Converging multiple product lanes into a smaller number of lanes may seem like a simple operation. In reality, the way products are collected, timed and delivered to the downstream machine can have a significant impact on the consistency of the entire process.

This is why designing a lane merger is not simply a matter of considering line speed. First of all, it is necessary to understand how the product behaves: its shape, stability, fragility, ability to run in contact with other products, and the pitch required by the downstream machine are all factors that help define the right solution.

Based on these parameters, M.H. Material Handling designs the merging configuration best suited to the characteristics of the line and the product.

The first criterion is the product: can it withstand accumulation?

Even before speed is considered, the assessment starts with the product and its ability to withstand accumulation.

A product that can tolerate accumulation can withstand the pressure generated by products touching and pushing against one another. Boxes, trays and products stacked in tightly packed formats fall into this category.

A fragile product, or one prone to overlapping, cannot withstand this type of stress, and a pressure-based system could compromise its integrity.

This is why resistance to accumulation is the first factor to be assessed, as it determines whether a pneumatic or dynamic lane merger is required even before line throughput is considered.

There is, however, one useful exception to bear in mind.

Even with a product that can withstand accumulation, the presence of many formats with significantly different widths often makes a dynamic solution preferable. This avoids format changeovers using adjustable or automatically controlled guides and, because the products do not come into contact with one another, eliminates the risk of misalignment.

Pneumatic, DU Series or HP Series: the right technology for each product

A pneumatic lane merger is the simplest and most cost-effective solution, but it is suitable only for products that can tolerate accumulation.

It operates using gates on the infeed lanes, which release the product rows in sequence, and requires two conditions: the products must be able to withstand pressure during accumulation, and the downstream machine must be capable of receiving products in a continuous train without being adversely affected.

The second requirement has a specific technical reason. At the outlet, the products are close together or touching. When this train reaches the downstream machine, the instantaneous speed seen by the machine is therefore twice the average speed. Either the downstream equipment must be able to handle this, or the flow must be normalised using a deceleration conveyor followed by an acceleration conveyor, at the cost of a larger footprint, two additional motors and more complex control logic.

The pneumatic solution is also well suited to a particular application: where the carton itself is the primary package, as is common in the pasta industry, in the section between secondary packaging and the case packer, where the product can be accumulated.

When, on the other hand, the product is delicate or must be handled without contact, dynamic lane mergers are used. M.H. offers two series.

The DU Series merges products by reducing the number of lanes through anti-overlap timing belts operating at controlled differential speeds, one for each infeed lane. Products are handled individually and without contact, making the system suitable for fragile products or products prone to overlapping, at speeds of up to approximately 240 pieces per minute.

The HP Series is the evolution of the DU Series, developed specifically for high-speed flow-wrapping lines and for connections between primary and secondary packaging. In this case, pressure is completely eliminated because the products must never come into contact. Each item is individually timed by means of a multi-belt system with independent brushless drives for every infeed lane, combined with blower-generated vacuum for higher acceleration rates, reaching up to 600 pieces per minute at the outlet. In flow-wrapping applications, precise product timing is essentially mandatory, as it is the only way to prevent products from overlapping.

Outlet pitch: a detail that should not be underestimated

As speed increases, it becomes essential to achieve the most consistent possible product pitch at the outlet of the lane merger, because this determines how the downstream machine receives each item.

A product flow delivered in trains can push the downstream machine beyond its production limits because of the instantaneous speed peaks described above. Individual product timing, on the other hand, controls the distance between packs and transfers them without contact, reducing the risk of jams and overlaps.

The choice always starts with the product

In every case, the starting point is always the product. The first step is to determine whether it can withstand accumulation, then assess its fragility and shape, the required production rate and the number of lanes to be merged, and finally the type of downstream machine, particularly whether it is a flow wrapper positioned between primary and secondary packaging.

The right technology emerges from these answers: a pneumatic lane merger for products that can withstand pressure, the DU Series for products requiring contact-free handling, and the HP Series for high-speed flow-wrapping applications.

At M.H. Material Handling, we manufacture material-handling systems and efficiency solutions for packaging lines in the food industry and related sectors. Over more than forty years of field experience, from food & beverage to pharmaceuticals and packaging, we have developed the expertise required to identify where lane merging can make a real difference and where it is unnecessary. On this basis, we design customised pneumatic and dynamic lane mergers from the DU and HP Series, starting with an analysis of the production line.

If you are planning a new line or a revamping project and lane merging is still an open issue, we can assess it together to identify the most suitable configuration.