Routing Powder to Multiple Destinations in Pet Food

After the coater the product is adhesive. Fat and palatant transfer to every surface, and a diverter body with a seal face and an idle branch accumulates a layer that nobody sees. The layer is the carryover path, and carryover in this industry runs into the claims printed on the bag: single protein, poultry free, prescription diets, life stage formulations.

The product is also fragile. Extruded kibble breaks at an abrupt change of direction, and the broken pieces are screened out as fines. On a line running several tonnes an hour, a junction that costs one percent of the product is a line item.

Upstream, the meal and premix side has the mirrored problem: fine, fibrous material that bridges in a narrow junction and sits in dead space, with the same carryover consequence for restricted ingredients.

And the plant switches often. Several recipes a shift is normal, which means any cleaning that takes real time will not happen as specified.

A junction whose entire product contact volume can be inspected and cleaned inside the changeover window, or whose contact element is replaceable so cleaning is not the control.

A flow path with generous radii and no step, so finished kibble passes without breaking.

A documented place in the changeover procedure, with a verification step, so the carryover risk has an owner.

For a plastics plant the question is the consequence of a misroute and the streamers a hard junction makes, not carryover.

The finished product side and the meal side are specified separately, because they fail differently. For finished kibble the priority is a smooth, generously radiused path, which usually means gravity diversion with a blade or a plug rather than anything that pinches the stream.

Build up is addressed with geometry and access. Self wiping sealing surfaces, no ledges, no horizontal shelves inside the body, and a hatch large enough to see and reach the seal face. A junction that can be checked in a minute gets checked.

Where changeover frequency is high, a replaceable contact element changes the economics. A flex tube that leaves with the recipe removes the cleaning validation question entirely, provided the pressure duty allows it.

Then the junction is written into the changeover procedure with a verification step, because the only reliable control on a surface that accumulates fat is somebody looking at it on a schedule. Carryover found by a finished goods test is found too late.

• Finished product and meal junctions specified separately against different failure modes.
• Generous radii and no steps in the kibble path to limit breakage.
• Self wiping seal faces, no internal ledges, and an inspection hatch that can be used quickly.
• Replaceable contact element where changeover frequency is high and pressure allows.
• Junction named in the changeover procedure with a verification step.
• Position confirmed by sensors, since a misroute reaches a packed bag.

• Fat and palatant content of the stream, which decides the sealing geometry and the inspection interval.
• Kibble fragility, measured on the product, since breakage reports directly as fines.
• Claim sensitivity of the recipes sharing the line, including prescription and single protein diets.
• Changeover frequency and the time allowed, which decides cleaning versus a replaceable element.
• Number of destinations and the consequence of a misroute at packing.
• Cleaning method, dry or wet, and whether the junction can be dried afterwards.