INJECTION MOLDING MACHINES: TYPES AND BENEFITS
You are here: Home » News » Product News » INJECTION MOLDING MACHINES: TYPES AND BENEFITS

INJECTION MOLDING MACHINES: TYPES AND BENEFITS

Publish Time: 2024-06-04     Origin: Site

Injection molding machines are fascinating and crucial for plastic manufacturing. Have you ever wondered how everyday plastic items are made? Injection molding machines play a significant role. They produce consistent, high-quality plastic parts efficiently.


In this post, you'll learn about the different types of injection molding machines and their benefits. We’ll explore hand, plunger, screw, and hybrid machines. You'll discover how each type impacts production and product quality.


Types of Injection Molding Machines

Hand Injection Molding Machines

Hand injection molding machines are simple and cost-effective. They consist of a barrel, plunger, and heaters. The operator manually clamps and heats the machine. These machines are ideal for understanding basic injection parameters.


Advantages:

  • Low cost

  • Simple operation

  • Good for small-scale production

Disadvantages:

  • Production depends on operator skill

  • Variable cycle times

Typical Applications:

  • Prototyping

  • Educational purposes

  • Small batch production


Plunger Type Injection Molding Machines

Plunger type machines can be horizontal or vertical. They operate using pneumatic or hydraulic systems. These machines can be semi-automatic or fully automatic, depending on the setup.

Configurations:

  • Horizontal

  • Vertical

Operation:

  • Pneumatic

  • Hydraulic

Types:

  • Semi-automatic

  • Automatic

Benefits:

  • Versatile

  • Suitable for various applications

Drawbacks:

  • Higher cost than hand machines

  • More complex operation


Screw Type Injection Molding Machines

Screw type machines include a hopper, screw, and barrel. The screw rotates to melt and inject plastic into molds. This type provides consistent and efficient production.

Components:

  • Hopper

  • Reciprocating screw

  • Barrel

Working Principle:

  • Melts and injects plastic via screw rotation

Benefits:

  • Consistent production

  • Efficient material mixing

Limitations:

  • Higher initial cost

  • Requires more maintenance


Plunger-Plunger Injection Molding Machines

These machines use a two-stage plunger process. The first plunger plasticizes the material. The second plunger injects it into the mold.

Two-Stage Process:

  1. First plunger plasticizes material

  2. Second plunger injects material

Advantages:

  • Faster production

  • Better material compaction

Disadvantages:

  • More expensive construction

  • Higher operational cost


Screw Plunger Injection Molding Machines

Screw plunger machines combine screw and plunger mechanisms. The screw melts the material, and the plunger injects it. This combination improves mixing and reduces stress on materials.

Mechanisms:

  • Screw for melting

  • Plunger for injection

Benefits:

  • Enhanced mixing

  • Better for heat-sensitive materials

Drawbacks:

  • Higher cost

  • Longer cycle times than screw type machines


Types of Injection Molding Machines by Driving Technology

Hydraulic Injection Molding Machines

How they work:

Hydraulic machines use hydraulic fluid to generate force. The fluid moves pistons, which control the injection and clamping actions. They are powerful and robust, ideal for heavy-duty applications.

Advantages:

  • Lower price

  • Cheaper parts

  • Stronger parts

  • High clamping force

  • Simple maintenance

Disadvantages:

  • Higher running costs

  • Longer start-up time

  • High power consumption

  • Difficult precision control


Electric Injection Molding Machines

How they work:

Electric machines use electric motors for all movements. They are precise and energy-efficient. These machines excel in high-speed, high-precision applications.

Advantages:

  • Energy efficient

  • Less downtime

  • Faster process

  • Clean operation

  • High precision and repeatability

Disadvantages:

  • Higher initial cost

  • Limited injection speed

  • Requires routine maintenance


Hybrid Injection Molding Machines

Combining benefits of hydraulic and electric machines:

Hybrid machines blend hydraulic power with electric efficiency. They offer the best of both worlds, ensuring high performance and flexibility.

Advantages:

  • Design flexibility

  • Energy savings

  • Variable-speed pumps

  • Less downtime

  • Competitive price point

Disadvantages:

  • Machine-to-machine differences

  • Risk of mismatching

  • Requires both hydraulic and electric maintenance


Types of Injection Molding Machines by Mechanism Construction

Horizontal Injection Molding Machines

Horizontal injection molding machines are the most common type. They are widely used due to their versatility and efficiency.

Advantages:

  • No height restriction

  • Automatic ejection

  • Easy feeding and maintenance

  • Side-by-side arrangement

These machines come in two main designs:

  • Two-platen toggle design

  • Three-platen toggle design

Both designs offer stability and precision, ensuring consistent production quality.


Vertical Injection Molding Machines

Vertical injection molding machines have a smaller footprint. They are ideal for factories with limited space.

Advantages:

  • Convenient for inserts

  • Gravity-assisted molding

  • Suitable for complex and delicate products

These machines are equipped with transmission devices for automation, enhancing production efficiency. Vertical machines support a variety of automation devices, making them versatile for different applications.


Common Problems and Solutions in Injection Molding

Air traps, short shots, and brittleness are common issues faced in injection molding. Let's dive into each problem and explore their causes and solutions.

Air Traps

Air traps occur when air gets trapped in the mold cavity during injection. This leads to visible bubbles or voids in the final product.

Causes:

  • Improper venting design in the mold

  • Inconsistent wall thickness of the part

  • Injection speed too high, trapping air

Solutions:

  • Improve mold design by adding proper vents

  • Ensure consistent wall thickness in part design

  • Adjust injection speed to allow air to escape


Short Shots

Short shots happen when the mold cavity isn't completely filled with molten plastic. The result is an incomplete part.

Causes:

  • Low melt temperature, reducing material flow

  • Insufficient injection pressure

  • Inadequate raw material plasticity

Solutions:

  • Increase melt temperature for better flow

  • Raise injection pressure to pack mold fully

  • Optimize mold design to reduce flow resistance


Brittleness

Brittle parts crack or break easily under stress. Several factors in the molding process can cause this.

Causes:

  • Improper drying of raw material

  • Incorrect melt temperature settings

  • Incompatible gate and runner design

Solutions:

  • Use high-strength engineering plastics

  • Optimize drying and melt temp for the material

  • Redesign gates and runners for even filling


Factors to Consider When Choosing an Injection Molding Machine

When it comes to selecting an injection molding machine, there are several crucial factors to consider. Let's break them down one by one.


Molding Machine Specifications and Model

When picking an injection molding machine, start with its specifications and model. Each machine has unique features. Match these to your project needs. Look at the manufacturer’s guide. Ensure it fits your technical criteria.


Example:A medical device company needs high precision. They choose a model known for accuracy. This ensures consistent product quality.


Mold Dimensions

Mold dimensions are crucial. Measure length, width, and height. The machine must open to twice the product height. This helps with easy product removal.

Case Study:

An automotive parts maker has large molds. They select a machine that handles big dimensions. It boosts their production efficiency.


Table: Mold Dimensions and Machine Compatibility


Mold Size (cm) Machine Type Production Use
50x40x30 Medium Horizontal Consumer Goods
100x80x60 Large Vertical Automotive Components
20x15x10 Small Electric Medical Devices


Injection Rate

Injection rate impacts product quality. High-speed injection is key for some items. Check if the machine meets this need.

Fact:

Ultra-thin products need fast injection rates. A slow rate can cause defects.

Example:

A tech company makes thin phone cases. They need a machine with a high injection rate. This ensures smooth, defect-free products.

Production Capacity

Production capacity varies by machine. Identify your production goals. Choose a machine that meets these targets.

Example:

A toy manufacturer has high demand. They pick a machine with high capacity. This meets their production needs without delays.

Chart: Production Capacity Comparison


Production Capacity (units/year) Machine Type
100,000 Small Electric
500,000 Medium Hydraulic
1,000,000 Large Hybrid

Cycle Time

Cycle time affects output. Shorter cycles mean faster production. This is critical for high-volume needs.

Quote:

"Choosing a machine with a short cycle time was a game-changer for our output," says a factory manager.

Fact:

Machines with rapid cycles can be costly but boost efficiency.

Example:

A packaging company needs quick cycles. They invest in a fast-cycle machine. This speeds up their production line.

Number of Core Pullers

Core pullers manage mold parts. Ensure your machine has enough core pullers. This is vital for complex molds.

Fact:

More core pullers allow for intricate designs.

Example:

An electronics company uses detailed molds. They need machines with multiple core pullers. This ensures precision in their components.

Conclusion

Injection molding machines come in various types, including hand, plunger, screw, and hybrid. Each type has unique features and benefits. Choosing the right machine is crucial for meeting specific manufacturing needs. It ensures efficiency, quality, and cost-effectiveness.


Selecting the appropriate machine depends on factors like specifications, mold dimensions, and production capacity. Injection molding machines play a vital role in the plastic industry. They enable the mass production of high-quality plastic parts, driving innovation and growth.


In summary, understanding and selecting the right injection molding machine is key to successful plastic manufacturing.


Injection molding is complex, with numerous factors affecting your final product. Team Mfg's experts are here to guide you through the process, from machine selection to production optimization. Contact us today to discuss how we can bring your vision to life!

Contact us

TEAM MFG is a rapid manufacturing company who specializes in ODM and OEM starts in 2015.

Tel

+86-0760-88508730

Phone

+86-15625312373

Email

Copyrights   2024 Team Rapid MFG Co., Ltd. All rights reserved.