Torsten’s Training Tip: Mold Functionality
An important step in the molding process is preparing the mold for optimal functionality. Every plastic injection mold is unique and requires a tailored set-up strategy. There are several important steps to take prior to beginning the molding process development phase. These include setting up and checking the functionality of the following: Molding machine Mold Ejector […]
Torsten’s Training Tip: Thermal Properties
During the injection molding process, a polymer is heated in different ways, beginning inside the machine cylinder. Electric heater bands around the cylinder create heat which is transferred through convection from the cylinder to the polymer. Then, the rotating screw creates shear heat which transfers to the polymer on top of the convection transfer. In […]
Torsten’s Training Tip: Jetting
Injection molding polymer through small gates creates complex three-dimensional fluid flow behaviors. Jetting occurs in injection molding when polymer material is injected through a nozzle, runner, or gate at high velocity, into open, thicker areas, without forming contact with the mold wall. The jetting effect is like water flowing through a hose. If you place your thumb on […]
Torsten’s Training Tip: Parallel and Serial Coolant Circuits
An injection mold is effectively a heat exchanger. Molten polymer material that is injected must be cooled by the mold cooling system. As part designs become more complex, cavitation requirements increase, and larger overall mold bases are needed. Mold designers have several options when designing effective heat removal systems. Coolant circuits can be parallel or […]
Torsten’s Training Tip: Understanding Flow-Induced Molded-In Stress
Injection molding is a complex manufacturing process involving temperature and pressure. During the molding process polymer materials experience complex molecular chain deformation while undergoing temperature and pressure changes. Molded part properties and performance are dependent on, and influenced by, design complexity and the molding process. Understanding molded-in stress, specifically flow induced molded-in stress, is an […]
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, […]
New Training Topics Coming Soon
At Kruse Training we pride ourselves on the ability to consistently add new content and topics that meet the needs of the injection molding industry. With this in mind, we are currently undertaking a series of new topics focusing on areas that move beyond the basics of injection molding to the more complex aspects of […]
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: 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 […]
