Compactor bags are available in many different sizes, shapes, and materials to match the various trash compactor machines in the marketplace. The size of the bag depends on the compactor's manufactured width, which is usually between 15 and 18 inches (38 and 46 cm). Most compactors are designed with a round or rectangular shape, requiring a bag that fits these dimensions. Additionally, the bag may be made of plastic or paper.
Most trash compactors are designed to fit into a standard kitchen cabinet space, much like a dishwasher. As a result, compactor bags are offered in only a few different widths. The 15 inch (38 cm) bag width is common for under-the-counter compactor installations; however, 18 inch (46 cm) bags are available for compactors that are freestanding. Since they do not need to adhere to a cabinet space installation, freestanding compactors have fewer design restrictions. Typically, these compactors are therefore larger, and require the wider bag.
Compactor bags also need to conform to the machine's shape, which is usually either a round or rectangular. Most rectangular compactors are under-the-counter machines that fit within the cabinetry. Freestanding compactors can use either round or rectangular compactor bags, based on the manufacturer's overall design. The consumer should verify the compactor's shape before purchasing to ensure that the correct bag is chosen; incorrectly sized or shaped bags are prone to breaking.
Some bag manufacturers offer a universal bag that conforms to both the round and rectangular shaped compactors. Consumers should confirm that the bag is marked as universal before placing it in the machine. These bags are helpful alternatives, especially if the local store has run out of a specific compactor bag shape choice.
The material from which compactor bags are made is also an important consideration. Weak material can cause a bag to leak under the compaction pressure, leading to messy spills. Plastic compactor bags are not basic trash bags, rather they have a specialized design that allows them to adhere to the compactor's walls so that the material does not move during the machine's operation.
Paper compactor bags normally have an internal liner that allows them to resist breakdown from trash moisture. The paper bag design is more sturdy than the plastic, which allows the bag to retain its rectangular shape when removed from the compactor. Many consumers prefer this older bag style, compared to the plastic, since there is less chance of an accidental leak during transport from the compactor to the outside trash can.