This page contains a Flash digital edition of a book.
Energy management theory Map your energy use


To identify where your energy is going you need an ‘energy map’ for your moulding plant. This will list your main energy users, typical power drawn (kW) and operating hours and will help you identify the biggest consumers.


Your energy supply bills can help you save money and energy but you need to understand and analyse the information they contain then make informed management decisions.


Available capacity (measured in kVA) is the maximum amount of power that can be drawn from the supply and is paid for whether it is used or not. Maximum demand (also measured in kVA) is the maximum amount of power actually drawn. If maximum demand greatly exceeds


available capacity you will pay penalties; if much less you are buying capacity that is not needed. Select an appropriate capacity figure.


Power factor (cos φ) is the ratio of ‘useful power’ (kW) to ‘apparent power’ (kVA). The ideal is a value of 1.0; for most plastics processors it is around 0.95. If your power factor is very low you will need more available capacity and may be charged for reactive power (kVArh). In such cases, it may be worth investing in power factor correction equipment.


Interval data can be used to analyse energy use by time and is a good way to check for costly usage patterns, such as shut-downs and start- ups. It is usually available free from your supplier.


Benchmark your performance


While your PCL formula allows you to monitor your plant effectiveness, benchmarking allows you to compare it against other injection moulding operations or machine types. Tangram Technology, which compiled this guide, has carried out energy surveys of more than 200 injection moulding sites around the world and has compiled benchmark curves1


allowing site or machine performance to be benchmarked against global averages.


1 More details of the Tangram Technology Ltd benchmarking method are provided in the book referred to at the end of this publication.


An energy saving guide for injection moulders 5


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80