When creating a molded part, designers and manufacturers should be aware of all elements that could potentially impact the appearance and function of the final product. One such factor to consider is the state of parting lines on the product. You’ll gain a better understanding of what parting lines are and the impact they can have by consulting this guide on what to know about parting lines in a molded product.
What Is a Parting Line?
In a molded product, a parting line refers to a seam located where the two separate pieces of a molded part—the clamp and the cavity—join together during its production. A parting line is generally a thin line of material that runs along the outer periphery of a molded part. Depending on the geometry of your product, you may have the option of determining the parting direction and location of your parting line. You can do this by strategically planning out the meeting point between the different parts in the mold.
Impacts of Parting Lines
Another important thing to know about parting lines in a molded product is the impact that they can have on the final part. Some of the most notable effects of parting lines include:
- Reduced Aesthetic Appearance: Perhaps the most obvious impact of parting lines is that they generally reduce the aesthetic appearance of the final molded product. Often, the presence of a line running through a product can make it look less sleek and sophisticated.
- Less Sterile Parts: Parting lines can also reduce the sanitation of a final product. The more parting lines a product has, the more opportunities exist for dirt and other contaminants to get trapped inside them. As such, it’s important to minimize parting lines as much as possible, especially in industries such as the laboratory or medical fields, where optimum sanitation is essential.
- Reduced Strength: Depending on where a parting line sits, it could also decrease the strength of a molded product by creating a more vulnerable breaking point.
Ways To Minimize Parting Lines
While entirely eliminating parting lines in molded products is nearly impossible, you can implement several measures to reduce them as much as possible. Decreasing the use of extra processes and reducing the amount of excess material that escapes a mold during the production process can minimize parting lines.
Low-pressure overmolding is also highly effective at reducing parting lines in a molded product to create a more seamless part. By molding a component directly into a part instead of attaching it using secondary methods, manufacturers can almost completely eliminate the presence of parting lines in certain products.
