In everyday tea brewing, laboratory operations, or high-temperature industrial settings, heat-resistant glass cups are the preferred choice due to their excellent light transmittance and strong chemical stability. However, the quality of products on the market varies greatly, and some cheap products falsely claim to be "heat-resistant," which can easily lead to breakage. Mastering the following purchasing points can help you avoid pitfalls and select high-quality products that meet your needs.
Material is key to high-temperature resistance; prioritize high borosilicate glass. This type of glass contains 12%~15% boron oxide, has a thermal expansion coefficient of only 3.3×10⁻⁶/℃, and can withstand sudden temperature changes from -20℃ to 150℃, with sustained temperature resistance reaching 300~500℃, making it an ideal choice for home use and ordinary laboratories. Beware of imitations made of soda-lime glass; its temperature resistance is less than 80℃, and it easily cracks when exposed to boiling water. It is often falsely advertised as "heat-resistant glass" by unscrupulous merchants.
Manufacturing details directly determine safety and durability. The cup body should be a seamless, one-piece design to prevent dirt accumulation and ensure a more stable structure. The surface should be smooth, free of bubbles and cracks. The rim should be laser-cut for a rounded finish that doesn't scratch the lip. The bottom thickness should be at least 5mm, ideally with a non-slip silicone ring to enhance explosion resistance and reduce the risk of tipping. For printed products, the inner wall should be plain, and the outer wall printing must be FDA or LFGB certified to prevent the leaching of heavy metals such as lead and cadmium at high temperatures.
Product specifications must be precisely matched to the usage scenario. For home use, choose double-walled insulated high borosilicate cups for brewing tea and coffee; an air gap of ≥5mm effectively prevents scalding. For laboratory settings, prioritize graduated high borosilicate glassware to ensure dimensional accuracy and chemical stability. For high-temperature applications such as industrial windows, select products with appropriate thicknesses based on temperature requirements; for example, quartz glass used in 1200℃ environments requires a thickness of ≥15mm. Also, pay attention to the lid material; food-grade silicone is temperature resistant from -40~230℃, offering superior safety compared to ordinary plastic lids.