B&C Coatings

1.WASTE MINIMISATION

Introduction

Waste minimisation is the process of systematically reducing waste production. The process covers raw materials consumption, product loss, energy and water consumption, packaging, effluent production, wasted effort, and all other solid, liquid and gaseous wastes.

Companies that reduce the amount of waste produced not only reduce waste management costs, but also save in raw materials costs through reduced resource wastage. Minimising waste can also help reduce environmental liability and insurance costs, and yield income from the sale of reusable waste.

Waste Survey

A waste survey of B&C Coatings was undertaken on the 26^th October, 1999. The survey was carried out as an initial review using data collected on site and involved:

• Identifying wastes. A site tour, detailed discussions with Mr J King proprietor of B&C Coatings, and observations were used to identify wastes generated by each process/area.
  
  
• Gathering basic quantity and cost data. Historical waste and purchase record data was collated to determine raw materials consumption, waste quantities and disposal costs. Although information gathered from historical data did not cover all wastes (i.e. product loss, handling costs, etc.), it was sufficient to identify opportunities for reducing waste. The majority of waste routes need to be better defined.
  
  
• Identifying opportunities for reducing waste. Using the available data and our experience of energy and waste management, areas of the business where there are opportunities to reduce waste were identified.
  
  
• Identifying legal obligations. All companies have a duty of care to ensure that wasted materials are managed correctly. An assessment of compliance with relevant legislation was also made.
  
  

Recommendations

• Targets are needed for a reduction in paint and powder waste. Initially, we suggest a figure of 2% reduction against a production baseline given in terms of sales value or monthly turnover. We recognise that the blend of work has changed significantly over recent months so that new targets need to be "flexed" against sales value by work category.
  
  
• Improved technology is needed to speed up the coating/curing process and to allow more flexibility in terms of components sizes in the various processes. There is significant scope for reducing energy cost and improving throughput. For example, we envisage that for certain finishes the throughput cycle could be halved in time through adoption of improved handling and drying technology.
  
  
• Coating technologies have improved significantly over recent years. B&C keep abreast of current technologies but are often restricted by customer specification. A formal waste management, quality control and environmental management system will assist in giving weight to any requests made by B&C to use alternative coatings.
  
  

  It must be noted that due to the jobbing nature of B&C, colour changes in the process occur regularly (small component batches) so that no attempt is made to recover powder. Powder coating is an effective but extremely wasteful process.

  We have undertaken some crude calculation based on manufacturers figures, B&C figures and assumed powder coat densities.

  Manufacturers of powders typically state that for an 80 micron coat 1 kg of powder will cover 10 sq. m. of component. This is optimistic since this relates to the spraying of large flat objects rather than for example, railings.

  B&C estimate work based on a figure of 6 sq. m per kilo of sprayed powder. The component coating has an average density of 0.5.

  We estimate wastage as follows:
  
  6 sq m of coat per kg at a thickness of say 80 microns
  
  = 240g adheres to metal
  
  = 760 g to waste

  This means that out of the £21500 per annum spent by B&C on powders, powder to the value of £16,340 is sent as waste. B&C cost this waste into the work. However, this issue is worthy of further consideration.

• Increase the degree to which packaging is returned to the customer. Disposal of waste packing can be expensive as well as having an adverse effect on the appearance of the site. Storage of an excess of non-returnable wooden packing also presents a fire risk close to the building.
  
  
• Store all waste records in a central file and ensure that all waste transfer notes and consignment notes are retained. These should be indexed and if possible entered into a spreadsheet by waste category.
  
  
• Consideration is needed with regards to the disposal of wipes and rags used for cleaning of work. Organic solvents are used for cleaning since an effective aqueous alternative has not been found. It was noted that some of the solvent cleaners in use contain DCM (Dichloromethane) which is extremely hazardous to personnel and to the environment.
  
  
• Disposal of liquid waste proves expensive since there is an unknown mixture of inorganic pigments and chlorinated/non-chlorinated organic solvents. Segregation into say three different containers may make waste disposal easier and less costly. Indeed, paint residues from a single type or source of product can be distilled for valuable solvent recovery rather than incinerated.
  
  
• A large amount of paint and solvent materials are delivered to site in metal drums (i.e. 25 litres). These containers accumulate at the rear of the factory in a steel cage. This cage fills until an operative can find time to crush the drums with a fork lift truck and place them in the skip for disposal. The company should seriously consider a small can crusher or compactor since this would save personnel time, increase skip loadings, improve the appearance of the site and reduce the risk of fire due to a large number of empty containers being stacked at the rear of the factory.
  
  
• The waste routes on site are relatively complex. Powders are not recycled due to the jobbing nature of the shop. A further investigation is need into defining waste streams on site. The streams should be shown as flow charts or on a suitably detailed site plan to allow improvements in routing, handling, segregation and disposal to be strategically planned.
  
  
• In order to reduce wastage of energy for the drying curing processes it will be necessary to redesign and to an extent replace the ovens used for dying.
  
  
• The company has carried out certain modifications to date to prevent the egress of powder from the site.
  
  
• B&C needs to ensure that compressed air generated on site is utilised effectively. At the present time the valve at the base of the in-line pre-filter is left partially open to expel condensate form the air line. This is not acceptable. Firstly, wasting air is expensive since it results in excessive compressor run/load hours and unproductive electrical energy consumption. Secondly the condensate contains mineral oil. This cannot be allow to enter surface water drains and should not be piped onto the ground. This material must be collected and disposed of in a suitable manner.
  
  

  There are two main items in need of rectification. A timed solenoid type condensate blow down valve should be fitted to the filters and other points of blow-down in the system such as the receiver. This will allow say 10 seconds of blow-down per hour and will reduce air wastage significantly.

  The oil/water emulsion (condensate) must be collected in a container and sent as special waste or an oil water separator should be installed. This would allow the water to be piped to the foul drain, the oil being collected in a suitable, labelled, closed 205 litre containers for collection as special waste by an approved oil recycler once per annum (or less). The less air that is wasted the less condensate is produced.

• It is important that liquid waste (solvents/oils/etc.) stored to the rear of the premises are treated correctly. These liquids should be identified, sampled and decanted into suitably labelled sealed steel drums. The waste drums should be placed in a safe, dedicated, labelled, bunded area to the rear of the site where they can await collection as special waste by an approved contractor.
  
  
• Skip usage is small. Three 6 yard lidded special waste skips are utilised per annum at a cost of £600.00 total.
  
  
• The process of burning waste packing on site needs to be reviewed. This is not generally acceptable. An alternative disposal method should be considered.
  
  
• At the present time a large number of empty drums are left open (to minimise explosion risk). These fill with rain water. This water is then poured onto the ground or into a surface water drain prior to crushing the container. This process is not acceptable and could result in severe penalties should a watercourse become contaminated. Drums should ideally be stored under cover or crushed straight away and placed in the skip.
  
  
• Waste produced by re-work can be reduced. At the present time inclusions in the finish mean that around 5 to 10% of work requires re-work. This is expensive and wasteful. Inclusions result form the poor fabric of the building as well as particulates dislodged from the track due to vibration and operator error. Other problems such as over-spray, drag etc result from operator error in the wet finishing process. Issues such as using the wrong colour on a component are few and far between. Rework could be reduced significantly by the adoption of a formal work and order processing system employing job cards that stay with the work through its progression around the site.
  
  
• Use of 2 packs is increasing on site. There will be an increase in waste paint residue due to the process. Approximately 1 litre is required to prime the paint gun line. A 2 pack is not re-usable since it will cure and cannot be placed back in the tin, thinned and mixed like a traditional solvent based 1 part paint.
  
  
• A great deal of personnel training is required in order to reduce waste. This ranges from basic awareness (e.g. when on site the hot water tap in the toilet was left on) to methods of reducing managing and segregating waste.
  
  

2. BASIC COST DATA

The company's principal resources, waste outputs, quantities and cost (where available) are listed below. This data was collated from historical purchase and waste records. Although different units of measurement make it difficult to determine annual quantities, the data is useful in highlighting high consumption and cost resources and wastes.

B&C utilise the following materials. A detailed analysis of the quantity of each material i.e. the solvent content of paints and thinners, is very complex and is not given. However the principle areas of waste can be associated with the materials utilised in the processes.

• 2 pack wet products.
• Traditional wet paints/primers/etch primers.
• Thinners (e.g. cellulose) gun wash, degreasers, paint thinners etc.
• Polyester powders.
• Epoxy-polyester powders.
• Pre-treatments for galv components.
• Rags and tack-rags.
• Polymeric and bubble pack packaging and adhesive tapes (PVC).
• Paint strippers.
• White spirit.
• Waxoyl.

Records show that B&C spend annually in the region

3. COMPLIANCE WITH WASTE MANAGEMENT LEGISLATION

Controlled Waste

Part 2 of the Environmental Protection Act 1990 (EPA) defines any waste that comes from industrial, commercial or domestic sources as being controlled waste. The EPA established a duty of care on anyone (except householders) who has control of, or responsibility for, controlled waste at any stage from its production to its disposal.

Special Waste

Certain controlled wastes are considered to be potentially hazardous and require special handling and treatment. The handling of these wastes is controlled by the Special Waste Regulations 1996 (SWR) as amended, which defines a more stringent system of control.