What Causes Rust to Form on the Metal Lids of Your Glass Jars?

What Causes Rust to Form on the Metal Lids of Your Glass Jars?

Dealing with rusted metal lids can be a major headache for both you and your business. When tinplate lids corrode, it’s not just the lids that are compromised — the contents inside, whether hot sauce, pickles, plum wine, honey, bird’s nest, or other foods, are at risk of contamination. Even worse, such issues can seriously damage your brand’s reputation.

This problem often arises because, in various canning environments, liquids from glass jars may come into contact with lids that are of poor quality or simply not suited for the specific product. Over time, these liquids can seep into the lid material, triggering oxidation and leading to rust.

The overall quality of a metal lug depends on multiple factors, including its thickness, type of coating, printing method, manufacturing techniques, and the sophistication of the equipment used in production.

As experts in glass packaging solutions, we’re here to assist you in selecting the optimal metal closure lids tailored to your business needs. Let us help you safeguard your products and your brand.

Guide to Purchasing Rust-Resistant Tinplate Metal Lids for Glass Jars and Bottles

To begin with, selecting a reliable and reputable manufacturer is essential. Please specify which food items you intend to package in glass bottles or jars. Will the products undergo machine-based heat sterilization after being canned? Alternatively, do you plan to use an oven for hot filling? Once we have this information, we can suggest the most appropriate metal cap to fit your glass containers.

The lids are made from tinplate (SPTE: Steel Plate Tin Electrolytic), which consists of a thin layer of tin coated onto steel. Since tin and iron have distinct chemical properties, they can easily undergo oxidation when exposed to air, resulting in rust and corrosion on the metal lugs.

Nonetheless, with the proper manufacturing techniques for high-quality twist-off metal lugs, this problem is effectively addressed. Before shaping the screw caps, the tinplate undergoes anti-corrosion treatment to protect it from rusting.

Additionally, we apply food-safe, acid-resistant coatings and lubricants during the production process. This not only enhances the appearance of the metal lids through decorative printing but also provides extra protection: both the printed ink and a top layer of varnish act as barriers, ensuring the underlying steel remains shielded from moisture and corrosion.

Why Our Tinplate Metal Lids Are High-quality and No-rust?

Our tinplate lids feature a coating of food-safe ink that offers excellent protection for both the lid and the food inside. The ink used on the surface of our tinplate is eco-friendly and safe for direct food contact, posing no health risks. Our food-grade ink meets FDA and SGS certification standards in the United States, ensuring it is completely safe to touch food. This means both children and adults can use our products with confidence. We are committed to manufacturing the ideal tinplate metal lugs for your glass bottle packaging, tailoring our processes and materials to match your unique requirements. Feel free to contact us anytime via WhatsApp or Email!