HVAC is commonly known for disposable pads, framed pads and pleated filters. These are used in residential applications in furnaces and central air conditioning. Pre-filters are similar but used as first step filtration to high efficiency filters in clean rooms, pharmaceutical manufacturing, health care facilities, bio hazard applications and food processing plants. These pre-filters are less expensive than the high efficiency filters and are changed often to prolong the life of the high efficiency filters. GMD designs and builds many types of machines for producing these types of filters such as Laminators, Pusher Bar Pleaters, Rotary Gear Pleaters, Pleat Cutters, Drying Chambers, Frame Making Machines and Re-Heat Systems for re-activating glue on disposable framed filters.