There are more and more applications of injection mould base in engineering. How to choose the right one is a problem. Today we summarize several criteria for selecting injection mould base. Let's take a look. Injection mould base generally uses standard mold base and standard accessories, which helps to shorten manufacturing cycle and reduce manufacturing cost. In actual production, it is often determined according to price of mold, structure, and complexity of mold processing.
In case of special circumstances or customer specified requirements, shape, size and material of injection mould base can be changed, or mold base can be completely redesigned. In this case, mold base supplier must provide with details when ordering mold base and indicate difference between ordered mold base and standard mold base. Size of injection mould base and insert are determined mainly by size and structure of plastic product. For surface of mold, the more compact of structure, the better. According to product's external dimensions (planar projected area and height) and structure of product itself (such as structure of lateral splitting slider), outer dimensions of insert can be determined. After determining size of insert, injection mould base can be roughly determined. Size of square iron height square iron should ensure sufficient ejecting stroke, and then leave a certain margin (5~10mm) to ensure that ejector pin does not hit moving plate or moving die when fully ejected. Overall structure of injection mould base is determined After basic mold base is selected, overall structure of mold base shall be checked to see if determined mold base is suitable for selected or customer-specified injection molding machine, including size, thickness and maximum of injection mould base, mold opening stroke, ejection mode, and ejection stroke. Performance of mold insert material should have four aspects: 1 hardness; 2 wear resistance; 3 strength and toughness; 4 corrosion resistance. Choice of mold insert material is mainly determined according to batch size and plastic category of plastic product. For products that are general plastics such as: ABS, PP, PC and other plastics, usually type P20 and other types of pre-hardened quenched and tempered steel are used. If batch size is large, quenched and tempered steel such as model H13 should be used. High-gloss or transparent plastic products, such as: PMMA, PS, AS and other plastics or glass fiber-containing plastics, type 420 and other types of corrosion-resistant stainless steel are mainly selected. In addition to above selection, there are several key points to choose from.

 

01 Thickness of mold base H and closing distance of injection mould machine L. For different types and sizes of injection mould machines, different types of clamping mechanisms have different configurations of closed distance.
02 When designing size relationship between distance from mold opening stroke to fixed and movable molds,stroke required to push plastic parts, it must be calculated and determined that opening stroke of injection mould machine should be larger than fixed and movable molds required to take out plastic parts. Distance between mold and plastic part to be pushed out must be smaller than rated ejection stroke of hydraulic cylinder of injection mould machine.
03 Selected injection mould base should be paid attention to during installation and disassemble on injection mould machine: outer dimensions of mold base should not be affected by spacing of drawbar of injection mould machine; positioning aperture and size of positioning ring should be well matched; position of injection ejector hole and ejection stroke is well matched; whether nozzle aperture and spherical radius match size of gate sleeve and concave spherical surface of mold; position and aperture of mold mounting hole match with moving template of injection mould machine and corresponding screw hole on fixed template.
04 Selection of injection mould base should meet technical requirements of plastic parts and its molding process. To ensure quality of plastic parts, performance and reliability of molds, it is necessary to accurately determine mechanical properties of mold parts, especially their strength and stiffness. Check and calculate to determine length, width and thickness of the moving and fixed stencils and support plates, so as to correctly select specifications of injection mould base.