Etiqueta: TTT

Torsten’s Training Tips: PVT

The Pressure-Volume-Temperature (or PVT) relationship of different materials is a calculation of the compressibility of material during the packing and cooling phase. Since this affects a parts’ shrinkage and warpage after ejection, having a clear understanding of PVT is essential for success. Polymer material shrinkage inside a mold must be compensated for with packing and […]

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 […]

Torsten’s Training Tips: Packing Pressure Profiles (Amorphous and Semi-Crystalline Materials)

One of the key steps in the injection molding process is the packing and holding phase, sometimes also referred to as the compensation phase. During the packing phase material is continuously “packed” into a cavity, thereby compensating for the shrinkage that occurs due to material cooling inside the mold. To optimize a packing profile, it […]

Torsten’s Training Tips: Nozzle Tip Designs

Molding high quality parts is dependent on many factors, including skillful part and mold design, an understanding of polymer material behavior, and an optimized process. The three common nozzle tip designs found in the injection molding industry are general purpose, reverse taper, and free flow. Nozzle tip design and size will impact mold filling, process […]

Torsten’s Training Tips: Ejector Pin Sub-Gates

Gate design and placement are key factors in mold design. Because parts often need to be molded without surface marks or gate vestige, certain gate styles are more appropriate than others. Although many gate systems will leave behind a witness mark, selecting a gate that can be hidden inside the ejector pin with an automatically […]

Torsten’s Training Tips: Mechanical Material Behavior

Injection molding manufacturing produces many everyday parts, from pipet tips to car bumpers in a variety of polymer materials. Some parts are produced from neat, unfilled materials and some from materials that are filled with reinforcements and additives. Part designers should be able to evaluate the mechanical material behavior and properties of these different polymers […]

Torsten’s Training Tips: Designing Cold Runner Systems

Designing effective cold runner systems is as important as designing a molded part. After optimizing the gate location for a new part design, the next step is to determine the best cold runner size. Cold runner size will influence overall part quality, molding cycle time, and overall profits. Identifying critical material process characterizations that will […]

Torsten’s Training Tips: Nominal Wall Thickness

What is nominal wall thickness and how is it relevant in designing functional plastic parts?  Although parts can have various wall thicknesses to accommodate form, fit, and function, designers are generally tasked with minimizing thickness to lessen material consumption, achieve a faster cycle time, and reduce manufacturing costs. But parts with thin walls are more […]

Torsten’s Training Tips: Fill Speed Profiles

Evaluating and understanding fill speed profiles is an important aspect of injection molding. Polymer materials can flow by heating them to their melting range. Every polymer has a melt and mold temperature range, and within that range the polymers flow and can be injected into a mold. Molten polymer is injected into the mold by […]