Semi-automatic vs fully automatic stretch film rewinding machines

What both machines do

Both types unwind a jumbo roll and rewind the film onto smaller rolls, stopping at a preset length or weight. The winding itself is automatic on both. The difference is what happens at the end of each roll, and a rewinder finishes a roll every few seconds or minutes, all day long.

Semi-automatic rewinders

At the end of every roll the operator:

1. stops or slows the machine,
2. cuts the film,
3. removes the finished roll,
4. slides a new core onto the shaft,
5. fixes the film end to the new core (by wrapping it round by hand or with adhesive) and restarts.

The machine takes care of length counting and winding speed; on simpler models the jumbo roll is also centred by hand. Winding speeds vary by model; what limits the output is the time lost at every roll change.

Fully automatic rewinders

When the set length is reached, a fully automatic rewinder cuts the film with a flying knife, takes a new core from its core magazine, catches the film on it (a static charger helps the film grip the core) and ejects the finished roll, without stopping the line. The operator's job becomes loading jumbo rolls and cores, and packing.

All Öncümak rewinders are fully automatic. The SR-1500, for example, runs at up to 1210 mt/min, holds 100 paper cores (Ø50 mm) in its magazine and produces three 200 m rolls per minute.

Side by side

How much does it change output?

A simple way to compare is rolls per hour = 3600 ÷ (winding time + changeover time), where winding time = roll length ÷ speed.

• Semi-automatic example: even at the same 1210 mt/min as the SR-1500, a 200 m roll takes about 10 s to wind. With a 30 s manual changeover, one roll takes about 40 s, or about 90 rolls per hour, if the operator never pauses.
• Fully automatic example: the SR-1500 finishes three 200 m rolls per minute, which is 180 rolls per hour.

The shorter the roll, the more the changeover dominates. That is why automation matters most for short hand rolls, and less for long machine rolls that are changed less often.

Which one to choose?

If you sell standard rolls in steady volumes, a fully automatic machine usually pays for itself through output and labour. For a step-by-step choice, see how to choose a stretch film rewinding machine.