Introduction to Stretch Film
Let me introduction to Stretch film. also known as Wrap film and heat shrinkable film, is the foremost PVC stretch film produced in China with PVC as the base material. DOA as the plasticizer, and tone-tenacious function. Due to environmental protection issues, high cost( compared with PE, larger proportion, lower unit packaging area), poor stretchability, and other reasons, the product of PE stretch film in my country was gradationally excluded in 1994- 1995. PE stretch film first used EVA as tone- tenacious material, but its cost is high and tasteful.
Latterly, PIB, and VLDPE were used as tone-tenacious accouterments, and the base material was substantially LLDPE, including C4, C6, C8, and metallocene PE( MPE).
Early LLDPE stretch flicks were substantially blown flicks, ranging from single subcaste to two layers and three layers; LLDPE stretch flicks were substantially produced by the casting system because the product of the casting line has the advantages of invariant consistency and high translucency, which can be applied to high- exaggeration-stretching conditions. Since single-subcaste casting can not achieve single-sided lamination, the operation field is limited. Single-subcaste and double-subcaste casting isn’t as wide as three-subcaste casting in terms of material selection, and the expression cost is also high, so the three- subcaste-extrusion structure is more ideal. A high-quality stretch film should have the characteristics of high translucency, high longitudinal extension, high yield point, high transverse gash strength, and good perforation performance.
Editing and broadcasting of product
It’s produced by imported direct polyethylene LLDPE resin and tackifier with a special addition rate. It can produce a multi-functional stretch film for hand use, resistance machine use,pre-stretch machine use,anti-ultraviolet,anti-static, and anti-rust. It has the following advantages.
1. Using a double- subcaste-extrusion outfit, the extruded stretch film can maximize the characteristics of each polymer, and its translucency, tensile strength, and perforation resistance reach the stylish when it reaches the melting point. state.
2. Good tensile performance, good translucency, and invariant consistency.
3. It has a longitudinal extension, good adaptability, good transverse gash resistance, and good tone- tenacious imbrication.
4. It’s an environmentally friendly and recyclable material, tasteless and non-toxic, and can be packaged and eaten directly.
5. It can produce single-sided tenacious products, reduce the noise generated during winding and stretching, and reduce the dust and beach during transportation and storehouse.
Good adhesion makes the external packaging film and subcaste of the goods stick together, making the establishment of the good. There are two main ways to gain density one is to add PIB or its masterbatch to the polymer; the other is to mix VLDPE. PIB is a translucent thick liquid, direct addition requires a special outfit or outfit revision, and PIB masterbatch is generally used. PIB junking is a process that generally takes three days. In addition, it’s also affected by temperature. When the temperature is high, the density is strong; when the temperature is low, it isn’t too sticky, and the density is greatly reduced after stretching. thus, the finished film is stylishly stored within a certain temperature range( recommended storehouse temperature is 15 °C to 25 °C).
Blended with VLDPE, the density is slightly lower, but there’s no special demand for the outfit. density is fairly stable, not controlled by time, but also affected by temperature. It’s further thick when the temperature is advanced than 30 °C, and slightly lower thick when the temperature is lower than 15 °C. The needed density can be achieved by conforming to the quantum of LLDPE in the tenacious sub-caste. Three- subcaste-extrusion substantially adopts this system.
Control of physical and mechanical parcels
High translucency is conducive to the identification of goods; high longitudinal extension is conducive to-stretching and saves material consumption; good perforation performance and transverse gash strength allow the film to meet sharp corners or The edge doesn’t break; the high yield point makes the packaged goods more secure.
The film produced by the casting system has high translucency, which won’t be bandied then. As the number of C titles in the material comonomer increases, the length of the branch chain increases, the degree of crystallinity diminishments, and the” winding or kink” effect of the performing copolymer increase, so the extension increases and the perforation strength and gash strength also increase. MPE is a largely stereoregular polymer with a narrow molecular weight distribution, which can directly control the physical parcels of the polymer, so the performance is further bettered; and because of the narrow molecular weight distribution of MPE, the processing range is also narrow, and the processing conditions are delicate to control. Add 5 LDPE to reduce the melt density and increase the flatness of the film.
The price of MPE is also high.
In order to reduce the cost, MPE is generally used together with C4- LLDPE, but not all C4- LLDPE can be matched with it, so it should be named. Machine stretch film substantially adopts C6 and C8 accouterments, which are easy to reuse and can meet colorful packaging conditions. Due to the low stretching rate of homemade packaging, C4 materials are substantially used.
Material viscosity also affects film performance.
As the viscosity increases, the degree of exposure increases, the flatness is good, the longitudinal extension increases, and the yield strength increases, but the transverse gash strength, perforation strength, and light transmittance all drop. Add an applicable quantum of medium viscosity direct polyethylene( LMDPE) to the sub-caste. Adding LMDPE can also reduce the disunion measure of the-adhesive subcaste and avoid the adhesion of the packaged charger to the charger.
Influence of cooling roll temperature.
As the temperature of the cooling roll rises, the yield strength increases, but other parcels drop. thus, it’s generally judicious to control the temperature of the cooling roll I at 20 °C to 30 °C. The pressure of the casting line affects the flatness and winding miserliness of the film. However, it’ll also affect the migration of PIB and reduce the final density of the film, If PIB or its masterbatch is used as the tenacious sub caste. The pressure is generally not further than 10 kg. Too important stress remains in the film roll, which reduces the extension and other parcels and fluently causes film breakage.
Operation form of stretch film
Stretch film has a wide range of operations, substantially used in confluence with pallets to package scattered goods as a whole, rather of smallholders. Because it can reduce the cost of bulk weight transportation and packaging by further than 30, it’s extensively used in the packaging of colorful products similar as tackle, minerals, chemicals, drugs, food, ministry, etc.; in the field of the storehouse, it’s also extensively used abroad. Stretch stretch film charger packaging for three-dimensional storehouses and transportation to save space and land occupation.
Form of use
1. Sealed packaging
This kind of packaging is analogous to shrink film packaging, the film is wrapped around the charger to fully wrap the charger, and also two heat grippers toast seal the film at both ends. This is the foremost form of use of stretch film and therefore developed further packaging forms
2. Full- range Packaging
This kind of packaging requires the film to be wide enough to cover the charger, and the shape of the charger is regular, so it’s suitable for use with a film consistency of 17- 35 μm
3. Homemade quilting
This kind of packaging is the simplest kind of stretch film packaging. The film is mounted on a rack or held by a hand, and the charger is rotated or the film is rotated around the charger. It’s substantially used for repacking after the packaged pallet is damaged, and for ordinary pallet packaging. This kind of packaging speed is slow, and the suitable film consistency is 15- 20 μm;
4. Stretch film winding machine packaging
This is the most common and widest form of mechanical packaging. The charger rotates or the film rotates around the charger. The film is fixed on the type and can move over and down. This kind of packaging capacity is veritably large, about 15 to 18 plates per hour. The suitable film consistency is about 15- 25 μm;
5. Vertical mechanical packaging
Different from another packaging, the film is wrapped around the composition, which is suitable for long-weight packaging, similar to carpets, boards, fiberboards, shaped accouterments, etc.;
6. Packaging of paper tube
This is one of the newest uses of stretch film, and it’s better than the old-fashioned paper tube packaging with stretch film. The suitable film consistency is 30- 120μm;
7. Packaging of small particulars
This is the rearmost packaging form of stretch film, which can’t only reduce material consumption but also reduce the storehouse space of the pallet. In foreign countries, this kind of packaging was first introduced in 1984. Only one time latterly, numerous similar packaging appeared on the request. This packaging format has huge eventuality. Suitable for film consistency 15
8. Packaging of tubes and lines
This is an illustration of the operation of stretch film in a special field. The packaging outfit is installed at the end of the product line. The completely automatic stretch film can’t only replace the swatch to bind the material but also play a defensive part. The applicable consistency is 15- 30 μm.
9. Stretching form of pallet medium packaging
The packaging of the stretch film must be stretched, and the stretching forms of pallet mechanical packaging include direct stretching and pre-stretching. There are two types of pre-stretching, one is comberpre-stretching, and the other is electric stretching.
Direct stretching is done between the charger and the film. This system has a low draw rate( about 15 to 20). still, the original yield point of the film is exceeded, and the film range is reduced, If the draw rate exceeds 55 to 60. easy to break. And at a stretch rate of 60, the tensile force is still veritably large. For light goods, it’s likely to distort the goods.
Pre-stretching is done by two breakers.
The two breakers of comberpre-stretching are connected together by a gear unit. The stretch rate can be different according to the gear rate. The pressure is generated by the turntable. Since the stretch is generated at a short distance, the disunion between the comber and the film It’s also large, so the film range doesn’t shrink, and the original perforation performance of the film is also maintained. No stretching occurs during factual winding, reducing breakage due to sharp edges or corners, and this stretching can increase the stretching rate to 110.
The stretching medium of electric stretching is the same as that of comberpre-stretching, the difference is that the two breakers are driven by electricity, and the stretching has nothing to do with the gyration of the pallet. thus, the rigidity is stronger, and it’s suitable for light, heavy, and irregular goods. Due to the low pressure during packaging, the pre-stretching rate of this system is as high as 300, which greatly saves accouterments and reduces costs. The suitable film consistency is 15- 24μm.
This is one of the biggest characteristics of stretch film packaging. With the super winding force and retractability of the film.
2. Primary protection
Provides face protection of the product, forming a veritably light and defensive appearance around the product, so as to achieve the purpose of dustproof, oilproof, moistureproof, leakproof, and anti-theft. It’s particularly important that stretch film packaging can make the packaged particulars unevenly stressed and avoid damage to the particulars caused by uneven force, which can not be achieved by traditional packaging styles( speeding, packaging, tape recording, etc.).
3. Compression fixity
Wrap and wrap the product with the help of the stretching force of the stretch film to form a compact unit that doesn’t take up space, so that the pallets of the product are tightly wrapped together, which can effectively help the transportation process. The collective disturbance and movement of medium and medium products, and the malleable stretching force can make hard products stick nearly and soft products shrink, especially in tobacco assiduity and cloth assiduity, which has a unique packaging effect.
4. Cost saving
Using stretch film for product packaging can effectively reduce the cost of use. The use of stretch film is only about 15 of the original box packaging, about 35 of the heat-shrinkable film, and about 50 of the tinderbox packaging. At the same time, it can reduce the labor intensity of workers, and ameliorate packaging effectiveness and packaging grades.
To add up, the operation fields of the stretch film are veritably wide, but numerous fields in China haven’t been involved, and numerous fields that have been involved haven’t been extensively used. With the expansion of operation fields, the quantum of the stretch film will increase greatly, its request eventuality is bottomless. thus, it’s necessary for us to roundly promote the product and operation of stretch film.
PE stretch film and stretch film
PE stretch film( also known as Wrap film) has high tensile strength, gash resistance, and good tone- cohesion, so it can wrap objects into a whole and help them from falling piecemeal and collapsing during transportation. The film has excellent translucency. The wrapped object is beautiful and elegant and can make the object leakproof, dustproof, and damage- evidence. The film is extensively used in pallet packaging of goods, similar to the packaging of electronics, erecting accouterments, chemicals, essence products, bus corridors, line and string, diurnal musts, food, paper, and other diligence. Specifications machine film range from 500 mm, homemade film range from 300 mm, 350 mm, 450 mm, and 500 mm, consistency 15um- 50um. It can be cut into colorful specifications online. Adhesive can be divided into single-sided glue and double-sided glue, and the products can be divided into two series homemade stretch film and machine stretch film.
The product has good buffer strength, perforation and gash resistance, thin consistency, and good performance- price rate. It has high tensile strength, gash resistance, translucency, and good retraction force. The pre-stretching rate is 400. It can be assembled, leakproof, dustproof,anti-scattering, and anti-theft. Uses Used for pallet wrapping and another winding packaging, extensively used in foreign trade import, bottle timber, paper timber, tackle and electrical appliances, plastics, chemicals, erecting accouterments, agrarian products, food, and other diligence.
PE stretch film is an artificial film product with high tensile strength, high extension, good tone- cohesion, and high translucency. It can be used for homemade stretching film, and also can be used for machine stretching film, and can be extensively used in centralized packaging of colorful goods.
PE stretch film is substantially made of several different grades of polyolefin resin mixed and extruded. It has perforation resistance, super strength, and high performance. It wraps the goods piled on the pallet to make the package more stable and neat Strong leakproof effect and is extensively used in foreign trade import, paper timber, tackle, plastic chemical assiduity, erecting accouterments, food, and medicinal diligence.
PE Stretch Film LLDPE Stretch
Stretch Film is made of high-quality LLDPE as the base material, with high- a quality tackifier added, heated, extruded, cast, and also cooled by chilling breakers. It has the advantages of strong durability, high pliantness, gash resistance, high density, thin consistency, cold resistance, heat resistance, pressure resistance, dustproof, leakproof, single-sided glue, double-sided glue, etc. It can save accouterments and labor when used, Save time, extensively used in papermaking, logistics, chemical assiduity, plastic raw accouterments, erecting accouterments, food, glass, etc.
Stretch film principle
With the help of the super strong winding force and retractability of the film, the stretch film bundles the product curtly and fixedly into a unit. Indeed in an inimical terrain, the product doesn’t have any tautness and separation, and there’s no sharp edge and stickiness, so as to avoid causing damage.
Stretch film can be divided into PE Wrap film, PE stretch film, LLDPE stretch film, PE slit stretch film, etc.
Welcome inquiry to Linyi Kaigao Plastic Packaging and visit us.