First, PP is an environmentally friendly material. Seco […]
First, PP is an environmentally friendly material.
Second, the difference between PP sheet and PVC sheet can be clearly distinguished from the appearance and feel;
PP feels hard and PVC is relatively soft. The best test method is to burn these two materials with an open flame. The black dust is PVC and PP is not. It can also be distinguished from the smell, PVC has a choking smell, while PP is odorless.
The monomers of PVC (polyvinyl chloride) and PP (polypropylene) are different.
Identification by combustion identification method:
PP is easy to burn, melt and drip, and the burning flame state is less yellow and blue smoke. It continues to burn after fire, and the smell of petroleum.
PVC is difficult to burn, melts and softens, and the flame state is yellow, green and green with smoke, extinguished from the fire, and irritating sourness.
PP A thermoplastic resin produced by the polymerization of propylene. There are three configurations: isotactic, non-regular and inter-regular, and industrial products use isotactic as the main component. Polypropylene also includes copolymers of propylene and a small amount of ethylene. Usually a translucent colorless solid, odorless and non-toxic. Due to the regular structure and high crystallization, the melting point is as high as 167 ℃, heat resistance, products can be steam sterilized is its outstanding advantage. With a density of 0.90g/cm3, it is the lightest general-purpose plastic. Corrosion resistance, tensile strength 30MPa, strength, rigidity and transparency are better than polyethylene. The disadvantage is that the low temperature impact resistance is poor, and it is easier to age, but it can be overcome by modification and addition of antioxidants.
Non-toxic, odorless, low density, strength, stiffness, hardness and heat resistance are better than low-pressure polyethylene. It can be used at about 100 degrees. It has good electrical properties and high-frequency insulation is not affected by humidity, but it becomes brittle at low temperatures. Not wear-resistant, easy to age. Suitable for general mechanical parts, corrosion-resistant parts and insulation parts. Common acid and alkali organic solvents have almost no effect on it and can be used in tableware.
Combustion characteristics: It is flammable and will continue to burn after leaving the fire. The upper end of the fire is yellow, the lower end is blue, and there is a small amount of black smoke. When burning, it will drip and dissolve. It will emit a petroleum smell. The injection temperature is 190-240.
PVC is one of the largest plastic products in the world. It is cheap and widely used. Polyvinyl chloride resin is white or light yellow powder. Different additives can be added according to different uses, and PVC plastics can exhibit different physical and mechanical properties. Adding an appropriate amount of plasticizer to PVC resin can make a variety of hard, soft and transparent products.
The density of pure PVC is 1.4g/cm3, and the density of PVC plastic parts with plasticizers and fillers is generally 1.15-2.00g/cm3.
Rigid PVC has good tensile, bending, compression and impact resistance, and can be used alone as a structural material.
Soft PVC will increase in flexibility, elongation at break, and cold resistance, but brittleness, hardness, and tensile strength will decrease.
Polyvinyl chloride has good electrical insulation properties, can be used as low-frequency insulation materials, and its chemical stability is also good. Due to the poor thermal stability of polyvinyl chloride, long-term heating will cause decomposition, release HCL gas, and change the color of polyvinyl chloride. Therefore, its application range is narrow, and the use temperature is generally between 15 and 55 degrees.
PVC is difficult to burn and extinguishes from the fire, but when burning, the upper end of the fire is yellow, the lower end is green, and there is white smoke. When burning, the rubber is soft and emits a pungent odor of hydrochloric acid. PVC is slightly poisonous, but there are also food-grade PVC . English abbreviation for PVC. There are two kinds of hard and soft.
There are two types of toxic and non-toxic. The hard plastic used in family life is basically PVC. Such as water pipes, wire sheaths. PP polypropylene. Plastic carbonated beverage bottles are PP (Coke) can withstand a little pressure. In addition, there is a tool case with the bottom and cover integrated, which can be opened and closed repeatedly without hinges. This material must be PP.