Bulk bags for chemicals

Fill heads, scales and the dust they make

Most chemical fill stations hang the empty bag by its four loops on a frame, clamp the spout top around a fill tube, and inflate the bag with a puff of air so the corners open before product flows. Product comes in by auger, gravity gate or vibratory feeder, and a scale under the frame stops the feed at the target weight. A dust hood or vent sleeve pulls displaced air back to the collector.

That sequence is why the top spout diameter matters. Too narrow and it will not seal on the tube; too wide and it leaks dust around the clamp. Send us the fill tube's outside diameter and we'll match the spout to it rather than guessing.

Unloading at the customer's discharge station

At the receiving plant the full bag goes onto a discharge frame over a hopper or a weigh bin. An operator unties the spout inside a closed chamber, often fitted with an iris valve that pinches the spout to stop flow part way. Massage paddles or a vibrator break up product that bridges, which caking powders like soda ash and some pigments tend to do after weeks in a warehouse.

A spout that is too long kinks in the chamber, and one that is too short cannot be tied off again. The receiving plant's drawing of its discharge station is the best reference for spout length, so ask your customer for it before you order.

Where the wrong spec costs you

Static is the expensive mistake. Fine organic powders and solvent-wet products can build charge as they slide down a fill tube. A Type A bag offers no protection. Type B fabric prevents high-energy propagating brush discharges but cannot be grounded, and it is for dry flammable powders only, with no flammable vapour or gas present. Type C has conductive threads and must be clipped to ground during filling and emptying; left unclipped it is unsafe. Type D dissipates charge without a ground. Read NFPA 77 and IEC 61340-4-4 alongside the bag maker's documents, and follow your site's hazardous-area assessment before choosing.

Moisture comes next. Hygroscopic salts and caustic beads pull water through uncoated fabric and arrive as a solid block. Coated fabric with a sealed PE liner keeps them free-flowing. Sifting is third: fine pigment escapes through stitch holes unless the seams are sift-proofed with filler cord or tape, and a dusting bag on a forklift spreads product across the whole plant.

Production campaigns and export bookings

Chemical plants rarely buy bags evenly. A unit runs one grade for a campaign, switches, and runs another, and each grade may need its own printed bag. Export lots pile up before vessel cutoffs, and Gulf Coast product often leaves through Port Houston, which owns and operates eight public facilities along the 52-mile Houston Ship Channel, including the Bayport and Barbours Cut container terminals.

Plan bag stock to the campaign, not the calendar month. Tell us when the grade starts and how many bags the run fills, and we'll set the deliveries so each print arrives before its line does.

What a chemical bag request needs

With these answers we can price the bag and the freight together. Skip the bulk density and we have to guess the body height, which is how a plant ends up with bags that are half air.

• Product name, and whether it is a regulated dangerous good
• Bulk density, or the weight you fill per bag
• Fill tube and discharge chamber dimensions
• Static type from your hazardous-area assessment
• Liner type, and whether it is tabbed or glued in
• Print and document pouch requirements
• Delivery ZIP, dock type and how many bags per drop

Where we ship chemicals bags most

• Texas
• Louisiana
• New Jersey
• Ohio
• Illinois
• Pennsylvania