Injection Molding Process

Injection Molds and Plastic Injection Molding Products

The injection molding process in china， the process produces large numbers of parts with high quality， great accuracy, and quick cycle time. The production of plastic injection molds from both thermoplastic and thermosetting plastic materials. The plastic material, in the form of particles, is melted until it is soft enough to be injected under pressure, either through a reciprocating screw or a ram ejector, into the mold cavity. In China, when a part is designed by the customer, then manufacturing molds by an injection mold company, it needs a mold maker (or toolmaker) team to build. The result is that the shape is exactly copied. Once the plastic injection molding has cooled sufficiently to harden the mold opens releasing the part. The whole injection moulding process then repeats.

Injection mold making in China. We usually manufactured using steel or aluminum. And precision-machined to form the features of the desired parts. Injection molding is widely used for manufacturing a variety of parts, including household appliances, consumer electronics, power tools, and automotive dashboards. Other common thin-walled products include different types of open containers, such as buckets. Injection molding is also used to produce several everyday items such as toothbrushes or small plastic toys. Many medical devices, including valves and syringes, are manufactured using injection molding as well.

 

Injection Mold situation in China

China’s rapid economic development of the tooling industry put forward higher requirements and has provided great impetus for its development. In the past 10 years, China’s mold industry has been rapidly developing at about a 15 % per year growth rate. In recent years, the mold industry to accelerate the pace of structural adjustment, mainly for large, sophisticated, complex, long-life mold standard parts, standard mold growth rate higher than the overall growth rate of the industry; a larger proportion of plastic and Die-casting mold; Despite the development of China’s mold industry, there is an imbalance in the geographical distribution of the mold industry， The most concentrated area of mold production is pearl river delta and Yangtze river delta. Which accounts for over two-thirds of the country’s mold output value.

China’s market leader Dies, Shanghai is China’s leading injection molds market today and is China’s largest export mold city. 40% of the value of the multinational mold from Shanghai, and the performance rate of NC mold processing equipment and equipment, mold processing technology, the degree of specialization in production levels and standards ahead of other provinces. With further industrial structure optimization, developing IT, automotive, high-tech, and other industries are Shanghai mold manufacturing to higher requirements. Next few years, Shanghai mold manufacturing will become increasingly sophisticated, and complex. Private companies such as CNMOULDING’s growth rate of 100 %, become important members of the china injection mold industry.

Applications of China Injection Molds

Plastic Injection molding in China is the most commonly used manufacturing process for the fabrication of plastic parts. A wide variety of products are manufactured using injection molding, which varies greatly in their size, complexity, and application. The plastic injection molding process requires the use of an injection molding machine, raw plastic material, and a mold. The plastic is melted in the injection molding machine and then injected into the mold, where it cools and solidifies into the final part. The steps in this process are described in greater detail in the next section a popular material for Injection Molds

IMPORTANT: The information below is a general materials description overview, and is intended for preliminary material identification ONLY.

Equipment

China Plastic Injection Molding Machine-Injection Molding Process

Injection molding machines, also known as presses, consist of a material hopper. An injection ram or screw-type plunger, and a heating unit. The molds are clamped to the platen of the molding machine. Where plastic is injected through the sprue orifice to create injection molds.

Here we especially introduce a high-speed injection molding machine in China.

1. High-speed injection molding machine Clamping Unit

The new generation toggle mold locking device. And computer emulation optimized toggle parameter makes motions of the moving plate fast and steady.

2. High-speed injection molding machine Hydraulic Unit

High efficiency, energy-saving, and high precise proportional pressure. And the flow variable displacement pump system makes the hydraulic system output match. The required power for the entire machine operation without high-pressure throttle and overflow energy loss.

3. High-speed injection molding machine Injection Unit
The short and forceful double-cylinder injection system is used to ensure steady injection motions. The strain-free fixed mold plate and screw assembly with optimized design help to reach better plasticating capacity and effect.

4. High-speed injection molding machine Control Unit
The high-performance special control for injection molding machines. Switch of Chinese and English, clear and visual, and easy operation.

Mold making in China

Mold is the common term used to describe the tooling used to produce injection molded plastic parts.
It is mainly the production of thermoplastic products the most common kind of mold. Plastic injection mold processing equipment for the plastics injection molding machine. Plastic melt is first heated in the heated barrel of the end of the injection machine. And then injection molding machine into the mold cavity under the impetus of a screw or a plunger. The injection machine nozzle and mold casting system. Plastic cooling hardening molding, and mold release to get the products. Its structure is usually molded parts, casting systems, and parts-oriented components. The introduction of institutions, thermostat systems, exhaust systems, and support components.

Manufacturing materials commonly used plastic mold steel modules, commonly used material is mainly carbon structural steel, carbon tool steel, alloy tool steel, and high-speed steel. The injection molding process usually applies only to the varieties of products. Production of the thermoplastic injection molding process to produce plastic products is very extensive. From the daily necessities of life to all kinds of complex mechanical, electrical, and transport parts are injection molding. It is the most widely used in the production of plastics processing methods.

Custom Mold Design – Injection Molds

Molds consist of two primary halves, injection molds (A plate) and ejector molds (B plate). First, plastic resin enters the mold through a sprue in the injection mold. The sprue bushing is to seal tightly against the nozzle of the injection barrel of the molding machine to allow molten plastic to flow from the barrel into the mold, also known as a cavity. The sprue bushing directs the molten plastic to the cavity images through channels that are machined into the faces of the A and B plates. These channels allow the plastic to run along with them, so they are referred to as runners. The molten plastic flows through the runner and enters one or more specialized gates, and into the cavity geometry to form the desired injection molded part.

According to the size of the production capacity, product structure, to determine the appropriate number of cavities, more precision molds, processing difficulty, the higher the cost of the mold cavity. However, the unit price of injection molded parts dropped significantly.

Factors that affect the size of the multi-cavity:

1, Precision injection mold processing. Such as cavity discharge, each chamber is a discharge. The discharge process is not well controlled, cavity size deviation.

2, The injection mold assembly precision. Because of these reasons the assembly results in the internal structure of position deviation.

3, Injection mold design factors. Such as the design of the flow channel. And reasonable uniformity into the plastic, unreasonable runner advanced gum near the nozzle chamber, away from the last glue. Because of contractions are inconsistent, holding pressure situation size will also inconsistent deviation. Into the rubber mouth. The diameter size will cause the size of the deviation. Mold waterway design is unreasonable, in the cavity waterway layAccording to the size of the production capacity, product structure, to determine the appropriate number of cavities, more precision molds, processing difficulty, the higher the cost of the mold cavity. However, the unit price of injection molded parts dropped significantly.

 

Plastic injection mold cost and useful in China

High-quality plastic injection mold includes a fast running cycle, long mold life, easy maintenance, and safe operation. The mold design, mold material, mold tooling machines, and mold assembling are very important to making a high-quality injection mold Usually customers would doubt why for the same mold, different suppliers quoted a different price, some even have a big difference. For mold manufacturers in china, offer an inquiry, engineers will check the mold structure according to the original sample pictures or drawing estimate the mold size, mold ejection method, injection gate, and so on. After we got the above information. We could calculate the mold cost according to the customer’s requirement.

Mold cost includes mold material cost, mold design cost, mold tooling cost, managing cost, and after-sales service cost. We suggest using good steel material for a high quantity requirement mold. If the mold structure is complex, we need to consider the mold tooling more. The mold could run a long time with high-quality injection molds, and it is easier for mold maintenance. The production efficiency is much higher with continuously manufacturing. We suggest do not only compare the mold price when investing in a new mold. Because after the mold runs in a customer’s factory, it would also affect working much. injection mold cost estimate. The Mold price difference in China, high-quality injection molds, high-efficiency molding lines, and famous mold suppliers in China. Mold after-sales service. The length of time from closing the mold to ejecting the finished plastic molding is the cycle.

The size of an injection molded part will depend on several factors (material, wall thickness, shape, process, etc). The initial raw material required may be measured in the form of granules, pellets, or powders. Here are some ranges of sizes.

CNC-EDM-WIRE CUT MACHINE-Injection Molding Process

Injection Mold Companies use three main methods to manufacture molds: CNC number control milling machining and EDM, Wire cut machine… With technological development, CNC machining became the predominant means of making more complex molds with more accurate mold details in less time than traditional methods. Computer numeric controlled machining centers are used to produce a wide range of components. And tooling costs involved have continued to become more affordable. In general, large production runs requiring relatively simple designs are better served by other methods, although CNC machining can now accommodate a wide range of manufacturing needs. CNC milling centers are ideal solutions， everything ranging from prototyping and short-run production of complex parts. The fabrication of unique precision components.

The basic EDM process is really quite simple.

An electrical spark is created between an electrode and a workpiece. Electric Discharge Machining The spark is visible evidence of the flow of electricity. This electric spark produces intense heat with temperatures reaching 8000 to 12000 degrees Celsius, melting almost anything. The spark is very carefully controlled and localized so that it only affects the surface of the material. The EDM process usually does not affect the heat treatment below the surface. With wire EDM the spark always takes place in the dielectric of deionized water. The conductivity of the water is carefully controlled making an excellent environment for the EDM process. The water acts as a coolant and flushes away the eroded metal particles.

WIRE CUT MACHINE

Wire cutting uses a metallic wire to cut a programmed contour in a workpiece. Extrusion dies and blanking punches are very often machined by wire cutting. Cutting is always through the entire workpiece. To start machining it is first necessary to drill a hole in the workpiece or start from the edge. In the machining area, each discharge creates a crater in the workpiece and an impact on the tool. The wire can be inclined, thus making it possible to make parts with taper, or with different profiles at the top and bottom. There is never any mechanical contact between the electrode and the workpiece (see above). The wire is usually made of brass or stratified copper and is between 0.1 and 0.3 mm in diameter.