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Manufacturing Injection Molded Medical Components

There has been sustained, long-term growth in the field of medical polymers, which will be maintained over the next several decades as generational population shifts drive the need for advances in healthcare. This growth is not limited to just one sector of the medical polymers industry. Advancements of all kinds will find a niche in this booming healthcare market.

Quality Of Injection Molded Plastic Components used for the Medical Applications depends on factors that include part design, material selection, quality of machines, the design and quality of Moulds as well as the processing conditions.

So, you want to be a medical device molder?

Many injection molders currently serving markets that are slumping are beginning to recognize the value of diversification, and the mantra of many has become, I want to get into medical molding. Its easier said than done.

The medical industry, while it may look a stable, high-volume segment, is a tough market to enter. The barriers are primarily regulatory, and Good Manufacturing Practices (GMPs), clean rooms, and the high cost of compliance restrict many molders from gaining entry.

A major misconception in the molding community is that big money is to be made in medical devices, however, the reality is that the pricing pressures are just as heavy in medical as in automotive or consumer products.

While molded components for nearly all markets require quality, on-time delivery, and best cost, meeting those requirements in medical device molding is much different from other markets because of compliance issues. The overall company culture requires a different mindset for employees who need to understand the medical device manufacturing business.

Molding medical device or healthcare products tends to require more resources.

The goal of the medical part designer should be to provide a part that combines maximum functionality with minimum complexity. Some of the important principles as enlisted below, when overlooked results in increased mold costs, a defective final product, or premature part failure.

Wall Thickness

The most basic principle of plastic part design is that uniform wall thickness should be maintained wherever possible. Thin sections are weak structurally and difficult to fill; they can restrict flow and require increased injection pressure. Thick sections are easier to fill but difficult to cool and pack out; they are subject to increased shrinkage, and may cause sink marks, voids, and high levels of molded-in stress. When thickness variations are unavoidable, they should be designed with a gradual transition, which will help reduce the level of molded-in stress at the transition region.

Corners are often problem areas because of non uniform thickness. If the outer radius is too small, a thick section is created in the corner; this increased thickness then causes cooling and war page problems. If the outer radius is too large, the corner will be thinner than its adjoining walls. Besides being weak structurally, the change in thickness can serve as a flow restrictor. The best approach is to have the inner and outer radii originating from the same point, ensuring a uniform wall thickness through the corner.

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