stability against heat and light, and therefore, stabilizers shall be added therein to avoid discoloration or decomposition upon the materials' being processed into finished products. Various stabilizers are available, including metal soap and organic tin compounds and they fall into such types as transparent, opaque, soft and hard ones. The processing temperature of soft PVC is 70C-100 C. Hard PVC requires less time for processing, yet the temperature therewith must rise to approximately 150C. Due to its low fluidity during fusion, hard PVC tends to be more difficult to be injected and molded than polystyrene(PS). However, even without intensifier, hard PvC still boasts a pretty high mechanical intensity; it is also sound in electric insulation, acid resistance kali resistance as well as water resistance; moreover, it is transparent and can be colored freely and processed effectively. Soft PVC is endowed with sound plasticity and hence is inferior to hard PVC in the aforementioned properties, yet it can be made into soft membranes or thin plates. The softening temperature whereof is approximately 80C and the decomposition temperature is round273℃ PVC, with such shortcoming as weak heat resistance capacity, will soften promptly under the temperature of 65C-80C and can decompose easily under high temperature PVC can be used to make tablecloth, packing membranes, vehicle curtains, briefcases handbags and chemical shoes etc. Its glue film can absorb ultraviolet radiation and therefore embodies sound thermal insulation property. Hard PVC can be applied to such fields watercourse piping, chemical plant piping, building materials, signboards, telephones, electric parts as well as drug-proof apparatus etc 2. Polystyrene(PS)Resin The composite ethylene gas made from benzene(adopted from coal tar or petroleum) and ethylene gas, is dehydrogenated by metal oxide catalyzer heated to 600C into styrene monomer which is then catalyzed and aggregated into polystyrene resin through such catalyzer as inorganic or organic peroxide The polystyrene resin in the market is colorless and transparent, hard and slightly crispy, with an average molecular weight of 70 thousand -100 thousand. It is excellent in water resistance and electric insulation and can fight against erosion from strong acid or alkali, yet it is devoid of resistance against organic solvent and oil and is weak in heat resistance. Another important feature of polystyrene resin is that it is endowed with sound thermal stability and fluidity in fusing resin, and thereby can be molded very well. Though a bit crispy, the PS can be colored freely. High impact polystyrene(HIPS)resin is obtained by adding butadiene and styrene copolymerized rubber in styrene resin, wherein the two substances are in several hierarchies respectively; in addition, ultraviolet radiation absorbent or antioxidant can be added therein to improve lightfastness and also fiberglass is sometimes added into the basal material to increase PS caters to the transparency and color tone of modern visual beauty. It can be extensivel applied to the manufacturing of table articles like bread boxes and beef oil cans, commodity containers, toys, fruit dishes, toothbrushes, handles of brushes, soapboxes as well as flavoring containers etc 3. ABS Resin and As resin The aggregation of styrene monomer, acrylonitrile monomer and butadiene rubber can produce a polymer(ABS)constituted by acrylonitrile(A), butadiene rubber(B)and styrene(s)instability against heat and light, and therefore, stabilizers shall be added therein to avoid discoloration or decomposition upon the materials’ being processed into finished products. Various stabilizers are available, including metal soap and organic tin compounds and they fall into such types as transparent, opaque, soft and hard ones. The processing temperature of soft PVC is 70℃-100 ℃. Hard PVC requires less time for processing, yet the temperature therewith must rise to approximately 150℃. Due to its low fluidity during fusion, hard PVC tends to be more difficult to be injected and molded than polystyrene (PS). However, even without intensifier, hard PVC still boasts a pretty high mechanical intensity; it is also sound in electric insulation, acid resistance, alkali resistance as well as water resistance; moreover, it is transparent and can be colored freely and processed effectively. Soft PVC is endowed with sound plasticity and hence is inferior to hard PVC in the aforementioned properties, yet it can be made into soft membranes or thin plates. The softening temperature whereof is approximately 80 and ℃ the decomposition temperature is around 273 . ℃ PVC, with such shortcoming as weak heat resistance capacity, will soften promptly under the temperature of 65℃~80℃ and can decompose easily under high temperature. PVC can be used to make tablecloth, packing membranes, vehicle curtains, briefcases, handbags and chemical shoes etc. Its glue film can absorb ultraviolet radiation and therefore embodies sound thermal insulation property. Hard PVC can be applied to such fields as watercourse piping, chemical plant piping, building materials, signboards, telephones, electric parts as well as drug-proof apparatus etc. 2. Polystyrene (PS) Resin The composite ethylene gas made from benzene (adopted from coal tar or petroleum) and ethylene gas, is dehydrogenated by metal oxide catalyzer heated to 600℃ into styrene monomer, which is then catalyzed and aggregated into polystyrene resin through such catalyzer as inorganic or organic peroxide。The polystyrene resin in the market is colorless and transparent, hard and slightly crispy, with an average molecular weight of 70 thousand ~100 thousand. It is excellent in water resistance and electric insulation and can fight against erosion from strong acid or alkali, yet it is devoid of resistance against organic solvent and oil and is weak in heat resistance. Another important feature of polystyrene resin is that it is endowed with sound thermal stability and fluidity in fusing resin, and thereby can be molded very well. Though a bit crispy, the PS can be colored freely. High impact polystyrene (HIPS) resin is obtained by adding butadiene and styrene copolymerized rubber in styrene resin, wherein the two substances are in several hierarchies respectively; in addition, ultraviolet radiation absorbent or antioxidant can be added therein to improve lightfastness and also fiberglass is sometimes added into the basal material to increase intensity. PS caters to the transparency and color tone of modern visual beauty. It can be extensively applied to the manufacturing of table articles like bread boxes and beef oil cans, commodity containers, toys, fruit dishes, toothbrushes, handles of brushes, soapboxes as well as flavoring containers etc. 3. ABS Resin and AS Resin The aggregation of styrene monomer, acrylonitrile monomer and butadiene rubber can produce a polymer (ABS) constituted by acrylonitrile (A), butadiene rubber (B) and styrene (S) in