An Introduction to Injection Molds

Injection molding is a highly versatile manufacturing process. It is used to create components in a range of shapes and sizes for various industries and applications. A key element of the process is injection molds.

What Are Injection Molds?
Injection moldingInjection molds are hollow forms—typically made from stainless steel—into which molten plastic is injected to make the desired part or product. They have holes in the middle—referred to as mold cavities—in the shape of the part or product. In addition to the shape of the mold cavity, the number of mold cavities can vary depending on the number of different components or individual pieces that need to be produced during each cycle.

Single-Cavity vs. Multi-Cavity vs. Family Injection Molds
Injection molds can be classified into three main categories: single-cavity, multi-cavity, and family.

Single-Cavity Injection Molds
Single-cavity injection molds have a single hollow and can be used to produce one product at a time. They are an efficient, cost-effective option for production operations with low order volumes or parts that are oversized or complex. Single-cavity molds allow operators to devote more attention to each individual product to ensure there aren’t air bubbles, unfilled portions of the mold, or other potential flaws. These molds are also less costly than multi-cavity injection molds of the same part.

Multi-Cavity Injection Molds
Multi-cavity injection molds have multiple identical hollows. They enable manufacturers to inject molten plastic into all of the hollows at once and create multiple products simultaneously. As a result, they offer shorter lead times for batches of goods, which increases production efficiency, reduces delays, and decreases costs for large-volume or expedited orders.

Family Injection Molds
Family injection molds are very similar to multi-cavity molds. However, rather than having multiple identical hollows, each hollow has a different shape. Manufacturers can use these molds to produce prototypes or different products that are sold together in a single variety pack. This type of mold is convenient for producing different products made of the same elastomeric material. However, the hollows need to be carefully arranged and sized; if the family mold is imbalanced, the fluid won’t be injected evenly and may cause production flaws.

When to Use or Look for a Custom Injection Mold
While there are many standard injection molds available, there is not an appropriate existing mold for every project. Custom injection molds are generally necessary when an organization needs parts or products with:

Exacting standards. Custom molds can be built to produce components that meet the customer’s exact requirements and restrictions. This is vital for parts and products used in highly regulated markets, such as aircraft pieces or medical devices.
High precision requirements. Custom molds are specifically designed to suit the customer’s product and production demands, so they are more likely to make the desired components to the necessary specifications and volumes.
Complex designs. Custom molds are not restricted to producing standard component designs. They can be tailored to accommodate nearly any component shape or size, so they can be used to produce highly unique or complex parts and products.
Key Factors for Successful Mold Making Operations
Once you’ve decided that a custom mold is appropriate for your injection molding project, it is important to find the right custom mold making partner. Some of the factors to look for in a custom mold maker include:

Good design and engineering capabilities
*Quality mold making materials
*Modern manufacturing equipment
*Capacities for tight tolerances
*Commitment to high standards

Case Studies: Custom Plastic Injection Molding Projects at molding
The injection molding experts at The Rodon Group provide high-quality custom solutions to customers in a wide range of industries.

*Molds for residential window hardware.
A customer in the door and window industry turned to us for a replacement production solution for residential window hardware. The existing tooling was nearing the end of its life, resulting in the generation of lower-quality pieces. After determining the functionality and manufacturability of the original design, we re-engineered the components for better performance, reliability, and moldability. We created new, multi-cavity molds to produce a higher volume of pieces at a lower cost.

*Molds for medical waste product caps.
A customer in the healthcare industry approached us with a request to modify a custom injection molded cap for a medical waste product. The previous supplier could not produce a functional version of the component. However, our team overcame all of the project challenges and created molds to produce the 200,000 pastic parts.

*Molds for polystyrene diagnostic kits.
A customer in the medical industry asked us to create dies and provide injection molding services for lateral flow in-vitro diagnostic test cartridges made from polystyrene. We designed and built long-lasting molds that produced high-quality pieces at a lower weight and cost.

High-Quality Custom Injection Molds From DJmolding
Molds are an investment, which is why you want ones that are durable and reliable. For injection molds you can trust to provide superior performance in your injection molding operations, turn to DJmolding. We offer quality tooling products and extensive molding services. To learn more about injection molding and injection molds, check out our infographics library. To get started on your solution, contact us today.