TRUCK dunnage bags

A dunnage bag consists of an inlay made of PE (polyethylene) film which acts as an air chamber. This inner layer is surrounded by a PP (polypropylene) fabric to ensure protection against abrasion and weathering.

In contrast to dunnage bags where the outer layer is made of paper, protection against moisture, e.g. from splashing water or container rain, is guaranteed. In addition, PP/PE dunnage bag can be used between the goods and the container wall. The combination of two plastics also makes disposal more environmentally friendly than with a paper-wrapped dunnage bag with a PE inlay.

Two options have proven successful for filling dunnage bags with air.

If a stationary compressed air system is available, the dunnage bag can be filled using a compressed air gun and a suitable adapter for the installed valve. The advantage is a high filling speed due to the high air volumes available.

When using compressed air, however, precautionary measures must also be taken to avoid overfilling and bursting of the dunnage bag. For example, it is advisable to use a compressed air gun with an automatic blow-off function if the pressure is too high. In addition, the values specified by the manufacturer, such as working pressure and maximum filling pressure, should be observed.

Battery-powered filling devices are a relatively new alternative. Due to their design, there is no compressed air supply line, which reduces the risk of accidents caused by hoses lying around.

Furthermore, it is not so easy to overfill the dunnage bags as the power of the battery-powered devices generally allows somewhat lower pressures. However, these are generally sufficient for the required securing forces in load securing.

The correct size of a stowage cushion depends on the stowage gap to be filled. The aim is to achieve maximum form fit between the adjacent goods or container wall or truck. The dunnage bag should be selected in such a way that it prevents the goods from slipping and at the same time does not damage the goods themselves. To achieve this, the contact surface of the pad with the adjacent surfaces must be as large as possible.

To ensure this, it may be necessary to use different types of construction. In addition to the use of a classic dunnage bag, there are also cubic, 3D dunnage bags or special solutions such as a dually bag consisting of two firmly sewn dunnage bags. The different load carriers such as trucks or containers and their shipping routes such as sea, rail or road also place different demands on the load securing equipment. There is therefore a high variance in the types of dunnage bags available.

The higher the load weight to be secured, the greater the load capacity of a dunnage bag must be. In order to classify performance, the AAR (Association of American Railroads) guidelines define various level classifications. This independently certified load securing equipment guarantees the buyer the quality required for his loading.

The correct selection of the appropriate stowage cushion is regulated in the CTU code.

It describes both how large a dunnage bag must be dimensioned in order to secure a load weight at defined accelerations and friction coefficients.

Another point defined in the CTU code is the load forces that a dunnage bag with known dimensions can absorb.

To select the right dunnage bag, the user must know both criteria and make the selection using predefined formulas.

Practical experience has shown that a pad which is dimensioned according to the load can generally absorb considerably more load force than is actually required. However, this does not release the user from the possibility of consulting the manufacturer of dunnage bags and requesting specific handling data.