What is the basic process of thermoforming Engineering Plastic?
Engineering Plastic thermoforming equipment are manual, semi-automatic and fully automatic points. Manual equipment in all operations, such as clamping, heating, evacuation, cooling, stripping, etc. are manually adjusted to complete. Semi-automatic equipment in a variety of operations, in addition to clamping and stripping need to be done manually, the other are pre-set by the conditions and procedures automatically completed by the device. All operations in a fully automated device are performed automatically by the device.
The basic process of thermoforming is: sheet clamping → heating → forming → cooling → stripping. Which is the most important and complex shape. Most of the thermoforming is carried out on a molding machine, with a large difference depending on the thermoforming method. A variety of molding machines are not to complete the above five processes, according to the actual production needs to choose. The maximum size and maximum forming depth of the clamping device are usually used as the main parameters of the thermoforming machine.
① material clamping. When the material is gripped, it is necessary to maintain the release shape in order to prevent heat shrinkage and self-weight sagging when the Engineering Plastic sheet (sheet) cut to a certain size is used.
② heating. The heating system heats the plate (sheet) at regular intervals and constant temperature to the temperature required for molding, making the material in a high elastic state and ensuring the smooth progress of the next molding process.
③ forming. The sheet (sheet) material, which is softened by heating, is molded into a desired shape by means of molds and related means.
④ cooling system. The basic molding of a certain temperature of the Engineering Plastic products cooled to heat distortion temperature below the product cooling and curing, the stripping device from the mold, the size of fixed, the product is not deformed.
Recently, a microblogging online users raised concern: "Most of the bottom of the beverage bottle has an arrow with a triangle, the triangle which has a '1' word, which is a sign of PET, PET is a kind of Engineering Plastic, Repeated use of the bottle will be carcinogenic crisis. "This argument in the end do not fly?
With the doubt, the reporter visited the Wuhan City Group of light underground supermarket, Wal-Mart, in the parity and many other supermarkets, to visit the Engineering Plastic beverage bottles. Flip the Master Kong ice tea, uniform rock sugar and other drinks, the bottom of its Engineering Plastic bottles have a triangle with the arrow logo. Triangle with the number "1", the bottom are marked - PET.
When the reporter asked the number of the bottom of the bottle, is the purchase of drinks, Mr. Zhang said: "never noticed those numbers, used to lose, and no repeated use." Some elderly people said, run out of the Mineral water bottles will be used to install water, wine, edible oil and so on.
Huazhong University of Science and Technology School of Environmental Science and Engineering Associate Professor Yu Junfang said, "1" on behalf of PET, is a very common polymer materials, we usually drink mineral water, fruit juice Engineering Plastic bottle is used to do it. This material is low temperature non-toxic and tasteless, the human body is also very safe, but after the high temperature and exposure to the release of harmful organic solvents, it is best not to use hot water, , Because it is easy to dissolve harmful substances.
She introduced the general Engineering Plastic are divided into seven grades, on behalf of different materials, PE can be used to install drugs and bath products, it is best not to use; PVC material can be used to make raincoats and so on. "Drink bottle repeated use without harm, as long as not a long time to withstand high temperatures." Yu Junfang said.