Sauce packets are everywhere, right? The ketchup that comes with your fries, the soy sauce with your takeout—these tiny, unbreakable packets are part of daily life. But have you ever wondered what they’re actually made of?

Surprisingly, a sauce packet isn’t just a single layer of plastic. It’s more like a “multi-layer sandwich,” made by laminating several thin films together—sometimes even including a layer of aluminum foil. Common materials include polyester (PET), polyethylene (PE), polypropylene (PP), and aluminum. Combined, these layers make the packaging strong, fresh, and easy to seal.

1. The Role of Each Layer

Each layer in a sauce packet has a specific job:

• Outer layer: Usually made of PET (polyester), this layer is like the “jacket” of the packet—responsible for strength, durability, and appearance. It prevents tearing and provides a smooth surface for printing logos and designs.
• Middle layer: Often aluminum foil or metallized film, this acts like a “security door.” It blocks light, air, and moisture to protect the sauce from spoiling or losing flavor.
• Inner layer: Typically made of PE (polyethylene) or PP (polypropylene), this is the layer that directly touches the sauce. It melts and seals under heat, ensuring the packet is tightly closed and leakproof.

When these layers are combined, the result is a flexible yet durable packet—perfect for acidic, oily, or oxygen-sensitive sauces.

2. Why Use Multi-Layer Packaging?

The reason is simple: combine the best properties of each material.

• PET is tough but can’t form a good heat seal.
• PE seals easily but doesn’t block air well.
• Aluminum foil is an excellent barrier but too rigid on its own.

By layering them, manufacturers create a lightweight, flexible, and highly protective package—a true “all-rounder.” This combination keeps sauces fresh for months, even without refrigeration.

3. Different Sauces, Different Packaging “Gear”

Each type of sauce needs a specific material combination:

Ketchup, barbecue sauce: Use PET/Aluminum/PE for maximum protection against oxygen and light.

Mayonnaise: Because it contains oil, it also needs PET/Aluminum/PE or PET/Nylon/PE to prevent oxidation.

Vinegar or acidic sauces: These are less perishable but corrosive, so a simpler PET/PE structure works well.

Chili sauce: Uses PET/Aluminum/PE to resist moisture and oil, preserving its rich flavor.

4. How Are Sauce Packets Made?

The entire process is fully automated:

• Film feeding: Rolls of multi-layer film are loaded into the machine.
• Forming: The film is folded into the shape of a small pouch.
• Filling: Precise pumps fill each pouch with sauce.
• Sealing: Heated sealing jaws close the top tightly to prevent leaks.
• Cutting: The connected pouches are cut apart and boxed.

Our sauce packaging machines are designed to handle sauces of various viscosities with high precision and speed. We also offer a five-year warranty, showing our confidence in our equipment’s quality and reliability.

If you’re interested in our sauce packaging machines, feel free to contact us anytime!