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: 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: 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. […]
Industry 4.0 Meets Learning 4.0
We don’t want to just revolutionize the training industry; we want “evolutionize” your way of learning. Everyone has heard the maxim “time is money” and nowhere is that truer than with training. Consider the time your employees are attending off-site or on-site training, away from their desks or the molding floor, and not productive in […]
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 […]
