3. Mold material and hardness
1) The mold base should be a standard mold base that meets the standard.
2) Mold forming parts and gating system (core, movable and fixed mold inserts, movable inserts, split cones, push rods, sprue sleeves) are made of materials with performance higher than 40Cr.
3) When molding plastic that is corrosive to the mold, the molded parts should be made of corrosion-resistant materials, or the molding surface should take anti-corrosion measures.
4) The hardness of the moulded parts should not be lower than 50HRC, or the hardness of the surface hardening treatment should be higher than 600HV.
4. Mold out, reset, pull out the ferrule, take the part
1) The ejection should be smooth, without jamming, and without abnormal sound.
2) The inclined top surface should be polished, and the inclined top surface is lower than the core surface.
3) The sliding parts should be provided with an oil groove, and the surface needs to be nitrided, and the surface hardness after treatment is HV700 or higher.
4) All ejector rods should have stop rotation positioning, and each ejector rod should be numbered.
5) The ejection distance should be limited by a limit block.
6) Standard parts should be used for the return spring, and both ends of the spring should not be polished or cut off.
7) Slider and core puller should have stroke limit, small slider is limited by spring, if spring is inconvenient to install, corrugated screw can be used; cylinder core puller must have a travel switch.
8) Slider core pulling generally adopts oblique guide post, and the angle of oblique guide post should be 2°-3° smaller than the angle of the locking surface of the slider. If the stroke of the slider is too long, the oil cylinder should be used for drawing.
9) When the end surface of the core-pulling forming part of the cylinder is covered, the cylinder should be equipped with a self-locking mechanism.
10) There should be wear-resistant plates under the large slides with a width of more than 150mm. The wear-resistant plate material should be T8A. The hardness after heat treatment is HRC50-55. The wear-resistant plate is 0.05-0.1 mm higher than the large surface. Oil making tank.
11) The ejector rod should not move up and down.
12) Add barbs to the top rod, and the direction of the barbs should be consistent, so that the barbs are easy to remove from the product.
13) The clearance between the ejector pin hole and the ejector pin, the length of the sealing section, and the surface roughness of the ejector pin hole should be in accordance with the requirements of the relevant enterprise standards.
14) The product should be convenient for the operator to remove it.
15) When the product is ejected, it is easy to follow the inclined jack, and the ejector should be grooved or etched.
16) The top block fixed on the top rod should be firm and reliable, the non-formed parts around the circumference should be processed with a slope of 3°-5°, and the lower periphery should be chamfered.
17) There should be no iron filings in the oil passage hole on the mold base.
18) The end face of the return rod is flat and there is no spot welding. No gasket at the bottom of the embryo head, spot welding.
19) The gate plate of the three-plate mold slides smoothly, and the gate plate is easy to open.
20) Three-plate mold limit rods should be arranged on both sides of the mold installation direction, or pull plates should be added to the mold base to prevent the limit rods from interfering with the operator.
21) The oil circuit and air passage should be smooth, and the hydraulic ejector reset should be in place.
22) An exhaust port should be opened at the bottom of the guide sleeve.
23) There should be no gap in the positioning pin installation.
