Screw top tins are common for spice containers. The lids are made of tinplated steel and typically have six holes punched in them to release the spice. Then another cap goes on top. But screw top tins come in all shapes and sizes and can used as packaging for many other products as well. Food, pharma or cosmetic items are widely packaged this way. Here are points to know about the strength and reliability of screw top tins.
Tin Provides a Strong Barrier
Containers for pouring liquids or particles go well with screw top tins in achieving security. Tins usually are designed with curved edges to avoid a knife-like feel. Caps on tins commonly contain self-sealing silicone, which creates a stronger barrier from air and other environmental elements. Teabags are often stored in screw top tins because the containers are reliable at blocking out unwanted air, which can compromise the taste of tea. Other typical items that can be stored in tins include mints, candles and jewelry.
Seals Embedded in Screw Caps
Various types of seals add protective qualities to a screw-on tin container. A pressure sensitive liner, for example, provides tamper protection. Liquids are better protected by a foil heat induction liner. Some bottle cap liners use a layer of different thickness made of foam or cardboard as a barrier to ensure air does not enter the container. These liners are commonly found in medicine containers and honey jars.
Features for Hassle-free Opening
Common tin lid designs are the standard screw-on/twist-off cap with threading and the crown cap used for beer that requires a prying tool. When it comes to wine, corks are still popular caps but are not as air-tight as metal solutions. Screw-on caps provide leak-proof seals. Another advantage to screw-on caps is they are more sustainable due to easy recycling compared with non-renewable natural cork.
When caps have threads, they are easy to control. Twisting to the left opens the container while turning to the right closes it. Internal threads help facilitate long-term storage at freezing or boiling temperatures. The best screw top lids resist harmful chemicals and acids. Ideal screw top tins have ribbed sides that allow the hand to grip the container while unscrewing the lid without strain.
Confidence in Re-sealing Tight Caps
One of the problems with plastic screw tops is that they wear out fairly quickly if they've been used frequently. Tabs attached to these tops can easily break after a few turns and become useless disposable trash. Sometimes poorly-made threaded plastic tops simply don't turn well and can even get damaged from too forceful of a turn. Tin screw tops, by contrast, offer much more strength and durability.
A key advantage to tin caps is that they can be used for different packaging materials such as glass. In fact, it's common for glass jars to use tin lids due to their air-tight capabilities.
In the event a tin lid gets jammed and is hard to open, it's still possible to open it without wasting anything in the process. Applying pressure from the palm of the hand is the secret to loosening a stuck tin lid.
Another solution involves using a knife and wedging it under the lid while twisting. A lesser known trick is to wrap a rubber band around the lid then twist it off. A similar solution is to just use rubber gloves while gripping the container with one hand and turning the lid with the other. Yet another trick is to heat the jar with steam (unless it's made of plastic), then allow the heat to provide easier turning.
Reasons why the lid can get stuck include extreme temperatures, not cleaning the lid thoroughly before resealing or not screwing the lid with proper thread alignment.
Perhaps it's understated, but screw top tins are excellent to use for travel. Keeping the containers tucked away in a carry-on bag is a safe bet the contents will not end up spilled and scattered within the bag. Even cheap versions of screw top tins offer impressive protection if the threading is designed properly.
Going for the Most Reliable Storage Solution
Using screw top tins is a practical and proven way to keep certain foods and beverages fresh and free of air penetration. These tins often have a silver appearance but are also easy to print on. If the goal is to use the strongest type of protective packaging imaginable for long-term storage, the solution is screw top tins.
