Skip to content
Close this search box.

Welder classification

As a leading welding machine manufacturing company, we understand that each customer has its own unique needs and challenges. Therefore, our services not only include the supply of high quality standard welding equipment, but also strive to provide customized welding machine solutions for each customer.

IBC Cage Production Line
Steel Grating Welding Line
Rebar Mesh Line
Industrial Mesh Line
Lattice Girder Welding Line
Wire Products Welding Line
Sandwich Panel Welding Line

What’s the Difference Between Molding and Extrusion

We strive to provide our customers with first-class machinery manufacturing and design services. Our team is made up of highly skilled professionals who have worked in the machine building, construction industry for many years and are committed to getting great work done.

Get Quote Now

Future is efficient power vitality and sustainable power source

What’s the Difference Between Molding and Extrusion

The Difference Between Molding and Extrusion

Molding and extrusion are two fundamental processes in manufacturing, used extensively to shape materials such as plastics and metals. Although both are crucial in producing various products, they differ significantly in their techniques, applications, and outcomes. Below is a detailed comparison to highlight the key differences between molding and extrusion.


Definition: Molding involves shaping material within a mold cavity to form discrete parts. The process typically includes placing material, often in a liquid or semi-liquid state, into a mold where it cools and solidifies into the desired shape.

Types of Molding:

  • Injection Molding: Molten material is injected into a mold, commonly used for creating complex and high-precision parts in large volumes.
  • Blow Molding: This method inflates a heated preform inside a mold to create hollow objects.
  • Compression Molding: Material is placed directly into a heated mold cavity, compressed, and cured to form the final product.
  • Rotational Molding: The mold filled with material is rotated to produce large, hollow parts.


  • Injection Molding: Ideal for automotive parts, medical devices, toys, and consumer goods.
  • Blow Molding: Commonly used for bottles, containers, and hollow plastic parts.
  • Compression Molding: Suitable for large, durable items like automotive panels and electrical components.
  • Rotational Molding: Used for large hollow items like tanks, kayaks, and playground equipment.


  • Complex Shapes: Capable of producing intricate and complex shapes with high precision.
  • Variety of Materials: Suitable for various materials, including plastics, metals, and ceramics.
  • High Volume Production: Efficient for mass production with consistent quality.


  • High Initial Costs: Mold creation can be expensive and time-consuming.
  • Material Waste: Some processes generate significant material waste.


Definition: Extrusion is a continuous process where material is pushed through a die to create objects with a fixed cross-sectional profile. The material is usually in a molten or semi-molten state when extruded through the die.


  1. Feeding: Raw material in pellets or powder form is fed into the extruder.
  2. Heating and Melting: The material is heated and melted as it moves through the extruder barrel by rotating screws.
  3. Shaping: The molten material is forced through a die to shape it into a continuous profile.
  4. Cooling: The extruded product is cooled, typically using water baths or air cooling, to solidify it.
  5. Cutting: The continuous length of extruded material is cut into desired lengths.


  • Pipes and Tubing: Used in plumbing, automotive, and medical industries.
  • Profiles and Frames: Used for window frames, door frames, and structural components.
  • Films and Sheets: Used for packaging, construction, and industrial applications.


  • Continuous Production: Ideal for producing long, continuous lengths of products with uniform cross-sections.
  • Cost-Effective: Lower production costs due to minimal material waste and continuous operation.
  • Versatility: Handles a wide range of materials, including various plastics and metals.


  • Limited Complexity: Best suited for simpler shapes with consistent cross-sections, not for intricate designs.
  • Cooling Time: Plastic extrusion products may require significant cooling time, affecting production speed.

Key Differences

  • Production Method:
    • Molding: Produces discrete parts by shaping material within a mold.
    • Extrusion: Creates continuous profiles by pushing material through a die.
  • Product Shape:
    • Molding: Can produce complex, three-dimensional shapes.
    • Extrusion: Best for long, continuous products with uniform cross-sections.
  • Applications:
    • Molding: Used for detailed parts like automotive components, consumer goods, and medical devices.
    • Extrusion: Ideal for products like pipes, tubing, sheets, and profiles.
  • Material Waste:
    • Molding: Often involves more material waste.
    • Extrusion: Generates minimal waste.
  • Cost and Time:
    • Molding: Higher initial costs and longer setup times.
    • Extrusion: Generally lower initial costs and faster setup.

Understanding these differences helps manufacturers choose the right process for their specific needs, ensuring efficiency and cost-effectiveness in producing high-quality products.
Address:No. 610, Qiaoqian East Road, Yushantou Industrial Zone, Dongqiao Town, Haishu District, Ningbo

Reliable Welder Manufacturer

A professional engineering team with more than 20 years of experience in the welding industry is at your service. 24-hour fast online service.