Electric blankets should be considered as the earliest electric heating appliances to enter residential households. After more than 30 years of development, the appearance and packaging of electric blankets are no longer the same as before, and the technology of the key internal component, the heating wire, has also made significant progress. The reporter learned that QB/T2163-2012 "Heating wire for electric blankets, electric mats and similar flexible heating appliances" has been implemented since June 1st, and the new standard includes new types of heating wires within the scope of the standard.

It is reported that China produces and sells tens of millions of electric blankets every year. Due to the simple production process, many enterprises that do not have the production conditions have also entered the industry. According to statistics from relevant departments, about half of the total consumption of low-quality electric blankets enters the market every year. At the beginning of this year, the Guizhou Provincial Administration for Industry and Commerce released the results of targeted monitoring of the quality of electric blankets in the circulation field. Among the 30 randomly sampled batches, 11 batches were found to be unqualified, accounting for nearly 40%. Unqualified indicators include multiple important items closely related to usage safety, such as structure, power connection and external flexible cords, input power and current.

At the beginning of this year, after investigating the electric blankets sold in the Beijing market, it was found that the sales of electric blankets were mainly concentrated in supermarkets, small and medium-sized department stores, and wholesale markets. The variety and brands of products sold in supermarkets and department stores are relatively limited, and the prices are also relatively high. Wholesale markets offer a wide variety of seasonal products, some packaged in simple plastic bags, while others come in exquisite packaging boxes. A vendor told reporters that products that fully comply with national standards and have passed 3C certification are the most expensive, costing 150 yuan, while others are cheaper, selling for just a few dozen yuan. "Actually, they can all be used," he explained.

Is that really the case? The horizontal evaluation of electric blankets conducted by the Evaluation Center of China Household Appliances Research Institute shows that products at different price points not only have significant differences in product comfort, but also in product safety. For example, for the same heating wire, some companies use a double-layer spiral structure. The heating wire in the heating wire is made of carbon fiber material, which is a type of heating material different from metal heating wires. It has the characteristics of low temperature (soft thermal sensation) and bending resistance. However, in the evaluation, it was found that there is a seemingly single-layer spiral heating wire, which is called a pseudo single-layer spiral heating wire by experts. It is wrapped around a nylon core wire with a very exaggerated large pitch (basically in a straight wire state). When the temperature is too high, even if the nylon core/polyester wire melts, it will not cause a change in the pitch of the heating wire, and it cannot provide overheating protection at all.

Ling Honghao, director of the Electric Heating Appliance Laboratory at the National Household Electrical Quality Supervision and Inspection Center, introduced that due to fatal defects in single straight wire and single spiral heating wire, automatic temperature limitation cannot be achieved, which poses safety hazards. Therefore, since January 1, 2004, the country has implemented the "Safety Standards for Electric Blankets". Since then, some large enterprises have eliminated single straight wire and single spiral heating wire and started using double spiral heating wire. The double helix heating wire is composed of two heating wires inside and outside, with a special insulation material in between. When the temperature of any part of the heating wire of the electric blanket rises abnormally and reaches a certain temperature, the insulation material between the two heating wires in the heating wire will melt, causing a short circuit between the two heating wires. The controller in the switch will sense the change in current and automatically cut off the power supply.

The heating wire is a key component in electric blankets and plays a decisive role in the cost of electric blanket materials. Some small businesses use their brains on hotlines to reduce costs, such as using high-power hotlines and arbitrarily increasing their spacing, which not only reduces product comfort but also cannot guarantee product safety. And well-known enterprises have made significant technological investments in this area to improve product safety and comfort, successively developing products with overheating control protection, folding resistance, dry cleaning and washing resistance, and low radiation.

Experts remind consumers not to underestimate the technological content of electric blankets, as they are not meant to be used as long as they still generate heat. It is important to choose products with brand reputation and quality assurance, and to check if there is a 3C certification mark on the outer packaging when purchasing.