Waste Minimisation in Plastics Processing - Part 3 Assessing Performance

The third in a series of waste minimisation worksheets by Dr. Robin Kent for Envirowise to help the plastics industry reduce costs through waste minimisation.

UK Government Environment and Energy Helpline 0800 585 794

Calculating the costs

A formal waste minimisation programme can save you up to 1% of turnover (or more than 10% of profit) from effective and low cost waste minimisation efforts. These gains are substantial and you should be doing something about it?

To find out your current costs and performance, use the tables on the right to calculate your specific costs. The information you need should be easy to obtain:

• Use accounts records of purchased material and invoices for contract recycling, waste disposal, etc.
• Use production records to find out how much polymer is used, rather than how much is ordered and delivered.
• Use waste transfer notes (a legal requirement) to find out how much solid waste has left the site. You may have to estimate the waste polymer percentage if you do not segregate your wastes.
• Companies or suppliers covered by the packaging waste regulations will already have data on packaging use.

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If you don’t measure it then you can’t manage it.

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Polymer usage

Identify your three main polymers, group the rest under ‘Others’ and complete the first table.

Polymer usage
Polymer	Amount used (tonnes / year)	Cost (£ / tonne)	Annual cost (£)
1.
2.
3.
Other
Total polymer use	A	B	C

Cost of polymer waste

Complete this table to determine the cost of waste polymer.

Cost of polymer waste
Polymer Waste Route	Amount (tonnes / year)	Cost (£ / tonne)	Annual cost (£)
1. Waste / rejects reground on site
2. To contract recycler
3. Loss in value of polymer sold as scrap.
4. Sent for final disposal
Total polymer waste	D	E	F

Waste reground on site

The cost of regrinding is about 5% of the polymer cost. This includes rejects, trimmings, etc which are reground. Some of these wastes may not be measured and may be hidden.

Waste reground by contractor

You may use a contractor to regrind. This can be cost-effective, but it is useful to examine the full financial case.

Loss from polymer sold as scrap

Sending polymer for scrap will reduce the value by at least 50%. Any income from scrap represents, at best, a corresponding loss of revenue to the same sum. Fill in the amount received for your scrap as the value lost will be at least this.

Polymer sent for disposal

This may include items such as purgings which require specialist regrinding, or items which have become contaminated with oil or dust.

If your waste costs are high, then change the disposal route to maximise the value, e.g. use a contract regrinder or regrind in-house rather than selling as scrap.

First pass polymer waste

Calculate your first-pass polymer waste rate. Is your site better or worse than the industry average of 10.5%? This means that industry average first pass polymer utilisation rate was only 89.5%. This may seem acceptable but it is not just the cost of the polymer that is lost or recycled. There will also be associated losses in direct and additional labour, overhead costs such as energy, consumables and the simple costs of recycling. A steady FTY of 90% therefore costs around 1.4% of turnover (equal to nearly 15% of profits) in the short term and in the long term costs 4% of turnover or nearly 50% of typical profits. First-pass polymer waste has a large and direct impact on profitability!

First-pass polymer waste
Waste percentage = Total polymer waste (D)  / Total polymer used (A) x 100	%

Cost of general waste disposal

Calculate the cost of general waste from the final part of the table.

Cost of general waste disposal
General Waste Route	Amount (tonnes / year)	Cost (£ / tonne)	Annual cost (£)
Disposal charges e.g. skip lifts
Less income from segregated waste			-
Total general waste (tonnes)	G	H	I

Benchmarking

To benchmark yourself against the rest of the industry, get “Benchmarking waste in plastics processing” (EG252) from the Helpline (0800 585 794). This gives figures for other processing companies and the initial waste survey provides a base-line to measure improvement in your performance. Shouldn’t you be doing one now?

The "Waste Minimisation" series is designed to give plastics processors an insight into how to minimise wasting  valuable resources. The series is being published in British Plastics and Rubber on a monthly basis and published here after the BP&R publication. The series is:

Part 1: The Business Reasons

Part 2: A Waste Walk Around and Action Plan

Part 3: Assessing Performance (This Section)

Part 4: Improving Performance

Part 5: Waste Minimisation Tools

 

Download the complete series as an Adobe Acrobat file.

 

Last edited: 29/03/04

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