Twist-off Caps: The Perfect Closure for Glass Jars of Food Products

Twist-off caps are a popular type of closure used for sealing glass jars of jams, chutneys, sauces, and other food products. These metal caps consist of a threaded section that screws onto the jar's mouth, a lug that provides a grip for twisting, and a sealing compound that ensures an airtight seal. At JBC, we provide a wide range of twist-off caps in sizes ranging from 38mm to 110mm, and we can supply them in boxes or pallets. Our products are manufactured to the highest quality standards and we can provide BRC certification to ensure their safety and suitability for food packaging.

Manufacturing of Twist-off Caps:

The manufacturing process of twist-off caps starts with metal sheets that are cut into circular discs of the required size. The discs are then fed into a stamping machine, which punches out the caps and shapes them into the desired form. The caps are then polished, coated with a layer of lacquer to prevent rusting, and finally fitted with the sealing compound. The sealing compound is a food-grade material that is applied to the cap's inner surface and helps to create an airtight seal when the cap is screwed onto the jar.

Uses of Twist-off Caps:

Twist-off caps are widely used for packaging food products, including jams, chutneys, sauces, pickles, and more. They provide an airtight seal that helps to keep the contents fresh and protected from contamination. Twist-off caps are also used for non-food products, such as chemicals, paints, and oils.

Techniques of Application:

To apply a twist-off cap to a jar, the jar's mouth needs to be clean and dry. The cap is placed on the jar's mouth, and the lugs are lined up with the jar's threads. The cap is then twisted clockwise until it's tightly sealed. To open the jar, the cap is twisted counterclockwise, and the seal is broken.

One technique for applying twist-off caps to glass jars is called the hot fill and cap method. In this method, the food or liquid is heated and poured into the jar while it's still hot. The twist-off cap is then immediately screwed on, and as the contents cool, they contract, creating a vacuum seal. This technique is used for high-acid foods like jams, pickles, and sauces.

Another technique for applying twist-off caps is called the cold fill and cap method. In this method, the food or liquid is filled into the jar at room temperature, and the twist-off cap is screwed on. The jar is then pasteurized to kill any bacteria that may be present, and the heat causes the contents to expand, creating a vacuum seal. This technique is used for low-acid foods like vegetables and meats.

At JBC, we understand the importance of quality and safety in food packaging. That's why we offer BRC certification for our twist-off caps to ensure they meet the highest industry standards. With our high-quality twist-off caps, you can be confident that your products will stay fresh and protected, no matter what they contain. Contact us today to learn more about our products and how we can help you with your packaging needs.