What is Vertical Form Fill and Seal machines VFFS?

What is Vertical Form Fill and Seal machines VFFS?

Working Principle of Vertical Form Fill and Seal machine

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The following Vertical Form Fill Seal diagram shows the different components of the machine and its and principle of operation :

1.What is a Vertical Form Fill Seal Machine ?

Vertical form, fill, seal machines are extremely flexible machines. Widely

ranging products can be packed efficiently and effectively, and can be

attractively presented – from your daily coffee to hand-crafted tortellini,

from a selection of fresh vegetables to frozen shrimp. And of course,

insecticides, detergents and marbles are also packed in bags.

The first VFFS machines were built in the middle of the last century. The

development of these machines, partially made possible by the

introduction of plastic packaging materials, was an effective answer to the

increasing demand for the mechanization of all possible aspects of the

production processes.

Thousands

Over the past decades, the VFFS machine has become the machine of

choice for many different product types. We can only speculate about the

number of machines in use around the world. It is clear that hundreds of

VFFS machines are sold annually. Practical knowledge, based on our wide

experience with the many possibilities these machines offer, suggests

there are thousands of these machines in operation around the world.

Broadly deployable

The broad use of VFFS machines is simple to explain. To start with, one

single machine can be used to produce wide-ranging bag shapes. This is

made possible due to a large variety of simple-to-exchange parts such as

forming shoulders and forming tubes. Chips, for example, are usually

packed in a simple, brightly colored, pillow-shape bag, while breakable

cookies are presented in a deluxe, transparent bag with a block bottom –

and both bags can be produced by the same machine.

3 VFFS Machines

Chip bag and deluxe, transparent bag with a block bottom for cookies.

Low cost

A second factor is the low price of this type of packaging. The machines

allow for high packaging speeds, and machines that are well-selected,

and set optimally and maintained can continue to operate uninterrupted

for a long time.

Materials

There is a huge variety of packaging materials that can be processed on

VFFS machines: however, virtually every product has a number of unique

requirements. Screws should not poke through the packaging, salty

snacks have to remain crispy as long as possible, and the aroma of the

coffee cannot be lost, just to name a few obvious examples. In addition

to single-layer packaging materials, laminates are often used, in which

each layer has a specific function attuned to the product.

Air-tight

A frequently occurring requirement is that the product requires an airtight

package. An additional level of protection occurs in a modified

atmosphere package “MAP” where the air in the packaging is replaced by

an inert gas that combats oxidation and extends shelf life.

Printing

Both printers and labelers can be added to a VFFS machine, separately

or in combination. A printer (or date coder) is usually supplied to print a

“date used by” for perishible products or other product specific

information. A labeler is used to apply label stock that can be pre-printed

or printed by the labeler within the VFFS machines.

Extras

In addition to labels, other extras can also be added to packaging by

VFFS machines, varying from techniques that make the packaging easier

to open to aids that make it possible to reclose bags multiple times.

Efficient output

The examples that are named in this introductory chapter are just a few

of the hundreds of possibilities that the VFFS machines offer. It is

especially impressive that these machines, no matter what the packaging

requirements are that have to be met, are usually able to provide a

reliable and efficient output even at a high speed. 

2. MACHINE OVERVIEW

In order to make the later chapters in this book more understandable, in

this chapter you will find a general description of the most important

elements and functions of VFFS machines. A brief introduction of the

various bag types and the packaging materials used for them is also

included here. All of these subjects will be discussed in greater detail

later.

In order to make the later chapters in this book more understandable, in

this chapter you will find a general description of the most important

elements and functions of VFFS machines. A brief introduction of the

various bag types and the packaging materials used for them is also

included here. All of these subjects will be discussed in greater detail

later.

VFFS machines are suited to a broad range of products that can be

divided into the following four main groups:

• bulk goods, varying from nuts and cookies to bolts and screws;

• powders, such as ground coffee and dehydrated milk;

• grains or granulate, such as detergent;

• liquids: usually one-time (portion) packages such as ketchup,

mayonnaise, salad dressing or bath gel, for example.

Bag Making

In theory, all vertical packaging machines work the same. A flat web of

film, originating from a large roll of film at the start of the machine, is

shaped into a tube. This tube is closed at the bottom: this is the bottom

of the new bag. As soon as the product is dispensed into the bag, the top

side is also closed. The time and steps that are needed to make one bag

are collectively called a machine cycle.

Three seams

A bag produced in this manner theoretically has three seams. The

longitudinal seam is the seam that runs down the length of the bag: here

the left and right side of the originally flat film web come together. The

bottom seam closes the bottom of the bag; the top seam closes the top.

Both of these are also referred to as the cross seams.

Sealing

The seams are closed by sealing. To do this, the packaging material is

compressed and heated briefly, and the sealing medium (usually

polyethylene) melts. As soon as the sealing medium has cooled off

enough, the seams are stable. This occurs in milliseconds.

Bottom, top and cutting

The sealing unit, at the bottom of the forming tube, contains four sealing

bars. The lower two sealing jaws form the top seam of the bag that has

just been filled. At the same time, the upper two jaws closer to the

forming tube form the bottom seam of the next bag. The blade that cuts

and separates both the bags is located between the two sets of sealing

jaws.

The film material is compressed together and heated by the sealing jaws.

The film material is compressed together and heated by the sealing jaws

Forming tube and forming shoulder

Every packaging machine can form various different bag sizes, fill them and

seal them. The size and shape of the bag are determined by two important

components: the forming tube and the forming shoulder. The web of film is

pulled over the forming shoulder, so that the material around the forming

tube is shaped from a flat film to a tube. The shoulder and tube are

collectively called the forming parts. Every bag width requires its own

forming parts.

Overlap seam or fold-over seam

There are two types of longitudinal seams. In the overlap seam or lap seal

one edge of the web of film is placed over the other edge, so that the

material overlaps. In this way, the inside of the first edge is sealed to the

outside of the other edge. With a fold-over seam or fin seal, one edge of

the web of film is folded over, so the inside of the one edge is sealed to

the inside of the other edge. 

Dispensing

In order to ensure that the correct quantity of product is always packaged,

a doser is required. Depending on the product, the doser works on the

basis of a filling weight per bag (filling scale) or on the basis of a certain

volume per bag (dispensing cup or auger dosing). For liquids, a special

pump is used that dispenses a certain amount of liquid for each package.

When packaging a certain number of product units per bag, a counting

machine is used.

Exterior of film on interior of

film (overlap, lapseal)

Interior of film on interior of

film (fold-over, fin seal)

Bag types

In principle, VFFS machines produce three types of bags. Within these main

types, there are countless possible variations in model, length and width.

• Products such as fresh vegetables, chips or candy are usually packaged in

a pillow bag. This bag shape is also called a flat bag.

• A common variation on the pillow bag is the gusset bag and it is usually

presented in combination with a carton or box around it. It is commonly

used for packaging breakfast cereals.

• A bag that can stand up with a flat bottom, often referred to as a block

bottom bag and is used for cookies or coffee, for example.

• The doy bag, is another form of stand-up bag, and is often referred to as a

stand up pouch. 

Film material requirements

Nearly every product influences the selection of packaging material.

Combined with the ever increasing demands that consumers, organizations

and governments place, there are now countless different packaging

materials. Some film materials consist of a single layer (monofilm); but

usually materials consisting of multiple layers (laminates) are used.

Monofilm

Polyethylene is often used as a sealing medium. In addition, this stretchable

material is also used as a monofilm. It is not air-tight but it is moisture proof,

rendering it suitable for packaging frozen products, cereal, for example, that

do not emit any odor and that cannot spoil due to oxygen exposure. A

second type of monofilm is polypropylene, a material that can be sealed

reasonably well. It is very clear and easy to tear open, which explains why it

is used for transparent candy packages, among other things. 

Materials and sealing systems

Laminates are sealed by briefly pressurizing them with heat (heat sealing).

Polyethylene is an ideal sealing medium because it has a relatively low

melting point. This low melting point does mean that bags made entirely

of polyethylene must be sealed in a different way. Therefore, pure

polyethylene is sometimes referred to as non-heat sealable material

although it is in fact sealed using heat. 

3.VFFS machine manufacturers

There are many manufacturers proposing vertical form fill seal machine for sale, 

however the quality of the delivery can be quite variable as these machines, 

especially the fast ones, require a high precision of Engineering and assembly to work reliably in factories.

Here at Smart-Packer, we design and manufacture a full range of vertical bagging machines, 

with options to accommodate nearly any type of bag requirement. Please submit a quote or give us a call to learn more!