Common Problems and Solutions When Packing Multi-Wall Paper and Poly Valve Bags

 A Pasted Valve Stepped End (“PVSE”) bag, is a common industrial packaging style designed to package a wide variety of dry flowable products. Valve bags are packed on equipment that deposits material into the bag via horizontal filling spout. Valve packing equipment can range from manual, hand-spouted equipment to modern fully-automated equipment. 

Manufacturers of quality valve bag packing equipment include: Premier Tech, Haver & Boecker, Choice Bagging, and Magnum Systems.  


Valve bags are filled through an opening located in the top corner of the bag. Product is pumped or forced into the bag via air pressure, impeller, or auger. Properly sizing the bag is critical to achieving your operational objectives.

No matter what type of packing equipment you use, you will eventually run into packing problems. The perfect packing operation requires constant fine tuning and preventative maintenance to run efficiently and effectively. 

Problem #1: Material spews out of the valve when discharged from the filling equipment

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Product has not had the opportunity to dearate resulting in a rooster tail effect when the bag falls off the filling spout. Bag size being too small may also contribute to this problem. 


Momentary delay to allow the product to dearate before the product is kicked off the fill spout. Also, turning down the air flow may improve this problem. A larger bag size should also be considered.  


Problem #2: Valve won’t seal properly


Filling tube is too short and will not let the end of the filling tube clear the insert causing:

  1. Improper ventilation of the bag
  2. Product to stay in the valve area
  3. Weak sealing of the sonic seal sleeve 


Present the bag further onto the filling tube or increase the length of the filling tube.


Problem #3: Bag won’t fill to the desired weight


Too much air on an air bagger will aerate the product which decreases bulk density of the material


Turn down air flow of the packing equipment


Problem #4: Sudden loss of bag capacity


Bag Chair too high or too low will cause the bag to not fill properly, resulting in loss of volume or capacity.


Adjust the bag chair to up or down to achieve the desired fill capacity. 


Problem #5: Bags palletize poorly

Cause: The bag is not sized properly. 

Signs of a bag that is too SMALL:

  1. Rounded Bag
  2. Rolling on transfer conveyor
  3. Poor Weight Accuracy
  4. Excess Spillage 
  5. Valve doesn’t seal
  6. Increased filling time

Signs of a bag that is too LARGE:

  1. Valve doesn’t seal properly
  2. Sloppy palletizing


Properly sized valve bags should not appear too tight or too loose. A general rule of thumb is the amount of freeboard in the top of the bag should be equal to finger length. Freeboard is the distance between the top of the product and the top of the bag when the bag is placed upright.


Are you in need of paper or poly valve bags? 

Our multi-wall paper and poly valve bags are produced with state-of-the-art converting equipment in plants located domestically and abroad. Available in traditional kraft, high performance extensible paper, polyethylene film, or woven polypropylene, Southern Packaging offers a wide variety of bag styles to suit all your valve bag needs.

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Strategically located near Dallas, Texas, our company buys, sells, and delivers more than 1,100 different industrial packaging products to nearly 900 locations across the U.S.

Our substantial inventory includes all styles of FIBCs, paper bags, UN-certified bags, BRC & AIB food quality bags, Poly bags, BOPP bags, dunnage bags, and bulk shipping supplies.