Extruder

▏Product Vedio

▏Basic Concepts

Plastic extruder is the host of plastic extrusion molding equipment, after more than 100 years of development, has been derived from the original single screw twin screw, multi-screw, and even no screw and other models. It is usually matched with various plastic molding auxiliary machines (such as pipe, film, holding material, monofilament, flat wire, packing belt, extrusion mesh, plate (sheet) material, profile, granulation, cable coating and other forming machines) to form a variety of plastic extrusion molding production lines for the production of various plastic products.

▏System Composition

The main machine of the plastic extruder, the extruder, is mainly composed of three parts: extrusion system, transmission system and heating and cooling system.

1. Extrusion system: including screw, barrel, hopper, head and mold. The plastic raw material is molded into a uniform melt through the extrusion system, and is extruded from the head under the continuous extrusion of the screw.

Screw: the most important component of the extruder, directly related to the application range and productivity of the extruder, made of high-strength corrosion-resistant alloy steel.

Barrel: Made of alloy steel with high heat resistance, high pressure strength, strong wear-resistant, corrosion-resistant or composite steel lined with alloy steel, with screw to achieve plastic crushing, softening, melting, plasticizing, exhaust and compaction, and to the forming system continuous uniform delivery of rubber material.

Hopper: The bottom is equipped with a cut-off device to adjust and cut off the material flow; The side is equipped with a viewing hole and a calibration metering device.

Head and mold: The head is composed of alloy steel inner sleeve and carbon steel jacket, which is equipped with forming mold. The role of the head is to transform the rotating motion of the plastic melt into a parallel linear motion, evenly and smoothly into the mold, and give the plastic with the necessary molding pressure.

2. Transmission system: drive screw, supply screw in the extrusion process required torque and speed, usually composed of motor, reducer and bearings.

3. Heating and cooling system: the heating device is temperature-controlled and monitored by a thermoregulator or thermocouple to ensure that the plastic raw materials are heated to the temperature required for process operation; The cooling device is used to eliminate the excess heat generated by the shear friction of the screw rotation to avoid the decomposition, scorch or difficulty in shaping the plastic due to high temperature.

▏Classification

Plastic extruders can be classified according to different criteria:

1. According to the number of screws: can be divided into single screw extruder, twin screw extruder and multi-screw extruder.

Single screw extruder: widely used, suitable for extrusion processing of general materials.

Twin-screw extruder: Good feeding characteristics, suitable for powder processing, with better mixing, exhaust, reaction and self-cleaning functions, in the processing of poor thermal stability of plastics and blends is more advantageous.

Multi-screw extruders: Developed on the basis of twin-screw extruders for easier processing of blends with poor thermal stability.

2. According to the screw running speed: can be divided into ordinary extruder (speed below 100r/min) and ultra-high speed extruder (speed of 300\~1500r/min).

3. According to the assembly structure: can be divided into integral extruder and separate extruder.

4. According to the screw space position: can be divided into horizontal extruder and vertical extruder.

5. According to whether there is a screw: can be divided into screw extruder and plunger extruder.

▏The Working Principle

The plastic extruder works by feeding a hard plastic wire (such as ABS or PLA) into the brass nozzle of the heating head through the wire feed wheel of the stepper motor. The nozzle has a heating chamber and is connected with a heating resistor to heat the wire to a predetermined temperature (for example, the processing temperature of PLA is 170°C\~230°C, and the melting temperature of ABS is 217°C\~237°C). After the material wire is heated and melted, the rotation of the stepper motor drives the subsequent unmelted material wire forward, and the melted material wire is pushed out to complete the extrusion process.

▏Scope of application materials

Plastic extruders are suitable for a variety of plastic raw materials, including but not limited to PVC, PE, ABS, PA, etc., which have good thermoplastic and processing properties.

▏Product application field

Plastic extruder products are widely used in many fields, such as:

1. Construction industry: Used to produce building materials such as doors and Windows.

2. Automotive industry: Used to produce car water tank, tool box, car fuel tank, skylight guide rail and other parts.

3. Pipeline industry: Used for the production of water supply pipe, gas pipe, drainage pipe, power casing and other pipeline products.

4. Daily life: Used for the production of lamps, refrigerator hollow lattice board, mobile phone film, luggage, plastic bottles, toys and other daily supplies.

5. Medical industry: used to produce parts for some medical devices.

In addition, road barriers are also made of plastic extrusion mechanisms.

▏The main features

1. Easy operation: plastic extruder can achieve automated production, simpler operation, higher efficiency and stable quality.

2. Wide range of applications: can be used in plastics, rubber, composite material processing, plastic coloring, mixing, granulation, plastic blending modification and other fields.

3. Less investment and quick effect: simple equipment, low investment cost, suitable for mass production, quick effect.

▏Environmental protection and energy saving advantages

Modern plastic extruder design advanced, with significant environmental protection and energy saving advantages. For example, the involute gear transmission has the characteristics of low noise, smooth operation, large bearing capacity and long life. At the same time, its energy consumption is low, in line with the modern production requirements of energy saving and environmental protection. In addition, by precisely controlling extrusion parameters and cutting methods, waste generation in the production process can be reduced and resources can be recycled.