What is plastic molding?
Plastic forming is the use of the plasticity of the material, under the external force of the tool and mold, to process the part with less or no cutting process.
There are many types, including forging, rolling, extrusion, drawing, stamping, etc.
Types of Plastic Forming Process
（1）Forging
What is forging ?
It is a processing method that uses forging machines to apply pressure to metal parts to plastically deform them and obtain forged parts with certain mechanical properties, certain shapes and sizes.
Types of forging
According to the forming mechanism, forging can be divided into free forging, die forging, ring forging and special forging.
Free forging:
A type of processing method generally used in hammer or hydraulic press forging, using simple tools to hammer ingots or blocks of metal into the required shape and size.
Hot forging:
It is formed using a die in a forging hammer or a hot forging press.
Ring Grinding:
It refers to the production of ring parts of different diameters by special ring grinding equipment, which is also used to produce wheel parts, such as automobile wheels and train wheels.
Special forging:
Including forging methods such as roll forging, cross wedge rolling, radial forging, liquid die forging, etc. These methods are more suitable for producing some special shaped parts.
Technological process:
Forging billet heating → roll forging stock preparation → forging → cutting → punching → correction → intermediate inspection → heat treatment of forgings → cleaning → correction → inspection
Technical characteristics:
- The quality of forged parts is higher than that of cast parts, which can withstand large impact forces.
The plasticity, toughness and other mechanical properties are also higher than those of castings and even higher than those of rolled products. - Save raw materials and reduce processing time.
- High production efficiency.
- Free forging is suitable for single-piece small batch production and has greater flexibility.
Application :
Rollers of large rolling mills, herringbone gears, rotors of steam turbine generator sets, impellers, retaining rings, huge cylinders and columns of hydraulic presses, locomotive axles, crankshafts and connecting rods for automobiles and tractors, etc.
（2） Lamination
What is roll lamination
A pressure processing method in which a metal billet is passed through a gap (various shapes) of a pair of rotating rollers, and the cross-section of the material is reduced due to compression molding of the rollers, and the length is increased .
3 types of lamination
According to the movement of rolling stock: longitudinal rolling, transverse rolling, oblique rolling.
Longitudinal rolling: Process in which the metal passes between two rollers that rotate in opposite directions and plastic deformation occurs between them.
Crossing – rolling: The movement direction of the rolled product is consistent with the direction of the roll axis after deformation.
Skew rolling : The rolled product makes spiral movement, and the rolled product and the roll axis have no special angles.
Technological process:
Application :
It is mainly used in metal material profiles, plates, tubes, etc. There are also some non-metallic materials such as plastic products and glass products.
（3）Extrusion
What is extrusion
Under the action of three-dimensional uneven pressure, the blank is extruded from the die hole or gap to reduce the cross-sectional area and increase the length. The processing method to become the desired product is called extrusion. This processing of the raw part is called extrusion molding.
Technological process:
Preparation before extrusion → casting rod heating → extrusion → stretch and twist straightening → sawing (fixed length) → sampling inspection → manual aging → packaging
Advantage :
- Wide production range and many product specifications and varieties.
- Great production flexibility, suitable for small batch production.
- The product has high dimensional accuracy and good surface quality.
- 4. Less equipment investment, small factory area, easy automated production.
Disadvantages:
- Large loss of geometric residues;
- The metal flow is irregular;
- Low extrusion speed and long service time;
- Large loss of tools and high cost.
Production scope: It is mainly used for manufacturing long rods, deep holes, thin walls and special-shaped cross-section parts.
（4）Drawing
What is it?
A plastic processing method that uses an external force to act on the front end of the pulled metal and pulls the metal blank from a die hole smaller than the cross section of the blank to obtain a product with corresponding shape and size.
Advantage :
- Precise size and smooth surface;
- Simple tools and equipment;
- Continuous high-speed production of long products with small cross-sections.
Disadvantages:
- The amount of deformation between passes and the total deformation between the two annealings is limited;
- Limited length.
Production scope: Drawing is the main method of processing metal tubes, bars, profiles and wires.
（5）Stamping
What is compression
It is a forming and processing method that uses presses and dies to apply external force to plates, strips, tubes and profiles to plastically deform or separate them to obtain workpieces (stamping) of the desired shape and size.
Technical characteristics:
- Lightweight and highly rigid products can be obtained.
- Good productivity, suitable for mass production and low cost.
- Products with uniform quality can be obtained.
- 4. High material utilization, good shearing and recycling.
Scope of application:
60 to 70% of the world's steel is plate, and most of it is finished by stamping.
The car body, chassis, fuel tank, radiator fins, boiler steam drums, container shells, iron core silicon steel sheets of engines and electrical appliances are all stamped.
There are also many stamped parts on products such as instruments, household appliances, bicycles, office machines and household items.
Environmental and recycling considerations
Sustainability in the Plastic Industry
As an industry individual, I believe it is essential to consider the environmental impact and sustainability of the plastics we produce. When creating new products, I always consider using more ecological and bio-based materials.
In this way, it will help reduce dependence on fossil fuels and limit greenhouse gas emissions during the production process. The incorporation of these sustainable materials also ensures that our products have a lower carbon footprint throughout their life cycle.
Furthermore, I also consider it crucial to optimize manufacturing processes and prioritize energy efficiency. By doing so, I contribute to minimizing waste and reducing energy consumption during plastics production.
Plastics Recycling
Recycling has a significant impact on the environment; That's why I always strive to create products that can be easily recycled. By considering the recycling process during the design and development phases, I can increase the recyclability of my products and reduce the waste they generate.
Here are some recycling principles I follow:
- Simplify material selection: I prefer to use fewer types of materials in my products, making them easier for recycling facilities to process.
- Use recyclable materials: Whenever possible, I try to use materials that are widely accepted by recycling centers.
- Marking: I ensure my products have clear and accurate labels that indicate the type of plastic used, which helps recyclers identify and classify materials efficiently.
Recycling plays a crucial role in managing the environmental impact of plastics. By keeping sustainability and recycling at the forefront of my work, I am contributing to a more environmentally conscious and responsible plastics industry.
