Specific purchase method
A straightforward way to check the vacuum insulation performance is to pour boiling water into the thermos cup, close the cork or cup tightly, and let it sit for 2-3 minutes. After waiting, touch the exterior of the cup with your hands. If you feel that the cup body is warm to the touch, it suggests that the product has lost its vacuum and cannot provide optimal heat preservation.
To determine the sealing performance of the cup, simply add water and screw on the cork and lid clockwise. Place the cup on a flat surface and check for any water leakage. The lid and mouth of the cup should also be screwed on tightly and without any gaps, allowing for flexible movement.
When it comes to identifying plastic parts, one of the key factors to consider is the type of plastic used. For food-grade plastics, they tend to have a bright surface with low odor, and the products have a long service life without aging or breaking easily. However, when using ordinary plastics or recycled plastics, it's easy to tell the difference due to their strong odor, dark color, and many burrs. Also, these types of plastics tend to age and break much faster than food-grade plastic parts.
A straightforward way to identify the capacity of a thermos cup is by comparing the depth of the liner with the height of the outer shell. These two should be almost equal, with only a slight difference of about 16-18MM. Furthermore, the actual capacity should match the nominal value. Unfortunately, some low-quality thermos cups try to compensate for their poor capacity by adding sand or cement blocks to their cups. It's important to understand that having a heavier cup doesn't guarantee better quality.
Stainless steel materials come in various specifications, but one simple identification method is the 18/8 standard. This means that the material contains 18% chromium and 8% nickel, which makes it food-grade and environmentally friendly. Products made from this material are well-known for their rust-proof and preservation properties, making them ideal for daily use. When it comes to identifying ordinary stainless steel cups, you should note that they usually have a whitish or dark color. However, if you soak them in 1% salt water for 24 hours, rust spots will appear if the cups contain elements that exceed the standard. It's important to avoid using such products as they could harm your health. Opt for materials that meet the 18/8 standard as they are safe, durable, and environmentally conscious.