In the world of industrial adhesives, two of the most commonly used options for paper-based packaging are starch and dextrin glues. While both are eco-friendly, biodegradable, and offer excellent bonding properties, they differ significantly in their composition, uses, and performance characteristics. In this blog, we’ll explore what makes starch and dextrin glues unique, their applications, and when one might be preferred over the other.
What is Dextrin Glue?
Dextrin glue is a water-based adhesive derived from corn starch and made unique through the process treatment of starch.. The result is a low-molecular-weight carbohydrate that, when heated to around 200°F in water, forms a versatile and easily customizable glue solution. One of the most appealing aspects of dextrin glue is its flexibility; manufacturers can tweak the glue's tack time, open time, and even its color to fit specific applications. It comes in two main types: white dextrin and canary (yellow) dextrin.
Dextrin glue excels in clean machining and bonding cellulosic materials—such as wood, certain grasses, and non-edible plant fibers—which makes it particularly popular in packaging and paper-related industries.
Common Uses of Dextrin Glues
- Coated board and board lining
- Laminating paper to cardboard or paper
- Bottle and can labeling
- Corrugated carton and paper bag production
- Litho-laminating and product packaging
- Envelope and stamp adhesive
- Lay-flat labels and game boards
Dextrin glue's versatility and adaptability make it a go-to option for projects that need strong bonding without flexibility. One unique property of dextrin glue is its ability to lay flat, which prevents curling—an essential feature when creating products like paper bags and labeling.
When to Use Dextrin Glue
Dextrin glue is ideal for applications that require medium tack and quick drying, such as labeling, carton display production, or manufacturing envelopes and paper bags. Its re-moistenable properties make it a good choice for items that need to be sealed and opened later, like stamps and envelopes. Additionally, dextrin glue performs well in both hot and cold conditions, offering excellent bonding strength even at low temperatures.
What is Starch Glue?
On the other hand, starch glue is made from natural carbohydrates derived from roots, tubers, and seeds, including common plants like maize, potatoes, wheat, rice, and tapioca. Starch glues are generally made by cooking the starch at temperatures around 180-190°F, creating a viscous glue solution. Like dextrin, starch glue can be applied either at room temperature or heated up to around 140°F, depending on the required viscosity.
Starch adhesives are prized for their affordability, ease of application, and natural origins, making them an excellent choice for environmentally conscious companies. These glues offer a wide range of viscosities and are thick enough to create strong bonds in high-volume production, making them a favorite for large-scale packaging applications, such as corrugated boxes.
Common Uses of Starch Glues
- Corrugated boxes and cartons
- Paper bags (like grocery bags)
- Laminating foil to paper or cardboard
- Tube winding for products like paper towels
- Bottle labeling and wallpaper paste
- Envelopes
Starch glue is a moisture-curing adhesive, meaning it cures as moisture evaporates from the solution. This quality makes it particularly effective for bonding porous materials like paper and cardboard. The thicker viscosity of starch glue also means it provides a stronger bond in these applications compared to some other adhesives.
When to Use Starch Glue
Starch glue is the best choice for high-volume, paper-based packaging applications that require quick tack and strong bonds, such as corrugated boxes or tube winding. It is especially cost-effective when used in large quantities and offers easy cleanup. If your production process demands a glue that can handle thick, viscous applications, starch glue will likely meet your needs better than dextrin glue. Additionally, starch glue is moisture-curing, making it ideal for applications where a strong, quick-drying bond is essential.
Key Differences Between Dextrin and Starch Glues
Although both dextrin and starch glues are derived from starches, their performance characteristics vary in important ways. Here are the key differences:
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Composition:
- Dextrin: Derived from the hydrolysis of starch and usually customized for specific tack, open time, and color.
- Starch: Made from natural carbohydrates in roots, seeds, and tubers.
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Viscosity:
- Dextrin: Offers a lower to medium viscosity, making it suitable for applications that require more precision, like labeling or carton displays.
- Starch: Known for its thicker, more viscous consistency, which is perfect for heavy-duty tasks like corrugated box production.
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Tack and Open Time:
- Dextrin: Medium tack and open time, ideal for applications that need a strong bond without rapid drying, such as envelope sealing or bottle labeling.
- Starch: Provides quick tack and can handle fast-paced, high-volume applications like laminating and tube winding.
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Temperature Flexibility:
- Dextrin: Can be applied at various temperatures, including hot and cold.
- Starch: Usually applied at ambient conditions but can also be heated for specific uses.
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Customization:
- Dextrin: Easily customizable in terms of tackiness, open time, and color, making it highly adaptable.
- Starch: Offers less customization but excels in cost-effectiveness and strength for large-scale production.
Which Glue is Right for You?
The choice between dextrin and starch glues largely depends on the specifics of your project. If you need an adhesive for high-volume packaging, corrugated boxes, or paper bags, starch glue is likely the best option due to its strength, viscosity, and cost-effectiveness. On the other hand, if you require glue that can offer precision, customization, and clean machining for products like envelopes, bottle labels, or game boards, dextrin glue is the better choice.
In the end, both starch and dextrin glues offer strong bonding capabilities and eco-friendly benefits, but understanding their unique properties will help you choose the best option for your adhesive needs. Let our experts know if you have questions about which glue is right for your application.
