How automatic bucket washing saves water, cuts costs and frees up skilled talent

In paper and cardboard printing, efficiency, consistency and sustainability are key. One often overlooked opportunity to improve all three is found in the humble 20-litre polypropylene (PP) ink bucket. These containers, commonly used to store water-based inks, can either be a costly waste item or a valuable reusable asset – depending on how you handle them.

In this article, we reveal why cleaning these buckets is more than just good housekeeping: it’s a smart business decision.

While empty buckets are usually not classified as hazardous waste, ink residues can turn them into special waste, which drives up disposal costs. This is particularly relevant when using ready-mixed inks, but even more so when you’re mixing your own colours using an ink dispensing system, or when you’re tapping CMYK or extended gamut inks from large containers into 20L buckets.

Water-based inks dry out inside the bucket, forming hardened particles on the walls and bottom. When reused without proper cleaning, these particles can contaminate fresh ink, causing defects in the printing process.

Another issue is microbial contamination. Water-based inks are highly susceptible to mold and bacteria. Dirty containers are a breeding ground for these, putting your print quality – and even food safety compliance – at risk.

A new PP bucket costs around €5 in Europe. For medium-sized printers consuming 150 tonnes of ink annually, with an average dispense batch size of 15 kg that’s about 10,000 buckets per year. Cleaning and reusing them significantly reduces purchasing costs and waste volume.

Many printers still rely on manual cleaning: two hoses – one with water plus detergent (30:1 ratio), the other with clean water – are used to rinse, soak, and then scrub the buckets. Lids are usually cleaned in separate trays. Water-based inks dry irreversibly, so every empty bucket should be cleaned quickly. Operators, however, tend to save up a batch first before washing, increasing the risk of dried-in ink.

Even with light soiling, this process takes at least four minutes per bucket. With stubborn ink or dried residues, it can take significantly longer. Besides the time and labour involved, manual cleaning quality varies per operator, making it less reliable and water-intensive.

Moreover, in an industry facing a skilled labour shortage, having operators manually clean buckets is not the best use of talent.

Automatic bucket washers with rotating brushes offer a faster, more consistent solution. These machines use high-pressure water and detergent to clean inside and outside surfaces thoroughly. The bucket is rotated during cleaning, for maximum effect.

A cleaning cycle takes around two minutes, with the operator only spending seconds loading and starting the machine. Some machines come with a detergent unit for even better cleaning results.

Automatic washers can be fitted with an optional water-saving system with filters, reducing water use by up to 80% – down to just six litres per cycle instead of 30. The system works in three phases:

1. Initial rinse with detergent (dirty water is discarded)
2. Wash with recycled and filtered water (returns to storage tank)
3. Final rinse with fresh water (flows back into the tank)

This makes a significant impact. Cleaning 10,000 buckets annually with a water saver saves around 240 m3 – equal to the water usage of more than two average Dutch households.

And with global water tariffs surging – by almost 10% in this year alone – reducing consumption is also an economic imperative, as well as an ecological one.

Without an in-house water treatment system, disposing of polluted wash water can be expensive and legally sensitive. In the Netherlands, for example, wastewater containing ink is not permitted to be discharged into the sewer system; it must be collected and treated as industrial waste. All the more reason, therefore, to use less – and filter more.

These tables show that automatic bucket cleaning can bring huge time and cost savings. Please note that projected cost savings are based on water and electricity tariff and wage data for the Netherlands, and may vary from region to region.

Factoring in labour, water and disposal costs, a bucket washer typically pays for itself within about two years, based on the metrics discussed above. Add a water saver, and ROI is achievable in also two years. After that, it’s all savings. These figures are based on 2025 costs – but if a volatile climate raises the risk and severity of water shortages, such investments will become a necessity, rather than a matter of ROI.

Clean buckets aren’t just cleaner – they’re smarter. By investing in automatic bucket cleaning, you improve print quality, cut costs, reduce waste and support food safety compliance.

In a time of rising environmental pressure and operational costs, that’s a win on every front.

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