I have been in the field of Custom Plastic vertical injection machine for about 21 years now as of the writing of this article. I am currently working as a Process Engineer, which I have done for about 15 of my 20+ years in the field of vertical injection machine and I have primarily worked for molders that were involved in the automotive field.
Plastic vertical injection machine, by definition, is the process of injecting plastic into a mold (or mould in European circles), cooling the plastic, ejecting it from the mold, and packing the finished product for sale to the customer. This sounds simple and in it's basic form it is, but the process involved with making all this happen is actually quite complicated. Plastic can be injected into the mold with low pressure, but typically is done under high pressure upwards of 30,000 PSI cavity pressure.
There are many diverse types of vertical injection machine and as many different types of plastic vertical injection machine machines to go with it. Some of the more common types of plastic molding are standard mold injection, insert molding, plastic extrusion, blow molding, multi-color or material molding, stack molding, and rotary molding just to name a few. There are custom plastics as well, from common every day plastic resins to the more exotic engineering grade resins used in most automobiles today. There are even vertical injection machine grade 'metals' being experimented with and used these days.
There are many types of vertical injection machine machines all made for specific purposes. There are the standard horizontal vertical injection machine machines which range in size from a few tons all the way up to 9000 tons and more. You could drive car between the platens of a press that large. Vertical vertical injection machine machines are often used for insert molding (although this can also be done horizontally) and share a common cover with two ejection halves of the mold.
This allows for de-molding and loading of inserts in one half, while the other half is producing the next shot of parts. There are also two and three shot vertical injection machine machines for producing multi-color or multi-material parts such as lenses for tail lights and gear shift knobs with hard plastic inner core and a soft vinyl out covering.
The newest machines are 'all electric versions' which stray from the standard hydraulic injection machines used now for years. These vertical injection machine machines are much more efficient and repeatable then their hydraulic cousins are. Common vertical injection machine machine manufacturers are Toshiba, Husky, Cincinnati, DeMaag, Engel, Nissei, UBE, Arburg and Boy, just to name a few.
The basic steps to producing a plastic injection molded part on a stand vertical injection machine machine are:Heating the plastic resin to the required range of the product being used.Developing the shot size through use of a reciprocating screw which conveys the melted plastic to the front of the screw.
The injection rod 237 is advanced, forcing liquid metal across the gap into the mold 250. In a preferred embodiment of the invention, the mold 250 has an inverted sprue 254 having a roughly funnel shape with the large opening 252 facing the injection nozzle 240 and the small opening 256 connecting to a gate 258 (FIG. 5). The injection machine 200 remains in the upper position until the casting and the gate 258 solidify. Then the injection rod 237 is lowered. Any molten or semi-solid metal remaining in the sprue 254 and the nozzle tip 240 is sucked back into the injection chamber 230. In this manner of operation, no solid plug is formed in the injection nozzle 240, and the metal remains in the liquid state in the nozzle throughout the entire cycle.
Vertical injection machine the plastic into the mold under pressure to fill the cavity of the mold.Packing the plastic to create a full part inside the mold.Cooling the plastic in the mold through the use of cooling channels most commonly with water.Ejecting the cooled part from the mold.Repeating the process over and over again.