Ejector plate

Force (Male Cavity) Guide Pin Bushing Rear Cav. Retainer PI. Push-back Pin Support Plete Ejector Pin Sprue Lock Pin Support Pillar Ejector RetBiner PI. Ejector Plate Clamp Slot Ejector Housing... 

KNOCKOUT PINS EJECTOR HOUSING EJECTOR PLATES... 

Ejector plate Fixed plate Elector bolt... 

Ejection of a molded plastic article from a mold can be achieved by using ejector pins, sleeves, or stripper plates. Ejector pins are the most commonly used method because they can be easily fitted and replaced. The ejector pins must be located in position where they will eject the article efficiently without causing distortion of the part. They are worked by a common ejector plate or a bar located under the mold, and operated by a central hydraulic ejector ram. The ejector pins are fitted either to the bottom force or to the top force depending on whether it is necessary for the molding to remain in the bottom half of the female part or on the top half of the male part of the tool. The pins are usually constructed of a hardened steel to avoid wear. 

Ejector Pin Sprue Lock Pin Support PiUat Ejector Retainer PI. Ejector Plate Clamp Slot... 

Ejector plate n. A plate that backs up the ejector pins and holds the ejector assembly together. 

At the end of the molding cycle, the mold opens and cooled parts are ejected from the injection mold. This requires the ejection system shown in Fig. 5.64.1 When the mold opens, the plastic part typically stays with the B side of the mold. Once the mold is opened, the hydraulic ejection cylinder extends, forcing the ejection platen forward (in all-electric machines, the cylinders are replaced by servomotors). Since the platen is usually tied to the mold s ejector plate by ejector rods, the ejector plate also moves forward. This forces the ejector pins (in the mold) forward... 

The point at which the cap is cool enough to eject, yet warm enough to strip off the core, will vary according to the means of ejection employed. Ejector pins provide very localized forces at the base of the cap. An ejector plate creates an ejection force which is distributed uniformly across the base of the cap. Therefore the cap can be ejected in a softer condition with the use of a stripper plate. That results in a cycle... 

The support plate backs up the B plate in the mold, and melt is delivered from the nozzle to the sprue bushing. The locating ring aligns the mold with the nozzle, whereas the leader pins and bushing align the two sides of the mold. In the ejection system, the sprue puller and ejector pins, are attached to the ejector plate, which is, in turn, connected to the machine s ejection plates by the ejector rod. When the mold is opened, the sprue puller draws the part to the B side of the mold, whereas the... 

Ejector Box Ejector Retainer Plate Ejector Plate... 

A stripper plate mold is a two-plate mold in which the core and ejector plates are combined into a stripper plate. It is used for thin wall parts and parts with symmetry and no undercuts. A three-plate mold has two parting Unes, thereby providing automatic separation of the parts and runner system. This does not work with all materials brittle materials tend to fracture on ejection. It also limits the selection of gate locations and does not eliminate scrap. A stack mold is used to mold two layers of parts without increasing clamp force. Because stack molds are not as precise as two-plate molds, they are used for low-tolerance parts such as polystyrene drinking cups. 

Figure 1 Basic variants of injection molds (a) two-plate mold (one cavity) (b) three-plate mold (multi-cavity). Designations a, coupling link b, ejector nxi cl + 2, center rings dl -f- 2, clamping plates e, ejector plate t, ejector pins g, distance plate h, cavity plate i, cavity j, transition plate k, sprue with cone gate 1, runner with 4 sprues m, center bolt n, runner plate o, nozzle rl + 2, insulation plates s, high performance nozzle.

As the moving machine platen continues to open, striker pins bearing on the ejector plate strike an ejector block on the machine which pushes the ejector pins forward, releasing the casting. The casting falls through an opening in the machine base, down a chute, and into a container or... 

Support plate Ejector pins Ejector retainer plate Ejector plate... 

A knockout system is required to eject the part from the mold (see Chapter 7 Mold Design"). On most machines there is an adjustable stationary ejector plate containing ejector bars which go through the movable platen. As the mold closes, the ejector bars go through the holes in the back platen of the mold, contact, and stop the mold knockout plate. The rest of the mold continues to close to a predetermined distance and stops. A superior method to activate the knockout system is by use of hydraulic cylinders. This permits advancing or retracting the knockout system with any speed or force. This can be particularly useful in cam and insert molding. 

A. Ejector nues and Pins. Ejector pins are countersunk into the ejector plate. The pins extend through the mold to the core or cavity molding surface. Pins are made from a high chrome vanadium or nitriding steel. The ejector plate also contains four push-back pins. These push the ejector plate to its back position when the mold closes so that the ejector pins and cavities are not damaged. 

The ejector pins are activated by the movement of the ejector plate in conjunction with the knockout system of the press. As the mold opens the ejector plate pushes the ejector pins forward, pushing them through the mold and forcing the... 

A sprue puller pin is attached to the ejector plate, directly opposite the sprue. An undercut (Z-shaped) or reverse taper is designed on the sprue puller so that GRTP material will mold around it. When the ejector plate moves forward, the pin is raised above the mold surface so that the runner can slide off the undercut. 

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