How to distinguish plastic raw materials
Due to the limitation of factory conditions, analysis of laboratory instruments and not available, only with the appearance of recognition. The preliminary judgment of different plastics by the combustion method, need certain experience and long-term contact. But there are also limitations, such as a workpiece by several materials, to increase the recognition of appearance of great difficulty, it is difficult to identify the combustion method from a variety of combustion to distinguish contained plastic material characteristics, smell.
Here are several commonly used methods of identification of materials:
Appearance identification method
(a) PE, PP and PA have different bent, hands touch hard wax like creamy, when struck with a soft cutin voice. Compared with ABS, PC, PS, PMMA, etc., no extension, hand touch has just struck a sexy, crisp sound.
(two) the relative density of PE and PP is less than 1, so it floats in water, and most of the other plastics are more than 1, so it sinks in water
(three) in the dyeing, LDPE plastic particles, milky white Guan transparent, soft, soft and tough, slightly elongated, easy to bite teeth deformation of.HDPE is milky white, opaque, hard texture, late extension, with the teeth call.PP deformable white translucent, high transparency and PE lighter, more rigid, extremely difficult to bite with teeth deformation.
(four) the difference between PS and HIPS and ABS are PS HIPS and ABS is brittle, ductile, so when it is bent PS brittle. Both are difficult to break, in the bending part. In the pale before dyeing is very easy to identify; PS HIPS ABS transparent, milky white, pale ivory.
Two, combustion observation
Different materials have different combustion behaviors in combustion, such as flame color and smell (in actual machining process because the plastic heat degradation will also have a taste of low molecular characteristics), basic method which is also commonly used identification materials.