PE can be manufactured by a wide range of different processing methods. With ethylene as the main raw material, propylene, 1-butene and hexene as the copolymer, slurry polymerization or gas-phase polymerization process is adopted under the action of catalyst. The polymer obtained will go through flash evaporation, separation, drying, granulation and other processes to obtain a finished product with uniform particles. It includes, for example, sheet extrusion, film extrusion, pipe or profile extrusion, blow molding, injection molding and rotational molding.
▲ Extrusion: grades used for extrusion production generally have melt index less than 1 and MWD of medium to wide width. During processing, low MI can obtain appropriate melt strength. Wider MWD grades are more suitable for extrusion because they have higher production speeds, lower die pressures, and reduced melt fracture trends.
PE has many extrusion applications, such as wires, cables, hoses, pipes and profiles. Pipe applications range from small section yellow pipes for natural gas to thick wall black pipes with a diameter of 48 inches for industrial and urban pipelines. The use of large-diameter hollow wall pipes as alternatives to rainwater drainage pipes made of concrete and other sewer pipelines is growing rapidly.
Plate and thermoforming: thermoforming lining of many large picnic type refrigerators is made of PE, which has toughness, light weight and durability. Other sheet and thermoformed products include mudguards, tank liners, pan shields, transport cases, and cans. A large number of sheet materials with rapid growth are applied in plastic film or pool bottom village, which is based on the toughness, chemical resistance and impermeability of MDPE.
▲ Blow molding: More than 1/3 of the HDPE sold in the United States is used for blow molding. These range from bottles of bleach, engine oil, detergent, milk and distilled water to large refrigerators, car fuel tanks and cans. The characteristics of blow molding grades, such as melt strength, ES-CR and toughness, are similar to those used for sheet and hot forming applications, so similar grades can be used.
Injection blow molding is usually used to make smaller containers (less than 16oz) for packaging drugs, shampoo and cosmetics. One of the advantages of this process is that the production bottle can be automatically de edged, without the need for post dressing steps like the general blow molding process. Although some narrow MWD grades are used to improve surface finish, medium to wide MWD grades are generally used.
▲ Injection molding: HDPE has countless applications, ranging from reusable thin-walled beverage cups to 5-gsl cans, and consumes 1/5 of domestic HDPE. The injection grade generally has a melt index of 5~10, and has a lower toughness fluidity grade and a higher workability fluidity grade. Uses include daily necessities and thin wall food packaging; Tough and durable food and paint cans; High resistance to environmental stress cracking applications, such as small engine fuel tanks and 90 gal garbage cans.
▲ Rotational molding: the materials processed by this method are generally crushed into powder, which is melted and flows in the thermal cycle. Two types of PE are used for rotational molding: general purpose PE and crosslinkable PE. The general grade MDPE/HDPE usually has a density range from 0.935 to 0.945g/CC, with a narrow MWD, which makes the product have high impact and minimum warpage, and its melt index range is generally 3-8. Higher MI grades are generally not applicable because they do not have the impact and environmental stress cracking resistance desired for roll molded products.
High performance roll molding applications utilize the unique properties of its chemically crosslinkable grade. These grades have good fluidity in the molding cycle, and then cross-linked to form their excellent resistance to environmental stress cracking and toughness. Wear resistance and weather resistance. Crosslinkable PE is suitable for large containers, ranging from 500 gal storage tanks for transporting various chemicals to 20000 gal agricultural storage tanks.
▲ Film: PE film is generally processed by ordinary film blowing or flat extrusion. Most PE is used for film, and general low density PE (LDPE) or linear low density PE (LLDPE) are available. HDPE film grade is generally used where superior tensile property and excellent impermeability are required. For example, HDPE film is commonly used in commodity bags, grocery bags and food packaging.
Plastic garbage can manufacturer Instructions for Plastic Barrel Shipping
1. Dangerous goods that can be shipped in plastic packaging barrels include: dangerous goods Class I: d ≤ 1.2: acetic acid (acetic acid, glacial acetic acid) acetic anhydride aniline cresol phenol hydrochloric acid (36%) crude oil diesel kerosene (lamp kerosene) petroleum solvent hydrofluoric acid (≤ 60%)
Class II: d>1.2: formic acid, silicic acid, hydrogen bromide solution, hydrogen iodide solution, chromic acid (30%), perchloric acid (≤ 50%), potassium hydroxide solution, sodium hydroxide solution, nitric acid (≤ 55%), sulfuric acid, waste sulfuric acid
Class III: d ≤ 1.2: propionic acid, acrylic acid, methacrylic acid, ammonia, aqueous solution, formaldehyde (≤ 35%), furfuryl alcohol, ethylene glycol, monoethyl ether, hypochlorite solution (≤ 16%), alkyl phenols (including C2-C8 homologues)
Class IV: d>1.2: ferric chloride phosphate alcohols (limited to Class II and III), such as methanol, ethanol (alcohol), propanol, butanol esters (limited to Class II and III), such as di-n-butyl phosphite ketones (limited to Class II and III), ethers (limited to Class II and III), fatty hydrocarbons (limited to Class II and III)
Non dangerous goods Dimethyl acetylsuccinate Ethoxyethyl phosphate Trimethylphenyl phosphate Polyacrylamide Polyamide Polyvinyl alcohol Polyethylene glycol Dibasic alcohol Ethylene glycol (Glycol) Diethylene glycol triethylene glycol methyl ethylene glycol butyl ethylene glycol propylene glycol glycerol glutaraldehyde higher aldehyde fatty acid polysiloxane ammonium sulfite solution ammonium thiosulfate solution sodium bisulfite solution adhesive antifreeze bleach disinfectant dispersant stabilizer plasticizer (DBP DOP) Emulsifier, demulsifier, suspending agent, fire extinguishing agent, foam inhibitor, acid invasion agent, wetting agent, industrial cleaning agent, leather additive, papermaking additive, textile additive, dyeing additive, harvest protector, fiber protector, fluorescent whitening agent, concrete additive, additive for building, casein additive, paste adhesive, concentrated fruit juice, betaine, spindle oil, lactic acid tannin tanning agent, latex dispersion medium, liquid dyeing Water based emulsion, paraffin emulsion, brake fluid, oil, liquid fertilizer, cosmetic raw material, triacontanol emulsion, sodium silicate (sodium silicate, sodium silicate), calcium dodecyl benzene sulfonate
2. Items that cannot be shipped in plastic packaging barrels include: dangerous goods requiring Class I packaging, such as fuming sulfuric acid, concentrated nitric acid with concentration above 55%, and fuming nitric acid. Benzene, toluene, xylene, chlorobenzene, gasoline, condensate, liquid ammonia, liquid chlorine, ethylene oxide, etc.
