There are many well-known brands of plastic injection molding machines: Demag, bettenfeld, engel, krauss-maffei, jsw, kawaguchi, arbug, cincinnati, jsw, nessei, toyo, etc.
Whatever selection you make must consider the typical applications in part requirements and which region of the world that your production location is.
First and foremost, you must consider which company has the Field Tech Service and Spare Part support that is local to your site in the event you require various repairs/parts to support production.
Secondly, you should evaluate what types of molding parameters you require: a) High Speed Injection (for Thin Wall Part Designs) or b) Standard Parts. Also, Will you require 2 shot capability using Rotary tool design or just conventional single shot processing.
Your Part size and Weight will also determine Press Size which will narrow the selection of manufactures, you will see that among your list of plastic injection molding machines, there are some that are very well suited for smaller parts whereas other excel in very large tonnage presses. The Resin used in your applications will also determine your choice of Barrel specified on your selection of the injection molding machines, this will relate to your part weight as it must be calculated to resident time in the barrel.