The quality of a product is closely related to its core components, just like when purchasing a car where the core components are known as the “three major parts”: the engine, transmission, and chassis. Similarly, the quality of silicone products is determined by their core aspects, which include size, appearance, and color. Today, we will discuss one of the seemingly inconspicuous yet crucial core aspects, which is appearance, with a particular focus on the parting line.
The appearance quality of silicone products is influenced by various factors, with the control of parting lines being crucial. Parting lines, also known as mold separation lines, contact lines, or mold joint lines, are the lines where molds separate during the production of silicone products. The quality of parting lines directly affects the appearance and performance of silicone products. Here are some methods for controlling parting lines in silicone product manufacturing:
One significant factor affecting the parting line is the mold itself. The collaboration between molds and silicone product manufacturers is crucial. A well-designed mold can reduce the need for frequent repairs and allow the silicone product manufacturer to focus on other production issues. The impact of the parting line primarily manifests in the mold’s self-separation area. Questions such as how wide and deep the self-separation should be or whether it should be flat or sharp are essential considerations. These aspects are typically determined by the mold manufacturer based on industry experience, but input from the silicone product manufacturer can also be valuable. While self-separation is usually well-executed, one common issue encountered is misalignment, which can occur when molds open and close. Misalignment can hinder the production of high-quality silicone products, even with the use of quality vulcanization machines or skilled operators. Therefore, mold alignment is a critical aspect when controlling the parting line of silicone products.
2. Positioning of Parting Lines:
When designing molds for silicone products, the precise positioning of parting lines is essential. Parting lines are typically located at the edges or bottoms of silicone products to minimize their impact on the appearance. Parting lines should be concealed as much as possible within natural bends or connections in the product.
To control the parting line of silicone products, it’s essential to establish effective control measures within the silicone product manufacturing facility. During the production of silicone products, strict control of the vulcanization machine’s temperature and pressure is paramount. The pressure level directly affects the thickness of the parting line. If this isn’t calibrated correctly, even with good molds, achieving the desired quality of the parting line will be challenging. Additionally, the speed of the operators plays a crucial role. Since production involves high-temperature vulcanization, the longer the time, the lower the mold temperature will become. This can potentially result in subpar products in subsequent runs. Thus, operators must effectively control the material placement and mold removal timing to address parting line issues in the next cycle.
Additionally, manual finishing is crucial. After the parting line forms during production, there may be some residual material, commonly referred to as “flash” or “burrs.” During manual finishing or edge removal, it’s essential to use the appropriate tools. For example, scissors should be used when necessary, and needles or other tools should be used for different types of flash. Using the wrong tool for the job can inadvertently worsen the parting line’s appearance, resulting in a less attractive product.
Choosing high-quality silicone materials can also help reduce the formation of parting lines. Lower-quality silicone materials may be more prone to noticeable parting lines.
Conduct thorough quality inspections to ensure that the appearance of the final product meets requirements. Any noticeable parting lines or defects should be promptly identified and repaired.
Provide comprehensive training to operators so they can pay attention to and control the quality of parting lines during the production process.