1、 Injection molding

Injection molding: also known as injection molding, its principle is to add granular or powdery raw materials into the hopper of the injection machine. The raw materials are heated and melted into a flowing state. Driven by the screw or piston of the injection machine, they enter the mold cavity through the nozzle and the pouring system of the mold, and are hardened in the mold cavity.

Factors affecting injection molding quality: injection pressure, injection time, injection temperature

Process characteristics:

advantage:

1. Short forming cycle, high production efficiency and easy to realize automation

2. It can form plastic parts with complex shape, accurate size and metal or non-metal inserts

3. Stable product quality

4. Wide adaptability

Disadvantages:

1. The price of injection molding equipment is high

2. The structure of injection mold is complex

3. The production cost is high, the production cycle is long, and it is not suitable for the production of single piece and small batch of plastic parts

Application:

Among industrial products, injection molded products include kitchen supplies (garbage cans, bowls, buckets, pots, tableware and various containers), electrical equipment housings (hair dryers, vacuum cleaners, food mixers, etc.), toys and games, various products of the automobile industry, and parts of many other products.

2、 Insert injection molding

Insert molding: insert molding refers to the molding method of filling the pre prepared inserts of different materials into the mold and injecting resin. The molten materials are bonded and solidified with the inserts to form an integrated product.

technological process:

In the insert molding process, the injection molding machine is usually only a part of the whole system. The inserts usually need to be oriented first, and a shaking table can be used to accomplish this task. The insert is then placed into the mold by the end tool of the robot arm (eoat), which can usually be entered into the mold by means of a pre positioning device. After the finished product stage, ejection positioning is the most important step, and the repeatability of the mold opening action of the injection molding machine is crucial here. After the insert is closed into the mold, it is fixed in a vacuum state or mechanically (such as using a slider). While the insert is inserted, the last finished product is ejected.

Technical features:

1. The pre molding combination of multiple inserts makes the post engineering of product unit combination more reasonable.

2. The combination of the resin's formability, bending property and the metal's rigidity, strength and heat resistance complements each other to make complex and exquisite metal plastic integrated products.

3. In particular, the combination of the insulation of resin and the conductivity of metal is used, and the molded products can meet the basic functions of electrical products.

4. For the rigid molded products and the bending elastic molded products on the rubber sealing pad, after the integrated products are made by injection molding on the base, the complicated operation of arranging the sealing rings can be eliminated, making the automatic combination of the subsequent processes easier.

3、 Two color injection molding

Two color injection molding: refers to the molding method of injecting two different colored plastics into the same mold. It can make the plastic appear two different colors, and can make the plastic parts present regular patterns or irregular moire patterns, so as to improve the usability and aesthetics of the plastic parts.

Technical features:

1. The core material can use low viscosity materials to reduce the ejection pressure.

2. In consideration of environmental protection, recycled secondary materials can be used as core materials.

3. According to different use characteristics, for example, soft material is used for the skin material of thick finished products, hard material is used for the core material, or foamed plastic can be used for the core material to reduce the weight.

4. Lower quality core materials can be utilized to reduce costs.

5. The material with high price and special surface properties, such as anti electromagnetic wave interference and high conductivity, can be used for the skin material or core material to increase the product performance.

6. Proper combination of the skin material and core material can reduce residual stress of the molded products, increase mechanical strength or surface properties of the products.

4、 Micro foaming injection molding process

Micro foaming injection molding process: it is an innovative precision injection molding technology, which fills products by the expansion of pores and completes the molding of products under low and average pressure.

Basic principle:

The microcellular foaming process can be divided into three stages: first, the supercritical fluid (carbon dioxide or nitrogen) is dissolved into the hot melt adhesive to form a single-phase solution; Then, the switch type nozzle is used to shoot into the mold cavity with low temperature and pressure. Due to the instability of molecules caused by the decrease of temperature and pressure, a large number of bubble cores are formed in the product, and these bubble cores gradually grow to form tiny holes.

Process characteristics:

1. Precision injection molding;

2. Breaking through many limitations of traditional injection molding, it can significantly reduce the weight of parts and shorten the molding cycle;

3. The warpage deformation and dimensional stability of the workpiece are greatly improved.

Application: automobile instrument panel, door panel, air conditioning duct, etc

5、 Nano injection molding (NMT)

NMT (nano molding technology): it is a method of combining metal and plastic with nanotechnology. First, the metal surface is nano treated, and then the plastic is directly injected onto the metal surface, so that the metal and plastic can be formed integrally.

Nano molding technology is divided into two types of processes according to the position of plastic:

1. Plastic is one-piece molding with non appearance surface

2. Integrated molding with plastic as external surface

Process characteristics:

1. The product has a metallic appearance and texture,

2. The design of product mechanism is simplified, making the product lighter, thinner, shorter and smaller, and more cost-effective than CNC processing.

3. Reduce production cost and high bonding strength, and significantly reduce the utilization rate of related consumables

Applicable metal and resin materials:

1. Aluminum, magnesium, copper, stainless steel, titanium, iron, galvanized plate, brass;

2. Aluminum alloy has strong adaptability, including 1000 to 7000 series;

3. The resins include PPS, PBT, PA6, PA66 and PPA;

4. PPS has a particularly strong adhesive strength (3000n / C ㎡).

Application:

Mobile phone case, laptop case, etc