Plastic Commodity Mould

What is mold in the plastic industry?

Injection molding can be used to make many items such as packaging, bottle caps, toys, storage containers, machine parts, and most plastic products. Our Plastic Commodity Mould is a hollow metal structure that can be formed into a specific shape when molten plastic is injected into it. This production method is suitable for the mass production of products with complex shapes and can ensure that the quality of the products produced is very stable, and it occupies a large proportion of applications in the field of plastic processing.

What is the process of injection molding production?

Raw material injection: Use an injection molding machine to melt raw materials such as plastic or rubber, and then use the fluidity of the raw materials to inject them into the mold.

Molding: After the raw material enters the mold, it passes through the runner and is introduced into the cavity, where it is shaped into a specific shape.

Open the mold and remove the product: After cooling, open the mold and the ejector of the injection molding machine can push out the formed plastic product.

What are the benefits of injection molding? Why is it popular?

Plastic injection molding is the most widely used component manufacturing process and its advantages are numerous.

Providing Uniformity: All parts molded from the same mold can maintain nearly the same dimensions. Production tolerances can reach ±0.125 mm, which is comparable to CNC machining or 3D printing. Since all products come from the same mold, they remain consistent even if they have complex shapes and high quantities.

Increasing Speed of Production: Manufacturing methods such as CNC machining tend to involve different processing around each part, while injection molding only requires processes such as injection of material and cooling (however, products for some applications require secondary processing). The design of multiple cavities can further increase production. Once the process is stable, injection molding can produce thousands of products per hour.

Flexibility: Manufacturers can choose from different molds and thermoplastic types, meaning they can produce a variety of different components. It is very convenient even for batch manufacturing of complex, high-precision parts.

Compatibility: High-strength molds are not only strong, but also wear-resistant and corrosion-resistant, and can be compatible with thousands of plastic materials and additives. This means that manufacturers can mix different materials for production.

Decreasing Cost: Injection molding production is mainly done by machines, so labor costs are limited to supervision, quality inspection, etc. Once the mold, injection molding machine, and raw materials are prepared, this manufacturing method can be repeated repeatedly, which means extremely low labor costs and time costs. The more parts you produce, the less each unit costs. At the same time, scrap materials that can be recycled also help reduce costs.

What are the common suitable materials used in injection molding?

Acrylic acid

Acrylic is a strong, clear thermoplastic that is lightweight, waterproof, and unbreakable. Good transparency makes it suitable for a wide range of applications. Injection-molded acrylic can be used to make home accessories.

Acrylonitrile Butadiene Styrene (ABS)

ABS is an opaque polymer that accepts a variety of surface treatments and provides excellent toughness even at low temperatures. Although it has good strength and impact resistance, it lacks strong resistance to sunlight (UV), and water, and is therefore used in injection molding to produce many types of plastic parts, such as sockets and sports equipment, etc.

Nylon (polyamide)

Nylon is a synthetic polyamide that combines toughness, heat resistance, and abrasion resistance. By adding stabilization, it can also have good outdoor performance. Compared with other materials, nylon's strength and acid and alkali resistance are not outstanding, and it is easy to shrink and affect the injection molding effect, so it is generally used for injection molding of mechanical parts.

Polycarbonate (polycarbonate)

Polycarbonate is strong, lightweight, and transparent. It has excellent optical properties and relatively stable physical properties, so it can sometimes replace acrylic. Higher processing temperatures mean higher costs and the material contains BPA, making it unsuitable for food containers.

Polyethylene

Polyethylene is the most commonly used plastic in the world and can be classified based on density. Polyethylenes of varying densities are chemically resistant but vary in hardness, flexibility, melting point, and optical clarity. Since they are not resistant to high temperatures and have low UV resistance, these plastic materials are generally used in products such as household goods, toys, food containers, etc.

Polypropylene

Polypropylene is the second most commonly used plastic in the world. It has good chemical resistance and toughness, but it will degrade under ultraviolet light and is extremely flammable. It can easily produce harmful aromatic hydrocarbons at high temperatures. Its injection molded products generally include toys, electrical appliances, sporting goods, etc.

What are examples of Plastic Commodity Mould?

Injection molds are molds used to manufacture plastic goods. Many plastic products in our daily lives can be produced through injection molding, and this production process is inseparable from various molds. For example:

Food container mold

Our Plastic Commodity Mould is made of high-quality mold steel, has a reasonable structure and cooling system, and can be used for the production of various plastic boxes, such as storage boxes, fresh-keeping lunch boxes, etc. The smooth cavity and customizable quantities make production more flexible.

Bucket mold

We have a variety of plastic bucket molds with volumes ranging from 50ml to 20L. We also offer different designs, shapes, and sizes as per the specific requirements of our clients.

Crate mold

Our molds can be used to produce various crate molds, such as fruit crates, thin-walled crates, folding crates, etc. Mold steel and hot runner systems ensure long mold life.

Pallet mold

We have extensive experience in manufacturing large pallet molds. The professional design team can manufacture various molds to produce single-sided pallets, double-sided pallets, two-way pallets, four-way pallets, etc.

Trash can mold

We can design and manufacture household waste bin molds, medical waste bin molds, and industrial waste bin molds. Both the output and quality are imporved a lot.

What is the structure of Plastic Commodity Mould?

Injection molds basically consist of fixed parts and movable parts. The fixed part of the mold is generally installed on the fixed plate of the injection molding machine, while the movable part is fixed on the moving plate of the injection molding machine.

1. Molding part

This refers to the various parts that outline the shape of the product, including the core (convex mold), cavity (concave mold), inserts, etc. When the mold is closed, the core and cavity form the mold cavity, giving various plastic parts their unique shape, structure, and size.

2. Gouring system

The pouring system is the channel through which the molten plastic material flows into the mold cavity through the nozzle, and mainly includes the pouring port, main flow channel, branch flow channel, etc.

3. Guiding mechanism

The guide mechanism is divided into two categories: the guide mechanism between the movable mold and the fixed mold and the guide mechanism of the ejection mechanism. The first guide mechanism can ensure the accurate alignment of the movable mold and the fixed mold when closing the mold, thus ensuring the quality of plastic parts. The latter is set up to avoid problems such as the skewing of the ejection plate of plastic parts during the ejection process.

4. Release mechanism

The device that ejects plastic parts from the mold is called an ejection mechanism, which generally includes ejector rods, top plates, return springs, locking screws, and other components.

5. Heating and cooling system

In order to meet the temperature requirements of the injection molding process, the mold is equipped with a temperature adjustment system. There are heating elements or hot water channels in or around the mold to melt the solidified raw material. The cooling system generally consists of cooling water channels, which can quickly cool down and shape the product.

6. Exhaust system

During the injection molding production process, the air in the cavity needs to be exhausted to avoid air paths or scorch marks on the product surface. When injecting molten material, the original air in the cavity also needs to be discharged, otherwise, problems such as pores will appear in the product. The exhaust volume of small plastic parts is not large, so it can be directly exhausted by mold separation. In other cases, some grooves on the parting surface of the mold can play a role in the exhaust, and the gap between the mold push rod and the slider can also play a role in the exhaust.

How to judge the quality of Plastic Commodity Mould?

Dimensional accuracy: Injection mold processing accuracy is very important. Excessive dimensional deviation will lead to unqualified product quality. Therefore, the quality of the mold can be judged by checking the dimensional accuracy of the mold processing. However, it should be noted that it is not only about the static accuracy but also about its working accuracy to see whether the accuracy is within the reference data range when it is working.

Surface quality: The surface quality of the mold directly affects the appearance and surface quality of the product. Generally speaking, injection molds will undergo polishing, grinding, and other processing after manufacturing to ensure surface smoothness. The quality of the mold can be judged by observing whether the mold surface is smooth and whether there are scratches, bubbles, impurities, and other defects.

Mold material: The material of the mold is also one of the key factors affecting the quality of the mold. High-quality mold materials have high strength, high hardness, and good wear resistance, which can ensure the service life and production efficiency of the mold. The temperature during the production process of injection molded products is generally high, and the size of mold steel that has been tempered at high temperatures will not be affected even in high-temperature environments, thus ensuring production accuracy. At the same time, during the injection molding production process, plastic product raw materials and various additives will corrode the surface of the injection mold and affect the overall accuracy of the injection mold. Therefore, the mold steel must be corrosion-resistant steel. In addition, the high-speed flow of plastic raw materials will cause great friction on the entire mold surface. Therefore, it is necessary to choose wear-resistant and highly rigid mold steel to avoid deformation of the mold during the working process.

Injection molding product quality: Injection molding quality is also one of the important indicators for judging mold quality. Manufacturers judge the quality of the mold by checking the dimensional accuracy, appearance quality, physical properties, and other indicators of the product during the injection molding process.

Mold life: Mold life is one of the important indicators for judging mold quality, which can reflect the situation and level of mold materials, processing technology, maintenance, etc. Manufacturers can also judge the quality of the mold by checking its service life——whether it is easily damaged, whether it requires regular maintenance, etc.

High Quality Plastic Commodity Mould Customization Service

1. Mold designers have a detailed understanding of product structure, product size, parameters, and other information, and evaluate whether the existing mold structure can achieve mass production;

2. Based on the evaluation results, the designer designs 3D engineering drawings, mold parting drawings, assembly drawings, EDM drawings, electronic circuit diagrams, etc.;

3. Purchase materials, modify and adjust drawings;

4. Mold engineers inspect and analyze the workpiece after heat treatment, including hardness, offset, scars, and other issues;

5. Electrode processing;

6. Wire cutting processing (pay attention to the standards when processing each accessory);

7. Finishing;

8. Carry out EDM processing according to the drawings;

9. Polish flow channel surface;

10. Conduct product inspection before assembly, complete cleaning and rust removal treatment;

11. Injection mold assembly;

12. Trial the mold.