Plastic Injection Molding Machine
A.Design –Main Structure
1.Injection Unit
2.Clamping Unit
3.General Features / Hydraulic Circuit
B.Machine Components
1.Injection System
-The Hopper
-The Barrel
-The reciprocating
-The Nozzle
2.Mold System怎样养肺
发动机油泥
-Two/Three –plate mold
-Cooling channels (circuits)
3.Hydraulic System
4.Control System
5.Clamping System
6.Molded System
7.Delivery System
-Sprue + Gate
-Cold runners
-Hot runners碳酸钙有什么作用
电脑配置模拟装机A. Design –Main Structure
1. Injection Unit
: 35 mm : 120 mm : 200 rpm .: 8,5 kg/h Max. : 96 cm3 Max. : 82 gr Specific : 1187 kg/cm2 : 1,6 tones Injection Force : 13 KN .: 3,9 kW
2. Clamping Unit
天赋测试
: 65 tones Mold .: 170 mm Min. : 100 mm Max : 280 mm Size of : 355 x 410 Clearence Between : 200 x 260 3. General Features
: 20 pieces/min : 7,5 kW : 2150 kg
: 120 lt : 120 bar : 650 x 2550
Hydraulic Circuit:
B. Machine components
Injection system
The injection system consists of a hopper, a reciprocating screw and barrel asmbly, and an injection nozzle, as shown in Figure 1. This system confines and transports the plastic as it progress through the feeding, compressing, degassing, melting, injection, and packing stages.
FIGURE 1. A single screw injection molding machine for thermoplastics, showing the plasticizing screw, a barrel, band heaters to heat the barrel, a stationary platen, and a movable platen.
The hopper
Thermoplastic material is supplied to molders in the form of small pellets. The hopper on the injectio
n molding machine holds the pellets. The pellets are gravity-fed from the hopper through the hopper throat into the barrel and screw asmbly.
The barrel
As shown in Figure 1, the barrel of the injection molding machine supports the reciprocating plasticizing screw. It is heated by the electric heater bands.
The reciprocating screw
The reciprocating screw is ud to compress, melt, and convey the material. The reciprocating screw consists of three zones (illustrated below):
∙the feeding zone
∙the compressing (or transition) zone
∙the metering zone
While the outside diameter of the screw remains constant, the depth of the flights on the reciprocatin
g screw decreas from the feed zone to the beginning of the metering zone. The flights compress the material against the inside
diameter of the barrel, which creates viscous (shear) heat. This shear heat is mainly responsible for melting the material. The heater bands outside the barrel help maintain the material in the molten state. Typically, a molding machine can have three or more heater bands or zones with different temperature ttings.
FIGURE 2. A reciprocating screw, showing the feeding zone, compressing (or transition) zone, and metering zone.
地址的英语九回The nozzle
The nozzle connects the barrel to the sprue bushing of the mold and forms a al between the barrel and the mold. The temperature of the nozzle should be t to the material's melt temperature or just below it, depending on the recommendation of the material supplier. When the barrel is in its full forward processing position, the radius of the nozzle should nest and al in the concave radius in the sprue bushing with a locating ring. During purging of the barrel, the barrel backs out from the sprue, so the purging compound can free fall from the nozzle. The two barrel positions are illustrated below.
FIGURE 3. (a) Nozzle with barrel in processing position. (b) Nozzle with barrel backed out for purging.
Mold system
话题聊天
The mold system consists of tie bars, stationary and moving platens, as well as molding plates (bas) that hou the cavity, sprue and runner systems, ejector pins, and cooling channels, as shown in Figure 4. The mold is esntially a heat
exchanger in which the molten thermoplastic solidifies to the desired shape and dimensional details defined by the cavity.
FIGURE 4. A typical (three-plate) molding system.
An mold system is an asmbly of platens and molding plates typically made of tool steel. The mold system shapes the plastics inside the mold cavity (or matrix of cavities) and ejects the molded part(s)
. The stationary platen is attached to the barrel side of the machine and is connected to the moving platen by the tie bars. The cavity plate is mounted on the stationary platen and hous the injection nozzle. The core plate moves with the moving platen guided by the tie bars. Occasionally, the cavity plate is mounted to the moving platen and the core plate and a hydraulic knock-out (ejector) system is mounted to the stationary platen. Three-plate mold
The three-plate mold is typically ud for parts that are gated away from their edge. The runner is in two plates, parate from the cavity and core, as shown in Figure 5 below.
