The various tools and products we use in our daily production and daily life, ranging from the base of machine tools and the outer shell of the machine body to a small screw, button, and the outer shell of various household appliances, are all closely related to molds. The shape of the mold determines the appearance of these products, and the processing quality and accuracy of the mold also determine the quality of these products. Due to the different materials, appearances, specifications, and uses of various products, molds are divided into non plastic molds such as casting molds, forging molds, die-casting molds, stamping molds, and plastic molds.

Technology application

1. For example, in many fields such as household appliances, instruments and meters, construction equipment, automotive industry, and daily hardware, the proportion of plastic products is rapidly increasing. A well-designed plastic component can often replace multiple traditional metal components. The trend of plasticization of industrial and daily products is constantly increasing.

2. General definition of molds: In industrial production, various presses and specialized tools installed on the press are used to produce metal or non-metallic materials into the required shape of parts or products through pressure. These specialized tools are collectively referred to as molds.

3. Injection molding process description: A mold is a tool for producing plastic products.

4. The general classification of molds can be divided into plastic molds and non plastic molds:

⑴ Non plastic molds include: casting molds, forging molds, stamping molds, die-casting molds, etc.

A. Casting mold - faucet, pig iron platform

B. Forging Die - Automotive Body

C. Stamping Die - Computer Panel

D. Die casting mold - superalloy, cylinder body

⑵ Plastic molds can be divided into:

A. Injection molding mold - TV casing, keyboard buttons (most commonly used)

B. Blowing mold - beverage bottles

C. Compression molding mold - bakelite switch, scientific ceramic bowl and dish

D. Transfer Forming Mold - Integrated Circuit Products

E. Extrusion molding mold - glue pipes, plastic bags

F. Thermoforming mold - transparent formed packaging shell

G. Rotary Forming Mold - Soft Adhesive Doll Toys

Injection molding is the most commonly used method in plastic processing. This method is applicable to all thermoplastic and some thermosetting plastics, and the quantity of plastic products produced is unmatched by other molding methods. As one of the main tools for injection molding processing, injection molds have a high level of quality accuracy, manufacturing cycle, and production efficiency during the injection molding process, which directly affects the quality, output, cost, and product updates of the product, It also determines the responsiveness and speed of enterprises in market competition.

The injection mold is composed of several steel plates and various parts, which are basically divided into:

A forming device (concave mold, convex mold)

B positioning device (guide pillar, guide sleeve)

C fixing device (I-shaped board, code mold pit)

D cooling system (water outlet)

E constant temperature system (heating tube, heating wire)

F channel system (nozzle hole, channel groove, channel hole)

G Ejection system (ejector pin, ejector rod)

According to the different types of pouring systems, molds can be divided into three categories:

(1) Large water outlet mold: The runner and gate are on the parting line and demoulded together with the product during mold opening. The design is the simplest, easy to process, and the cost is lower, so many people use the large water outlet system for operation.

⑵ Fine nozzle mold: The runner and gate are not on the parting line, and are usually directly on the product. Therefore, it is necessary to design an additional set of nozzle parting lines, which is complex in design and difficult to process. Generally, the selection of a fine nozzle system depends on the product requirements.

⑶ Hot runner mold: The structure of this type of mold is generally the same as that of the fine nozzle, with the biggest difference being that the runner is located in one or more hot runner plates and hot pump mouths with constant temperature, without cold material demolding. The runner and gate are directly on the product, so the runner does not need demolding. This system, also known as the no nozzle system, can save raw materials and is suitable for situations where raw materials are expensive and product requirements are high. Design and processing are difficult, and mold costs are high.

The hot runner system, also known as the hot runner system, mainly consists of a hot runner sleeve, a hot runner plate, and a temperature control electrical box. Our common hot runner systems come in two forms: single point hot gate and multi-point hot gate. Single point hot gate is a plastic mold that uses a single hot gate sleeve to directly inject molten plastic into the mold cavity. It is suitable for single cavity and single gate plastic molds; Multi point hot gate is a method of branching molten material into each sub hot gate sleeve through a hot gate plate and entering the mold cavity. It is suitable for single cavity multi point feeding or multi cavity molds

Advantages of Flow Channel System

(1) Without water mouth material, there is no need for post processing, making the entire forming process fully automated, saving work time, and improving work efficiency.

⑵ Low pressure loss. The temperature of the hot runner is equal to the nozzle temperature of the injection molding machine, which avoids the surface condensation of raw materials in the runner and reduces the loss of injection pressure.

Repeated use of nozzle materials can degrade plastic properties, while using a hot runner system without nozzle materials can reduce the loss of raw materials and thus reduce product costs. In the mold cavity, the temperature and pressure are uniform, the plastic stress is small, and the density is uniform. Under lower injection pressure and shorter molding time, injection molding produces better products than general injection molding systems. For transparent parts, thin parts, large plastic parts, or high demand plastic parts, their advantages can be better demonstrated, and larger products can be produced using smaller models.

The hot nozzle adopts standardized and serialized design, equipped with various nozzle heads to choose from, and has good interchangeability. The uniquely designed and processed electric heating ring can achieve uniform heating temperature and long service life. The hot runner system is equipped with hot runner plates, temperature controllers, etc., with exquisite design, diverse types, convenient use, and stable and reliable quality.

Shortcomings in the application of hot runner systems

The overall height of the mold closure has increased due to the installation of hot runner plates, etc., resulting in an increase in the overall height of the mold.

⑵ Thermal radiation is difficult to control, and the biggest problem with hot runner is the heat loss of the runner, which is a major issue that needs to be addressed.

⑶ There is thermal expansion, and thermal expansion are problems we should consider when designing.

The increase in mold manufacturing costs and the high price of standard accessories for hot runner systems have affected the popularity of hot runner molds.

Common software

PTC's EMX, Siemens' NX Mold Wizard, CimatronE, Topoil, Delcam Moldmaker, Mixler's Topsolid Mold, Think3's Mold Design, Manusoft's IMOLD, R&B's MoldWorks, Solidworks, Pro-e, UG (the latter three are mainly product design, but can achieve mold design integration), etc.