652 results about "Linear low-density polyethylene" patented technology

The invention discloses a high-strength polyethylene film and a preparation method thereof, and relates to the technical field of high polymer materials. The invention discloses a high-strength polyethylene film. The high-density polyethylene composite material is prepared from the following raw materials in parts by weight: 35 to 45 parts of high-density polyethylene, 25 to 35 parts of linear low-density polyethylene, 12 to 18 parts of ethylene-vinyl acetate copolymer, 5 to 10 parts of nano silicon dioxide, 3 to 7 parts of organic montmorillonite, 1.5 to 3.5 parts of hindered amine light stabilizer, 1.5 to 2.5 parts of antioxidant 1010, 0.8 to 1.2 parts of calcium stearate, 0.8 to 1.2 parts of zinc stearate, 0.8 to 1.2 parts of silane coupling agent and 4 to 6 parts of maleic anhydride grafted polyethylene. The composite material is prepared from the following components in parts by weight: 1.5-3.5 parts of a quaternized chitosan-nano silver compound, 6-9 parts of a modified toughening agent, 4-7 parts of a modified heat-resistant agent, 1.5-3.5 parts of a processing aid, 0.15-0.35 part of dibenzoyl peroxide and 0.5-1.5 parts of a nucleating agent DBS. The composite material is excellent in comprehensive performance, high in strength, good in flexibility and puncture resistance, excellent in aging resistance, heat resistance, chemical resistance and antibacterial property, good in processability, capable of meeting the requirements of multiple fields such as packaging and agriculture, scientific in preparation method and high in practical value.

The invention relates to the technical field of cables, and provides a fireproof flame-retardant 10kV power cable and a preparation method thereof. The fire-resistant flame-retardant 10kV power cable comprises a conductor and a fire-resistant flame-retardant layer, the fireproof flame-retardant layer is prepared from the following raw materials in parts by weight: 35 to 45 parts of linear low-density polyethylene, 40 to 50 parts of ethylene-vinyl acetate copolymer, 25 to 30 parts of modified aluminum hydroxide, 5 to 8 parts of polyethylene grafted maleic anhydride, 10 to 12 parts of phosphate modified halloysite nanotube, 5 to 8 parts of ZIF-8 loaded zinc borate core-shell particles, 15 to 20 parts of magnesium hydroxide and 2 to 3 parts of silane coupling agent. 0.5 to 1 part of antioxidant, 0.5 to 1 part of calcium stearate and 1 to 1.5 parts of polyethylene wax. According to the cable prepared in the invention, the situation that a conductor is exposed and the fire resistance is lost due to cracking and falling under long-time high-temperature baking is avoided; the continuous effectiveness of the flame retardant at high temperature is improved.

The invention relates to the technical field of packaging films, and particularly discloses a heat-resistant polyethylene composite packaging film and a preparation method thereof.The polyethylene composite packaging film comprises an inner layer, a middle layer and an outer layer, the inner layer is prepared from, by mass, 100 parts of linear low-density polyethylene, 28-32 parts of polypropylene and 8-10 parts of hydrotalcite modified blending materials, the middle layer comprises the following raw materials in parts by weight: 100 parts of low-density polyethylene, 40-60 parts of linear low-density polyethylene, 3-5 parts of a coupling agent and 0.5-1 part of an antioxidant, the outer layer comprises the following raw materials in parts by weight: 100 parts of modified PA6, 20-30 parts of metallocene polyethylene and 5-8 parts of a compatilizer, functional gradient distribution is realized by adopting layered extrusion of three-layer co-extrusion, and PA6 and polypropylene have a synergistic effect, so that the composite film has excellent heat resistance, and the service life of the composite film is prolonged. The hydrotalcite and the graphene oxide have a synergistic effect, the layered structure effectively obstructs oxygen and water vapor, and the obtained polyethylene composite packaging film is good in barrier property and has excellent mechanical property and heat resistance.

The invention relates to the technical field of cables, and provides a high-temperature-resistant flame-retardant power cable and a preparation method thereof. A high-temperature-resistant flame-retardant power cable comprises a conductor and a high-temperature-resistant flame-retardant outer layer wrapping the conductor. The high-temperature-resistant flame-retardant outer layer is prepared from the following raw materials in parts by weight: linear low-density polyethylene, an ethylene-vinyl acetate copolymer, ethylene propylene diene monomer, chopped polyimide fibers, nano-coated magnesium hydroxide, zinc borate, zinc stannate, polyethylene grafted maleic anhydride, an anti-aging agent, dicumyl peroxide, an antioxidant, polyethylene wax, calcium stearate and cerium dioxide. According to the cable prepared in the invention, the reliability of an existing high-temperature-resistant flame-retardant power cable under thermal cycle is improved, and the problem of local temperature resistance difference caused by agglomeration and high-temperature migration of nanoparticles in a polymer matrix is improved.

The invention discloses a large-current-carrying-capacity flexible power cable, which belongs to the technical field of cable preparation, is used for solving the technical problem that the flame retardant property and the mechanical property of the power cable need to be further improved in the prior art, and specifically comprises a cable core, a wrapping layer, an insulating layer and a sheath layer which are sequentially arranged from inside to outside. The preparation method comprises the following steps: preparing alkoxy silane containing a benzocyclobutene group, preparing flame-retardant particles by using a sol-gel method, preparing modified polyurethane by using modified polysiloxane and 2, 5-furandimethanol as soft segments, naphthalene diisocyanate as a hard segment and trimethylolpropane as a chain extender, and preparing the flame-retardant flame-retardant polyurethane. The linear low-density polyethylene, the MAH-g-PE, the modified polyurethane, the flame-retardant particles and the auxiliary additive are melted and extruded outside the wire core to form the insulating layer, so that the power cable is obtained, the flame-retardant property of the power cable is effectively improved, and the mechanical property and the current-carrying stability of the power cable are also improved.

Disclosed in the present invention are a 90°C thermoplastic halogen-free low-smoke flame-retardant polyolefin sheath material and a preparation method therefor. The sheath material is prepared from raw materials comprising the following components in parts by mass: 20-40 parts of an ethylene-vinyl acetate copolymer, 20-40 parts of a linear low-density polyethylene, 2-10 parts of a high-density polyethylene, 20-40 parts of a metallocene ethylene-octylene copolymer, 10-15 parts of a maleic-anhydride-grafted metallocene linear low-density polyethylene copolymer, 58-73 parts of aluminum hydroxide, 20-25 parts of modified magnesium hydroxide, 64-84 parts of a synergistic flame retardant, 2-3 parts of a coupling agent, 1-4 parts of a lubricant, 1-3 parts of an antioxidant, and 2-7 parts of a coloring agent, wherein the synergistic flame retardant comprises lithium oxide. A matrix resin has low-temperature performance, mechanical properties and cracking resistance. With regard to flame retardance, a large amount of the synergistic flame retardant, i.e., lithium oxide, is added to a traditional magnesium-aluminum compound flame-retardant system, and therefore an off-white hard shell can be formed during a combustion process while low heat release is ensured, thereby ensuring no dripping during the combustion process.

The invention discloses a high-toughness polyethylene composite film and a preparation method thereof, and belongs to the field of high polymer materials. The outer layer is prepared from linear low-density polyethylene, an ethylene-butyl acrylate copolymer, an antioxidant 1010 and an ultraviolet light absorber UV-531; the middle layer is prepared from linear low-density polyethylene, a polyolefin elastomer, an ethylene-butyl acrylate copolymer, stearic acid modified calcium carbonate, an antioxidant and an ultraviolet light absorber; and the inner layer is composed of linear low-density polyethylene, an ethylene-butyl acrylate copolymer, an antioxidant 1010 and an ultraviolet light absorber UV-531. Drying the raw materials; mixing heavy calcium carbonate with stearic acid; each layer is mixed at a low speed according to a ratio; and carrying out three-layer co-extrusion film blowing, two-way stretching, corona and annealing. The surface tension of the composite film reaches 40 mN / m, the maximum longitudinal and transverse tensile strength is 23 MPa, the tearing strength is 120 kN / m, the elongation at break is 700%, and the performance of the composite film is superior to that of traditional casting and blow molding process products.

The invention relates to the technical field of cables, and provides a 10kV flame-retardant wire cable and a preparation method thereof. The 10kV flame-retardant wire cable comprises a bunched wire core and an outer sheath layer, the outer sheath layer is prepared from the following raw materials in parts by weight: 40 to 50 parts of linear low-density polyethylene, 30 to 40 parts of ethylene-vinyl acetate copolymer, 18 to 20 parts of microencapsulated ammonium polyphosphate, 6 to 8 parts of organic modified nano montmorillonite, 4 to 6 parts of zinc borate, 1 to 2 parts of silane coupling agent, 0.5 to 1 part of antioxidant and 0.4 to 0.6 part of calcium stearate. According to the 10 kV flame-retardant electric wire and cable prepared in the invention, the flame-retardant grade of the flame-retardant electric wire and cable is improved, but the problem that the elongation at break of the material is reduced due to excessive addition of the inorganic flame retardant is solved; and the problems of environmental adaptability and mechanical performance of sheath cracking easily caused by insufficient bending radius of the cable are improved.

The present invention relates to an olefin-based polymer, a film made therefrom, and a method for producing the same. The olefin-based polymer according to a specific example of the present invention has excellent processability, and the film made therefrom, particularly a linear low-density polyethylene film, has excellent mechanical strength, particularly impact strength.

A lid assembly for an in-ground meter box that can withstand substantial loads (e.g., 22, 500 lbs) without deformation. The lid assembly includes a metal frame secured to the bottom side of a plastic lid to allow the plastic lid to seat tightly for covering the in-ground meter box. The metal frame provides the rigidity and strength to withstand the loading while simultaneously providing the lid with sufficient weight to make it non-bouyant, i.e., should the surrounding ground environment become flooded, the lid is heavy enough to remain in place, covering the meter box and will not float away. The metal frame also is detectable by a metal detector should the lid every be covered over with debris and need to be located. The plastic lid body (e.g., linear low-density polyethylene (LLDPE)) of the lid assembly avoids radio signal interference or attenuation emanating from a transmitter positioned within the meter box.

The invention belongs to the technical field of waterproof and drainage boards, and provides a waterproof and drainage board with high compressive strength and tensile strength and a preparation method and application thereof.The waterproof and drainage board is formed by compounding an upper layer, a middle layer and a lower layer, and the upper layer and the lower layer are each prepared from 30-40 parts of high-density polyethylene, 10-20 parts of chlorinated polypropylene, 10-15 parts of metallocene polyethylene and 1-3 parts of carbon nanotubes; 2-5 parts of nano calcium carbonate, 1-5 parts of polyethylene wax, 1-3 parts of an antioxidant and 1-3 parts of an anti-ultraviolet agent; the middle layer is prepared from the following raw materials: 35 to 55 parts of linear low-density polyethylene, 15 to 30 parts of metallocene polyethylene, 10 to 15 parts of ethylene-vinyl acetate copolymer, 5 to 10 parts of POE (Polyolefin Elastomer), 5 to 10 parts of aramid chopped fiber, 1 to 3 parts of antioxidant and 1 to 3 parts of ultraviolet screening agent; the nano calcium carbonate is subjected to modification treatment. The waterproof and drainage board has relatively high compressive strength and tensile strength, and has a good application prospect.

The invention discloses a high-barrier polyethylene film and a preparation method thereof, and relates to the technical field of high polymer materials. The invention discloses a high-barrier polyethylene film. The high-density polyethylene composite material is prepared from the following raw materials in parts by weight: 25 to 40 parts of high-density polyethylene, 15 to 30 parts of linear low-density polyethylene, 8 to 16 parts of ethylene-vinyl alcohol copolymer, 3 to 8 parts of nano montmorillonite, 5 to 10 parts of modified layered double hydroxide, 2 to 6 parts of nano silicon dioxide aerogel, 0.2 to 0.6 part of antioxidant 1076, 0.1 to 0.4 part of light stabilizer UV-770, 3 to 7 parts of tributyl citrate and 1 to 3 parts of octadecanamide. 1-3 parts of polyethylene wax, 0.6-1.2 parts of a silane coupling agent KH560 and 7-12 parts of a functional additive. According to the high-barrier polyethylene film disclosed by the invention, by using the modified layered double hydroxide and the functional additive, the barrier property and the antibacterial property are enhanced, the mechanical property is improved, the comprehensive performance is excellent, and the application prospect is good.

The invention relates to the technical field of cables, and provides a high-temperature-resistant flame-retardant cable and a preparation method thereof. The high-temperature-resistant flame-retardant cable comprises a conductor and a flame-retardant outer sheath, the flame-retardant outer sheath is prepared from the following raw materials in parts by weight: 40 to 50 parts of linear low-density polyethylene, 35 to 45 parts of ethylene-vinyl acetate copolymer, 10 to 15 parts of ethylene propylene diene monomer, 15 to 18 parts of modified aluminum hydroxide, 10 to 14 parts of modified magnesium hydroxide, 5 to 8 parts of polyethylene grafted maleic anhydride, 5 to 8 parts of microencapsulated red phosphorus, 2 to 3 parts of silane coupling agent and 0.8 to 1 part of antioxidant. The composite material is prepared from the following components in parts by weight: 0.5-1 part of a light stabilizer, 0.5-1 part of calcium stearate, 0.8-1 part of polyethylene wax and 0.5-0.9 part of carbon nanotubes. According to the cable prepared in the invention, the performance stability of an existing high-temperature-resistant material in a high-temperature environment is improved, and the problems of softening, melting and the like of the cable are avoided.

The invention discloses a low-smoke halogen-free self-crosslinking cable material for a photovoltaic cable and a preparation method of the low-smoke halogen-free self-crosslinking cable material. The low-smoke halogen-free self-crosslinking cable material for the photovoltaic cable is prepared from the following components in parts by weight: 40 to 50 parts of ethylene-vinyl acetate copolymer, 20 to 30 parts of polyolefin elastomer resin, 10 to 15 parts of linear low-density polyethylene, 3 to 5 parts of modified montmorillonite, 3 to 5 parts of magnesium hydroxide, 5 to 10 parts of vinyl siloxane, 0.5 to 2 parts of initiator, 1 to 2 parts of antioxidant, 1 to 2 parts of ultraviolet light absorber, 0.1 to 5 parts of compatilizer, 0.5 to 3 parts of lubricant and 0.1 to 1 part of antioxidant. And 0.3 part of a catalyst. According to the cable material provided by the invention, through collaborative design of a modified montmorillonite / magnesium hydroxide flame-retardant system, a silane self-crosslinking technology and an anti-aging functional aid, triple breakthrough of flame-retardant high efficiency, weather-resistant long-term effect and environmental protection safety is realized.

The invention relates to the technical field of pearl wool composite materials, in particular to a pearl wool composite material based on an ethylene polymer and application of the pearl wool composite material in building heat preservation, the pearl wool composite material comprises the ethylene polymer, pearl wool particles and nano aerogel, the ethylene polymer is a mixture of linear low density polyethylene and metallocene polyethylene in a specific proportion, the pearl wool particles are treated by the silane coupling agent, the particle size is 0.5-2 mm, the porosity of the nano aerogel exceeds 90%, the average pore size is 2-20 nm, the components are proportioned according to specific parts by weight, the performance of the composite material is improved through the synergistic effect, and the composite material can be used in the field of building heat preservation. The composite material disclosed by the invention has the advantages of excellent thermal insulation performance, capability of effectively reducing building energy consumption, good mechanical property, high deformation resistance, long service life, good flame retardant property, capability of guaranteeing building safety, simple preparation process, low cost, wide application, capability of being used for multiple parts of a building, convenience in construction and high comprehensive benefit.

The invention discloses a high-performance color master batch for automobile engineering plastics and a preparation method of the high-performance color master batch, and belongs to the technical field of color master batches. Comprising the following raw materials in parts by weight: 83-95 parts of polypropylene resin, 33-41 parts of linear low-density polyethylene, 12-16 parts of toner, 6-10 parts of an antioxidant, 7-21 parts of an auxiliary agent and 3-5 parts of a lubricant. Wherein polypropylene is used as a main matrix, so that the color master batch is endowed with excellent mechanical strength; in addition, the linear low-density polyethylene added into the raw materials has good flexibility, and the impact resistance of the color master batch can be improved; in addition, molecules of the auxiliary agent contain various functional groups, so that the anti-ultraviolet performance and the flame-retardant performance of the matrix can be remarkably improved; in conclusion, the color master batch prepared by the invention has excellent mechanical properties, ultraviolet resistance and flame retardance, and has important application value in the technical field of color master batches.

The invention relates to the technical field of plastic packaging films, in particular to a casting CPE composite film material and a preparation method thereof.The casting CPE composite film material is characterized in that a corona layer is prepared from, by weight, 72-75 parts of LLDPE, 18-22 parts of LDPE, 5-6 parts of EVA and 1.5-2 parts of an opening slipping agent; the middle core layer is prepared from the following components in parts by weight: 70 to 75 parts of LLDPE (Linear Low Density Polyethylene), 20 to 25 parts of HDPE (High Density Polyethylene), 5 to 8 parts of mPE, 3 to 5 parts of modified nano silicon dioxide and 1 to 3 parts of processing aid; the heat sealing layer is prepared from the following components in parts by weight: 25 to 30 parts of mLLDPE, 68 to 72 parts of LDPE, 0.3 to 0.5 part of antistatic agent and 1 to 2 parts of processing aid. The prepared composite film material has multiple functions of flame retardance, aging resistance, static electricity resistance and the like on the basis of keeping excellent heat sealing performance and mechanical strength.

The invention relates to the technical field of power cables, in particular to a fire-fighting special double-flame-retardant power cable and a preparation method thereof, and the fire-fighting special double-flame-retardant power cable comprises a circular conductor, an insulation shielding layer, a metal layer, a metal armor layer and a polyethylene flame-retardant outer sheath which are sequentially arranged from inside to outside; the polyethylene flame-retardant outer protective layer is prepared by mixing a P / N / S / S i quaternary modified boron nitride flame retardant and linear low-density polyethylene in an internal mixer, heating, melting and extruding; the preparation of the flame retardant comprises the following steps: carrying out substitution reaction on three flame-retardant element modified DOPO (9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) containing amino groups, namely P / N / S, and bis (chloropropyl) tetramethyldisiloxane to prepare a P / N / S / S i quaternary flame-retardant material; carrying out substitution reaction on the C < l > group of the P / N / S / S quaternary flame-retardant material and hydroxylated boron nitride to obtain a P / N / S / S quaternary modified boron nitride flame retardant; according to the invention, the power cable can maintain good flame retardance under the condition of long-time damp-heat aging.

The invention belongs to the technical field of high polymer materials, and particularly relates to special resin for a polyethylene film as well as a preparation method and application thereof. The special resin for the polyethylene film is prepared from the following components in parts by weight: 50 to 70 parts of HDPE (High-Density Polyethylene) resin, 20 to 30 parts of LLDPE (Linear Low Density Polyethylene) resin, 0.5 to 3 parts of nano zinc oxide, 5 to 10 parts of maleic anhydride grafted POE (Polyolefin Elastomer) and 0.1 to 0.5 part of antioxidant. The HDPE, the LLDPE and the grafted POE form a three-phase topological structure, so that the bending modulus and the notch toughness can be synchronously improved. The special resin for the polyethylene film, which is prepared by adopting a low-temperature second-order blending process, can keep the toughening effect of an elastomer. The special resin for the polyethylene film prepared by the invention can realize ultrahigh toughness while keeping high rigidity, has long-acting weather resistance, can meet the requirements of packaging films and other high-end fields, is high in processing adaptability, and is suitable for a high-speed film blowing production line.

The invention relates to the technical field of modified plastics, in particular to a high-toughness modified plastic and a preparation method thereof. Specifically, the material comprises the following components in parts by weight: 70-90 parts of polypropylene, 30-40 parts of thermoplastic elastomer, 5-15 parts of linear low-density polyethylene, 5-15 parts of polypropylene grafted maleic anhydride and 1-10 parts of stearic acid modified calcium carbonate. The calcium carbonate is further modified, so that the calcium carbonate has better impact strength and tensile strength when being compounded with the polypropylene, the linear low-density polyethylene, the polypropylene grafted maleic anhydride and the thermoplastic elastomer.

The invention relates to the technical field of insulating materials, and discloses a crosslinked polyethylene insulating material which comprises the following components: 40-50 parts of linear low-density polyethylene, 10-20 parts of low-density polyethylene, 3-8 parts of polypropylene resin, 2-3 parts of a silane coupling agent, 0.8-1.5 parts of an initiator and 0.9-1.5 parts of a polycyclic conjugated antioxidant, and further comprises a preparation method of the crosslinked polyethylene insulating material. Comprising the following steps: S1, compounding and pretreating a matrix material, namely mixing low-density polyethylene and linear low-density polyethylene, adding polypropylene resin, an antioxidant and a lubricant, premixing, and drying to form a polyethylene matrix; according to the invention, through a multi-component collaborative design concept, the cross-linked polyethylene insulating material has remarkable advantages in the aspect of electrical performance, and the long-acting stability of the insulating layer material is enhanced, so that the service life of the insulating layer material is prolonged.

An extreme-cold resistant low-fume halogen-free flame-retardant polyolefin sheath, a preparation method therefor, and a cable. The sheath comprises the following raw materials in parts by mass: 4-16 parts of an ethylene-vinyl acetate copolymer, 7-13 parts of a phosphate group functionalized linear low-density polyethylene, 9-15 parts of an ethylene-octene copolymer, 5-10 parts of a maleic anhydride-grafted ethylene-methyl methacrylate copolymer, 10-15 parts of magnesium hydroxide, 40-50 parts of aluminum hydroxide, etc. The preparation method for the phosphate group functionalized linear low-density polyethylene comprises: adding a catalyst to a pre-cooled ethylene monomer, adding a vinyl phosphate ester and an initiator after the reaction, and reacting for 1-2 hours at a temperature of 65-75°C and a pressure of 15-35 Mpa and then terminating the reaction, thereby obtaining the phosphate group functionalized linear low-density polyethylene. Compared with unfunctionalized polyethylene, the phosphate group functionalized polyethylene used has greatly improved low-temperature and flame-retardant performance, and can improve the overall flame-retardant and low-temperature performance of the formula.

The invention belongs to the technical field of high polymer materials, and particularly relates to a maleic anhydride grafted polyethylene composition with high grafting rate and low gel content as well as a preparation method and application thereof. The maleic anhydride grafted polyethylene composition is prepared from raw materials such as linear low-density polyethylene, EVA (Ethylene Vinyl Acetate), r-PP (Resin-Propene Polymer), a compound initiator and MAH (Maleic Anhydride). In the maleic anhydride grafted polyethylene composition, the r-PP and the compound initiator are used as an initiation system to synergistically improve the reaction degree so as to improve the grafting rate; in addition, the synergistic initiator system reduces the dosage of a compound initiator, so that the influence of a cage shielding effect caused by excessive initiators on the gel content of the product is avoided while the cost is reduced; the grafting rate is further improved by adding a small amount of EVA. Therefore, when a product with a high grafting rate (greater than 0.9%) is obtained, the gel content is low (less than 4%), a blow-molded casting product has few crystal points, and the product also has good mechanical properties and can be better applied to the field of high-end functional adhesives.

The invention belongs to the technical field of cable materials, and particularly relates to an anti-aging cable and a preparation method thereof. The anti-aging cable sequentially comprises a conductor, an insulating layer and a sheath layer from inside to outside, and the sheath layer is prepared from, by weight, 90-100 parts of PVC resin, 15-20 parts of linear low-density polyethylene, 10-15 parts of ethylene-octylene copolymer, 12-18 parts of plasticizer, 5-8 parts of anti-aging agent, 3-5 parts of calcium-zinc stabilizer, 3-5 parts of modified carbon nano tube and 2-3 parts of lubricant. Through molecular structure design, the prepared anti-aging agent not only can significantly improve the anti-aging performance of a cable sheath material, but also can effectively enhance the flame retardant property of the material. In addition, the modified carbon nanotube prepared by the invention can significantly improve the mechanical properties and waterproofness of the cable sheath material.

The invention relates to the technical field of cables, in particular to an aluminum alloy cable which is composed of an aluminum alloy conductor, an inner insulating layer, a fireproof wrapping tape layer and an outer sheath. The outer sheath is prepared from the following raw materials in parts by weight: 50 to 60 parts of ethylene-vinyl acetate copolymer, 20 to 30 parts of linear low density polyethylene, 10 to 20 parts of polyolefin elastomer, 5 to 10 parts of PPO-g-MAH, 20 to 30 parts of carbon black, 1 to 10 parts of organic phosphorus flame retardant, 20 to 30 parts of crusting agent and 1 to 3 parts of antioxidant; the aluminum alloy cable provided by the invention is light in weight, high in strength and excellent in fireproof and flame-retardant performance.

The invention belongs to the technical field of fresh keeping of agricultural products, and particularly relates to a fresh-keeping packaging film capable of inhibiting browning and a preparation method of the fresh-keeping packaging film. The fresh-keeping packaging film sequentially comprises a first PE layer, a second PE layer, a third PA layer, a fourth PA layer and a fifth PE-EVA-POE layer from the first layer to the fifth layer from outside to inside, the first PE layer comprises the following raw materials in parts by weight: 25-40 parts of low-density polyethylene, 15-30 parts of linear low-density polyethylene, 30-60 parts of high-density polyethylene and 2-5 parts of a modified nano material; the modified nano material is prepared by mixing nano titanium dioxide, nano silicon dioxide and nano zinc oxide and then sequentially reacting with a silane coupling agent KH570 and a hyperbranched polymer. The prepared fresh-keeping packaging film has an excellent fruit browning prevention effect and is high in puncture resistance and good in low-temperature resistance effect.

The invention relates to the field of packaging materials, in particular to an anti-puncture high-strength packaging film and a preparation method thereof, and is used for solving the problem that although a traditional packaging film can play a protection role to a certain extent, the anti-puncture performance and the strength are difficult to meet actual requirements. According to the packaging film, linear low-density polyethylene, high-density polyethylene and polypropylene are used as main raw materials for reasonable compounding, the packaging film is endowed with mechanical properties under the synergistic effect of the linear low-density polyethylene, the high-density polyethylene and the polypropylene, and after coating modified glass fibers and modified boron nitride are added into the packaging film, the overall performance of the packaging film can be remarkably improved; an effective enhanced network structure is formed in the packaging film, so that the packaging film can effectively resist puncture and tearing when being subjected to external impact, the safety and integrity of internal articles are kept, and more reliable and lasting protection is provided for various articles; moreover, the preparation method is simple in process, easy to control and suitable for large-scale industrial production.

The invention discloses an environment-friendly halogen-free flame-retardant composite special cable, and belongs to the technical field of cable preparation, the special cable sequentially comprises a conductor, an insulating layer, a glass fiber rope layer and an outer protective sleeve from inside to outside, and the insulating layer and the outer protective sleeve are prepared from a modified flame-retardant copolymer. The modified flame-retardant copolymer is prepared from the following raw materials in parts by weight: 65 to 80 parts of linear low-density polyethylene, 20 to 38 parts of ethylene-vinyl acetate copolymer, 5 to 10 parts of modified P-N-Si flame retardant 1, 3 to 6 parts of modified P-N-Si flame retardant 2, 0.5 to 1 part of initiator, 0.2 to 0.5 part of antioxidant and 25 to 35 parts of non-reactive flame retardant through melt copolymerization; a polyfunctional and rigid organic modified P-N-Si flame retardant is grafted, so that the migration of the flame retardant is reduced, the crosslinking degree is increased, and the mechanical and high-temperature-resistant properties are improved; the organic P-N-Si, the inorganic non-reactive flame retardant metal hydroxide and the nano inorganic particles have a synergistic effect, so that the cable is endowed with high flame retardance.

The invention discloses a high-strength rat-proof optical cable and a preparation method thereof. The high-strength rat-proof optical cable comprises at least one reinforcing piece, at least one cable core distributed outside the reinforcing piece, an inner protective layer wrapping the cable core, an armor layer wrapping the inner protective layer and a rat-proof outer sheath wrapping the armor layer, and the cable core is composed of at least one optical fiber and a loose tube; wherein the rat-proof outer sheath is prepared from the following raw materials in parts by weight: 70 to 80 parts of linear low-density polyethylene, 20 to 30 parts of nylon 12, 5 to 8 parts of compatilizer, 15 to 20 parts of modified composite filler, 1 to 3 parts of antioxidant and 0.5 to 1 part of lubricant. According to the high-strength rat-proof optical cable, the LLDPE / nylon 12 alloy matrix with a specific formula is adopted in the outer sheath, and the modified composite filler is introduced, so that the finally prepared optical cable outer sheath has excellent mechanical strength and wear resistance, and an efficient, long-acting and environment-friendly biological rat-proof effect is achieved.

The invention relates to the field of cable materials, and particularly discloses a high-strength fireproof cable and a preparation method thereof.The high-strength fireproof cable comprises a conductor, an insulating layer, a flame-retardant layer and an outer sheath; the outer sheath material comprises the following raw materials: modified polyamide-imide resin, linear low-density polyethylene, amino modified carbon fiber, a styrene-maleic anhydride copolymer and genipin; the preparation method comprises the following steps: firstly, heating and mixing the modified polyamide-imide resin, the amino modified carbon fiber and the genipin, and then adding other raw materials for melt blending granulation to prepare the outer sheath; and sequentially assembling the conductor, the insulating layer, the flame-retardant layer and the outer sheath to obtain the high-strength fireproof cable. The fireproof cable has the advantages that the mechanical strength of the fireproof cable is kept under the long-term high-temperature condition, and the mechanical strength and the thermal aging performance of the cable are improved.