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What You Need to Know Before Buying a Valve Bag?

Aug. 11, 2022

Valve bags are machine-filled packaging bags. They come in plastic or paper. ZHONGCHENG is a wholesale manufacturer, and our valve bags have various options. This article will provide some basic information about valve bags.


The benefits of valve bags

Valve bagging is the use of special machines to fill bags. The machine uses nozzles placed in or near the opening of the bag. Place a measured amount in each bag. This can be done in a fully automatic or semi-automatic manner. This ensures quantity consistency and minimizes product loss.


What you need to know before buying a valve bag?cid=3

The benefits of these machines are numerous and span multiple industries. The biggest benefit is the volume of bags that can be filled and closed per hour. The output is significantly higher than the output accomplished by the employees. Increased production translates into higher profits by fulfilling orders faster. Businesses that switch to this approach often find that the cost of the machine is quickly covered and a return on investment is quickly realized.


Valve bag filling

The valve bag is filled through an opening located in the top corner of the bag. Product is pumped or forced into the bag by gravity, air pressure, impeller or auger. When the bag is discharged from the packaging equipment, the force generated by the product within the bag causes the valve opening to self-seal. 


Valve bags can be equipped with different valve or "sleeve" types. Common sleeve types include paper inserts, polylocks, tucks, and sonic seals. Each socket type performs the same basic function. However, when designing a valve bag, you need to evaluate the type of sleeve that is right for your product and packaging equipment.


What's in the valve bag

Valve bags are ideal for fast and efficient packaging of flowing dry products. The valve bag construction creates a square bag that stacks very securely and product information can be printed on the side or end panels for easier product identification in pallet loads. 


Common valve bag applications include:

Cement, sand, flour, filter media, beans, seeds, corn, sugar, cocoa granules;

Mortar wax, silica, humate, stearate, calcium chloride, mineral clay, zeolite fiber, etc.



Once the size and type of closure is determined, the coating inside and on the bag is determined. The options are very extensive. We offer all the most common and some less common coatings. The exact coating depends on how the product and packaging are stored, shipped and displayed.


A variety of coatings are available. Coating options vary depending on whether the coating is placed on the inside or outside of the bag. Some products may benefit from a coating of both.


The inner coating is most important when the product in the bag is a food or non-food product. In these cases, a food-safe coating must be applied to the inside of the bag. This coating helps ensure that the contents remain safe to eat and maintain freshness. Interior coatings also help minimize moisture entry and/or prevent product oozing. These are very important features for many products.


Some exterior coatings offer the same or similar benefits. Coatings can be used to block moisture, block contamination from the outside to the inside, or make the bag easier to handle. While protecting the package contents is most important, ease of storage is also important. The outer coating can be used to minimize friction when the bags are rubbed together, thus helping to minimize bag damage and product loss. A simple coating can also help filled bags hold their shape.


Paper valve bags come in a variety of sizes. We offer paper valve bags from small to large and many sizes in between. It is important to verify the size your valve bag machine handles. You are welcome to contact us for customized services!

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