Multi-Wall Paper Sewn Open Mouth Bags

Traditional & Tough

A Sewn Open Mouth (“SOM”) multi-wall paper bag is a common industrial packaging style designed to package a wide variety of dry flowable products. The SOM bag is an open mouth bag that is closed using sewing thread.

Open mouth bags are packed on equipment that deposits material into the bag via hopper or vertical filling spout. The bottom of the bag is pre-closed by the bag manufacturer. Once the bag is filled, the flush cut open end of the bag is sewn closed by the user. SOM bags can be equipped with an easy-open pull tape feature to quickly open the bag and discharge its contents.

SOM bags were one of the earliest multi-wall bag constructions available in the market. Today they remain a tough, economical, workhorse bag style for a broad range of applications. Bags can be packed on manual or fully automated equipment.

Closure Types

To package basic free-flowing products such as animal feed, rice, seed, and fertilizer, a gross weight open mouth bagger under a control hopper would be considered. An operator places an empty bag on a conveyor that transitions to the filling mechanism. The bag's mouth is presented manually or automatically on the fill spout and filled until it achieves the desired weight. The filled unclosed bag then transfers to a sewing head where it can be manually or automatically fed through the sewing head. Once the bag is closed it will transition to the pallet for shipping.

Plain Sew

Used with larger size material that won’t leak out between stitches. Options include 1 thread (generally with portables) or 2 threads (fixed heads, high speed applications).

Plain Sew with Bag Top Fold Over

Reduces major leaking.

Tape Sew with an EZ Pull Tape

Allows quick opening of sewn bags.

Paper Types

Traditional Kraft Paper	High Performance Extensible Paper
Manufactured from short wood fiber	Manufactured from long wood fiber
Heavy, coarse sheet	Smooth sheet
Strength through high basis weight	Strength through superior stretch and flexibility
Limited stretch	6-7% stretch
Low levels of porosity	High levels of porosity
Limited energy absorption	Superior energy absorption
Ideal for 3-4 ply bag construction	Ideal for 2 ply bag construction