials

First mix the reclaimed rubber is vulcanized (NRR) andthe residue of tire crushed (GTR) at various proportions(10, 25, 50, 60 and 75%). This percentage corresponds
to the amount of waste tire (GTR) for the total mass used
for the sintering of the plates. The previous cases thesewere 150 grams, as is the amount needed to obtain a
final plate of about 4 mm thick and be able to make acomparison with results obtained in different plates ofprior testing.
After weighing the total amount of both materials, it isthen mixed into the hot dishes, which are at atemperature of 90º C. This step will add the fixed
percentage of sulfur and accelerator for vulcanization ofreclaimed rubber. Finally, perform the sintered using theconditions obtained previously.
The particle size used in the mixture is 250 μm, andthat is what is considered optimal in previous studies.
Finally, these plates are stamped to obtain the necessary
specimens for mechanical testing and the results will
indicate what percentage of waste tire which achieve
higher mechanical properties of the new material.
With respect to the tensile strength of reclaimed rubber
particles mixed with waste tire (GTR), is observed, Table
1, it increases in the first quantities up to 50% of each of
the materials, for then declining sharply, therefore,
greater resistance is achieved with the amount of 50%
and 50% reclaimed rubber elastomeric waste.
Table 1. Mechanical properties of the mixture of waste(GTR) and reclaimed rubber tire (NRR).
Reclaimedrubber (%)
010
25
5060
75

TensileStrength,
(MPa)
2,95
3,01
3,39
3,66
3,04
1,89

Elongation
at break,(%)
169,17145,21
158,75
162,21161,96
113,33Hardness(Shore A)
43,79
46,21
49,1753,79
53,2153,54

Regarding the elongation at break is observed, table 1,
as this greatly increases the quantities of 10 and 25% of
number of particles, then continues to grow slightly until
the maximum elongation for the number of particles of
50%. From this quantity is the reverse process, which isdown very slightly from the number of particles of 50 and
60% and produced a large decrease to the amount of
75% of waste.
Finally, we show the results obtained after conducting
the tests of hardness (Shore A) of the different
specimens of regenerated rubber particle. As you cansee, Table 1, it increased progressively to reachmaximum hardness in the amount of 50% of particle(GTR), and then declined and increased again in thenumber of particles of 75%.

the proportion of optimal particle addition, which isachieved with higher mechanical strength, in this casecoincides with the highest elongation and toughness isgreater than 50%.
Therefore, the addition of particles of waste tire rubbercomposition gives rise to a new material with greater
resistance than rubber base composition, although theelongation is slightly lower, also achieving a higher
hardness.

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Acknowledgements
The authors thank the Generalitat Valenciana Ref:
GV/2010/017 by the funding received for thedevelopment of this research through Projects Emerging
Research Group 2010.

4. Conclusions
After analyzing the results of mixing the reclaimed
rubber tire waste ground (GTR) yields the conclusion thatinteriores libro.indd 158

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