Kaysun Blog

Custom injection molding is, by nature, highly precise. Part performance and reliability hinge on production processes that ensure accurate, consistent outcomes. Being able to deliver on these nuances is often what sets custom injection molders apart — and generally typifies molders with engineers trained in scientific molding.

A surprising number of projects are completed without using a prototype tool. The general idea is that prototype tooling is an extra, unnecessary step that increases cost and decreases development and production times.

Actually, the opposite is true. Custom injection molding done without a prototype tool typically leads to a series of required production tool adjustments that are both costly and disruptive. The perceived savings of skipping prototype tooling quickly evaporate, and the higher risk of part defect introduces the possibility of incurring legal expenses and other related costs.

Depending on the complexity of the application, prototype tooling generally accounts for about 20-40% of overall production tooling costs. It's not an insignificant investment, but one that's well worth it when you consider the advantages.

Success in the injection molding business isn’t limited to having the right equipment or the latest technologies. It's a good start, of course, but it takes more to meet the needs of customers that require custom injection molding for complex applications completed under challenging time and cost constraints.

Custom injection molders must have top toolmakers in their supply chains that prioritize manufacturing excellence and customer service. Core to this philosophy is that toolmakers must treat the injection molders’ customers as their own.

Custom injection molding projects are, by nature, an expensive undertaking. Part development and  tooling design/build often account for the majority of the budget, particularly in the case of intricate components. The consistency, quality, and cost of the part produced largely hinge on optimizing these two aspects of the project. Missteps can lead to expensive setbacks, product defects, and lower profits.

Generally speaking, Design for Manufacturability (DfM) — or Design for Manufacturing — is the process of consciously and proactively designing products to optimize all facets of manufacturing. 

DfM methodology aligns engineering and production in the design phase, ensuring cost and time efficiencies, superior quality, regulatory compliance, and end-user satisfaction. Problems are identified and addressed early in the product development process, preventing costly issues that could impact manufacturability: raw materials selection, tolerances, and secondary processing.

Regardless of application, injection-molded parts and products are expected to perform to stringent quality and regulatory standards.

Ensuring successful outcomes requires application of scientific molding principles by experienced injection molders and trained engineering teams during development and production.

Custom injection molding is a go-to for OEMs across a range of industries because of design and engineering precision, production repeatability, and cost-effective solutions. 

Injection molders understand that consistently delivering defect-free parts and products to these standards is a top priority and a true value-add to their OEM partnerships.

Quality assurance begins in the design phase. Engineers are faced with many decisions, but among the most important are those that impact the end of the injection molding process — what has to happen to ensure the plastic part ejects cleanly?

Insert molding is a process that requires an insert — typically metal — to be pre-placed in the tool for injected plastic to flow around. Encapsulating the insert with plastic creates a single molded plastic piece that’s generally stronger than one created using secondary assembly.

Insert molding can be accomplished through two methods:

• Manual insert loading: The generally more cost-effective way to approach very low-volume applications or extremely complex part geometries
•  Automated insert molding: A better choice for part consistency. It minimizes human error, improves efficiencies, and ensures optimal cycle times.

Securing an insert in plastic requires precision and a thorough knowledge of how each individual substrate reacts to conditions during the injection molding process.

Shrink rates for injection molded plastic parts vary depending on the materials used andwall thickness. Designing uniform wall thickness offers substantial shrink rate control; on the other hand, non-uniform walls can lead to large pressure drops during filling, significant differences in shrink rates, and internal stresses within the injection molded part that could cause warpage or similar defects.