Injection molding

The plastic injection molding is Asytec’s area of expertise. Asytec in China has its own plastic injection workshop for thermoplastics processing.

Choose Asytec and plastic injection molding in China

The plastic injection molding is Asytec’s area of expertise. Asytec in China has its own plastic injection workshop for thermoplastics processing.

The injection molding machines are provided by Asytec or by their confidential partners: the qualified and quality certified Chinese plastic injection moldmakers and molding manufacturers.

ASYTEC has its own plastic injection molding machines in China. 17 injection molding machines with clamping force ranging from 80T to 480T allow the production of all types of plastics injection parts.
A metrological laboratory with air conditioning environment allows controlling the injected parts (dimensional control, profile projector).

ASYTEC is capable of injecting all part types, ranging from few grams to much bigger volumes:

Appearance/Decorative plastic parts

  • For all types of series of products (200, 2000, 20000 pieces injected...)
  • Injected materials: ABS, transparent PC, PMMA, ASA…
  • Injected plastic cases, boxes, lids and handles ...
  • Decoration and finishing of plastic parts

Technical plastic parts

  • From small series to mass production (from 2000 to 200 000 pieces injected)
  • Injected materials: PA, PP, TPU, POM, fiber reinforced thermoplastics....
  • Plastic supports, screws, covers, trolleys, …
  • Installing the inserts in hot state after plastic injection, parts to be finished manually

Transparent plastic parts

ASYTEC is particularly specialized in the realization of transparent plastic injection parts. These are for example the food grade containers from 0.2 to 5 liters, made of PC, PMMA or Tritan (without Pba).

Overmolding - ASYTEC’s expertise

We are particularly specialized in plastic parts overmolding. Our plastic injection workshop in China possesses the special tools for plastic overmolding. We do all types of molded plastic parts:

  • Double-component plastic overmolding (a technical plastic part molded over a metal part)
  • Double-material plastic overmolding (a plastic part molded over an insert from a different type of plastic).

What are the advantages of plastic injection?

The first advantage of the thermoplastics injection is the manufacturing flexibility. In fact, we are able to produce the extremely varied parts. Parts can vary from few millimeters to several meters, from few grams to several kilograms, parts with simple geometrical forms or much more sophisticated.

The simplicity and flexibility of manufacturing the plastic injection parts explain the reason why one can find the parts made by this process in many different fields:

  • Auto components
  • Household durables
  • Computer industry
  • Electrical and electronics industry
  • Power Tools
  • Medical material
  • Security industry

The second benefit of this process is the industrial production volume. In fact, the plastic injection molding is suitable to produce the big and very big series of products (up to tens of thousands).

This large production capacity allows to reduce the costs drastically. The excellent price-quality ratio is one of the key factors contributing to the growth of this production method.

It should be noted that in the case of injection molding, the molds (also called tools) are tailored and reusable. It is this feature that allows such production volume, in comparison with other less common molding techniques (sand casting, lost wax casting, etc).

Plastic injection or 3D printing?

Many people confuse these two manufacturing methods. 3D printing allows the production of plastic parts but the purpose is entirely different.

A 3D printer can produce parts with highly complex geometries, with nested elements for example. However the embodiment is slow and has a finish of lower quality. It is impossible to achieve the volumes and the production rate obtained with plastic injection.

3D printing is therefore a great prototyping tool for product design phases. However for the next step, industrialization and mass production, one would turn to plastic injection molding.

Here are some examples of parts we can do for you:









What is plastic injection?

The plastic injection, also known as thermoplastic injection molding or thermoplastic injection, is an industrial process for manufacturing plastic parts. The raw material used is the plastic in pellet forms. The pellets are melted by heat and friction in a worm. This stage is called lamination. It corresponds to the change of state of the plastic material, which passes from solid to fluid. The resulting plastic is now easier to work. It will be injected under pressure through hydraulic cylinders, in a mold. The mold consists of various channels made of cooled steel in which circulates a cooling liquid. The plastic hardens under the effect of cold which causes solidification of the desired part. It remains only to open the mold and eject the solid plastic. This last step, like all previous ones, is fully automated. The machine which carries out the whole process is called injection molding machine, injection molding or injection press.

For better understanding here are two important elements:
- Explanatory video
- Other Sources

How to recognize a part manufactured by plastic injection?

In our daily life, there is a very large amount of injected plastic parts. Chairs, garden tables, toys, parts of household appliances, car bumpers, ... A shrewd eye will easily distinguish an injected plastic part by the following elements:

- Parts full plastic
- Small round dishes (slot ejectors)
- Trapezoidal geometries facilitating the ejection from the mold
- Weld Lines
- Surface Defects

What are the injection plastics?

Not all plastics are injectable. It is however a great number of them that meets the necessary conditions and which may undergo a plastic injection cycle. Each of them has different specific advantages and technical specifications, which can guide us in choosing the best plastic for our final part.
We can group the injection plastics into three categories:

1. Heat hardening plastics
These plastics take their final form in the first cooling. This means they will be very strong, but cannot be reused and recast to make other parts. The reversibility is not possible either. They are used for big and massif parts, like garden furniture for example.

2. Thermoplastics
These plastics may be deformed when they rise in temperature. Conversely to the heat hardening plastics, thermoplastics will return to their initial shape by cooling, unless they are heated and cooled many times. Parts made with these plastics are relatively flexible, such as kitchen utensils or construction toys.

3. Elastomers
Heat hardening plastics and thermoplastic are members of polymers family. There is also another large family of injectable plastics: elastomers. The biggest advantages are their elastic and rubber properties. Elastomers are generally used to manufacture the tires, gaskets, cushions or insulation.

Design of injected plastic parts

Design of injected plastic parts Before the manufacturing stage, we must design the piece on computer. CAD specific software or Computer Aided Design is used for this. The design is an important step because it will determine the successful implementation of manufacturing and the quality of the parts obtained. Indeed, before starting the production, we must consider various constraints naturally related to the manufacturing process of plastic injection:

- Production of molds
- Geometry of the plastic part (the same thickness if possible)
- Spoils (to facilitate the ejection)
- Ribbing (to limit the risk of breakage)

Post-production treatment of injected plastic parts

IPost-production treatment of injected plastic parts In order to obtain a final result complying with technical specifications, some further steps may be added to the original manufacture. The overmolding is one of the examples. This process is to put a second layer of material on the previously molded part. One can thus obtain two colors or two textures (like toothbrushes). This overlay can also allow the protection of the starting piece for shockproof applications for example.
There is a wide variety of post-production surface treatments to work on the color, the properties and appearance of the outside part of the plastic product.

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