35 x 35 x 70 in bulk bag

Volume for the light end

35 x 35 x 70 = 85,750 cubic inches. Divided by 1,728 that is 49.6 cubic feet; times 28.3 it is about 1,405 litres. Because 70 is twice 35, this bag holds exactly twice the box volume of the 35 in cube on the same footprint: 49.6 cubic feet against 24.8.

At our assumed densities, plastic resin pellets at 34 lb per cubic foot fill the box at 1,686 lb and wheat flour at 36 lb at 1,786 lb. Both go in a 2,000 lb bag with margin. Seed corn at 45 lb reaches 2,232 lb, which needs a 2,500 lb rating if you want it full, and sugar at 50 lb comes to 2,480 lb, right under 2,500 lb.

Light material traps air. Pellets pour fast, but fine powders arrive aerated and keep sinking for a while after the spout closes, so the same bag can look full at the filler and slack a day later. Vibration, or de-aeration during filling, gets more product in and leaves a firmer bag for the forklift.

Pellet traffic follows the plastics chain: resin plants on the Texas and Louisiana Gulf Coast, compounders and distributors inland, then moulders, extruders and film lines across the Midwest and Southeast. Railcars and hopper trucks carry the big volumes; bulk bags carry colour concentrates, specialty grades and orders that a silo-fed line does not take.

Why sand never goes to the top

Run a dense product through the same sum and it runs off the rating table. Dry sand at 100 lb per cubic foot would be 4,960 lb at box volume, gravel at 95 lb 4,712 lb and cement at 90 lb 4,464 lb. All three exceed 4,400 lb, the highest rating in our tables. A tall bag with heavy product is filled to its SWL and no further: a 3,000 lb fill of sand takes 30 cubic feet, about 60 percent of the box, and leaves close to 28 in of slack fabric at the top.

Slack fabric is wasted bag, and a tall, part-full bag is less steady on the forks. For dense work the 35 x 35 x 35 or 35 x 35 x 45 is the better fit.

Clearance at seventy inches

A 70 in body is close to six feet before you add loops and a top spout. On the fill frame, the hook bar has to sit high enough that the bag's bottom reaches the scale deck or pallet with the loops on the hooks. On the discharger, the frame has to lift the bag clear of the hopper. Plenty of frames built around 50 in one-ton bags will not clear it, so measure, or look at the 41 x 41 x 60, which holds more on a wider base at 10 in less height.

A tall column of light powder can also bridge inside the bag or flow unevenly at discharge. A spout bottom sized to the product, and a discharger with massage paddles or a vibrator, helps; your equipment supplier knows how your product behaves.

Trailer math for pellets

The footprint gives two across and 18 rows in an assumed 53 ft van with 100 in by 630 in of floor: 36 positions. At 1,686 lb of pellets per bag, 36 bags would weigh 60,696 lb, so the 44,000 lb payload stops the load at 44,000 / 1,686 = 26 bags. Even light product in this bag runs out of payload before it runs out of floor. Stacking would not help in a van anyway: two 70 in bags stand 140 in, taller than the inside of a dry van.

Common builds for this height are a spout top or duffle top for pellets and flake, a spout bottom for metered discharge, 2,000 lb SWL at 5:1, and a static type set by the product and the site's assessment. Pellets moved by pneumatic conveying can carry charge; the FIBC bag types guide walks through Types A to D.

Regrind and flake from recycling vary from load to load: bottle flake, film fluff and purged lumps all weigh differently per cubic foot. Weigh a few filled bags from each stream before setting the rating, and treat the heaviest result as the one that counts.

Stored indoors single high, a 70 in bag leaves plenty of air above it in most warehouses, space you are paying for. Some sites put tall, light bags in pallet racking instead of block stacking them; the bag then needs a pallet that suits the beams, and a forklift that can reach the upper levels with a load that tall.