Environmental Engineering Reference
In-Depth Information
Figure 4.11
Total direct environmental damage as a percentage of revenue
for several selected industries.
Source: Based on data from Trucost Plc. (2013).
However, as already alluded to in the introduction, the plastics industry
constitutesonlyaverysmallfractionoftotalindustry.Aswiththeassociated
energy costs, the question is if the environmental “cost” is excessive
4.5 PLASTICS ADDITIVES
To ensure the desired properties and for facile processing of the material,
additives are mixed in with the resin during compounding. Some of these
are inert fillers or recycled plastic used to bring down the cost of the
manufactured product, while others are used to ensure specific
functionalities.
Table 4.8
indicates the ranges of levels at which these
additives are typically used. The exact level depends on the grade of resin as
well as on the properties demanded of the compound. The main classes of
additives in plastics are shown in
Figure 4.12
:
a. Stabilizers that protect plastic from thermal degradation during
processing and light-induced thermo-oxidative and biological damage
during use
b. Reinforcing fillers and plasticizers that improve the mechanical
properties such as the modulus of plastic material, to match the service
requirements
c. Processing aids that make the processing of the material easier
