An Introduction to Injection Molding applications

Plastic parts are widely used in all industries. Human activities are also associated with the use of plastics from building materials and household appliances to kitchen utensils. The most popular way to manufacture various products is hdpe mold technology.

Modern equipment makes it possible to automate the production process and receive products with excellent technical characteristics in a short time with minimal investment. Polymer products are recyclable. Therefore they are an environmentally friendly material.

Raw materials, materials for hdpe mold of plastics

The raw materials for plastic molding are thermosetting powders, as well as granules of thermoplastics and thermoplastic elastomers. All materials have different mechanical and physical characteristics.

The advantage of thermoplastic materials is that we can recycle them after the forming process. Thermosetting materials in the process of forming a product are subject to chemical processes. It leads to the transformation of raw materials into infusible and insoluble material.

Applications of polymer injection molding

Using the hdpe mold technology that involves injection molding of plastics, it is possible to produce simple and complex plastic parts. At the same time, there are no restrictions on the size and number of products.

This method use in the automotive, electronics, chemical and many other industries. Using the method of molding plastics, it is possible to quickly and with the required quality level produce:

• different packages, lids and different caps
• a wide range of toys for children
• enclosures and components for electronic equipment
• components for medical equipment and other products.

Phased production of hdpe mold

The injection molding process proceeds in stages. Complex work consists of preparatory operations and product formation.

Preparatory work includes 3D modeling of future products. In order to create a model, specialists analyze and study:

• drawings
• photographs and
• Product descriptions.

After creation with the help of special software and approval of the 3D model, the following operations are performed:

 

A prototype comes out, which is a sample of the part being produce. In order to speed up the process, modern equipment (printers) is common that performs 3D printing.

The manufactured prototype allows you to evaluate, test at ultimate loads and test the finished product. When inaccuracies and we find defects, we can quickly make the changes c to the three-dimensional model until we get a perfect part that meets all the requirements.

Methods used for injection molding of plastics

To implement the hdpe mold technology for the production of products from molten polymers, injection molding machines (TPA) are common. They are special injection molding units that differ in the location of injection units.

Injection of the melt comes vertically downwards or horizontally. By the type of raw materials used, injection molding machines get classification. It provides single-component or multicomponent injection molding of plastics. Moreover, we perform it in different ways.

Injection process

This method is the most common. The required portion of the molten mass accumulates in the cylinder and injects into the mold under pressure. The casting pressure sets at 200 MPa. The process of feeding the mass takes place in seconds.

As a result, it is possible to manufacture parts with complex configurations. Similarly, it is possible to obtain different wall thicknesses. We can use thermoplastics and thermosetting compounds as raw materials. It is possible to use a multi-cavity injection mold. The volume of the molten mass must match the sprues exactly.

Hdpe mold Injection press

Basically, this method of plastic injection allows the production of products with a large pressing area. The drop in pressure during the filling of the volume causes different strength characteristics in the center and in the extreme zones of the parts.

A feature of the hdpe mold technology is the formation of mass pressure not only due to injection, but also due to the use of the pressing mechanism of the moving unit. Therefore, forms are commonly applicable that structurally provide for the movement of parts after they are connected.

Multilayer

This method provides for the use of two or three injection units for the process in order to plasticize a polymer characterized by certain properties. As a result, multi-color parts easy to obtain. Subsequently, this structure of comes up of various types of polymer materials.

The multilayer injection molding method is common to produce hybrid structures in which non-critical parts are made from recycled materials.

Sandwich casting

The technology provides for a variable supply of molten polymer from different kneading machines to the mold. For this purpose, two injection modules connect to a sprue with a switching mechanism, which is used as a needle valve.

Generally, a valve with a specific sequence or at the same time connects them to the mold. From the first, a mass is injected under pressure to form the outer coating of the manufactured part. Internal cavities are filled with polymer coming from the second unit. At the last stage, the first node is switched again to add the melt.

Injecting or hdpe mold

The tool with which the required molded parts are produced has a so-called sprue bush. Only when the nozzle is exactly on the socket can the actual spraying process begin.

Pressing and shaping

After the injection process, the melt cools down in the mold and solidifies. In some cases, the cooling leads to massive volume shrinkage, which has a negative influence on the surface quality and the dimensional accuracy of the workpiece.

In order to reduce this volume shrinkage, the hdpe mold machine builds up a reduced pressure. Hence it allows material to flow in. The shrinkage can compensate by pressing down. The process continues until the spout freezes and the sealing point reaches.

Cool down time

As soon as the hold pressure switches off, the actual cooling time begins. Furthermore, the screw returns during the cooling process so that the next dose is possible to carry.

Demolding

After the cooling process, the molded part goes to demolding process with an integrated ejection system. Similarly, the mold closes again and the nozzle moves back to the closed mold. Subsequent finishing of the molded parts is not necessary in most cases.

Injection molding materials

In the spraying process, different materials use depending on the area of application or the molded parts to produce. These are each briefly present below:

hdpe mold products and uses

Hdpe mold has become an indispensable part of today’s industry. From the automotive industry to the electrical and household industries to defense technology, the area of application for plastic injection molding is extremely diverse. Moreover, the use of plastic continues to play an important role in industry. In the toy industry alone, the injection molding process is common to manufacture a wide variety of products, for example in model construction or for plastic building blocks. Moreover, further examples are:

• Interior parts for vehicles (information board, panels …)
• Exterior parts for vehicles (cable ducts, bumpers …)
• domestic appliances
• Components for defense technology
• Electrical industry (electrical housing, plug …)
• Various cladding and housing parts
• and much more.

HDPE molding processes in industry
Compared to other materials, hdpe mold offers many advantages. This includes in particular the low weight, the low susceptibility to breakage, the resistance to chemicals and the possible transparency of the packaging. The second largest dynamic sales market is products for the vehicle industry.