The ejection methods of a set of injection plastic mold can be divided into several forms: round thimble ejection, thimble ejection with support, flat ejector pin ejection, cylinder pin ejection, straight ejector pin ejection, etc. The ejection also determines the processing, research, and design difficulty of this product and this set of molds, as well as the precision of the plastic product. Let’s take a look at some of them below.
- Dome pin ejection
Dome pins are used in 99% of all injection molds. According to the mold design standards, the standard specifications of domestic positive steel, MISUMI, HASCO, and PUNCH are selected for the design. When the thimble is ejected from the product, it needs to withstand compressive pressure, which may break or bend, so the thimble must ensure sufficient compressive strength and bending resistance.
- Ejector with thimble
The thimble with support is a reinforced type of round thimble. When the diameter of the thimble is less than 3.00mm in diameter, the service life of the mold and the compressive strength of the thimble need to be added to ensure the strength of the pushrod. When the thimble strength is higher than 400.00mm, the thimble with a diameter of 4.00mm also needs to consider the compressive strength and use a thimble with support.
- Flat thimble ejection
According to the shape of the product, when the edge position of the product or the deep bone position cannot place the round thimble, the flat thimble is used for ejection. When using the flat thimble, it is best to cut out the insert at the matching position of the flat thimble to facilitate the fitter's mold matching and maintenance. Nowadays, the use of flat thimbles is becoming less and less common in molds. During molding, the flat thimbles are prone to burn out the die, and the long-term production thimbles are easy to wear off iron filings. Especially for export molds, it is required not to use flat thimbles, and directly use straight top blocks instead of flat thimbles.
- Cylinder needle ejection
The cylinder is divided into three parts: the cylinder needle, the push tube, and the pressure plate (tap) for fixing the cylinder needle.
When a small round product or a product with a boss column with a depth of more than 10.00mm, use the cylinder pin to eject the product to facilitate product demolding increase the exhaust effect during injection molding, and reduce the amount of discharge during mold processing, saving processing costs. . Therefore, almost every set of molds where there are boss pillars and products that can meet the location requirements will use a cylinder needle to assist product demoulding.
Taizhou Huangyan Jinhong Plastic Mould Parts Co., Ltd. is an injection mold manufacturer from China Ejector sleeve, its own plastic mold factory specializes in the production of plastic compression springs, positioning components, and other products and the company can provide special products.
