1. Clamping equipment
When the plastic sheet is formed, the sheet is fixed on the clamping device. In the thermoforming general-purpose and composite thermoforming machines, clamping devices that are convenient for fixing sheets of various sizes are often used. In some cases, the entire molding machine is equipped with a clamping frame.
Clamping devices can be divided into two categories: one is a frame type, and the other is a split type. The frame type clamping device is composed of an upper frame and a lower frame. The sheet is sandwiched between two frames. When the frame is opened, the lower frame generally remains fixed. Various types of simplex
The lower part of the upper frame of the position forming machine is directly fixed on the forming room. The manual and semi-automatic molding machines that load the parison and take out the finished product by hand are equipped with safety operation devices within the open range of the frame when the frame size is large. Great slippage for forming
For the parison, the clamping force is required to be adjustable in a relatively wide range. For this reason, two rubber-coated rollers are used, which are pressed against each other with springs, and are equipped with a pressure adjusting device. The clamping of the continuous pull forming machine is the joint action of the zippers on both sides and the front and rear brakes.
The clamping device is best to adopt automatic control, in order to move quickly, which can help improve the quality and efficiency of the parts.
2. Heating equipment
The vacuum blister forming process of thermoplastic plastic sheets and films, the main sequence I-is sheet heating. The duration and quality of electric heating depend on the structure of the heater, the thermal inertia of the temperature and heat transfer after radiating the surface, and the distance between the sheet and the heater
Isolation, the absorption coefficient of radiant energy, the characteristics of the heater surface and the thermophysical properties of the material. Commonly used heaters are electric heaters, crystal radiators and infrared heaters.
