Torsten’s Training Tip: Polymer Materials Overview
It is important for part and mold designers not only to understand design principles, but also to understand the fundamentals of plastics. The choice of a plastic, or polymer, has a strong impact on the outcome of a molded part. Polymers are categorized by processing methods and temperature behavior. The major groups are thermoplastics, thermosets, […]
Torsten’s Training Tip: Cold Runner Types and Designs
Cold runner systems are an important aspect of mold design. By optimizing cold runner shapes and sizes, important molding processes such as pressure drops, polymer shearing, packing and cooling behavior, gate sealing time, and overall cycle time can be made more efficient. Cold runners are simply unheated channels that transport molten polymer material from a […]
Torsten’s Training Tip: Gate Seal Time
Gate seal time is an important aspect of the packing phase that needs to be understood to produce high quality molded parts. Setting proper gate seal time plays a key role in packing parts. Properly packed parts will have even internal polymer molecular structure, fewer volumetric shrinkage differences, optimized part dimensions, and fewer sink marks […]
Torsten’s Training Tip: Thermal Pins
Designing thermally optimized molds becomes more challenging as part designs become more complex. There are various cooling design strategies, from using drilled coolant circuits or baffles and bubblers, to selecting mold steels or thermal pins (sometimes called heat pipes or heat tubes.) Thermal pins are a cooling strategy to optimize thermal behavior inside a mold. […]
Torsten’s Training Tip: Cashew Gates
Injection molded part quality is highly dependent on gate designs, sizes, and location. Because cashew gates, also called banana gates, can be placed in areas that are not visible, they are an option for molded parts that require perfect surface quality. Cashew gates, or banana gates, are sub-gates that are automatically de-gated and can be […]
Torsten’s Training Tip: Mold Steel Selection
Injection molds are designed and built to allow parts to be produced from various polymers and to be utilized for a variety of applications. A mold design team must possess the ability to evaluate and determine the optimal mold steel for each mold component to effectively produce high quality plastic parts. How do mold designers […]
Torsten’s Training Tip: Deformation Behavior and Reversing PVT Curves
Plastic part designers have an abundance of polymer materials to choose from, ranging from commodity to technical or engineered polymers. Selecting the optimal material for each design is key to a successful molding project. Polymer materials must be heated to their melt temperature ranges to be injection molded. Polymer strength, stiffness, and deformation behavior are […]
Torsten’s Training Tips: Warpage Due to Fiber Orientation
Fiber orientation plays a significant role in the shrinkage and warpage of a molded part. Let’s look at why. Fiber -filled composite plastic materials will induce anisotropic mechanical properties. Fiber reinforced parts have directional mechanical properties that are stronger in the direction (or parallel) to the flow and weaker transverse (or perpendicular) to the flow. […]
Torsten’s Training Tips: Understanding Shrinkage and Warpage Behaviors
Minimizing volumetric shrinkages and reducing part warpage are important considerations when designing injection molded parts. By understanding the interaction of part and mold designs, polymer material, and the molding process, preventative measures can be designed into the molding system to minimize shrinkage and warpage. Polymer materials naturally expand when they are heated and shrink as […]
Torsten’s Training Tips: Mold Design — Pin-Point Gates
Gate placement is an important aspect of mold design to achieve optimal part quality. Let’s look at some advantages and disadvantages to using pin-point (pinpoint) gates in mold design. Because gate placement options are often limited by design restrictions and other part-related constraints, understanding and utilizing industry best-practices can be helpful in achieving the desired […]
