It’s a topic that frequently comes up when we’re speaking to operators about their first investment in shredding technology – “Do I need a primary shredder or a secondary shredder?” In fact, even experienced materials handlers revisit the question when they’re expanding their facilities or pushing ahead with new innovations.

So, whether you’re an UNTHA customer, or you’ve never spoken to us before, we want to help – we’ve 50+ years of shredding knowledge to share, after all.

To explore this particular subject, Sarah Murray (UNTHA UK’s sales coordinator), it’s over to you…

There are usually three key reasons why a business invests in an industrial shredder:

• Volume reduction: To transform large, bulky materials into a smaller product – either to free up space, and/or improve the efficiency of onward transportation, or achieve a defined fraction size.

• Liberation: To ‘free up’ various composite materials that may otherwise remain ‘locked’ inside a product.

• Separation: To optimise the effectiveness of downstream material segregation processes to maximise recycling rates or alternative fuel production efficiency.

To understand whether you need a primary shredder or secondary shredder, you firstly need to think about these three factors, in relation to your own facility.

It’s then important to review which types of machinery exist in the market, which could help satisfy your objectives. Historically in the Waste to Energy sector, for instance, organisations wishing to produce a sophisticated Solid Recovered Fuel, would firstly need to pre-shred materials like C&I waste in a primary shredder. Once size reduced, a secondary shredder could achieve a more refined shred required for even the most complex SRF specification. Yet shredding technology has evolved which means one waste shredder alone can now often create an on-spec fuel – such as ‘Quick SRF’ for example – in a single pass. Think less capital outlay, less maintenance and less ongoing energy consumption – with a greater return.

Much depends on the application concerned.

Now, primary shredders have larger cutting chambers, higher torque (without the wear or energy impact), and increased throughput potential. They can cope with a more diverse range of input materials including bigger, more complex ‘wastes’ with larger bulk densities – as the new UNTHA ZR proved when it was launched in late 2021. I’d go so far as to say pre-shredding innovation has changed how the industry thinks about what remains a troublesome waste, and what can now be harnessed as a resource. We only have to consider ever-growing industry demand for shredders that can handle applications like tyres and mattresses, for example, to validate this point. These awkward materials aren’t discarded anymore.

Where a secondary shredder is required as part of a wider system, the effectiveness of primary shredders now means the post-shredding process is usually more efficient, and the technology can achieve far more – not least in terms of throughputs and specification versatility.

Want to discuss this topic in greater detail? Drop us a line or call the team on 0330 056 4455, and let’s chat!