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Food-grade PP material in the Rapid prototye

Mar 19,21

Food-grade PP material in the Rapid prototye
In our experience of rapid prototype, some customers require to do food grade PP material, so what material is food grade PP material? When we buy some tableware, drinking cups and so on, the material display is food grade PP, so what is food grade PP in the end? What should I pay attention to when choosing it? We'll summarize it for you as follows.

The Chinese name of PP is polypropylene, so far has a history of 100 years of development, PP features: low density, strength stiffness, hardness and heat resistance are better than low pressure polyethylene, can be used at about 110 degrees. PP is a semi-crystalline material. It is harder than PE and has a higher melting point. Because the homopolymer type PP temperature is higher than 0C is very brittle, PP has good electrical properties and high frequency insulation is not affected by humidity, but the low temperature brittle, not wear-resistant, easy to aging. Suitable for making general machinery parts, corrosion parts and insulation parts, widely used in automobile industry mainly use PP containing metal additives: fenders, ventilation pipe, fan, etc., instrument dishwasher door gasket, the drying machine ventilation tubes, washing machine frame and cover, such as the refrigerator door gasket, consumer goods of lawn and garden equipment such as lawnmowers and sprinkler.
Food grade PP processing technology PP melting temperature: 225~285C, pay attention not to exceed 280C. deformation temperature80

In the modification process of food-grade PP, attention must be paid to the compatibility between different polymers. When the two polymers with poor compatibility are blended, a third component, which is called compatibilizer, is often needed to be added, which has good compatibility with the two polymers. For example, the compatibility of polypropylene and nylon-6 is very poor, which cannot be mixed by mechanical force alone. At this time, if a little polypropylene has been grafted with maleic anhydride, due to the chemical reaction between maleic anhydride and the acylamine group of nylon-6, the compatibility of polypropylene and nylon-6 can be greatly improved. It is important to note that the desired modification effect can be achieved only when a heterogeneous system is formed which is not completely compatible and the two polymers are uniformly dispersed. Glass fiber is the main reinforcement material, which can significantly improve the tensile strength of PP plastics. The content of glass fiber is generally not more than 40%. It is generally believed that the modification effect can be achieved when the length of the fiber is greater than 0.2mm, and the effect is better when the diameter of the glass fiber is more than ten microns. When the content of glass fiber increases, the processing fluidity of reinforced PP decreases correspondingly, but it is still a plastic with good fluidity.
PP has food grade and industrial grade
(1)Food grade PP will not dissolve harmful substances under normal conditions and high temperature.
 (2) Industrial PP at room temperature or high temperature will dissolve harmful substances, harmful to human health, some used in food containers, a heat will have a very strong odor. 2. Generally speaking, PP manufacturers have produced food-grade PP(such as PC) with FDA certification, and non-food-grade specifications without FDA certification.
See the above introduction, when we buy this kind of products need to carefully observe the description of its material, what material is specific, this is so, in order to ensure our healthy life.
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