Category Archives: Scientific Molding: Theory and Application

This group’s purpose is sharing information as it relates to scientific and decoupled molding

Plastic411 introduces the CORE Processor Training System

CORE Processor Training System


I am now offering a training program that is specifically designed to address each company’s training needs individually. The CORE program is intended to enforce and compliment the standard training programs available for decoupled and scientific molding.

CORE builds the talents within your processing team by identifying, addressing and removing specific weaknesses through training, development and equipment. The system has a unique set of tools not found in any other program…


Click HERE for more information…

Top 10 Reasons Molders Fail at Scientific Molding


Rare is the occasion that you will find me writing an article in first person. I have always just felt that the best way to include my molding peers in the depth of the topics I cover is to put them in the driver’s seat. However this article is best presented with analogies and 30 years past experience. As such, I will be covering 10 scenarios that occur which cause “scientific molding” based companies to fail in their utilization of the principles they attempt to practice. Trust me.. there are many more I could outline, but to prevent readers from sleeping through my soap box episode, I will limit my scope to 10…..


Click HERE to read the article….


Plastic411: A Closer Look at Scientific Molding



By Garrett MacKenzie

Plastic injection processing has experienced massive change in the last 20 years. The days of molding by time and pressure have given way to molding by position, peak pressure and robust  process.  RJG and John Bozzelli  were major pioneers in the development of decoupled and scientific molding as the procedures were developed and given structure. Plastic injection as an “art” gave way to plastics processing as a science of repeatable, standardized processes.

Click HERE to read the article



Laws of Viscosity in Molding

By Garrett MacKenzie


Viscosity is a very large category that has huge effects on standardizing molding processes. It is also one of the most important  factors in a molder’s arsenal of making process changes. This article will first explain viscosity, and then delve into different situations where viscosity may help or be hurting  a processors goal of zero scrap and high output…..


Click HERE to read this article

Mold Watering/ Heating: Key of Process Control


By Garrett MacKenzie

When trying to establish process control in plastic injection, watering the tool is a key variable that is often overlooked. Water set-up and design are every bit as important as establishing and recording a repeatable process. The steps taken when watering a mold are key to a processor’s goal of consistency. If during the design and development stage, watering is put on the back burner as an “unimportant” variable, the potential for lost process control is huge. 

Below are some insights into the most important facets of cooling or heating your mold, as well as what recordable data are important in the initial stages of process engineering…

Click HERE to read the article

Bozzelli: Getting Good Data from DOE

Dealing with so many variables can get confusing. One way to get a handle on them is to organize or categorize the processing variables into groups. To do this I use Don Paulson’s four plastic variables (Don founded Paulson Training Programs Inc.), but I change the word “variables” to “categories.” This helps separate plastic variables from machine variables. So I review the process problem relative to four categories of variables—from the point of view of the plastic: flow rate (encompassing shear rate and injection velocity); temperature; pressure; cooling rate and time…..
Click HERE to read John’s PTOnline article