I received this as a follow-up question for a previous blog posting on The Future of Plastics…
We are adding a new machine this year and we are looking at a electric machine. Our biggest concern with electric is the hold time. Due to our thick wall parts we use extended hold times. Does anyone have any experience using extended hold time with a electric machines?
In reality, jobs with long hold and/or cooling times are very well suited for all-electric molding machines. In a hydraulic molding machine, the hydraulic pump is always providing significantly more hydraulic fluid flow than is necessary to mold the part. Even when a multiple stage, variable, or servo-driver pump is used, hydraulics are a relatively inefficient method of transferring electric energy to linear or rotary motion when compared to all-electric molding machines. These losses are amplified when you consider the added costs of water for the heat exchanger as well as additional maintenance expenses.
The latest news in all-electric molding machines is almost always focused on higher speeds, tonnages, and pressures intended to get all-electric molding machines into newer markets such as packaging and automotive where profit margins are razor-thin. As a result of this hype about the latest and greatest, the molding companies take for granted that the average injection molder already knows all the general benefits and how it applies to their own operation.
Industries such as robotics and automation are doing a good job in teaching the consumers about the benefits of servo-motor driven components. Many molders are replacing simple items such as pneumatic sprue pickers with high-efficiency servo-motor drive versions. When I hear molders tell me things like “I’d get an electric machine if I were doing more automotive” or “My cycle times are too long to justify an electric molding machine” it shows that the industry should return to the basics and teach it’s potential customers more about the fundamental benefits of all-electric molding machines.
We recently created a series of training programs focused on all-electric molding machines to help educate molders about the functionality, benefits, and optimal processing of all-electric molding machines