Key qualitative research in plastics processing

Today , plastics play an extremely important role in many industries, from automotive and electronics to packaging and consumer products. To guarantee high quality and reliability in manufactured products, the process industry relies on key quality tests in the plastics laboratory . In particular, the plastic injection process requires detailed research to ensure excellent properties and functionality of the products.

Selecting appropriate laboratory tests , such as strength, chemical resistance, thermal stability or sound absorption tests, allows you to meet the requirements of specific industrial sectors or applications . These tests enable plastics producers to more precisely adjust the material composition and injection parameters, which translates into the final quality and functionality of the products.

Key quality tests in the plastic injection molding process

The plastic injection process is one of the most popular forming methods for many products on the market. It is based on injecting heated plastic mass (plastic) into a mold, where it is then cooled and hardened, taking its final shape.

Key quality tests in the plastic injection process include:

• Raw material analysis

Before starting the injection process, the raw material (plastic in the form of granules) is analyzed, which includes checking its chemical composition, grain size, humidity and possible contamination. This initial inspection is necessary to ensure the consistency and quality of the raw material, which affects the final properties of the product and the stability of the plastic injection process.

• Viscosity and temperature testing

In the laboratory, the viscosity of the plastic is determined at various temperatures, which is important for properly selecting the parameters of the injection process. High or low viscosity may lead to problems with filling the mold or defects in the product.

• Mechanical properties testing

After injection, the products must be tested for mechanical properties such as strength, flexibility, hardness, etc. This allows you to assess whether the plastic meets design requirements and industry standards.

• Testing resistance to external conditions

Plastic products are often used in various conditions, such as variable temperatures, humidity, UV radiation, etc. Laboratory tests allow us to determine how the material will behave in extreme or difficult conditions.

• Shape and dimensions testing

Precise dimensions are crucial in many applications, so laboratory tests check the accuracy and dimensional consistency of products.

Quality tests of raw materials and finished products – why is it worth implementing?

Quality testing of the raw material and the finished product in the injection molding process is extremely important for several key reasons, affecting both customer satisfaction and the stability of the injection process itself. Firstly, the raw material (polymer, plastic) is the foundation of the entire injection process . Its quality and physical properties have a direct impact on the final quality of the molded parts. Raw material testing allows you to ensure that the raw material meets appropriate mechanical, chemical and thermal parameters, which translates into the durability, strength and aesthetics of the final products. Secondly, quality tests of the finished product allow for early detection of possible defects in moldings , defects or imperfections. Thanks to this, appropriate corrective steps can be taken at the production stage , which minimizes the amount of waste and reduces costs . High quality of molded parts is crucial for customer satisfaction because it affects their durability, functionality and aesthetics, which has a direct impact on the company’s reputation and customer loyalty.

Laboratory testing of plastics in Dopak – how can we help you?

Ensuring excellent product quality is a key element in building customer trust and achieving market success . In this respect, it is worth using the services of an experienced partner who will guarantee high knowledge and reliability of research implementation. Dopak’s plastics quality control laboratory offers you unrivaled opportunities for precise and reliable analyses. Thanks to advanced equipment and an experienced team of specialists, we are able to provide comprehensive tests that we tailor individually to your needs . Many renowned companies have already trusted us, and now you have the opportunity to see for yourself our competence and commitment.

So find out about the scope of laboratory testing at Dopak . Also learn about the Dopaka training program on Plastics Test Methods , thanks to which you will strengthen your competences in the quality of products in plastics processing. If you have any questions, please contact us by e-mail: cbr@dopak.pl and we will prepare an offer tailored to the specifics of the project. Together we will raise the bar for the quality of your products and achieve joint success on the market.

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What other qualitative tests are performed in the plastics processing industry?

The introduction of various laboratory tests in the plastic injection process allows for a more complete understanding of the properties and behavior of the material in various conditions , which leads to improvement of the production process and ensuring the highest quality of products. The plastic injection process is a complex process that requires many laboratory tests to ensure high quality and efficiency of products.

Below is a list of laboratory tests carried out in the plastic injection process:

1. Fatigue strength testing: Plastic products are often subjected to cyclic loads and stresses during use. Fatigue strength testing involves exposing samples to repeated loads to determine how the material behaves under dynamic conditions and how many load cycles it can withstand without failure.
2. Chemical resistance testing: Plastics are often used in environments where they may come into contact with various chemicals. Chemical resistance testing involves exposing samples to various chemicals and monitoring whether the material undergoes degradation, color changes, or other damage.
3. Thermal Stability Testing: The injection process can raise the temperature of the plastic, and the high temperature can affect its mechanical and chemical properties. Thermal stability tests determine the temperature at which the material begins to degrade to prevent overheating during the injection process.
4. Thermal conductivity testing: Some applications require the plastic to have adequate thermal conductivity. Laboratory tests allow you to determine how well a material conducts heat, which is important, for example, in the electronics industry or in the processing of materials for cooling or insulation.
5. Thermal expansion testing: Plastic products may be operated at different temperatures, which may affect their dimensions. Thermal expansion tests allow you to assess how the material reacts to temperature changes and what dimensional changes may occur.
6. Water absorption testing: Some plastics can absorb moisture, which may affect their mechanical properties and dimensions. Water absorption testing allows you to assess how much water a material can absorb and what changes it causes.
7. Electricity testing: In the case of electrical and electronic applications, electricity testing allows you to determine the electrical conductivity of a material and its ability to insulate.
8. Oxidation and reduction capacity testing: In some cases, such as when using plastics as food packaging, oxidation and reduction capacity testing is important to assess how the material affects the quality and durability of stored products.
9. UV resistance testing: Plastics used outdoors are exposed to ultraviolet radiation, which can cause material degradation, color fading and reduced strength. UV resistance tests allow you to determine how the material behaves when exposed to sunlight.
10. Abrasion resistance testing: In some applications, such as bearing components, plastics must be resistant to abrasion. Laboratory tests allow you to assess the material’s resistance to wear caused by friction.
11. Thermal degradation testing: During injection, the plastic is subjected to high temperatures, which may affect its chemical stability. Thermal degradation testing allows you to assess whether the material maintains its properties during processing.
12. Impact resistance testing: Plastic products, such as covers and housings, must be resistant to impacts and deflections. Impact resistance tests allow you to determine the material’s behavior when exposed to various dynamic loads.
13. Leak Testing: For some applications, such as packaging, it is important that the plastic is leak-proof. Leakage testing allows you to determine whether the material maintains its airtightness and prevents leaks.
14. Recyclability Testing: Modern ecological requirements focus on the sustainability and recycling of plastics. Recyclability testing determines whether a material can be recycled and reused.
15. Testing the structure of the crystal phase: Some plastics have a crystal phase structure, which affects their mechanical and thermal properties. Research on the structure of the crystal phase allows for a more detailed understanding of the material’s characteristics.
16. Sound absorption testing: In some applications, such as components in the audio industry, it is important that the plastic has the appropriate ability to absorb sound. Laboratory tests allow to determine the acoustic properties of the material.
17. Moldability test: The injection process involves injecting plastic into a mold of a specific shape. Formability tests allow you to assess what shapes and geometries can be achieved using a given material.
18. Life cycle analysis (LCA): Life cycle analysis is a comprehensive approach to assessing the impact of a product on the environment, from the acquisition of raw materials, through production, use, to disposal or recycling. LCA allows you to assess ecological sustainability and estimate the potential impact on climate change.
19. Dyeability Testing: Some applications require plastics to be easy to dye to produce a variety of colors. The dyeing ability test allows you to assess how the material absorbs dyes and pigments, which affects the final color effect of the products.
20. Testing of dielectric properties: For electrical and insulating applications, testing of dielectric properties allows determining the ability of a material to isolate electric current and its dielectric coefficient.
21. Testing the ability to undergo secondary processing: Plastic products often require additional processing operations, such as cutting, threading or mechanical processing. Reprocessability testing assesses how well a material is suitable for undergoing such processes.
22. Testing resistance to extreme weather conditions: In some industries, such as automotive or aviation, plastics must be resistant to extreme weather conditions, such as extreme temperatures, humidity, or salt exposure. Tests of resistance to extreme conditions allow you to assess whether the material meets the application requirements.
23. Material compatibility testing: In many applications, plastics must work with other materials, for example in complex systems composed of different components. Material compatibility tests allow you to determine whether there are any undesirable interactions between different materials.
24. Fire reaction testing: In some applications, such as fire safety equipment, it is important that plastics have certain anti-flame properties. Reaction to fire tests allow you to determine how the material behaves in contact with fire and whether it meets appropriate fire safety standards.
25. Antistatic ability testing: In some applications, plastics must be antistatic to avoid the build-up of electrostatic charges. Antistatic tests allow you to assess how the material behaves in terms of electrical conductivity and elimination of static charges.

Let us remember that the type of test and the conditions of the test are extremely important and depend directly on the working environment in which the product will be used. Therefore, regular and precise laboratory tests in the plastic injection process remain a key element in continuous improvement and innovation in the industry , as well as in meeting safety requirements, quality standards and sustainable development.

Author: M.Sc. Eng. Patryk Gratka, R&D engineer at Dopak

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