av一区二区三区在线观看_久久99精品国产自在现线_日日碰狠狠躁久久躁_东京热一区_来一水AV@lysav

There are many materials used in the manufacture and production of medical device shells, such as ABS, PP, PE, stainless steel and carbon steel plastic spraying. AB resin is a kind of thermoplastic polymer material with high strength, good toughness and easy processing and molding. AB resin is often used to manufacture the plastic shell of instruments because of its high strength, corrosion resistance, high temperature resistance and other characteristics.

Polypropylene is a high polymer. Due to its regular structure and high crystallinity, its melting point can reach 167 ℃. It is heat-resistant and corrosion-resistant, and steam disinfection is its outstanding advantage. The shell of medical devices made of this material has no problem of environmental stress cracking.

The main component of PVC is PVC, which is bright colored, corrosion-resistant and durable. Because some toxic excipients such as plasticizers and anti-aging agents are added in the manufacturing process to enhance its heat resistance, toughness and ductility, its products generally do not store food and drugs.

The manufacturing and sealing of the shell of medical devices shall prevent contact with live parts and parts that may be live under a single fault state. The position or size of any hole in the top cover shall be such that the test rod with a diameter of 4 mm and a length of 100 mm will not contact live parts when it is freely and vertically suspended in the hole throughout its length.

If the components with AC 25V or DC 60V or above line voltage in the shell of the medical device cannot be disconnected from the power supply through the external main switch or the plug device that can be pulled out at any time, additional covers shall be used for protection to prevent contact even after the shell is opened, or when the space is separated from each other, it shall be clearly marked with "live".

The shells of medical devices that prevent contact with live parts must be removed only with tools, otherwise, automatic devices should be used to open or remove the shells without these parts; The hole used to adjust these control devices shall be designed so that the adjusting tool cannot contact the basic insulation or any live parts, or any parts isolated from the power supply part of the network only through the basic insulation, without protective grounding.