INTRODUCTION
Polymeric solid waste presents challenges and opportunities to
societies regardless of their sustainability awareness and technological
advances. More and more attention is being focused on Polyurethane
(PU) recycling due to ongoing changes in both regulatory and
environmental issues. Increasing landfill costs and decreasing landfill
space are forcing consideration of alternative options for the disposal
of PU materials [1].
In 2012, the Brazilian consumption of PU represented about 4% of the
world consumption volume. For that year, it was estimated a Brazilian
consumption equal to 563,000 tons of PU that represents 1.4 billion
dollars in sales. The growth of the PU Brazilian market between 2008
and 2012 was 6% per year. It was due not only to the resilience of the
main local consumers industries but also due to the government
programs of incentives; e.g. automotive and appliance industry [2].
This study aims to identify and characterize the waste generation as
the initial stage of Cleaner Production Program (CPP) implementation
in an industrial plant of PU molded foams production designed to
components for seats and vehicles interiors. The results will support
the waste management and the proposition of alternatives to a proper
and noble destination of the PU foam wastes based on quality tools
applied to CPP [3]
CPPs is gaining emphasis in both the world and Brazilian production
sectors. Studies have shown that the companies reach financial,
spatial and productivity gains with the program implementation [4].
METHODOLOGY
The industrial plant under study is strategically located in the
Southeast region of Brazil and has an installed capacity of 8,745,000
linear meters per year of PU foams. Currently, it is serving the
automotive industry with an average production about 550,000 meters
per month. All the foams are currently made using TDI/SAN-filled
polyol chemistry.
PU foam wastes generation in the production process was quantified
by monitoring conducted from January 2013 to June 2014.
Representative and periodic sampling allowed the waste
characterization in terms of physico-chemical properties by
standardized assays according to Fiat Auto Normazione (1992).
Compression Set, Dry Heat, Dump Heat, Tensile Strength, Elongation
at Rupture, Tear Strength, Ash Content and Load Deflection assays
were performed in 10 samples and statistical analyses have allowed
the evaluation of possible correlations between the obtained results.
Thermogravimetric analyses (TGA) were performed with a
thermogravimetric analyzer (DTG 60H, Shimadzu). Runs of TGA were
conducted in the ramp mode from room temperature to 800 ºC under
nitrogen at a flow rate of 60 mL.min-1. Heating rate was 10 ºC min-1.
Sample weights of TGA were approximately 4 mg in their original state.
RESULTS AND DISCUSSION
CONCLUSIONS
Nowadays, as PUs are used in so many applications and industrial
uses, they enter the municipal solid waste stream, usually by way of
discarded consumer and industrial products. These products frequently
are durable goods with a long lifespan such as upholstered furniture,
mattresses and automobile parts [6].
In a comparative study of disposal technology, Yang et al. (2012) [7]
have indicated that PU wastes, shattered into fritter or powder, can be
used as filler to join a new PU product. In this sense, in finding
opportunities to the outskirts where the industrial plant is located, the
PU foam wastes destination as fillers can be a proper and sustainable
alternative which can promote a financial return to the process.
REFERENCES
[1] Zia K.M., Bhatti H.N. and Bhatti I.A., (2007). Methods for polyurethane and polyurethane
composites, recycling and recovery: a review. Reactive & Functional Polymers, vol. 67, 675–
692.
[2] Bain & Company, (2014). Potencial de diversificação da indústria química Brasileira:
Relatório 4 – Poliuretanos e seus intermediários. B&C, Rio de Janeiro (RJ), p. 42.
[3] Lopes Silva D.A., Delai I., Castro M.A.S. and Ometto A.R., (2013). Quality tools applied to
Cleaner Production programs: a first approach toward a new methodology. Journal of Cleaner
Production, vol. 47, 174-187.
[4] Vendrametto O., Palmeri N., Neto G.C.O. and Perretti O., (2010). Cleaner production: a
growing movement in Brazilian Companies, Revista Produção, vol. X, n. I, 49-70.
[5] Saha M.C, Kabir Md.E and Jeelani S. (2008). Enhacement in thermal and mechanical
properties of polyurethane foam infused with nanoparticles. Materials Science and Engineering
A, vol. 479, 213-222.
[6] Nikje M.M.A., Garmarudi A.B. and Azni B. (2011). Polyurethane waste reduction and
recycling: from bench to pilot scales. Designed monomers and polymers, vol. 14, n. 5, 395-421.
[7] Yang W., Dong Q., Liu S., Xie H., Liu L. and Li J., (2012). Recycling and disposal methods for
polyurethane foam wastes. Procedia Environmental Sciences, vol. 16, 167–175.
An average value equal to 19.44 g of waste per linear meter of product
was obtained in 2014 and it shows a downward trend that can be a
result of: a) the monitoring conducted in 2013; and b) the
implementation of the action plan to improve the process efficiency and
some steps of the CPP which involves:
Top management commitment Employee engagement
Organizing a CP team Presentation of the CP methodology
Company pre-assessment Data collection Definition of
performance indicators Data evaluation and Identification of
options of improvement [3].
PU foam wastes generated in the injection molding process are a
result of poor balance of expansion / gelification of foam in the injection
step, or caused by a failure in the mold surface conditioning.
Some correlation was observed between the results for Compression
Set vs. Elongation at Rupture and Tensile Strenght vs. Elongation at
Rupture. Thermal degradation at high temperatures is an inevitable
event and it can be a significant limitation to their applications [5].
Management in a Polyurethane Foam Industry designed
to meet the automotive sector: a Brazilian study case
Samuel R. Castro* & Gilson L. Carvalho** * Center for Innovation and Technology SENAI – campus CETEC / SENAI Institute of Technology in Environment
** UNA University Center – campus RAJA
Belo Horizonte / Minas Gerais - Brazil
15th INTERNATIONAL WASTE MANAGEMENT
AND LANDFILL SIMPOSIUM
Compression
Set (%)
Dry
Heat
(%)
Dry
Dump
(%)
Tensile
Strength
(N/m2)
Elongation
at Rupture
(%)
Tear
Strenght
(N/m2)
Ash
Content
(%)
Load
Deflection-
Thickness
Loss (mm)
Load
Deflection -
Stiffness
Loss (%)
Mean 9.5372 -0.4214 -5.9081 15.8994 120.1111 2.7558 0.1767 1.1417 12.8867
StdDv 1.0551 5.1195 13.6817 2.5890 11.6516 3.4331 0.1410 0.3669 6.7104
Asymetry -0.2929 1.9394 0.5694 0.0652 -0.3742 5.9698 1.5418 0.2760 0.7094
Min 7.46 -5.99 -19.66 11.46 92 2 0.05 0.62 4.18
Max 10.99 14.23 14.8 21.26 140 22.75 0.46 1.81 24.37
N 36 36 36 36 36 36 12 12 12
Table 1: Descriptive statistics obtained by the results of physico-chemical analyses.
Figure 2: Time series of PU foam wastes generation.
00
20
40
60
80
100
0.0
5.0
10.0
15.0
20.0
25.0
Cu
mu
lati
ve
Fre
qu
ency
(%
)
PU
fo
am
wa
ste
(gra
mes
of
was
te /
lin
ear
met
er o
f p
rodu
ct)
PU foam waste General Average = 21.05 g/m
2014 Average = 19.44 g/m Cumulative frequency
Figure 1: Moulded PU process.
0
20
40
60
80
100
0 100 200 300 400 500 600 700 800
Weig
ht
Lo
ss (
%)
Temperature (ºC)
T5% = 241.89 oC
T50% = 366.69 oC
Figure 3: TGA – PU foam wastes