Two forming method
Release date:2014-07-17 00:00 Source:http://www.hongweishiying.com Views:
Two forming forming
Two forming is one of the methods of plastics processing. The plastic profile or blank as raw material, the method of product of desired shape by heating and force become.
Two forming is a forming the sheet, pipe, plate, plastic material, heating in the rubber state by external force, the deformation and formed into various simple shape, after cooling and products. 2, methods Mainly includes the following several kinds of molding methods:
Hot forming is thermoplastic plastic sheet is heated to softening, the gas pressure, liquid pressure or mechanical pressure, using appropriate die or fixture and make it become a kind of molding products.
Many methods of plastic thermoforming, generally can be divided into:
Many methods of plastic thermoforming, generally can be divided into: Molding a single mode (male or female die) or to die, to use external mechanical pressure or gravity, forming method of the sheet material of various products, molding it is different from a processing.
This method is suitable for all thermoplastic plastics. Differential pressure forming a single mode (male or female die) or to die, also can not die, in under the action of gas pressure, the heating to the sheet of plastic soft close to the die surface, forming method into various products after cooling.
Differential pressure forming can be divided into the vacuum forming and molding. Differential pressure forming can be divided into the vacuum forming and molding.
Hot forming is especially suitable for thin wall, large surface area of the products manufacturing. The variety of the common plastics with various types of organic glass, polystyrene, polyvinyl chloride, polyethylene, polypropylene, ABS, polyamide, polycarbonate and polyethylene terephthalate.
Hot forming device comprises a clamping system, heating system, vacuum and compressed air system and mold.
As the molecules to thermoplastic films or plates such as re orientation, especially in the biaxial tensile process above the glass temperature for. The tensile orientation be carried out between the glass transition temperature and the melting point of the polymer, the directional tension and rapidly cooled to room temperature after the films or filaments, mechanical properties in the stretching direction is greatly improved.
Suitable for a directional stretching of the polymer are: polyvinyl chloride, polyethylene terephthalate, poly vinylidene two vinyl chloride, polyethylene, polypropylene, polystyrene, polymethyl methacrylate and styrene copolymer.
Solid molding of thermoplastic plastic material or material under pressure mould for shaping it into products method. The molding process in the plastic melt (a softening temperature below (at least) below the melting point 10-20 ℃). As solid phase forming. One of the non crystalline plastic above the glass transition temperature, high elastic region processing below the melting point is often referred to as the hot forming, and machining in the glass transition temperature are called cold forming or room temperature molding, cold processing method is also often called plastic or room temperature plastic processing.
The method has the following advantages: short production cycle; improve the products of the toughness and strength; the equipment is simple, can be used in the production of large and super large products; cost reduction. Disadvantages are: difficult to produce complex shape products, precision; it is difficult to control the production process, product deformation, cracking.
Solid phase forming include: sheet rolling, deep