1,000 lb SWL bulk bags

Who fills a half-ton bag

Half a ton is the rating for jobs where the batch, the forklift or the floor cannot take more. A specialty ingredient plant weighing out a recipe, a seed dealer splitting a load for smaller farms, a compounder with a light-duty lift truck, a pilot line that runs a few hundred pounds at a time. Each of them would leave a one-ton bag part full or overload the equipment that moves it.

Hand-operated gear sets the limit in some places: a manual chain hoist over a small hopper, an electric pallet truck in a narrow aisle, a mezzanine floor with a posted load rating. A half-ton bag lets those sites use bulk handling without buying new equipment.

It is also the right rating for light product in small bags. Plastic pellets at our assumed 34 lb per cubic foot fill a 35 x 35 x 35 at 843 lb and flour at 36 lb fills it at 893 lb, under 1,000 lb with the bag full.

The test-load arithmetic

SWL is the most the bag is made to carry in use. The safety factor is the multiple sample bags of the design had to survive in the type test. For a single-trip bag at 5:1, 1,000 x 5 = 5,000 lb. For a multi-trip bag at 6:1, 1,000 x 6 = 6,000 lb. Neither number is a loading allowance: the test is destructive, the bags tested were samples, and the label's 1,000 lb is the limit for every bag you fill.

In metric, 1,000 lb / 2.20462 = 454 kg. A bag rated at 500 kg is a different bag: 500 x 2.20462 = 1,102 lb. The two are close, but a label in kilograms is tested in kilograms, so order by the unit on your spec and do not swap one for the other.

A label that reads SWL 1,000 lb 5:1 is a complete statement; one that reads only 1,000 lb is not. Look for the safety factor, the static type, the standard, the maker and a production date, and do not fill a bag whose label is missing or unreadable.

Volume a 1,000 lb fill needs

Divide the weight by the density. At our assumed figures, 1,000 lb of plastic pellets at 34 lb per cubic foot takes 29.4 cubic feet; flour at 36 lb, 27.8; seed corn at 45 lb, 22.2; sugar at 50 lb, 20.0; granular fertilizer at 60 lb, 16.7; cement at 90 lb, 11.1; gravel at 95 lb, 10.5; dry sand at 100 lb, 10.0.

So 1,000 lb of pellets wants more room than the 35 in cube's 24.8 cubic feet, such as a 35 x 35 x 45 at 31.9, while 1,000 lb of sand fills 10.0 / 24.8 = 40 percent of even the smallest size in our tables. Dense product at this rating goes in short or smaller custom bags; send the product and the weight and we size it from there.

Lifting and loading half-ton bags

Light bags still lift by every loop. Put the forklift tines through all of them, or hang all of them on one crane hook or a lifting bar, and keep the loops vertical. Never lift a four-loop bag by one or two loops, never drag it, and stand clear while it hangs.

Small bags get mishandled precisely because they look manageable. Two people hauling a half-ton bag across a floor by its loops will tear seams that a proper lift never stresses. Move it on a pallet or by all its loops, and nothing else.

A truck adds up differently at this weight. An assumed 53 ft van with 44,000 lb of payload could take 44 bags of 1,000 lb, but the floor holds 36 bags of 35 in square single stacked, so the floor fills first at 36,000 lb. This is the one rating where stacking two high can matter, and only with bags rated for it and a product that holds its shape.

• Usual sizes: 35 x 35 x 35 and 35 x 35 x 45
• 5:1 single trip for most small-batch work
• Spout top and spout bottom for powders; duffle top for pellets
• Type A, B, C or D, set by the product and the site's hazardous-area assessment