1. CPE is a kind of saturated rubber, which has excellent heat-resistant oxygen aging, ozone aging, acid and alkali resistance, and chemical resistance.
2. CPE has general oil resistance. Among them, it has excellent resistance to ASTM No. 1 oil and ASTM No. 2 oil, which is equivalent to NBR; and it has excellent resistance to ASTM No. 3 oil, which is better than CR, and is equivalent to CSM.
3. CPE contains chlorine element, has excellent flame retardant performance, and has the characteristics of burning and dripping. It can be combined with antimony flame retardant, chlorinated paraffin, and Al(OH)3 in an appropriate ratio to obtain a flame retardant material with excellent flame retardancy and low cost.
4. CPE is non-toxic, does not contain heavy metals and PAHs, and it fully meets environmental protection requirements.
5. CPE has high filling performance and can be manufactured to meet various performance requirements. The processing performance of CPE is good, and the Mooney viscosity is available in a variety of grades between 50-100.
According to materials: PE is divided into LDPE, LLDPE and HDPE.
according to the production process is divided into: PE flat bag, ziplock bag, zipper bag, envelope bag, punching handbag, handle handbag, zipper bag, PE film.
1. PE flat bag is the simplest manufacturing process. After the film is blown by the machine, the bag is cut into a bag on the bag making machine, and the bottom is sealed.
2. The ziplock bag is equipped with a bone strip when the film is blown by the machine, which can be sealed manually. Unlike zipper bags, these two types of bags are generally easy to confuse.
3. The zipper bag is a bag made of PE film with 2 clip chains (this clip chain is separately produced). The two sides of the bag generally have relatively wide indentations, while the ziplock bag does not. Ziplock bags have few printing colors, while zipper bags can print complex patterns.
4. The envelope bag has a tongue like an envelope. A strip of glue is attached to the tongue, which can be folded to seal the bag. General clothing is used more. There is also a courier bag which is actually a kind of envelope bag.
5. The punching tote bag is to punch a hole at the top of the flat pocket to facilitate the lifting of the bag.
6. The handle bag is to add a plastic film strip on the top of the bag to facilitate the lifting of the bag. This process consumes labor and is relatively expensive.
7. The zipper bag is to install a zipper strip and a zipper cap on the sealing part of the bag.
8. PE film is the film that is not made into a bag after being blown out by the machine. It is also divided into stretch film and shrink film.
Commonly used in the market are counted by one and counted by length (roll). (A) The small bag is mainly used for the packaging of small accessories, electronic products
Most of the accessory bags of the products have anti-static effect, and the mouth of the bag is divided into flat mouth and self-sealing structure. The latter is also called bone bag (PE bone bag) or compact bag;
(Roll) bags need to be cut by themselves (for material packaging) and printed cuts (for supermarkets).
In addition, the cling film made of PE material can also be called a PE bag. Note that the cling film directly in contact with food must be made of PE material (the other is generally PVC), which is safer for the human body. Resolution method: The transparency, stretchability and viscosity of PVC cling film are stronger than PE cling film. When the PVC cling film is burned with fire, the flame will turn black, emit black smoke, have a pungent smell, will not drip oil, and will automatically go out after leaving the fire source. When the PE cling film burns, the flame is yellow, odorless, dripping oil, and can continue to burn after leaving the fire source.
Heat shrinkable film is mainly used for labels, heat shrinkable packaging or stretch film. The polymer resins suitable for preparing heat shrinkable film mainly include PVC, PE, PS, PET, etc. After the film is preheated, it is stretched, cooled and shaped (as long as it is not subjected to heat-setting treatment) to obtain a heat shrinkable film. Under the Tf close to the resin, the resin cast sheet is stretched in the transverse and longitudinal directions, and then quenched, so that the resin molecular chains are frozen in an oriented state, forming a heat shrinkable film. It is a process of entropy reduction from the raw material to the production of heat shrinkable film. The thermodynamic state of heat shrinkable film is unstable. When the shrinkable film is heat-treated, the oriented molecular chains will quickly return to random coils (curved state). , The film shrinks. This feature of the heat shrinkable film can be used to prepare labels for special-shaped bottles.
From the perspective of functional requirements, heat-shrinkable sleeve labels have the characteristics of moisture-proof, anti-corrosion, impact-resistant, tear-resistant, odorless and non-toxic; they can play a role in anti-counterfeiting; protect consumers from damage or rupture of the container. accidental damage. The most important thing is that this label can be recycled, which has significant advantages in saving costs and protecting the environment. However, there are also many difficulties in the design process of heat shrinkable sleeve labels.
When producing heat-shrinkable sleeve labels, the most widely used film material in the market is PVC heat-shrinkable film. This kind of film has many advantages such as waterproof, fire resistance, high transparency, high gloss, high shrinkage rate, etc., but the material is prone to produce toxic gas when burned, which is not conducive to environmental protection. As a new material, OPS heat shrinkable film is a kind of skin packaging material that meets environmental protection requirements. It has many advantages such as high strength, high rigidity, good gloss, high shrinkage, and compliance with food hygiene standards. However, due to the current market There are not many companies that produce this film in Shanghai, and they cannot fully meet the market demand for this film.
For the ink, the quality of the ink directly affects the printing effect of the heat shrinkable sleeve label. Practice has proved that UV flexo printing ink is a very good choice, and its biggest advantage is that it can achieve higher color strength through curing and drying, which also brings great challenges to traditional gravure inks.
PE is polyethylene plastic, which can be made into plastic film, plastic bag, etc. In order to reduce white pollution, a degradation agent can be added to the plastic to achieve rapid degradation. This type of polyethylene is called environmentally friendly plastic.
Polyethylene is odorless, non-toxic, feels like wax, has excellent low temperature resistance (the lowest temperature can reach -100~-70°C), has good chemical stability, and can withstand most acids and alkalis (not resistant to oxidation) Nature of acid). It is insoluble in general solvents at room temperature, has low water absorption and excellent electrical insulation.
The performance of polyethylene depends on its polymerization method. High-density polyethylene (HDPE) is produced by Ziegler-Natta polymerization under medium pressure (15-30 atmospheres) organic compound catalyzed conditions. Under this condition, the polymerized polyethylene molecule is linear, and the molecular chain is very long, and the molecular weight is as high as hundreds of thousands.
In recent years, with the rapid increase in the popularity of online shopping, express packaging has become more and more "high-end and high-end." It was learned from the Provincial Postal Administration on March 4 that the province will guide express companies to promote the use of recyclable packaging materials such as degradable tapes, and encourage users to pack appropriately and reduce express packaging waste.
"An extra layer of packaging means an extra layer of protection. For more delicate commodities such as glass products and tablet computers, at least four layers are required. The first layer is the packaging of the product itself, the second layer is bubble film, and the third layer is The carton is wrapped with a courier bag, and at the end it has to be wrapped with several circles of tape." A shopkeeper who sells craft wine glasses on Taobao said that the multi-layer packaging is mainly to prevent the items from breaking. In fact, in addition to worrying about damage to the goods, e-commerce companies have another important consideration. Because as an online seller, customer evaluation is very important, and because of this, many sellers know that excessive packaging will inevitably lead to increased costs, but in order to avoid negative reviews from customers, they have to bite the bullet and work hard on packaging.
Every year, packaging materials used for online shopping not only cause huge waste, but also cause environmental pollution problems. Take the transparent tape used for e-commerce packaging as an example. It is understood that the main raw material of this tape is polyvinyl chloride, which is commonly referred to as PVC. "It takes at least 100 years for waste PVC to decompose naturally in the soil." An associate professor from the Department of Chemistry of Shanxi University pointed out that the large-scale use of disposable PVC products will cause serious damage to the natural environment. The tape contains formaldehyde and benzene, which can harm people. Skin and respiratory tract.
To this end, a person from the Provincial Postal Administration said that in the future, the management of recycling and disposal of packaging waste will be strengthened. Among them, enterprises will be encouraged to renovate and update technology and equipment, and develop and promote the use of biodegradable tapes, environmentally friendly fillers, renewable paper and packaging supplies printed with environmentally friendly inks and other materials. (Qi Xiangzhen)
PE shrink film has played a big role in the heat shrink film industry, without pe shrink film, it will lose a certain market share. Because of its performance, it is trusted and used by a large number of users, and it has been adopted by all walks of life.
The main function of pe shrink film is puncture resistance, good self-adhesiveness, high transparency, tear resistance, good shrinkage, and good toughness. In addition, it is important to reduce costs for us.
In fact, PE shrink film is an early research and development product, which has already gained importance in the market. According to empirical analysis, furniture factories, hardware factories and electronics factories are all its main users. For example, furniture factories' seats, wheels and other parts are all packaged with it, and every piece of goods in hardware factories is also used for electronics. The factory's electronic components or mobile phones are the same, because the thickness can be made very thick, and the product is well packaged to avoid damage. So far, China's PE shrink film usage is quite large.
In view of the entire market, the existence of PE shrink film can be described as indispensable, and all walks of life are interdependent.