What is a large injection molding machine?
Updated: Feb 26
What is a large injection molding machine? Depending on who you ask, the answer will probably vary greatly. Some will say a large machine is anything over 700 tons, others will say it's over 1000 tons. Yet, what most don't know is that the only definition of a large machine has nothing to do with clamp tonnage or injection unit size. Instead, it has to do with a definition contained in the Safety Standard for Injection Molding Machinery and is a function of the machine tiebar spacing.
According to the American National Standards Institute (ANSI), under section 3.2.3 in the latest ANSI/PLASTICS B151.1-2017, a large machine has a space between tie bars greater than or equal to 47". This dimension is considered to be the lower limit for machines where “whole body” access to the clamp area is expected. Specifically, at this size clamp (and larger) a typical person would likely need to significantly reach into or entirely climb into the clamp area of a large machine to perform a manual removal of a part from the mold. Large machines which permit or require whole body access to the clamp area have additional protections such as Emergency Stop buttons inside the guarding and safety rated sensing system in platforms where personnel can stand.
Depending on the tiebar space, the transition to a Large IMM typically occurs on machines in the range of 1000 - 1200 US Tons .
Absolute Haitian is a member of the Plastics Industry Association and has been participating on the Machinery Safety Standards Committee for over 10 Years. We recommend all users of injection molding machinery purchase a copy of ANSI PLASTIC B151.1 - 2017 Safety Standards for Injection Molding Machines and use it as part of their employee training program.