Page 29 - Plastics News July 2020

Better Cooling - Higher Productivity

Cooling typically consumes 11% to 16% of the energy used If proper care is not taken then chances of
in a plastics processing plant and simple actions can Ÿ Scaling,
significantly reduce this energy use.
Ÿ Jamming of piping network components,
Mayur Shah
Ÿ Corrosion of metal components,
To improve productivity is most important than ever
before to face local and global competition. Though Ÿ Microbiological growth (algae, bacteria, fungus)
there are many reasons to improve energy efficiency but etc.
the bottom line is cost effectiveness. Ÿ Health issues of employees
Increased input cost like power, Labour, Raw material, Most of us rather all of us know the fact that moulding
Infrastructure etc. has compelled the plastic processing processes are cyclic in characteristic. Cooling time is
industry to increase efficiency. Ample scope of about 50 to 75% of the total cycle time and one of the
improvement in efficiency is present in the neglected deciding factors for the quality requirements.
area or one can say the grey area in plastic moulding Therefore, it is important and essential to optimise
industry and that is water distribution for cooling of cooling time to improve productivity. In spite of knowing
moulds, machines and other auxiliaries. The pumping this fact minimum attention is paid towards this, at
room is often quite far from the actual operational area leastby the domestic injection moulders and blow
and it is not looked after unless there is some problem or moulders. This minimum attention can be due to lack of
breakdown. It can also be called forgotten area. Regular knowledge of improvements possible or due to over
analysis of performance helps to find out any loss of confidence of running the industry for decades together.
efficiency corrective measures to be taken before Production costs can be reduced or controlled by
complete loss of service. This is particularly important incorporating systems which may require little or no
because cooling typically consumes 11% to 16% of the investment.
energy used in a plastics processing plant and simple
actions can significantly reduce this energy use. The problems often observed in the moulding shop with
respect to cooling along with quality of water are
Following figure shows the four basic cooling methods
Ÿ Cooling tower performance,
adopted. One needs to be conscious about the energy
consumed, efficiency and day to day maintenance cost. Ÿ Pump performance
Combination of the cooling methods can be adopted to Ÿ Pipe diameter
achieve better efficiency. The best way is to introduce
Ÿ Design of piping network
and follow cooling-water management plan.
Ÿ Cooling tank capacity etc.
From the above mentioned water cooling methods only
chiller cooling method is a close loop system, rest two
are open loop system. The open loop cooling tower
water cooling system is widely used but the chances of
water contamination due to airborne dust debris are
bright.

July 2020 29 Plastics News