Why injection moulded parts lose luster and solutions

Why injection moulded parts lose luster and solutions

Injection moulded parts can lose their luster due to a variety of factors including the material selection, mold surface quality, processing parameters, mold release agents, surface contamination, and post-processing operations. Maintaining the desired gloss and finish of molded parts requires proper maintenance and adherence to production standards.

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The reasons for the loss of luster of injection moulded parts

The loss of luster in injection molded parts can be attributed to several factors:

Raw materials:

Raw materials are one of the main reasons for the colour difference of injection moulded parts. Different raw materials have different colours and transparency, if the raw materials used do not meet the requirements, it will lead to injection molded parts with colour differences. For example, the use of low-quality pigments or dyes will lead to uneven colour or colour spots in the injection moulded parts.

Manufacturing process problems:

The manufacturing process of injection moulded parts includes many aspects such as injection cycle, injection temperature, and pressure, etc. If the injection moulding machine is not set up correctly or is not operated properly, this can lead to problems with the surface of the moulded part. The injection pressure of the moulding plastic machine is too low, the injection speed is too fast or the injection temperature is too high, it can lead to uneven flow of plastic in the mould and produce colour differences. If the injection pressure of the plastic injection machine is too high, the injection speed is too slow or the injection temperature is too low, it will lead to poor moulding of the plastic and produce colour difference.

Mould problem:

The quality and condition of the mould will also directly affect the surface quality of the injection moulded part. Unreasonable mould design will lead to uneven flow of plastic in the mould, making different parts of the plastic mixed unevenly, thus producing colour difference. Improper maintenance of the mould will also lead to colour differences in the injection moulded parts. If the mould has not been cleaned or maintained for a long time, it will lead to the internal dirt or wear and tear of the mould, which will make the plastic flow unevenly in the mould, resulting in chromatic aberration.

Environmental factors:

In the production process of injection moulded parts, the temperature and humidity of the environment and other factors also need attention. If the environment is humid, the injection molding machine can’t work properly, which will easily affect the surface quality of the injection molded parts.

How to solve the problem of injection moulded parts losing gloss

To resolve the issue of injection molded parts losing gloss, consider the following steps:

Raw material problem:

Choose good quality raw materials, try to buy in regular channels, avoid the use of low-quality raw materials, can effectively avoid the problem of injection moulded parts losing lustre.

Manufacturing process problem:

During the production of injection moulded parts, it is necessary to ensure that the parameters of the plastic molding machine are set correctly and that the work is done in strict accordance with the process flow to ensure the surface gloss of the injection molded parts.

Mould problem:

Check the condition of the mould regularly, repair or replace the mould in time to avoid the deterioration of the surface quality of the injection moulded parts due to the poor quality of the mould.

Environmental factors:

In the production process of injection molded parts, we must pay attention to the temperature and humidity of the environment and other factors, to keep the production equipment ventilated and dry, to avoid negative effects on the injection moulded parts.

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The injection moulded parts colour difference detection method

Visual inspection method

Visual inspection method is the simplest injection moulded parts colour difference detection method, by observing the appearance of injection molded parts to determine whether there is a colour difference. Although this method is simple and easy to use, it requires experienced inspectors to draw accurate conclusions.

Colour difference detection method

Colorimeter is a professional colour difference detection instrument that can accurately measure the colour difference of injection moulded parts. Through the measurement of the colour difference meter, the value of the colour difference of the injection molded parts can be derived, and it can be judged whether there is a colour difference or not. This method is highly accurate and easy to use, but you need to purchase professional colour difference measuring equipment.

Gloss meter detection method

Gloss meter is a kind of instrument to measure the gloss of plastic surface, can also be used to detect the colour difference of injection moulded parts. Through the gloss meter measurement, can be derived from the surface of the injection molded parts gloss value to determine whether there is a colour difference. This method is suitable for the smooth surface of injection molded parts colour difference detection.

 Infrared spectrometer detection method

Infrared spectrometer is a professional material analysis instruments, can be used for injection moulded parts colour difference detection. Through the measurement of infrared spectrometer, the content of various components in the injection molded parts can be obtained, and it can be judged whether there is colour difference. This method is highly accurate and complicated to operate, but it can be used to detect the colour difference of injection molded parts with high precision requirements.

Final Thought:

In summary, the reasons for colour difference in injection molded parts are mainly the influence of raw materials, mould design, injection moulding process parameters and mould maintenance. In order to reduce the occurrence of colour difference of injection molded parts, it is necessary to start from these aspects and strengthen quality control and management. At the same time, visual inspection method, colour difference meter detection method, gloss meter detection method, infrared spectrometer detection method and other detection methods can be used to detect the existence of colour difference of injection moulded parts to ensure the quality and appearance of products.

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Frequently Asked Questions

Daoben has the SOP (Standard Operation Procedure) and all the production steps must follow up this SOP. Every machine needs at least automatic running over 72 hours and must be inspected carefully before shipment.

Actually, the delivery time of the machines is depended on the machine options. Normally, the delivery time of a standard machine could be within 1-2 months.

12 months warranty after shipment for mechanical parts, hydraulic parts, and electric components excluding the screw and barrel 6 months (not including use for recycled material or reclaimed material).

Yes, Daoben will provide one set of standard spare parts to the customer including a heater, filter, screw head, screw washer, checking ring, sealings, etc.

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