What Is a Sachet? A Complete Guide to Sachet Packaging, Types and How It Is Made

Introduction

A sachet is a small sealed flexible package used to hold a measured amount of a product. Common examples include sugar packets, instant coffee, seasoning, shampoo samples, sauces, and supplement powders.

Sachet packaging can handle powders, granules, liquids, gels, creams, and other flowable products when the filling system and packaging material are matched to the product. This makes the format useful across food, nutraceutical, pharmaceutical, cosmetic, personal-care, and household applications.

Behind the small package is a complete packaging process: product behavior affects the filling method, protection needs influence the film structure, and the sachet design determines how the package is formed and sealed.

This guide explains what a sachet is, the main types of sachet packaging, what they can contain, the materials used, and how commercial sachets are formed, filled, sealed, and cut.

1. What Is a Sachet?

A sachet is a small flexible package that encloses a measured or limited quantity of product inside sealed packaging material. It is commonly used for portability, portion control, sampling, or one-time use.

The term sachet pack describes the finished package rather than one construction method. Common structures include three-side seal, four-side seal, and back-seal sachets, while the finished outline can be rectangular or specially shaped.

What Does a Sachet Look Like?

Most sachets are made from flexible packaging material supplied as roll film and contain three basic elements:

• The package body, which surrounds and holds the product.
• The sealed areas, which close the package and help protect the contents.
• An opening feature, such as a tear notch or easy-tear edge, when required by the package design.

The packaging material can be a simple film or a multilayer laminate that combines several functions.

Different layers can provide printability, mechanical strength, moisture or oxygen protection, light protection, and heat-sealing performance.

The correct structure depends on the product. Dry seasoning, moisture-sensitive supplement powder, and liquid sauce place different demands on barrier protection, sealing performance, and package strength.

Sachet vs. Pouch: What Is the Difference?

A sachet is a type of flexible package, while pouch is a broader packaging term.

In normal packaging use, a sachet usually refers to a smaller pack containing a measured or limited amount, while pouches cover a wider range of sizes and formats, including stand-up, zipper, and spouted pouches.

There is no universal size at which a sachet becomes a pouch, so the terms can overlap between industries.

Many small sachets are formed from roll film on a sachet packaging machine, while larger or more complex pouches are often supplied premade and then opened, filled, and sealed individually.

2. What Are the Main Types of Sachet Packaging?

The clearest way to classify types of sachet packaging is first by seal structure, then separately by shape and special features.

Three-Side Seal Sachets

A three-side seal sachet is typically formed from one film web folded to create one closed edge; the other three edges are heat sealed.

The result is a flat, compact package widely used for powders, granules, liquids, samples, and other small portions.

Four-Side Seal Sachets

A four-side seal sachet is typically formed from two film webs placed face to face and sealed around all four edges. The two webs may come from separate rolls or from a single reel slit into two webs.

It is commonly used for powders, granules, liquids, creams, and gels.

Back-Seal Sachets

A back-seal sachet is formed by wrapping film around a forming section, creating a longitudinal rear seal, and adding top and bottom cross seals.

Stick Packs: A Narrow Single-Dose Format

A stick pack is a narrow, elongated flexible package. Depending on the packaging design, it can use a back-seal or three-side-seal structure. Stick packs are widely used for beverage powders, supplements, sugar, granules, and some liquids.

Sachet Shapes and Special Designs

Three-side, four-side, and back-seal sachets can also use different outlines or convenience features.

Common examples include:

• Rectangular sachets, the most familiar and straightforward shape.
• Shaped sachets, with curved, rounded, or customized outlines for product presentation or specific use.
• Tear-notch sachets, designed to make manual opening easier.
• Sachets with hang holes, allowing packs to be displayed on retail hooks where required.

3. What Can Be Packed in Sachets and What Are Sachets Made Of?

Sachets can hold a wide range of products, including powders, granules, liquids, gels, creams, and pastes. The packaging material is then selected according to the product’s characteristics and the protection, sealing, and handling requirements of the finished sachet.

Powders and Granules

Fine powders can retain air, bridge, or stick, while free-flowing granules such as sugar and salt behave differently.

Powders can use auger dosing, while free-flowing granules can use suitable volumetric systems.

Seal-zone contamination is not simply a lack-of-space problem. Fine powder can remain airborne, cling to film through static, or continue to fall from the filling tube after dosing. Nozzle position, cut-off timing, dust extraction, static control, and settling time should be checked together to keep the sealing area clean.

Liquids, Gels, Creams and Pastes

The filling method depends strongly on viscosity: a thin liquid needs different pumping and nozzle characteristics from a thick sauce or cream.

Higher-viscosity products also require controlled filling and cut-off to keep material out of the seal area.

A sachet filling machine should therefore be selected according to both package size and product characteristics.

Sachet Packaging Materials

Sachets can use plastic films, aluminum-containing laminates, paper-containing structures, and other multilayer combinations.

Multilayer materials combine functions: an outer layer can support printing and strength, a barrier layer can reduce moisture, oxygen, or light exposure, and an inner layer can provide heat-sealing performance.

An aluminium foil sachet can be selected when stronger light, moisture, or gas barrier performance is needed.

Other products can use transparent, metallized, or paper-containing structures according to protection, appearance, cost, sealability, and storage needs.

4. How Are Sachets Made?

Commercial sachets are commonly produced by form-fill-seal equipment. Film is formed into the required structure, the necessary initial seals create a closed-bottom pocket or tube, product is dosed, and the package is finally closed and cut.

The exact web arrangement and sealing order vary with the sachet format and product.

Step 1: Film Unwinding and Feeding

Production begins with flexible packaging material supplied in roll form.

The small sachet packing machine unwinds and guides the film toward the forming area while controlling movement and tension.

With preprinted film, registration marks help align the print, seal, and cut positions.

Step 2: Registration and Sachet Forming

The film is positioned and formed according to the required package design.

A back-seal format wraps film around a forming section before creating a longitudinal seal. Three-side sachets typically use one folded web, while four-side-seal lines typically bring two webs together.

In a typical back-seal VFFS cycle, the longitudinal seal forms the tube and a cross seal creates the closed base before the product dose is released.

Step 3: Product Dosing and Filling

Once a closed-bottom pocket or tube is ready, the filling system measures and delivers the required dose.

Different products require different dosing methods:

• powders can use auger dosing;
• free-flowing granules can use suitable volumetric systems;
• liquids can use piston, peristaltic, or other suitable metering pumps;
• creams, gels, and pastes require filling systems designed for higher-viscosity products.

A sachet packaging machine must match both the package format and the product. Two products using the same sachet size can still require different filling systems.

Step 4: Closing and Sealing the Sachet

For a typical back-seal VFFS cycle, the bottom cross seal is already present before filling. After dosing and film advance, the horizontal jaws create the top seal of the filled sachet and the bottom seal of the next one in the same action. Three-side and four-side machines use different web paths and sealing sequences, but the product is still delivered into a package section that is already closed at the bottom or formed as a supported open pocket.

Heat-sealing performance depends on temperature, pressure, contact time, film structure, and clean sealing surfaces.

Powder dust, liquid droplets, or paste in the sealing area can interfere with reliable seal formation.

Step 5: Cutting and Discharge

After the closing seal, the web is cut into finished sachets.

The machine can produce individual or connected sachets, while coding, tear-notch forming, counting, or downstream transfer can be integrated when required.

For a typical back-seal VFFS line, the sequence is:

film feeding -> registration and forming -> longitudinal sealing -> bottom/cross seal -> dosing and filling -> top/closing seal -> cutting -> discharge

This continuous sequence allows a modern sachet filling machine to produce small packages automatically at production scale.

5. Why Is Sachet Packaging Used and How Do You Choose the Right Format?

Sachet packaging combines compact size, controlled portions, flexible material options, and convenient handling.

It is useful for single servings, samples, travel sizes, measured ingredients, and products kept individually sealed until use.

They are not ideal for every application. Small packs provide limited print space, product in the seal area can affect seal quality, and some multilayer high-barrier structures are difficult to recycle through conventional streams.

Choosing the right sachet should start with the product.

Production speed should not be considered alone. A faster machine adds little value if the dosing system cannot handle the product consistently or the film cannot form reliable seals.

For pharmaceutical, nutraceutical, food, and similar production environments, cleanability, product-contact design, material handling, and line integration are also important.

Conclusion

So, what is a sachet?

A sachet is a small sealed flexible package for a measured or limited amount of powder, granules, liquid, gel, cream, or another suitable product.

The finished pack reflects several connected decisions. Product flow behavior, viscosity, and target dose first determine the dosing or filling method. The target dose and package requirement then define sachet dimensions and seal format; where a forming tube is used, these dimensions determine the suitable forming set. Barrier and sealability requirements then determine the film structure.

The selection sequence is:

product characteristics and target dose -> dosing/filling method -> sachet dimensions and seal format -> forming set or tube where applicable -> film barrier and sealability requirements -> sachet filling and sealing machine configuration and production trial

With years of experience in pharmaceutical and packaging machinery, Rich Packing provides sachet packaging solutions with product-specific filling, servo-controlled dosing, and temperature-controlled sealing. These capabilities help match the filling and sealing system to different products and sachet formats.

Frequently Asked Questions

References

1. Vertical Form/Fill/Seal 101: Key Considerations. Packaging World.
2. Film Criteria for Vertical Form/Fill/Seal Applications. Packaging World.
3. Container Closure Systems for Packaging Human Drugs and Biologics. U.S. Food and Drug Administration.
4. Definition of Flexible Packaging. Flexible Packaging Association.