Ejector pin& Ejector sleeve

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Ejector pin

1. Definition of ejector pin: In the process of injection molding, when the mold cavity is filled with resin and begins to release, the ejector pin is pushed out to the preset position by the ejector pin after the mold, and the product is pushed out by the ejector pin so as to realize the separation of the product and the mold.

2.Ejector PIN classification:

A:According to ejector pin specifications

According to the usage habits of different countries and regions, the appearance of several mainstream companies in the mold and parts industry is slightly different, mainly reflected in the head size of ejector pin. Mainstream companies have formulated their own ejector pin head standards and specifications, among which the American standard represented by DME is the most commonly used. European standards represented by HASCO and MEUSBURGER, Japanese standards represented by MISUMI and PUNCH, and Taiwan standards widely used in China. When purchasing ejector pin, in addition to determining the length and diameter of ejector pin, please be sure to determine the head size of ejector pin, which is the main basis for distinguishing different ejector pin standards.

B: According to ejector pin raw material and heat treatment

Because ejector pin needs to be frequently pulled and pushed out in the template, ejector pin material needs to have a certain degree of hardness, wear resistance, etc., the common materials of plastic mold ejector PIN are SKH51, SKD61 (1.2344), SKD11 (1.2379), 65Mn, etc. SKH51 ejector pin has good toughness, SKD61 ejector pin surface after vacuum nitriding treatment can well improve the wear resistance of ejector pin , internal quenching and tempering hardness HRC40-45 degrees, after secondary tempering, SKD61 ejector pin has high toughness, High heat resistance, the working temperature can reach 550 degrees, suitable for long time use of high temperature mold. SKD11, due to its good wear resistance, high hardness and excellent machinability, is more commonly used to produce punch needles and other products. However, the ejector pin of 65Mn is brittle and easy to break due to its poor quality. Most companies that have requirements on mold quality have stopped using the ejector pinn of 65Mn material. Threeup is no longer producing 65Mn ejector pin products.

C: According to different Ejector pin appearance

According to the appearance of ejector pin, we are divided into ordinary ejector pin (round ejector pin), flat ejector pin, pin and so on.

Common ejector pin are round ejector pin, and flat ejector pin is also called flat pin, mainly used for the top part of the rib of plastic products, and there is a long strip of glue, round Ejector pin can not be placed, we choose to use flat ejector pin. Because the thinner ejector pin may break or bend under stress, we designed the ejector pin as a step type, and the back end is thicker than the ejector end, so as to enhance the strength of the ejector pin. This ejector pin is the holding pin.

3. Ejector pin design principles:

(1)Ejector pin layout should make the top force as balanced as possible. The part with complex structure requires larger demounding force, so the number of ejector pin should be increased accordingly.

(2)Ejector pin should be set in effective parts, such as bone position, column position, step, metal insert, local thick glue and other complex structure parts. The ejector pins on both sides of the bone position and column position should be arranged symmetrically as far as possible, and the distance between the ejector pin and the bone position and column position should be D=1.5mm, as shown in the figure below. In addition, the central Line of the ejector pin on both sides of the column position should be ensured to pass through the center of the column position.

  (3) Avoid crossing steps or setting ejector pin on the inclined plane, the top surface of ejector pin should be as gentle as possible, ejector pin should be arranged in the structure of the adhesive part with better force. See the figure below.

(4) Flat ejector pin should be used in deep bone position (depth ≥20mm) or difficult to arrange round ejector pin. When the flat ejector pin needs to be used, the flat ejector pin should be inlaid as far as possible to facilitate processing. The following figure

(5) Avoid sharp steel, thin steel, especially ejector pin top surface should not touch the front die surface. The following figure

(6)Ejector pin layout should consider the ejector pin and the channel side spacing, to avoid affecting the channel processing and water leakage.

(7) Considering the exhaust function of ejector pin, in order to discharge the exhaust, the ejector pin should be arranged in the part that is easy to form the vacuum. For example, cavity large plane, easy to form a vacuum, resulting in the increase of demoulding force.

(8) plastic parts with appearance requirements, ejector pin can not be arranged on the appearance surface, other ejection methods should be used.

(9) For transparent adhesive parts, ejector pin can not be arranged in the part requiring light transmission.

 

4. Ejector PIN selection principle

(1) Choose ejector pin with large diameter. In order to prevent, plastic deformation or damage to the correct analysis of plastic parts for the size of the adhesion of cavity and the parts, targeted to choose the appropriate ejection device, the output of the top ACTS on the rigidity and strength of the biggest plastic parts, namely the top edge of the wall as much as possible, rib, column below, function area as large as possible, that is at the top of the have enough under the condition of the position, Ejector pins with larger diameter and size preference should be used. To prevent deformation or damage of plastic parts.

(2) The specification of ejector pin should be as little as possible. When selecting ejector pin, the size of ejector pin should be adjusted to minimize the size specification, and the preferred size series should be selected as far as possible.

(3) The selection of ejector pin should meet the requirements of Ejector strength. When ejecting, the ejector pin should bear greater pressure. In order to avoid bending deformation of the small Ejector pin, the Step  ejector pin should be selected when the diameter of the Ejector pin is less than 2.5mm.

 

Q&A

1. What are the materials used by Threeup’s ejector pin?

The ejector pin of our company is usually made of SKD61(1.2344) material. We also produce the ejector pin of SKH51 material. Sometimes we also produce the ejector pin of other materials according to customers’ needs, but we generally do not recommend customers to choose those materials. Because of custom production, their delivery time is longer and the price is higher. 65Mn ejector pin because of its poor quality, Ejector pin is brittle and easy to break, most of the plastic mold has no longer used 65Mn material ejector pin. Currently, we no longer produce 65Mn ejector pin products.

Plastic mold ejector pin commonly used materials are SKH51, SKD61 (1.2344), SKD11 (1.2379), 65Mn, etc., among which SKH51 ejector pin toughness is better, SKD61 ejector pin surface after vacuum nitriding treatment can very well improve the wear resistance of ejector pin, internal quenching and tempering hardness HRC40-45 degrees, after two tempering, SKD61 ejector pin has high toughness, high heat resistance, the use of temperature up to 550 degrees, Suitable for long time use of high temperature mould. SKD11, due to its good wear resistance, high hardness and excellent machinability, is more commonly used to produce punch needles and other products.

2.What specifications of ejector pin do you offer?

We can produce all the ejector pin specifications in the current market, and we can also make customized production of ejector pin according to your needs. We have a large inventory of MISUMI standard ejector pin and PUNCH standardejector pin.

3.How about the quality of your ejector pin? Are you trustworthy?

We have more than 20 years of ejector pin production experience, our ejector pin through the use of thousands of customers in dozens of countries around the world, is trustworthy.

4. What are the main indicators to evaluate the performance of ejector pin mold?

Influence mold ejector pin main performance index is Ejector PIN tolerance, hardness, perpendicularity, concentricity, finish and so on.

5.What are the common quality problems of ejector pin?

Ejector pin common problems are insufficient hardness, easy to break, poor wear resistance, easy to wear.

6.How does your company solve these common problems of ejector pin?

Our company first in ejector pin material selection to ensure the quality of raw materials, the selection of domestic well-known manufacturers of raw materials, from the source to ensure the quality of the product material. In addition, all the products have to go through the vacuum and nitriding treatment, we cooperate with the heat treatment plant has many years of stable processing experience. We ensure that the product has a consistent verticality, which is also important to reduce the wear of the ejector pin in the die cavity. For customers with special requirements, we can do DLC coating processing to increase the hardness and wear resistance of products.

7.Do you have any in stock? What is the lead time for mold gas cap?

We will have some stock of some commonly used products, but some special specifications and sizes need to be pre-ordered for production. The production cycle is about 7 working days. If it is a large batch order, you are welcome to confirm the delivery time with us separately.

8. Is there a minimum order quantity for ejector pin?

No, but if you want a better price, we suggest you buy in bulk.

9. How to get the quotation of ejector pin?

You can make an inquiry on this page or send an email to tao@szthreeup.com. We will ship the goods by DHL or TNT.

10. Can you process the length and tail shape of ejector pin according to our requirements?

Of course, if you give us the confirmed drawing, we will process the tail shape and head shape of ejector pin into what you need according to your drawing requirements. We will be through wire cutting, discharge machining and other processing methods to meet your needs.

11. What kind of equipment do you have for gas cap production? What is your production capacity?

We have a number of automated ejector pin production lines, from raw material cutting to CNC processing and nitriding processing, which can all be operated automatically. Our monthly output is 150,000 PCS.