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KUMRU KİMYA
SANAYİ VE TİCARET LTD.ŞTİ. | ||
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Kumru Kimya whose main purpose is customer satisfaction was established in 1972 and since that time it has been trading plastic raw materials. In this direction, it is trading with the most important petrochemistry manufacturers in all over the world particularly Europe, Far East and Asia. Kumru Kimya exports mainly Urea formaldehyde, melamine-formaldehyde and phenol-formaldehyde (Bakelite) moulding powder, glazing powder (lamalit), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS) and ABS raw materials.
Plastic raw materials have quite different performance features depending on their chemical structures, as they are different from each other. Out of hundreds of different plastic raw materials, matching the required features in the final product and the right plastic raw materials, which will be used during the production, can be seen as a different profession. The first step of a successful production can be summarized as determining the most economical raw material which can provide the required features in the final product. Therefore, knowing different kinds of measurements which show the mechanical, electrical, chemical and thermal features of the plastic raw materials and what their results mean is essential to choose the right raw material.
We strongly recommend you to consider the list below while you are choosing plastic raw materials. The list summarizes what the measurements often seen in plastic raw material specifications mean.
1. Electrical Properties
Dielectric strength: It defines the voltage which plastic raw materials resist without being destroyed. It is one of the most important factors, which determines the electrical resistivity level of the plastic raw material. The higher the dielectric strength is, the better the resistivity feature of the plastic raw material. Dielectric strength differs according to the thickness of the product produced from the plastic raw material.
Arc resistance:It measures how easy a conductive way is formed on the surface of the plastic raw material. This feature is independent from the thickness of the moulded part. The higher the arc resistance is, the higher the electrical resistivity of the raw material.
Dissipation factor: It refers to how much the plastic raw material can dissipate the thermal energy, which it produces due to the electric flow passing through it, as heat. The fact that the dissipation factor is relatively low means that the raw material resists the electricity without getting warm.
22. Mechanical Properties
Tensile strength: It shows how much the plastic raw material can resist pressure by stretching before getting broken. Generally, the product, which is made from a raw material whose tensile strength is high, is elastic.
Flexural strength: It shows how much the plastic raw material can resist pressure by stretching before getting deformed. The plastic raw materials whose flexural strength is high, generally has low tensile strength. These raw materials can resist pressure without getting deformed but they are more fragile because their stretching rates are low. It is important in implementations where aesthetical concerns are in the foreground.
Impact strength: It measures the resistance of the plastic raw material against an impact. This feature is related to how equally the plastic raw material can dissipate the impact it comes across. Impact strength is especially important in final products by which hitting and dropping risks are high.
3. Thermal Properties
Heat distortion temperature: It states until which temperature the plastic raw material can preserve its mechanical structure without changing. The structure of the plastic raw material starts to change when it is above the specified temperature. It is important in plastic products which have contact with high temperatures.
Flammability: It defines the catching fire feature of the plastic raw materials at incidents such as fire. According to UL94 standard, V2 is the resistance to lowest burning, V1 to middle level burning and V0 to the highest burning. It is important in particles which have electric flow and may lead to fire in terms of safety.
4. Physical Properties
Water absorption degree: It shows at what proportion the plastic raw material absorbs the moisture in the air after being kept at a temperature for a while. This feature is significant for all the plastic raw materials. If the plastic raw material is hygroscopic, moisture in this raw material must be eliminated before processing. Otherwise, there will be big problems while processing the raw material.
5. Chemical properties
UV light absorption: UV light absorptions of plastic raw materials are different from each other. Generally, plastic raw materials are preferred to reflect UV lights. Plastics absorbing UV lights are deformed due to thermal degradation in time and become more fragile because their chemical structures are destroyed.
Resistance to alkalines and acids: According to usage areas, plastic raw materials can have contact with alkaline and acids. For example, detergents have alkaline and damage the structures of some plastic raw materials. Therefore, plastics which will have contact with other materials must be examined.
6. Processing properties
Melt flow index: : It shows in how much time the plastic raw material progress at a specific temperature and under pressure. Briefly, it is a feature showing the viscosity of the raw material. Raw materials having a high melt flow index give better results because of their fluid structures in mixed moulds. In very sinuous moulds, raw materials with low melt flow may have problems with filling the mould completely. This feature is not sought in thermoset plastics, because melt flow indexes of thermoset plastics show differences at different temperatures.
