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Master Guide to Large Molded Parts Using Injection Molding

Large molded components are essential in various sectors, from automotive and aerospace to consumer goods and medical equipment. Injection molding is a popular manufacturing procedure for producing these components, allowing for high-volume production while maintaining uniformity.

Lerner Molded Plastics is a manufacturing expert providing a comprehensive range of services and products to customers in Aurora, Ohio. We cater to injection molding, blow molding, plastic extrusions, thermoforming, rotational molding, tooling and design, and other needs. Our products vary from plastic injection mold components to water purification tanks.

This master guide will explore the ins and outs of large molded parts using injection molding.

The Injection Molding Process

Injection molding is one of the most widely used manufacturing processes for producing plastic parts. Here are the steps involved in the injection molding process:

Mold Preparation

To ensure optimal performance and limit the chance of defects, the mold must be sanitized, lubricated, and preheated before the injection molding process begins. This is a vital stage in producing a superior-quality final product.


When the mold has been created, plastic pellets are fed into the injection molding machine’s hopper. Afterward, the pellets are heated and melted to form a liquid resin that can be injected into the mold.


The melted plastic is injected into the mold at high pressure, filling the cavity and taking on the form of the mold. This stage considers whether the plastic is delivered at the correct temperature and pressure to produce the desired part.


This step allows the mold to solidify and take on the required shape. The cooling time varies according to the size and complexity of the part. Thus, it is critical to avoid early ejection, which can result in distortion or other defects.


The mold is opened when the plastic has solidified, and the part is ejected. Depending on the machine, ejection might be either automatic or manual.

Secondary Operations

Depending on the specific part you are working on and its application, the component may need extra processing, including trimming, machining, or assembly.

Injection Molding Considerations for Creating Large Molded Parts

Here are some key considerations to remember when creating large molded parts using injection molding:

Design for Manufacturability

Part design for injection molding necessitates careful consideration of size, form, and complexity. Larger parts need more intricate tooling, longer cooling periods, and greater pressures, all of which can impact the final product’s quality. DFM principles guarantee that the item can be manufactured effectively and with few defects.

Material Selection

The material used for large molded parts can significantly influence the finished product’s cost, performance, and aesthetics. When choosing a material, consider the size and shape of the part, the application requirements, and the processing circumstances. In addition, the material’s qualities must be compatible with the injection molding process and able to bear the stress and pressure of the molding operation.

Tooling and Mold Design

Tooling and molds for large molded parts need particular knowledge and experience. For example, the item’s size, form, injection pressure, and cooling time must all be considered while designing the tooling. In addition, the mold must be designed to release the part from the mold without being damaged or deformed.

Injection Molding Machine Selection

Due to their size and complexity, large molded items require specialized injection molding equipment. The machine should be able to handle the size and weight of the item, as well as retain exact control over the injection and cooling processes. The equipment should also be capable of high-pressure injection to guarantee that the material fills the mold cavity.

Quality Control

Maintaining high-quality standards is necessary while producing large molded parts. Hence, inspection and testing should be undertaken at various process phases to guarantee that the parts fulfill the specified criteria. Further, quality control techniques should include dimensional measurement, visual inspection, and material testing to discover errors and maintain consistency.

Advantages of Injection Molding in Creating Large Molded Parts

Here are the benefits of incorporating injection molding in large molded parts:

Efficient Production

Injection molding can produce large quantities of identical parts quickly and at a low cost per part. Therefore, it is a highly efficient production technique for large molded parts for various applications.

Versatile Design

The versatility of injection molding allows for a wide range of part sizes and shapes. This makes it ideal for high-volume component needs with complex geometries.

Accurate and Consistent

Injection molding offers high accuracy and consistency, ensuring that each part is produced to exact specifications with precision.

Material Flexibility

The injection molding process can be used on various materials, including thermoplastics, thermosets, and elastomers. Thus, it benefits manufacturers and companies looking to create parts and components with a broad material selection.

Durable and Resistant

The resulting large molded parts from injection molding are highly durable and can withstand harsh environmental conditions. They can also resist wear and tear for long-lasting use.

Sustainable Production

Injection molding produces little to no waste, with any scrap material easily recycled and reused in the production process.

Automated Process

Highly automated with computer-controlled processes and robotics, injection molding reduces the potential for human error and increases efficiency in large molded parts production.

Applications of Injection Molding for Large Molded Parts

Injection molding is a versatile manufacturing process that can produce various plastic parts for different industries. Here are some industries that frequently use large molded parts created using injection molding:

  • Automotive (e.g., large, complex elements like bumpers, dashboards, and exterior panels)
  • Consumer goods (e.g., household appliances, toys, and electronics)
  • Packaging (e.g., containers, caps, and closures for packaging applications)
  • Medical: (e.g., medical device components and drug delivery systems)
  • Aerospace (e.g., interior aircraft components and structural parts)
  • Construction (e.g., window frames, pipes, and fittings)
  • Industrial machinery (e.g., gears, bearings, and housings)

Why Choose Lerner Molded Plastics?

At Lerner Molded Plastics, we are committed to providing the highest quality injection molding services for large molded parts. Here’s why you should choose us:

Years of Experience

With many years of experience in the industry, we have the knowledge and expertise to meet your injection molding needs.

State-of-the-Art Facilities

Our cutting-edge facilities are equipped with the latest technology. This ensures your parts’ high-quality production and timely delivery and offers you a competitive edge in the industry.

Customized Solutions

At Lerner Molded Plastics, we understand that every project is unique. That is why we work with you to provide customized solutions that meet your requirements.

Exceptional Customer Service

Our team is dedicated to providing outstanding customer service, from the initial consultation to final delivery, to ensure a smooth and hassle-free experience.

Quality Assurance

Our comprehensive quality assurance program ensures that each part meets our high standards and exceeds your expectations.

Competitive Pricing

Lerner Molded Plastics offers competitive pricing for our injection molding services without compromising quality or service.


We are committed to minimizing environmental impact through responsible manufacturing practices, waste reduction, and recycling.


Master Guide to Large Molded Parts Using

Lerner Molded Plastics: Innovative Solutions for Large Molded Parts!

Looking for a partner that can help you take your large molded parts to the next level? At Lerner Molded Plastics, we provide innovative solutions that optimize efficiency, quality, and cost! With years of experience and a commitment to excellence, we work closely with our clients to meet their needs. Whether you’re looking for custom molding, design assistance, or expert advice, we’re here to help.

Contact us today to learn more about our capabilities, or request a quote now.