home black icon > News > What are the limitations in OEM plastic molding world?

What are the limitations in OEM plastic molding world?

November 10, 2021
no tag

What is OEM plastic molding world?

In this blog, we will talk about the OEM plastic molding world concept and its main components. This is a tool that serves to shape plastic raw materials entering it under high pressure. And at least high temperature, installed on an injection molding machine (TPA).

And providing solidification and cooling of the material to a state that allows you to remove the molded product.

Thus, the mold receives a raw material in its molten state of the injection molding machine, gives it a predetermined shape (in the form of a "negative" cavity die and punch), rapidly cools the product design and produces its extraction.

OEM plastic molding world

There are 3 main types of OEM plastic molding world:

  1. Molds 2-plate
  2. Molds 3-plate
  3. Moreover, molds with GCS (hot channel)

Fixation of the mold on the injection OEM plastic molding world machine (on movable and fixed plates) is provided by mechanical fastening (except for some cases when the injection molding machine allows other types of fastening), using screws and clamping plates / fastening strips.

Avoiding the following problems OEM plastic molding world

  • Cast product sizing problems(cavity mismatch)
  • Risk of damage to internal componentssuch as marks, sliders / gates, or forming surfaces
  • Displacement of two halves of the moldunder high pressure injection molding machine

The design of each mold includes centering elements to ensure perfect centering of the two main parts of the mold, its halves: matrix and punch, movable and stationary parts, during all operations and manipulations of the mold.

Some types of centering elements of OEM plastic molding world:

  • Guide columns / pins
  • Oblique guides
  • Also, Interlocks / Side centering elements
  • Cylindrical centering elements
  • However, Guide bushings

The set of components that ensure the extraction of the cast and hardened part is called a pushing system or ejection system and its main function is, as already mentioned, to remove the finished plastic product from the OEM plastic molding world cavities of the mold.

This system can be mechanically, hydraulically or pneumatically driven, depending on the mold design and product typology.

Some types of OEM plastic molding world:

  • Push rods with cylindrical head
  • Moreover, Tubular pushers
  • Push plate (used for hard-to-reach surfaces and areas)
  • Also, push bar (can also be a forming element)

When designing a mold, one of the most important aspects is the cooling system and its circuits / channels. The cooling system refers to the channels formed in the mold plates that allow the coolant to circulate. In the presence of a good and correctly designed cooling system, considering the specifics of the product being produced.

The manufacturer achieves a stable and sufficiently low temperature of the forming surfaces for cooling and solidification of the raw materials supplied to the OEM plastic molding world.

Directly affects the quality of the manufactured product

To ensure identical results and performance of the cast products at different production times / at different production sites, it is necessary to ensure that two parameters are maintained: compaction (holding under pressure) and the temperature of the product at the time of its extraction.

In the last paragraph of this blog, I would like to talk about systems for feeding material into the mold.

All molds divide into two main groups: cold runner and hot runner molds. In each group, there are a huge number of types of solutions, but we will discuss this topic in more detail in one of the following blogs.

Some limitations and disadvantages of OEM plastic molding world

The cold runner solution is the most economical, but at the same time presents some limitations and disadvantages, which are solved by using hot runner systems.

This solution makes it possible to supply the plasticized material to the forming surfaces in practically the same state to which it is in the TPA screw. The main advantages of this solution are a significant reduction in material waste - the so-called sprue is absent.

OEM plastic molding world 2021

Injection OEM plastic molding world: Material drying

The injection molding process requires complex preparation at different stages to obtain an optimal result on the final product: it must meet various requirements, not only in terms of external parameters (visual qualities), but also in terms of its mechanical properties (dimensions, durability, etc.).

OEM plastic molding world casting cycle reduces and the quality of the cast products significantly improves.

One of the preliminary processes is the drying of raw materials.

The presence of moisture in the casting material can lead to some unwanted problems:

  • Casting products with defective surfaces ("bubbles")
  • Also, Reduction of important properties of the polymer (molecular weight reduction
  • Inconsistencies in the injection molding process

Many experts believe that not all thermoplastics have to go through the dryer, and they decide to load the material “straight from the bag” into the injection molding machine, making a serious mistake.

OEM plastic molding world is important and necessary, because under normal conditions moisture migrates into the inner part of the plastic granule.

The moisture content of the granules depends on various factors:

  • Thermoplastic type
  • Also, Thermoplastic granule size
  • Moreover, Ambient temperature and humidity

To determine the humidity of the environment, the concept of Dew Point is common:

The higher the dew point, the higher the air humidity.

Furthermore, drying is determined solely by the degree of humidity in the environment.

There are various parameters for determining the proper drying of a polymer:

  1. Temperature: increasing the temperature increases the mobility of moisture, which makes it possible to shorten the time of migration of water molecules outside the thermoplastic granule.

Temperature too low => polymer not dry enough.

Excessive temperature => polymer degradation.

  1. Air: this one must be dry => The dew point temperature is equal to or less than -30 ° C.
  2. OEM plastic molding worldTime required to complete the process.

Too short time => polymer does not dry sufficiently.

Too long time => polymer degradation (gas evolution).

Conclusion OEM plastic molding world

Various companies in the plastic injection industry use recycled materials in their manufacturing processes. By correctly calculating the proportion of pure and recyclable materials and withstanding proper recycling processes, their physical and mechanical properties can be preserved.

chevron up icon
white close icon