PLASTIC MOLDING PROCESS(1)

PLASTIC MOLDING PROCESS(1)

1. Injection molding

Injection molding: The principle is to add granular or powdered raw materials to the hopper of the injection machine. The raw materials are melted and heated to a flowing state. The pouring system of the nozzle and the mold enters the mold cavity and hardens and sets in the mold cavity. Factors affecting injection molding quality: injection pressure, injection time, injection temperature.

Process characteristics:

Advantages:

1). Short molding cycle, high production efficiency and easy automation

2). Plastic parts with complex shapes, accurate dimensions, and metal or non-metal inserts can be formed

3). Stable product quality

4). Wide range of adaptation

Shortcomings:

1). The price of injection molding equipment is relatively high

2). The injection mold has a complicated structure

3). The production cost is high, the production cycle is long, and it is not suitable for the production of plastic parts in small quantities

Application:

In industrial products, injection molded products include: kitchen supplies (garbage cans, bowls, buckets, pots, cutlery, and various containers), housings for electrical equipment (hair dryers, vacuum cleaners, food mixers, etc.), toys and games, and automobiles Various industrial products, parts of many other products, etc.

2. Insert molding

Insert molding: refers to the molding method of inserting pre-prepared inserts of different materials into the mold and injecting resin. The molten material joins and solidifies with the inserts to form an integrated product.

Process characteristics:

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

2). The combination of the resin's easy formability, bendability and metal's rigidity, strength and heat resistance can be complemented to make a complex and exquisite metal-plastic integrated product.

3). Especially by using the combination of resin insulation and metal conductivity, the molded products can meet the basic functions of electrical products.

4). For rigid molded products and curved elastic molded products on the rubber sealing plate, after the injection molding on the base is made into an integrated product, the complicated operation of arranging the sealing rings can be omitted, making the automated combination of the subsequent processes easier.

3. Double-color injection

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

Process characteristics:

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

2). From the perspective of environmental protection, the recycled secondary material can be used as the core material.

3). According to different usage characteristics, for example, thick material finished skin material uses soft material, core material uses hard material or core material can use foam plastic to reduce weight.

4). You can use lower quality core materials to reduce costs.

5). Skin material or core material can use expensive and special surface properties, such as anti-electromagnetic interference, high conductivity and other materials to increase product performance.

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

4.Micro-foam molding

Micro-foam molding:It is an innovative precision injection technology, which relies on the expansion of pores to fill products, and completes the molding of parts under low and average pressure. The process of microcellular foam molding can be divided into three stages: first, the supercritical fluid (carbon dioxide or nitrogen) is dissolved in the hot melt to form a single-phase solution; then, the mold with a lower temperature and pressure is shot through a switch-type nozzle The cavity, due to the reduction of temperature and pressure, causes molecular instability to form a large number of bubble cores in the product, and these bubble cores gradually grow to generate tiny holes.

Process characteristics:

1). Precision injection

2). Break through many limitations of traditional injection molding, which can significantly reduce the weight of the parts and shorten the molding cycle

3). Greatly improve the warpage and dimensional stability of the parts.

Aplication:

Car dashboards, door panels, air conditioning ducts, etc.

5. Nano molding (NMT)

NMT (Nano Molding Technology): It is a method of combining metal and plastic with nanotechnology. After the metal surface is first nano-processed, the plastic is directly injection molded on the metal surface, so that the metal and plastic can be integrally formed. Nano-molding technology is divided into two types of processes according to the position of the plastic:

1). Plastic is an integral molding of non-appearance surface

2). Plastic is integrated into the exterior

Process characteristics:

1). The product has a metallic appearance and texture,

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

3). Reduce production costs and high bonding strength, and significantly reduce the use of related consumables

Applicable metal and resin materials:

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

2. The adaptability of aluminum alloy is strong, including 1000 to 7000 series;

3. The resin includes PPS, PBT, PA6, PA66, PPA;

4. PPS has particularly strong adhesive strength (3000N / c㎡).

Application:

Mobile phone shell, laptop shell, etc.

TAIZHOU HOYA PLASTIC MOLD CO., LTD

Any new mold projects or questions, welcome to contact us by mob:86-13867644770 or Email:ivy@hoyamold.com