Etiqueta: TTT

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: Short Shots

Injection molding is a complex scientific manufacturing process. By following a methodical set-up process, molders aim to minimize or eliminate common molding defects that affect part quality. Generally, molding defects are either part design, mold design, or process related. This training tip focuses on short shots. There are various potential design-related causes for short shots. […]

Torsten’s Training Tip: Sink Marks and Voids

Two common and related injection molding defects, sink marks and voids, are the result of excessive polymer material shrinkage. Because it is essential to produce high quality parts free of molding defects, understanding the causes in order to reduce or eliminate sink marks in molded parts can be very helpful. Let’s review some basics. 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 […]