General thermoplastics can be divided into crystalline and amorphous. The appearance of crystalline plastic is translucent, milky or opaque. It is transparent only in the film state, and its hardness ranges from soft to horny. Amorphous is generally colorless, fully transparent when no additives are added, and its hardness is from hard to horny rubber (plasticizers and other additives are often added at this time). Thermosetting plastics usually contain fillers and are not transparent. If they do not contain fillers, they are transparent. The elastomer has a rubber like feel and a certain tensile rate. 2. Heating identification of plastics can be identified by heating. Thermoplastics soften when heated, melt easily, and become transparent when melted. They can often pull wires from the melt and are usually easy to heat seal. The thermosetting plastic shall be heated until the material is chemically decomposed, its original hardness shall not be softened, its size shall be relatively stable, and it shall be carbonized at the decomposition temperature. When the elastomer is heated, it will not flow until the chemical decomposition temperature, and the material will decompose and carbonize at the decomposition temperature. 3. Solvent treatment and identification of plastics thermoplastics will swell in solvents, but generally insoluble in cold solvents. In hot solvents, some thermoplastics will dissolve, such as polyethylene dissolved in xylene, thermosetting plastics insoluble in solvents, generally no swelling or only slight swelling, elastomers insoluble in solvents, but usually swelling. 4. the density of plastics is different from that of plastics. The density of plastics is different. The density can be used to identify plastics, but foam products should be separated at that time, because the density of foamed plastics is not the true density of materials. In the actual industry, there are also ways to sort plastics by using different densities of plastics. 5. Pyrolysis test identification of plastics pyrolysis test identification method is to heat the plastics to the pyrolysis temperature in the pyrolysis tube, and then test the pH value of the escaping gas with litmus test paper or pH test paper. 6. Combustion test identification of plastics the identification method of combustion test is to use a small fire to burn plastic samples, observe the flammability of plastics in and out of the fire, and pay attention to the drop form and smell of molten plastics after flameout to identify the types of plastics. However, at present, the most commonly used method in general factories is the appearance identification method, which depends on many years of experience. That is, try to use the stretch and visual sense of plastic, that is, transparency. The key is to distinguish the types first from the visual sensory transparency, such as the difference between BOPP material and PP material. Or the difference between PE materials. For example, BOPP material is obviously more transparent than PP material. If you can’t distinguish between the two senses, you can see the hand feeling of the two materials through touch, that is, BOPP material has a stronger hard feeling than PP material, that is, it has a sound when kneaded, and it is the kind you can hear. The PP material has a much better hand feel, is relatively soft, crumpled into a ball, and the tension is not obvious. It shows excellent tensile properties. Or pull the two materials apart to try the tensile property, and also check whether the two materials meet the requirements. We can distinguish LDPE and HDPE in PE material by one look, two touch and three pull. What should we pay attention to in plastic identification? First, we should keep the plastic from chemical action, especially with solvent treatment method and pyrolysis test method. Once the chemical action is carried out, the tested structure will change. If the plastic is soaked in water for a long time, the result will become loose, which will also affect the identification results. Therefore, the key to the accuracy of plastic identification is to see whether the inside or outside of the plastic is damaged. Suggestion: keep the integrity of plastics before identification. More attention should be paid to the chemistry of composite membrane.
Test methods for plastic materials: Polyethylene (PE), polypropylene (PP), polystyrene (PS), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), phenolic molding compound, polycarbonate (PC), polyurethane, polyamide (PA, also known as nylon), epoxy resin, ABS resin, polymethylmethacrylate (PMMA), polyethylene terephthalate (PET), polyarylene vinyl acetate copolymer (EVA), PPS plastic Detection range of acrylonitrile butadiene styrene (ABS) resin, CO formaldehyde resin, Polyamide 1010 resin, etc
detectable plastic products: plastic pipe products detection: foamed pipe, drainage pipe, agricultural pipe, PP pipe, PVC plastic pipe, double wall corrugated pipe, HDPE Double wall corrugated pipe, polypropylene copolymer polyethylene pipe, etc
plastic pipe products testing: VC-U pipe fittings, double wall corrugated pipe fittings, PVC-U pipe fittings, PVC pipe fittings, aluminum plastic pipes, porous pipe
plastic hose products detection:
oil hose, spray hose, welding hose, reinforced hose, hydraulic hose, internal combustion hose, compressed air soft tube
plastic packaging material testing:
packaging bags, packaging bottles, packaging boxes, plastic shell packaging, foam materials, Packaging labels, etc.
plastic film testing:
preservative film, packaging film, agricultural film, protective film, geotechnical film, air cushion film
medical plastic products testing:
syringes, infusion sets, filters, urine collection bags, sterile umbilical cord clips, disposable PVC gloves
other plastic products testing:
nylon ropes, nylon socks, fishing lines, ropes, plastic electrodes, plastic substrates, etc