Ejector Blades (FLat Ejector Pin)

Concept of ejector Blades:

Because round parts and their matching mounting holes are easier to machine (especially grinding), the cross-sectional shape of the Ejector Pin is usually round. Due to the molding needs of injection molded products, Ejector Pins with a rectangular cross-section are sometimes used. We call this type of Ejector Pin Ejector Blades. Ejector Blades, also called FLat Ejector Pin, are mainly used for the ejection of the rib part of plastic products, as well as the long glue position. When the round Ejector Pin cannot be placed down, we choose to use Ejector Blades (FLat Ejector Pin).

Material and respective characteristics of Ejector Blades (FLat Ejector Pin):

The material of plastic mold Ejector Blades (FLat Ejector Pin) is SKH51 (SKH51 is high-speed steel, Japanese JIS grade, equivalent to German DIN 1.3343 or American M2.) SKD61 (equivalent to German DIN 1.2344 or American H13) , SKD11 (equivalent to German DIN1.2610, American D2), 65Mn, etc.

The toughness of SKH51 Ejector Blades (FLat Ejector Pin) is better than that of SKD61 material; the Ejector Blades (FLat Ejector Pin) of SKD61 material can withstand high temperature of 1600 ℃, and the surface of Ejector Blades (FLat Ejector Pin) of SKD61 material can be very high after nitriding treatment. It is good to improve the wear resistance of the product. Because of its poor quality, 65Mn Ejector Blades (FLat Ejector Pin) are brittle and easy to break. Most of the plastic molds have not been assembled and used 65Mn Ejector Blades (FLat Ejector Pin). THREEUP has now basically stopped using 65Mn material to produce Ejector Blades (FLat Ejector Pin).

Ejector Blades with R Corners (Flat Ejector Pin):

The corners of Ejector Blades (Flat Ejector Pin) (cross-sectional shape are rectangular) are sharp, and it is usually necessary to perform appropriate chamfering processing according to the shape of the inner corner of the assembled square hole during use. The rod diameter of Ejector Blades (Flat Ejector Pin) is cylindrical, and only the front end is flat-ground to a square cross-section. The connection between the square part and the round rod part is processed into an excessive arc R, which can buffer and concentrate the mechanical effect of stress when receiving compressive load or bending load, and is not easy to break during use. Ejector Blades (Flat Ejector Pin) with R angle tolerance +0,015/+0,005, the R angle is finely ground by a surface grinding shaper, which can ensure the accuracy of +0,015/+0,005. At the same time, because it is ground after heat treatment, it is not It affects the stability of the internal structure of the product. It has good toughness and is not easy to deform when used.

Some Reasons and Suggestions for Ejector Blades (Flat Ejector Pin) Easily Broken

There will be various problems in mold production that plague us, and how to solve them effectively is what our mold industry technicians always need to think about. Today, we will discuss some of the reasons why the mold Ejector Blades (Flat Ejector Pin) are easy to break.

Difficulty demoulding the mold and easily breaking the Ejector Blades (Flat Ejector Pin) seems to be a small problem, but due to the high maintenance cost in the later period, the replacement of the Ejector Blades (Flat Ejector Pin) delays production. Although this problem It cannot be completely eliminated, but it can be reduced by various means. First of all, we need to find the reason for the breakage of Ejector Blades (Flat Ejector Pin):

1. Whether the Ejector Pin material is reliable, Ejector Blades (Flat Ejector Pin) should be made of SKH51 material (1.3343), followed by SKD61 (1.2343), and 65Mn and other materials are not recommended. It is also worth noting that the Ejector Pin materials on the market are quite confusing. Many manufacturers pretend to be SKD61 materials with 38CrMoAl materials. They claim to be Chinese standard SKD61 materials. In fact, Chinese standard SKD61 materials are 4Cr5MoSiV1, and 38CrMoAl is not resistant enough. Heat, hardness and strength are not as good as SKD61 material, 38CrMoAl is easy to be scratched and broken when the mold temperature exceeds 200 degrees. THREEUP’s Ejector Blades (Flat Ejector Pin) are made of high-quality SKH51 or SKD61.

2. Pay attention to check whether the dimensional accuracy meets the requirements for use. If the Ejector Blades (Flat Ejector Pin) are not processed accurately enough, they will not fit smoothly with the wire-cut square holes on the template, and they will be easily stuck and broken.
3. Whether the heat treatment meets the requirements and whether the hardness meets the standard.Most Ejector Blades (Flat Ejector Pin) need heat treatment during the manufacturing process. After quenching, they are not tempered or the tempering time is not enough. Such Ejector Blades (Flat Ejector Pin) are prone to defects, such as excessive residual stress and other quality problems;
4. Surface treatment, in order to improve the wear resistance, Ejector Blades (Flat Ejector Pin) need to be more nitrided after processing, check whether the nitriding process is standardized, the higher nitriding temperature causes the material to be tempered or even annealed. invalid.
5. The R angle of the Ejector Blades (Flat Ejector Pin) at the transition from the cylinder to the flat position is too small, resulting in an unbalanced force at the connection, causing the Ejector Blades (Flat Ejector Pin) to break from this position during use.
6. Before installing the Ejector Blades (Flat Ejector Pin), check the size and roughness of the ejector pin hole on the template. If the Ejector Blades (Flat Ejector Pin) are installed loosely, the ejector Pin hole is easy to enter the resin material. When blocked in the ejector pin hole on the template, the Ejector Blades (Flat Ejector Pin) are easy to break. Pin) and hole fit must be mastered.
7. Daily maintenance and process debugging of molds. It is better to add lubricating oil every time the mold is installed, and the daily maintenance is mainly to apply lubricating oil regularly. The ejector pins of the mold are all 3-5μ clearance, and the general lubricating oil can support 3-5 days after smearing, and the metal powder formed by dust and mold friction accumulates into the gap of the ejector pin, the slider, and the inclined roof tunnel. Internally, the gap of the mating surface is getting smaller and smaller, and the finish is getting lower and lower, and then it is completely ablated and stuck until it breaks. Therefore, it is necessary to wipe off the dirt on the Ejector Blades (Flat Ejector Pin) and the die surface and apply a clean lubricant. During maintenance, pay attention to applying high temperature-resistant lubricant to the inclined top and Ejector Blades (Flat Ejector Pin) as much as possible to form a thin film.

8. In pursuit of a shorter cycle, the opening and closing of the mold is too fast, and the Ejector Blades (Flat Ejector Pin) are quickly inserted and pulled out in a short time, which exceeds the bearing capacity of the mold.
9. The opening and closing speed of the mold is too fast, and the air intake at the bottom of the product is insufficient, which will form a damping state of negative pressure and increase the resistance of the product to fall off. In this way, the Ejector Blades (Flat Ejector Pin) will also receive a lot of resistance.
10. If the Ejector Blades (Flat Ejector Pin) are relatively thin, especially the front flat part is too thin, it is also easy to damage.
11. The high temperature of the production environment causes fatigue, and the material of Ejector Blades (Flat Ejector Pin) is annealed and fails.

For Ejector Blades (Flat Ejector Pin), some subtle problems in processing can become part of the reason for easy crushing, which requires our processing technicians to observe more carefully during processing and make judgments in advance .

Processing flow of Ejector Blades (Flat Ejector Pin)

Ejector Blades (Flat Ejector Pin) seems to be a very simple mold part, but the whole processing process does have more than a dozen steps, each step is not well controlled, it may cause the poor quality of Ejector Blades (Flat Ejector Pin), Now I will briefly introduce the production process of Ejector Blades (Flat Ejector Pin).

1. Material selection and cutting

The best material for Ejector Blades (Flat Ejector Pin) is SKH51, but due to cost considerations, many mold factories use SKD61 material to produce Ejector Blades (Flat Ejector Pin), it can be said that most of the Ejector Blades (Flat Ejector Pin) on the market They are all Ejector Blades (Flat Ejector Pin) of SKD61, so we take SKD61 Ejector Blades (Flat Ejector Pin) as an example to illustrate. The raw material is cut according to the length requirements of the Ejector Blades (Flat Ejector Pin). Generally, the length of the cut is more than 20mm longer than the length required by the Ejector Pin.

2, rough pass, rough grinding

Because the Ejector Blades (Flat Ejector Pin) materials selected by THREEUP are basically black skin materials after vacuum heat treatment, it is necessary to straighten and grind the intercepted materials for the first time. After the straightening and grinding machine, the black skin materials become It has become a smooth material, and the roundness and straightness of the raw material can basically meet the requirements of Ejector Blades (Flat Ejector Pin).

3. Head molding

The straightened material is sent to the head forging press, and the head forging press instantly heats one end of the material to more than 800 degrees, and then forges. According to the different needs of customers, the head size of the Ejector Blades (Flat Ejector Pin) is forged. Size requested by customer. The head sizes of MISUMI, DME and HASCO are different. We should pay special attention to the specifications of the head size when purchasing.

4. Tempering

The dimensional accuracy and verticality of the forged Ejector Blades (Flat Ejector Pin) head are not high, and further processing by CNC is required. However, due to the high hardness of the material itself, it needs to be forged before CNC processing. The head of the Ejector Blades (Flat Ejector Pin) is tempered to reduce hardness and facilitate turning.

5. CNC machining head

According to the needs of customers, Ejector Blades (Flat Ejector Pin) needs to be finely processed by CNC on the head size, and the diameter, thickness and verticality of the head size must be controlled within 0.02mm (individual customers require it to be controlled within 0.01mm) .

6. Centerless grinding machine

After the head is processed, the Ejector Pin needs to be processed with a centerless grinder, in order to control the diameter of the entire Ejector Pin within the range required by the customer, and also to control the roundness of the product.

7. Surface grinder processing

The product processed by the centerless grinder is actually a qualified ordinary Ejector Pin (not yet nitrided). At this time, according to the customer’s drawings, the flat position of the Ejector Blades (Flat Ejector Pin) needs to be processed. The general size with small diameter can be processed directly on the surface grinder. Some Ejector Blades (Flat Ejector Pin) with large diameter and long flat position, in order to save the time of the surface grinder, we will first perform wire cutting, and then Grinder processing. When grinding, you need to pay special attention to turning over several times to avoid the bending deformation of the Ejector Blades (Flat Ejector Pin).

8. Nitriding

After the Ejector Blades (Flat Ejector Pin) are processed, a nitriding treatment is required to enhance the surface hardness and increase the wear resistance.

9. Polishing

Nitrided Ejector Blades (Flat Ejector Pin) need to be polished once because the nitrided layer of the epidermis is dark brown, and the polished Ejector Blades (Flat Ejector Pin) is shiny.

10. Secondary processing

After the above steps, Ejector Blades (Flat Ejector Pin) have been produced, but some customers need to carry out secondary fine processing of Ejector Blades (Flat Ejector Pin), including R angle forming, head forming, length control, etc., which requires According to the specific requirements of customers, we carry out secondary processing through slow wire walking, EDM discharge, various types of grinding machines, etc.

Q&A:

Q: What level of tolerance can THREEUP’s Ejector Blades (Flat Ejector Pin) achieve?

A: The dimensional tolerance of our Ejector Blades (Flat Ejector Pin) can be controlled within a maximum of 0.005mm. However, we also recommend that customers choose the tolerance range according to their own mold needs, because more precise tolerance means higher cost.

Q: Are the Ejector Blades (Flat Ejector Pin) of THREEUP Company in stock, and how long does the delivery usually take?

A: Our company has a large stock of common Ejector Pins. When customers need Ejector Blades (Flat Ejector Pins), we can start processing immediately and deliver them to customers on the same day. If the quantity is large, we can generally Delivery within 3 days.

Q: Are you able to accept OEM?

A: We OEM various mold accessories for many companies in Europe, including Ejector Blades (Flat Ejector Pin), we can engrave the logo you need by laser engraving machine after the product is finished.

Q: Do you have MOQ requirements for your Ejector Blades (Flat Ejector Pin)?

A: We do not have MOQ requirements, we understand that sometimes a set of molds does not use a lot of Ejector Blades (Flat Ejector Pin), and they may still have different specifications, it does not matter, even if you only order one Ejector Blades (Flat Ejector Pin), we will also serve you.

Q: How do I need to customize the Ejector Blades (Flat Ejector Pin)?

A: You can send your Ejector Blades (Flat Ejector Pin) drawings or instructions to our email: tao@szthreeup.com, when we receive your email, we will promptly quote you according to your needs, you can also directly Leave us a message on our website and we will contact you as soon as possible.