Mobile or stationary shredder?

This article explains how flexibility, throughput, and costs can be compared using a technically sound evaluation approach. The aim is to establish a comprehensible decision-making logic that leads to the most economical solution. It is based on the material, the location, and the planned mode of operation.

Starting point: Price is not the only factor influencing the purchase decision

When making investment decisions relating to processing, a mobile shredder is evaluated as part of a process concept: feeding, material flow, separation, and logistics are all interlinked. The purchase price (CAPEX) is therefore only part of the picture. The decisive factors are how much usable output per hour is produced at stable operating costs and how much material changes, impurities, or short site deployments influence availability.

For managing directors and plant managers, it is worth taking a look at the overall effect: if pre-shredding is possible directly at the point of origin, transport distances are shortened or trips are reduced. This can quickly make the difference between needing four trips of 35 km each per day or only two, with the same amount of material but a lower volume load. If you want to take a closer look at the general conditions, you can focus on typical scenarios from commercial waste recycling. There, it becomes clear how much the material mix and operating concept influence economic efficiency. Such kilometers add up to OPEX over weeks.

Would you like some advice? ARJES offers state-of-the-art shredding solutions in both mobile and stationary versions. We can advise you on suitable machine designs and bespoke solutions.

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Evaluation logic: This is how the comparison becomes reliable

In order for flexibility, real throughput, and CAPEX/OPEX to be truly reliable in comparison, a common evaluation logic with clear key figures is required. Three perspectives have proven themselves: technical parameters, operational constraints, and costs per ton.

Flexibility: Material mix, changeover, and tolerance to contaminants

– Range of material flows (e.g., commercial waste, wood recycling, tires, scrap recycling).

– Changeover effort (tool or shaft change, adjustment of counter jaws, inlet geometry).

– Tolerance to impurities (metal content, bulky fractions, varying moisture content).

At ARJES, adaptation to different material flows is conceptually designed using shaft types and adjustable counter jaws. In practice, it is less important whether a change is possible in principle, but rather how much downtime realistically occurs and whether changeovers can be scheduled into the course of a shift.

Throughput: Which factors determine the actual output

Throughput is often understood as t/h. However, the usable output is decisive for economic efficiency. The proportion that reaches the subsequent process steps in the desired quality is therefore the relevant reference value. Typical influencing factors are:

– Final grain size or required particle size
the finer the desired discharge size is set, the greater the reduction in real throughput

– Material density and structure
wood, rubber, mixed fractions, metal content

– Feeding
even vs. intermittent, hopper design, conveyor technology

– Contaminants
steel content in tires, foreign metals, long films, wire

A mobile shredder can score points if it runs stably with changing inputs and thus generates fewer unplanned stops. One hour of downtime usually has a greater impact on daily output than theoretical peak performance.

CAPEX/OPEX: Separate costs clearly and evaluate them over the entire service life

CAPEX typically includes the machine, peripherals, and commissioning. Depending on the project, this may also include conveyor technology, magnetic separation, protection and enclosure solutions, and infrastructural adjustments at the site.

OPEX includes energy (diesel or electricity), wear parts, maintenance, personnel, downtime, and logistics and disposal costs. Mobile applications in particular often have an additional logic: the machine travels to the material, not the other way around. If this eliminates six trips of 45 km each per week, that’s 270 km less, which has a direct impact on costs and capacities. Equally relevant are routes on site: an optimized layout can save 20 to 40 m of conveyor belt or reduce internal wheel loader distances by 200 to 400 m per hour. Such details become noticeable in OPEX over operating hours.

Direct comparison: operating models in the TCO check

The decision between “mobile or stationary” is rarely binary. Especially with changing material sources, from seasonal construction waste recycling to constant packaging fractions such as paper recycling, the economic advantage often only arises from the right mix of pre-shredding and downstream process steps.

– Flexibility in comparison: locations, changeover times, material changes
– Throughput comparison: stability, final grain size, and process reliability
– CAPEX/OPEX comparison: investment, energy, wear, downtime

Practical example tires: Why this fraction is technically challenging

Tire streams are considered challenging because rubber is elastic and also contains steel components. The process must therefore cope with changing material behavior without disproportionate increases in wear or instability in the material flow.

Typical technical challenges include steel belts and wire components, which affect tool geometry and material removal, as well as the desired particle size for downstream separation or granulation steps. Economic efficiency therefore depends not only on the shredding itself, but also on process stability: If pre-shredding is designed in such a way that subsequent separations run more smoothly, downtime across the entire line is reduced.

The connection to ARJES is obvious, because we explicitly see material flows for tire recycling as an application. The follow-up process is important for the design: desired particle size, intended metal separation, and consistency of input.

Decision matrix: Which priority suits which operation

Clear prioritization helps with quick preselection. The following key questions put flexibility, throughput, and costs in a verifiable order:

– How much does the material mix fluctuate over the week and month?

– What annual volume is to be processed, and how many shifts are planned?

– What logistics routes are currently involved (e.g., 20 to 60 km per tour), and how do they change with on-site pre-shredding?

– What downtimes are tolerable, and what service windows are realistic?

– Which cost item dominates in the operation: energy, wear and tear, personnel, or logistics?

Those with high material variance prioritize flexibility and predictable changeovers. Those who consistently process large quantities prioritize stable throughput and process reliability. Those who are strongly OPEX-driven prioritize energy per ton, wear per ton, and availability.

ARJES in context: Selection paths for mobile shredding

ARJES develops and manufactures recycling machines, in particular slow-running twin-shaft shredders. Two paths are helpful for internal orientation when classifying the portfolio:

For mobile applications with moderate use, it is worth taking a look at the COMPAKTOR series.

For an optimal cost-benefit ratio in the field of composting and wood processing plants as well as in the processing of commercial waste, the EKOMAXX line is recommended.

If higher performance requirements and robust material flows are the focus, the TITAN product line is a relevant point of comparison.

The project logic of material mix, final grain size, and application profile is important for making the right economic choice.

The quickest way to determine whether the COMPAKTOR, EKOMAXX, or TITAN line is the right fit is to talk to us. Let us advise you on the right solution for your material, location, and TCO.

Make an economical decision, compare technically clean

The best economic decision is made when material, final grain size, location, and mode of operation are considered together. A mobile shredder not only affects throughput, but also logistics, availability, and cost per ton. Those who consistently combine flexibility, real output, and CAPEX/OPEX in the TCO model will quickly recognize which solution is right for their own operation.