Plastic packaging materials performance characteristics
Advantages list
Good physical and mechanical properties
Good barrier
Excellent chemical resistance
Good processing adaptability
Disadvantages cited
Strength is not as good as steel
Heat resistance less than metal and glass
Part of the plastic containing toxic monomers
Easy to bring static electricity
Disposal of waste is difficult
Packaging common plastic and its performance
1, low-density polyethylene (LDPE, LLDPE)
Polyethylene is a white waxy solid, translucent, almost tasteless and non-toxic Polyethylene macromolecule chains have good flexibility and are easy to crystallize. Polyethylene is composed of partially crystalline and partially amorphous at high elastic state at room temperature .
LDPE
Performance characteristics
Low-density polyethylene processing performance, good transparency, but poor air tightness, low tensile strength, heat resistance and temperature is not high, chemical resistance, solvent resistance and high-density polyethylene, and Easy to absorb grease swelling, so that products sticky.
The scope of application
Blow molded bottles, squeeze hoses for condiments, medicines and other packaging; caps, corks and other container accessories; a variety of packaging films, containers and foam cushioning materials.
LLDPE
Performance characteristics
Impact resistance and stress cracking resistance are similar to HDPE, while transparency, hardness and processability are between HDL and LLDPE. Elongation and puncture resistance are among the best in all types of polyethylene .
applicability
Particularly suitable as a packaging film, the thickness of thinner than the low-density polyethylene 20%, is a promising plastic packaging materials.
2, high density polyethylene (HDPE) high density polyethylene
Performance characteristics
Strength, heat resistance, the maximum temperature up to 120 ℃, transparency, flexibility and poor processing performance, poor gas barrier, low gloss, surface treatment before printing.
The scope of application
Containers, trays, large barrels for the turnover of milk, chemical products, packaging, bottles with yogurt, detergent bleach packaging, caps, stoppers and other container accessories.
3, foam polyethylene-EPE (commonly known as pearl cotton)
Divided into sheets, plates, tubes, bars and their segmentation slice shape.
The scope of application
Widely applicable packaging any shape of goods, especially electronic products such as: computers, TVs, audio, speakers and other types of electrical anti-static buffer packaging. EPE is environmentally friendly, characterized by good elasticity, toughness. Can also create life jackets, floating Boards, travel bags, hats and more.
4, polypropylene (PP) polypropylene
Performance characteristics
Polypropylene is the lightest general-purpose plastic, its heat resistance is the highest in general-purpose plastic, long-term use at 100 ℃ ~ 120 ℃. High crystallinity, tensile strength and hardness are better than polyethylene, moisture resistance , Water resistance and good peculiar smell transmission, heat sealing, excellent bending fatigue resistance, capable of using acid, alkali, salt solution and most organic solvents such as polypropylene packing under 80 ℃ characteristic.
Cold resistance, poor aging resistance, poor air tightness, unsuitable for use at low temperatures, and susceptible to light, oxygen, adhesive or printing must be surface-treated.
The scope of application
Widely used in the production of food, chemical products, cosmetics, food and beverage, beer and other containers, blow bottles for shampoo, cosmetics and other packaging, screw caps or with hinged packaging, woven bags and packaging films, packing tape and Foam cushioning material and so on.
5, polystyrene (PS)
Performance characteristics
Colorless and transparent, odorless and non-toxic, good coloring and printing, low water absorption, good dimensional stability, rigid and non-ductile.Resistant to organic acids, alkalis, salts, lower alcohols and their aqueous solution, low impact strength, Surface hardness is small, easy to scratch and scratch; Moisture resistance, heat resistance is poor, vulnerable to many hydrocarbons, ketones, fatty acids and other split and softened.
The scope of application
Widely used in the production of food, medicine and daily necessities and other small packaging containers, such as boxes, cups, etc., and food packaging films. In addition, a large number for the production of foam cushioning materials, etc., for instruments, meters, electrical products Shockproof package and so on.
6, polyvinyl chloride (PVC)
Performance characteristics
Good rigidity and hardness, poor heat resistance, transparency of up to 76% to 82%. Mechanical strength, wear resistance, excellent pressure resistance, moisture resistance, water resistance and air tightness, good heat sealing. Combustible. Resistance to acid, alkali and non-polar solvents, vulnerable to the erosion of polar organic solvents, containing toxic vinyl chloride monomer, and used plasticizers, stabilizers and other toxic substances are mostly used in food And pharmaceutical packaging of PVC should be non-toxic additives, and the provisions of vinyl chloride monomer content does not exceed 1ppm.
The scope of application
Made of rigid packaging containers, transparent sheets and flexible packaging films. Polyvinyl chloride transparent sheet thermoformed into a variety of packaging containers, a large number for the food and pharmaceutical packaging. In addition, polyethylene can also be made of foam And cushioning material.
7, polyethylene terephthalate (PET)
Performance characteristics
Mechanical strength is very good, better hardness, wear resistance and folding resistance, heat resistance, cold resistance is good, with good moisture resistance, air tightness and excellent pest control to prevent the weak acid, weak base And most solvents, good oil resistance, suitable for printing, intolerant alkali, acid, chlorinated hydrocarbons etc also have its erosion; easy to bring static electricity, and there is no proper method to prevent static electricity, poor heat sealing performance ;Expensive.
The scope of application
Mainly used in the production of packaging containers and films, polyester film is suitable for the packaging of frozen food and cooking food due to its good air-tightness, heat resistance and cold resistance, while PET bottles are widely used in the packaging of beverages.
8, polyvinylidene chloride (PVDC)
Performance characteristics
Light brown with slightly tough material, strong crystallinity, water vapor, gas permeability has a very good air tightness and moisture resistance. Polyvinylidene chloride mechanical strength is good, resistant to acid, alkali And organic solvents, excellent oil resistance, self-adhesive, difficult to burn and with self-ignitability, aging resistance is poor, easily affected by ultraviolet light, easy decomposition of hydrogen, the monomer is also toxic.So for the food packaging should strictly control the quality standards .
9, polyamide (PA)
Performance characteristics
Tough, less transparent keratinous material, tasteless and non-toxic, when burning burning smell of wool.
High crystallinity, high melting point, oil resistance, resistance to common solvents, excellent mechanical properties, expansive strength and impact strength are obviously better than those of ordinary plastics, good abrasion resistance, self-lubricating property, high flexural fatigue strength, Low temperature resistance is good, but the high temperature stability is poor. Gas-tight than polyethylene, polypropylene, alkali and acid, no static, good printing performance. Strong water absorption, moisture permeability, dimensional stability under high temperature conditions Poor sex, after absorbing a sharp decline in air tightness, nylon are not resistant to formic acid, phenol and alcohols, concentrated alkali also has its erosion.
The scope of application
Mainly used for food packaging, especially for greasy food packaging.Nylon containers are also commonly used in chemical reagents and other packaging.
10, polyvinyl alcohol (PVA)
Performance characteristics
Generally does not have water resistance, but after heat treatment, aldehyde treatment or the use of appropriate organic molecules such as cross-linking between molecular chains and other methods, it can have water resistance. With good transparency and toughness, odorless non-toxic, with excellent gas-tight Sexual and balsamic, with good mechanical strength, excellent resistance to stress cracking, chemical resistance and oil resistance, without static electricity, good printing performance, and has heat-sealable. Water absorption, moisture permeability, Ease of alcohol, esters and other solvents erosion.
The scope of application
For food packaging, water-based polyvinyl alcohol can be used for the measurement of chemical packaging.
11, ethylene - vinyl acetate copolymer (EVA)
Performance characteristics
Resistance to stress cracking resistance, cold resistance, aging resistance and low temperature heat are better than polyethylene, resistant to alkali, weak acid erosion, the film is poor slippery, easy to adhesion; moisture-proof lower density polyethylene poor, and airtight Poor sex; poor heat resistance; vulnerable to strong acid and other organic solvents erosion, soluble in aromatic or hydrocarbon generation; poor oil resistance.
The scope of application
Because of its good elasticity, it is suitable for wrapping wrapping of trays.It is often used as a sealing layer of composite films because of its excellent low temperature heat sealability and is also used for packaging containers for medicines and foodstuffs.
12, polycarbonate (PC)
Performance characteristics
Colorless, transparent as high as 80% to 90%, refractive index of about 1.59, suitable for optical materials, has good moisture resistance and air tightness, excellent fragrance and heat-resistant, cold resistance, with outstanding impact toughness , Unnotched impact strength is the highest in the thermoplastics molding shrinkage is small, low water absorption, with good dimensional stability, without static electricity, excellent insulation properties, ability to dilute acids, oxidants, reducing agents, salts, aliphatic hydrocarbons, etc. , Good oil resistance. Easy to produce stress cracking phenomenon; bending fatigue strength is poor; poor heat sealing; not alkali, ketones, aromatic hydrocarbons, in many organic solvents steaming swelling and lead to stress cracking.
The scope of application
Mainly used for electrical insulation materials, mainly used in food packaging packaging, good abrasion resistance, suitable for hardware, there are sharp items of packaging.
13, polyurethane (PU)
Performance characteristics
Excellent flexibility to meet the requirements of density, flexibility, elongation and compressive strength, chemical stability, resistance to many solvents and oils, abrasion resistance than natural sponge 20 times, excellent insulation, noise, shock and Bonding, higher prices.
applicability
Shock-proof packaging or cushioning cushioning materials for precision instruments, expensive equipment, handicrafts, etc.
14, Bakelite (PF)
Performance characteristics
High mechanical strength, wear resistance and excellent electrical insulation properties, high temperature resistance, not easy to deformation, resistance to some dilute acid, good oil resistance, poor flexibility, brittle, dark products, mostly black or brown , Can not get colorless products, alkali and oxidizing acid can make it decompose, with micro-toxicity.
The scope of application
Widely used as electrical insulation materials in the packaging of its application is mainly used to make caps, boxes and chemical containers for acid-proof containers made of phenolic plastic cap, cap machine can withstand the torque and long-term Keep sealed without loosening.
15, Urea formaldehyde plastic (UF)
Performance characteristics
Surface hardness, good gloss and suitable translucency, good colorability, can make a variety of good appearance and bright colors of the product, not easy to absorb dust, with good electrical insulation, chemical stability, not with any Organic solvent effect, excellent grease resistance, poor water resistance, easy to water deformation, can not be steam sterilized, impact strength is also a slight lack of alkali and acid erosion.
The scope of application
For making exquisite packaging, cosmetic containers and caps, etc. Because of acetic acid or 100 ℃ boiling water immersion, there is free of toxic formaldehyde precipitation, it is not suitable for packaging food.
16, melamine plastic (MF)
Performance characteristics
High strength, not easy to deform, the surface is smooth and hard, looks like ceramic, odorless, non-toxic, good coloring, can be made into various colorful products.Heat resistance, water resistance, resistance to boiling water, acid, alkali, .
The scope of application
The price is better, more for the production of food containers, can also be used to make exquisite food packaging containers.
17, PVC heat shrinkable film
PVC heat shrinkable film, sub-ordinary packaging film, color film two.
Ordinary packaging film: suitable for all kinds of product packaging and packaging. The product features: transparency, shrinkage rate, easy to operate.
Packaging products can be sealed moisture-proof, insulated, bright, sturdy, beautiful color film, in addition to a variety of color printing labels, but also for product bottles, box packaging rotary body sealing heat seal.
18, POF shrink film
POF shrink bags environmental protection, longitudinal, horizontal contraction effect, mainly for gifts, stationery, hardware and other lighter items shrink packaging.
19, PET shrink film
It is internationally recognized as 'eco-friendly' heat-shrinkable packaging material and is manufactured using 'polyester resin chips'. Its technical specifications, physical properties, application range and method of application are close to 'PVC' heat shrinkable film.
With people's awareness of environmental protection, domestic products gradually to the needs of the international market, the current 'PET' shrink film is the best alternative 'PVC' packaging materials.
20, PE shrink film
PE heat shrinkable film divided into simple type, monolithic type, suitable for all types of products fully automatic packaging machine combination. The product features: toughness, not damaged, can replace carton packaging.