Comb binding is based on two individual processes – punching the documents that are to be bound and openingthe binding comb so that the punched documents can be inserted. Depending on the machine, punching can either be manual or electric, however the comb opener is always operated manually. Nearly all comb binding machines perform both processes, but it is important to read the description thoroughly because there are a few machines on the market that only offer comb opening (generally used in high-volume production environments to allow punching and inserting to be done simultaneously by two different people).
When researching comb binding machines, there are a number of factors to consider in terms of punching. The primary difference between available models is whether they are manual or electric, which has a major impact on the speed at which the operator is able to complete a job (with electric punches being much faster). Some punches only punch letter-sized paper, while others can accommodate larger sizes. The punch capacity (the number of sheets that can be punched at one time) ranges from 6-55 sheets, and some machines offer the ability to selectively disengage some or all of the punching pins (which allows the user to punch non-standard paper sizes or specialty paper, such as three-hole paper). Many machines include an adjustable depth margin, enabling the operator to move the placement of the holes relative to the edge of the paper. Select machines include other punching patterns in addition to the 19 hole comb pattern, making them a cost-effective option for organizations interested in performing multiple binding styles (such as coil and wire).
All comb openers generally function the same way – when the operator tugs on the handle, small hooks grab onto each of the rings and gently pull them open to allow the pages to be inserted. Depending on the machine, the opener itself is made from either metal or ABS plastic. Each model has its own maximum binding size, so it is important to evaluate your binding needs before making a purchase to help ensure that the machine you buy accommodates the sizes you will be utilizing.