UNIFORMITY ON THE EXTRUDER

Santiago hi,

the uniformity is in the width. First I tried with the screw but each row is 5 mm and therefore the screw damages the product. The rheology of the dough also changes across the 1200 mm width, having a dough more softer in the edges as the center.

Hi, Antonis,

  the uniformity problem is in the width or in time?

If it is in the width, and the weight curve is slanted to one side, the problem is that the gap between the rollers is not uniform accross, or the rollers and the filler block are not perfectly parallel.

If the dough piece weight accross is not slanted, but it is higher in some rows and lower on others, a solution can be to add restrictor screws. Not very elegant, but it can solve the problem. 

If it is a time variability, then the problem is that the dough that changes its rheology very quickly. Maybe a longer resting time before using the dough can help reach a plateau where the dough doesn't "dry in" anymore and the rheology is more stable from start to finish.

The same happens when the dough comes out cold of the mixer and heats up quickly afterwards, In this case the solution is to have hoppers (and even rollers) jacketed with cold water. 

Check also if the dough distribution inside the extruder hopper is uniform accross and over time.

It's strange that you should have a rheology difference in the width. All dough comes from the very same mixer and is fed equally in the width?

Is this a regular two-roll + filler block extruder? Or rather the type of RBS LP Extruder, where you have a series of hopper and double screws accross the width?