ABS injection mold manufacturing and design, multi cavity injection mold development
Plastic mold is the mother of the industry, the release of new products will involve plastic.
Plastic mold is a combination mold used for pressure molding, extrusion, injection, blow molding and low foaming molding. A series of plastic parts of different shapes and sizes can be processed by the coordinated change of mold convex, concave die and auxiliary forming system.
Classification of plastic moulds
A. Injection molding mold -- TV shell, keyboard buttons, electronic products, computer surrounding plastic products, toys, household items (the most common application)
B. Blow mold -- beverage bottle
C. Compression molding die - bakelectric switch, scientific porcelain dishes
D. Transfer molding die - Integrated circuit products
E. Extrusion mold -- glue tube, plastic bag
F. Thermoforming die -- transparent molding package shell
G. Rotary molding mold -- soft glue doll toy
Moulds can be divided into three types according to the different pouring system:
1.Large water mouth mold: the runner and gate are on the parting line, and the product is demoulded together when the mold is opened. The design is the most simple, easy to process, and the cost is low, so more people use large water mouth system operation.
2.Fine water mouth mold: the runner and gate are not on the mold parting line, but generally directly on the product. Therefore, it is necessary to design more than one set of water mouth mold parting line. The design is more complicated and the processing is more difficult.
3.Hot runner mold: The structure of this kind of mold is roughly the same as that of the fine water mouth. The biggest difference is that the runner is in one or more hot runner plates with constant temperature and hot mouth, and there is no cold material demoulding. The runner and gate are directly on the product, so the runner does not need demoulding. The mold cost is higher.
Hot runner system, also known as hot runner system, is mainly composed of hot gate cover, hot runner plate and temperature control electric box. Our common hot runner system has two forms: single point hot gate and multi-point hot gate. Single point hot sprue is a single hot sprue cover is used to directly inject the molten plastic into the cavity, it is suitable for a single cavity single sprue plastic mold; The multi-point hot gate is to branch the molten material into each hot gate cover and then into the mold cavity through the hot gate plate. It is suitable for single cavity multi-point feeding or multi-cavity mold.
◆ Advantages of hot runner system
1)No water mouth material, no need for post-processing, so that the whole forming process is completely automatic, save working time, improve working efficiency.
2)Small pressure loss. The temperature of the hot runner is equal to that of the nozzle of the injection molding machine, which avoids the surface condensation of the raw material in the runner and reduces the injection pressure loss.
3)The repeated use of water mouth material will degrade the performance of plastics, and the use of hot runner system without water mouth material, can reduce the loss of raw materials, thus reducing the cost of products. The temperature and pressure in the cavity is uniform, the stress of the plastic parts is small, the density is uniform, the injection pressure is small, the molding time is short, the injection molding system is better than the general product. For transparent parts, thin parts, large plastic parts or high requirements of plastic parts can show its advantages, and can be used to produce larger products with smaller models.
4)The thermal nozzle adopts standardized and serialized design, equipped with a variety of optional nozzle heads, good interchangeability. Unique design and processing of electric heating ring, can achieve uniform heating temperature, long service life. Hot runner system is equipped with hot runner plate, temperature controller, etc., exquisite design, various types, easy to use, stable and reliable quality.
◆ Shortcomings of hot runner system application
1.The closing height of the overall mold is increased. Due to the addition of hot runner plate, the overall height of the mold is increased.
2.Thermal radiation is difficult to control, and the biggest problem of hot runner is the heat loss of runner, which is a major issue to be solved.
3.There is thermal expansion, thermal expansion and cold contraction is our design to consider the problem.
4.The increase of mold manufacturing cost and the high price of standard parts of hot runner system affect the popularity of hot runner mold.
Five key points of mold making
1.effective management of product data management, process data management, drawing document management: effective mold product data management, process data management, drawing document management, can ensure the comprehensiveness of the document, drawing version consistency; So that the drawing can achieve effective sharing and effective inquiry utilization. A complete file management computer database can be established to collect and utilize the design drawings accumulated by the design department, scattered and previously scattered and isolated information, so as to prevent the confusion of 2d and 3d, the confusion of original, variable and maintenance versions, and the inconsistency between 3d model and 2d drawing data. The non-standard and chaotic 2d drawing design causes problems that are not easy to be found and corrected in time, resulting in mold modification and rework, or even scrap, increasing the manufacturing cost of the mold, lengthening the production cycle of the mold, and affecting the delivery time.
2.maintain the consistency and integrity of plastic mold drawings, processing technology, and physical data: through effective, meticulous, strict testing means to ensure the consistency and integrity of mold drawings, processing technology, and physical data.
3.The design and manufacturing costs of each set of plastic molds must be summarized in time: by effectively controlling the issuing of work summons in the workshop, effectively managing the scrap of tools; Through the accurate mold structure design, efficient mold parts processing and accurate parts testing, will effectively reduce the mold due to set changes, maintenance and additional costs, so as to obtain the actual cost of each set of mold, effectively control the quality of the mold.
4.Overall planning: organically organize and integrate the information of planning, design, processing technology, workshop production and human resources for overall planning, so as to effectively coordinate planning and production, effectively ensure the quality of plastic molds and deliver on schedule.
5.Develop a complete and practical plastic mold production management system: Develop a complete mold production management system, realize the mold production management process of product data management, process data management, plan management, schedule management of computer information management system, including plastic mold production plan formulation, mold design, process formulation, workshop task assignment and product inspection, warehouse management, etc. Make the mold manufacturing and related auxiliary information from the planning to the completion of the delivery can achieve a full range of tracking management.