There are essentially three types of portable bag closer designs.
The frame of the machine is smaller and lighter. The Cam and Looper system are easier to set and also the parts are smaller - hence the FISCHBEIN models are usually for fast portable work.
These bagclosers have the same working principle as in any bag
closer. The main difference is the cam and looper system. These
machines are far more heavier and sturdily built for thick materials
stitching. Also the carrier block which moves the main moving part
of the machine is bigger. Overall these type of machines are ideal
for long hour usage and coarse thick material stitching.
There is also a third style of machines - which is known as the SAC-UP type. The machine is much smaller & lighter. The machine can actually be strapped on the "wrist" while bag stitching. The motor is also of a lighter rating and as the parts are smaller - production load handled by this machine is lower.