If you need to buy a valve bag filling machine, you may be at a loss as to where to start.

A valve bag filler is an electro-mechanical unit used to pack material into a special type of bags called valve bags.

Valve bag filling machine

As shown in the image above, a valve bag comes with a tiny opening on its top end.

The design of the bag is such that it is also self-closing.

Benefits of Using Valve Bag Filling Systems

Breaking this down, the machine presents a range of technical as well as practical benefits that include;

• User-friendly operation
• High filling speeds
• Increased production efficiency
• Low aeration amount during filling which leads to high-density packaging
• An access door provides easy accessibility for effective cleaning and maintenance
• Minimal spillage
• Available in a range of options making it possible to adapt it to different product properties and bag sizes
• Provides continuous material filling with no clogging or bridging
• Dust minimization
• The self-closing feature reduces the labor required to fill and close filled valve bags
• Reduces material handling costs

These are some advantages that you should expect to enjoy when using a valve bag filler.

But be also prepared to face some challenges.

Disadvantages of Valve Bag Filler

Like any packaging machines, the valve bag filling machine has some downsides too.

They include:

• Limitations to the type of bags it can fill (fills only valve bags)
• Some models can cause mechanical shearing and degradation of the product
• Limited product range- works well-selected particle sizes
• Some models tend to add air to products during filling
• Risks bursting bags due to pressure
• Due to specification, Valve bag filling machines are relatively costlier than other bag filling machines

Open Bags vs. Valve Bags (What’s Difference/Similarities)

Open bag vs valve bag

Valve bags come with an upper part that is open on one end.

It is as if the bag is almost entirely closed, as there is just one small opening, the ‘Valve” that is used to fill the bag.

Once full, the internal pressure of the bag automatically closes the valve to stop the product from spilling over.

Open mouth bags, on the other hand, are open entirely on the upper part.

These could be paper, plastic, or any other material, and they are easily filled.

Open mouth bags may be sealed by gluing the top together or, sewing, etc. to prevent the product from trickling out.

Of the two, the valve bag filling machine is designed specifically for the valve bag.

The open mouth bags are mostly used together with the open mouth bag filling system.

Comparatively, valve bags are cleaner, safer, and more efficient to use for filling products.

Open mouth bags are mostly preferred for use in the food and chemical industries.

This is because, considering the various sealing options, open mouth bags ensure compliance with the industries’ high safety requirements

Also, valve bags are costlier than the open bag options.

Types of Valve Bag Filling Machines

If you look into valve bagging machines, you will soon find that they are not one size fits all.

There are quite a number of different valve bag filling machines in the market today.

Among the major types are the:

• Impeller filler
• Gravity filler
• Auger valve filler
• Vacuum filler
• Air valve liquid filler

Valve bag filling and sealing machine – Photo credits

These machines come in fully automatic, semi-automatic, and manual versions too.

If you are in the market for a valve bag filler, knowing the difference between these machines is essential.

I. Impeller Type Valve Bagging Machine

Impeller type of valve bag filling machine works best with powdery products.

This machine fills products into valve bags via the jet-flow system.

That is, the impeller or ‘slinger’ forces the products into the bag through the filling spout connected to the filler.

With the impeller rotating at high speeds, the product is densified to aid in fast filling of products.

Pros of Impeller Type Valve Bag Filling Machine

• Fast filling of products
• Fills bags tightly
• Less dusting during filling

Cons of Impeller Type Valve Bag Filling Machine

• Only works well for fine powders
• Presents cleaning challenges, especially during product changeover
• Tend to aerate products during filling
• High impeller pressure may burst bags

II. Gravity Valve Bag Filling Systems

The gravity filler loads products into valve bags using a time-based system.

In general, the machine will include a hopper held above the fill spout to supply the product.

Once the bags are in place under the fill spout, the spout will open for a pre-set amount of time, allowing products to flow into the bags.

After the pre-set time elapses, the shut-valves will close, and the supply of the product is cut off.

These economical valve bag fillers use, as the name applies, gravity to assist in the filling process.

Pros of Gravity Valve Bag Filling Systems

• Even product dosing
• Pre-set times allow for greater fill accuracy

Cons of Gravity Valve Bag Filling Systems

• Doesn’t work well with fine powders
• Tends to mess up operating area

III. Air Valve Bagging Machine

This type of machine works a bit similar to the impeller filler.

The difference is that this one uses pressurized air to force products from the hopper, into the tooling systems, and the valve bag.

Pros of Air Valve Bagging Machine

• Fast filling speeds
• Excellent fill accuracy
• Quite versatile as it works well with both fine powders and granulated products
• There are no moving parts in the product stream, so you don’t need to worry about abrasion/wearing of components
• Minimal degradation of products
• Very easy to use, clean and maintain

Cons of Air Valve Bagging Machine

• High filling pressure may burst valve bags
• May add air into bags during filling
• Doesn’t work well with sticky and very light products

IV. Grooved Belt Valve Bag Filler

You can also refer to this valve bagging machine as screw valve bag filler or auger valve bag filler.

Auger valve fillers are machines which fill the right amount of a product into valve bags.

The product, in this case, is stored in the hopper, and in each cycle, the filler dispenses a predetermined amount of the product into the valve bag.

Here, the bag can be held in hand for manual units or can be queued up for filling using a conveyor system for automated filling.

Understand that an auger is a drill in the shape of a screw for drilling accurate holes in materials.

Its function is to move materials forward as it rotates.

Thus, an auger valve filling machine dispenses materials using an auger screw, hence its name.

Pros Grooved Belt Bag Filling Machine

• Adds very little air into products during filling
• Minimal pressure reduces risk of bursting bags during filling
• Easy to operate
• Capable of handling a range of dry bulk products

Cons of Grooved Belt Bag Filling Machine

• Not suitable for some materials like fluidized powders, due to their nature and the way the machine works
• Quite slow compared to other filling mechanisms
• Presence of moving parts in product stream may subject it to abrasion and wearing of components
• Can cause mechanical shearing and product degradation

V. Vacuum Valve Bag Filling System

The vacuum valve bag filler comes with a vacuum pump which enables it to fill very light products into valve bags.

How does it work?

Well, the machine as I’ve said comes with a vacuum pump.

There is also a vacuum chamber and a bulk flow system.

These work together to draw product from the hopper into the tooling system and then the valve bag at uniform rates.

Pros of Vacuum Valve Bag Filling System

• Works superbly with very fine and light products
• High levels of accuracy
• Highly precise filling

Cons Vacuum Valve Bag Filling System

• Limited to fine powders only
• Relatively costlier than other filling machines
• May burst bags during the filling process
• Presents challenges to fill products into bags with poly barrier ply

Other Classification of Valve Bag Filling Machine

Based on the level of automation, Valve bag filling machines are can be categorized as follows;

· Manual Valve Bag Filling Machine

A manual valve bag filling machine relies heavily on human labor to do the “heavy lifting.”

Tasks such as placing the bag, removing the filled bag, palletizing, and removing full pallets are all done by operators.

There is not an ounce of automation.

· Semi-automatic Valve Bag Filling Machine

The semi-automatic machines will still require an operator to place bags on filling area manually.

Semi-automatic valve bag fillers may use simple indexing, but in most cases will still require some activation from the operator.

This type of machinery can be used with other packaging machines on a line or can act as a standalone filling machine.

· Fully Automatic Valve Bag Filling Machine

Automatic valve bag filling machines are fully automated.

These type of machines may be manufactured using the same frame as the semi-automatic models.

They will, however, include a PLC with a touch screen operator interface.

With the feature, it is possible for you to upgrade your semi-automatic unit in the future your production rates grow.

Fully automatic machines can roll up to almost any existing power conveyor system to begin running production.

Of course, most automatic valve bag filling machines will be a part of an inline packaging system.

This will include a conveyor system and other machineries such as cleaning equipment sealing machines and labelers.

It will generally include any machines that are necessary for the automatic preparation and packaging of the product.

Meaning, the need for packaging space will increase with your production capacity.

Keep in mind though that even an automatic filler can function as a standalone filling station.

This allows you to automate one portion of the packaging process to increase overall efficiency while still saving space.

The downside?

Other packaging functions will still be performed manually, limiting the actual efficiency of the automatic filler.

Parts and components of a Valve Filling Machine

Every valve bag filler machine includes unique characteristics and features.

And as we’ve noted before, because each packaging project is different, every valve bag filler is, in a sense, a custom machine.

That is, each unit is built specifically for the project at hand.

In this section, we look at the main parts, components, and functions of a valve bagging machine.

Valve bag filling station

Note that the presence of some of these parts may vary according to the type of machine in question.

· Impeller

An impeller is a part of the impeller type valve bag filling machine.

Its role is to direct product from filling spout to valve bag via force exerted by the impeller, or as otherwise known “slinger.”

· Spout

The filling spout is an external component of the machine that fills material into the valve bag.

Its design often varies depending on the machine layout, product requirements as well as the valve-bag specifications.

· Weighing System (Load Cell)

Valve bag filling machine filling spouts are often equipped with weighing systems.

These could be manual or automatic depending on the machine.

Specifically, the load cell helps to ensure the correct amount of product is filled into respective valve bags.

It also helps to regulate the dosing time, evaluate tolerance as well as control course flow and fine flow of material.

Besides controlling the weigher functions, the load cell also controls the filling machine as well.

For instance; it detects bag breakage, controls rapid discharge, controls bag chair adjustment, etc.

· Control System

The control system of a valve bag filler comprises physical and electronic systems that enable you to control access and operations of the machine.

· Valve Bag Placer

For automated systems, there is a valve bag placer that automatically places the valve bag on the filling spout.

This eliminates the need to transfer the bags to the filling spout by hand.

· Ring Gap Aeration

The role of the ring gap aeration is to reduce friction inside the filling channels using minimal aeration.

This way, you can enjoy a clean filling process even when doing it under high pressure.

· Drive Assembly

This includes the motor, transmission, and starts/ stop mechanisms for accurate filling.

Manual models may include a clutch and brake.

· Bag Sensor

Automatic systems come with a highly innovative bag sensor that detects the position of the valve-bag on the filling spout before filling begins.

The sensor helps to ensure a reliable and fully automatic valve bag filling operation.

· Shut Off Valve

The shut-off valves control product flow rate dosing and short reaction times in changeovers to course flow or fine flow.

The valve also closes the filling channels when necessary.

· Valve Bag Closing System (Ultrasonic Valve Bag Closing System)

The valve bag filling machine bag closing system helps to prevent unwanted material leakage from the bag valve.

This way, the filling process remains clean, without product spilling over the bag or operation area.

Note that adequately filling and closing bags improves storage as well as physical handling of the bags.

The ultrasonic closing system comes after the bag is filled and moved further away from the filling area.

Once moved, the ultrasonic system kicks in to seal the bags hermetically.

· Filling Hopper

The filling hopper is the vessel which holds the material that is being bagged.

The product is supplied to the tooling from the hopper.

· Tooling System

The tooling consists of those systems that can be changed to suit the requirements.

Tooling depends on the type of product being filled and the application.

Usually, it consists of the spout, agitator(s), funnel, and other filling components.

· Valve Shut

The valve shut closes the opening of the valve bag after it is filled with the right quantity of material.

· Bag Chairs

Bags chairs mainly support the valve bag during filling.

It where the valve bag sits during filling.

With the parts in mind, lets us now find out how the valve bag filler works.

How Valve Bag Filling Machines Work

For starters, you begin by placing an empty bag on the valve bag filler’s fill spout.

Note that the fill spout is often suspended from an electronic load cell that accurately weighs the quantity of a product in the bag.

Once the right amount of product in the bag is reached, the bag (depending on your machine) is placed on the fill spout.

For a manual machine, the placement is done by hand while automated machines do this via a robotic valve bag placer.

Once full, the bagged material pushes the sleeve or valve shut while the bag kicker removes the bag from the filler.

Please note that the fill spout can be designed with air reliefs that work in conjunction with bag perforations.

This way, displaced air can easily escape from the bag during filling.

That is the process of Valve bag filling.

Remember that the valve bags automatically seal themselves once full.

But if you need a positive seal, the bags can be hermetically sealed with ultrasonic sealing.

This method uses sound waves instead of heat to fuse the valve.

Note that ultrasonic sealing can be performed at the spout to help reduce dusting during the filling process.

And, it only works with automatic systems.

What to Consider when Buying Valve Bag Filler

The preferred valve bag filling machine for an application will depend on a variety of factors.

It not only has to match the type of products and bag but should also complement your current budget and future growth.

Here are a few things to help you identify the right valve bag filling machine:

Semi-automatic valve bag filling machine – Photo courtesy: SIGMA

· Product Type

A primary consideration with the valve bag filling machine relates to the type of products that you intend to bag.

Dry bulk products, note, can be powders (fine or coarse), granules or pellets.

Powder and granules

As such, it is essential to use a machine that matches the products.

For instance, fine powders are best paired with the Air fillers and vacuum fillers while granules go well with the gravity filler.

Some products can satisfactorily use the same machine.

However, it is often advisable to always stick to the specific type of machinery to compliment your product.

· Level of Automation

The level of automation of the machine is also fundamental when trying to find the ideal machine option.

Ask yourself these questions: do you need partial automation, full automation, or you can work with a manual machine?

Control panel

Which type do you think will work best with your needs and budget?

· Filling Speed

How many bags can you fill per minute/hour/production shift?

This one question is a must ask when looking to buy any bagging machine.

Please note that the level of automation varies with the different filling machines.

The fastest fill option is automated machines.

These are significantly faster than the alternatives and require minimal operator interaction once the filling is underway.

The semi-automatic ones have a much slower production rate.

This is because it is necessary to manually switch on the filling process and clear the filled bag/s as required.

In this case, the preferred valve bag filling machine should have the ability to meet your business’ production demands.

· Material for the Construction of the Machine

In that order, the material of the machine is also critical, and you should consider it carefully.

Most Valve bag fillers are made of either Carbon or stainless steel material.

Your choice of material will depend on you.

Stainless steel generally is known to be rust-resistant and easier to maintain.

It is also known to be more aesthetically appealing.

Carbon steel, on the other hand, is stronger and more durable.

It, however, lacks the corrosion resistance properties of stainless steel.

When exposed to moisture, carbon steel units may rust and corrode.

· Quality and Safety Standards

Each machine is usually made in adherence to specific industry standards.

Commonly, cGMP, CCC, UL, CE, and IP are the regulatory standards used by Valve bag filling machine manufacturers.

This is to tell that the unit you opt to purchase must be made according to the required standards.

It is the only way you can be certain to use it efficiently and safely in your application and environment.

· Cost of Valve Bag Filling Machine

It varies broadly depending on the type of machine you want to need for your packaging needs.

It can be a manual, semi-automatic or fully-automatic valve bag filling machine.

Of course, you should consider the operational and maintenance costs.

Lastly, you need to buy a reliable valve bag filling machine model.

Uses of Valve Bag Filling Machine

Valve bag filling machines are used by a variety of industries all over the world to do exactly what their name suggests.

These machines fill valve bags of all sizes for products that range from fine powders to pellets.

Some of the industries where the machine is used include;

a) Construction Industry

It is used to fill building materials such as cement, stucco, concrete, grout, plaster, sand, and refractories.

b) Milling Industry

It has also found great use in the milling industry where it is used to fill flour, sugar, flour mixes, cocoa, etc.

c) Industrial Minerals Packaging

Graphite, Barite, Garnet, Bentonite among other industrial minerals are also packaged using the valve bag filling machine.

d) Chemical Processing Industry

The Valve bag filler is also used to fill chemicals such as plastic pellets, hydrated lime, and zinc oxide into valve bags.

e) Agricultural Industries

You will also find the Valve bag filler being used to fill seeds, feed, fertilizer, and wood pellets in the Agricultural industry.

f) Pharmaceutical Industries

Quite a number of pharmaceutical powders and pallets are packaged in valve bags.

g) Food Processing Industry

Pet food and detergents can also be filled into valve bags using this machine.

Generally, this valve bag filler can be used in any applications where filling of dry bulk products into Valve bags is required.

Conclusion

There are lots of different options to consider when looking to buy a valve bagging machine.

You should focus on the working principle, design, filling capability, easier part changeover, operational costs, etc.

Generally speaking, a machine with fewer moving parts is easier to maintain, and automation provides more convenience.

So, always take time to find the right valve bag filling machine, or contact us for technical support.