506 results about "Melt flow index" patented technology

The invention discloses a method for testing a melt index. The method comprises the following steps: preheating a melt charging barrel to a preset temperature, and carrying out heat preservation for a first preset time; feeding to be measured is loaded into a containing cavity of a melting charging barrel, a piston rod is inserted into the melting charging barrel, a mass piece with the first weight is added to the piston rod, the feeding to be measured is melted into molten feeding under the pressure of the piston rod and is compacted, and therefore falling materials with the preset length are exposed out of a discharging opening of the melting charging barrel; switching the weight of the mass piece on the piston rod from the first weight to the second weight, so that the to-be-detected feed flows out of the discharge port under the pressure of the piston rod and is cut to obtain a plurality of sections of first to-be-detected samples, and calculating the melt index of the to-be-detected feed; the range of the first weight is 2.16 kg to 10 kg, and the range of the preset length is 1 cm to 30 cm. Therefore, the air in the melt charging barrel can be exhausted, the components of the to-be-tested feed are more uniform, the uniformity of the first to-be-tested sample is improved, the fluctuation of the tested melt index is reduced, and the accuracy of the test result is improved.

Processes for producing activated chromium catalysts such as titanated chromium / silica catalysts are disclosed, and these processes utilize a multistep process involving exposure to inert and oxidizing atmospheres at specific temperature conditions. The resulting activated chromium catalysts have unexpectedly high melt index potential and can produce ethylene-based polymers with lower gel counts in addition to higher melt indices.

The invention discloses a cross-linking type biodegradable POF heat shrink film and a preparation method thereof, and belongs to the technical field of heat shrink films, and the cross-linking type biodegradable POF heat shrink film is characterized by comprising three layers of films which are sequentially attached, each of the first-layer film and the third-layer film comprises the following raw materials in percentage by weight: 89.5-94% of PP, 2-6% of degradable master batch, 0.5-3% of an anti-blocking agent and 1-4% of a slipping agent; the second-layer film is prepared from the following raw materials in percentage by weight: 30 to 35 percent of LLDPE-A, 9 to 14.5 percent of toughening agent, 0.5 to 1 percent of degradable master batch, 40 to 45 percent of LLDPE-B and 10 to 15 percent of metallocene LLDPE; the melt index of the LLDPE-A is 2.5 g / 10min, the melt index of the LLDPE-B is 2.1 g / 10min, the melt index of the metallocene LLDPE is 1.0 g / 10min, and through the synergistic effect between the LLDPE with different melt indexes and the flexibilizer, the low-temperature tear resistance of the heat shrink film is effectively improved.

The invention belongs to the technical field of high polymer materials, and particularly relates to a polyolefin composite material as well as a preparation method and application thereof. The polyolefin composite material is prepared from the following raw materials: polyethylene, a polyolefin toughening agent, a compound flame retardant and a filler, the melt index of the polyethylene at 190 DEG C / 2.16 kg is greater than or equal to 18 g / 10 min, and the bending modulus is less than or equal to 160 MPa; the polyolefin toughening agent is selected from at least one of an ethylene-propylene copolymer, an ethylene-butylene copolymer and an ethylene-vinyl acetate copolymer, and the melt index at 230 DEG C / 2.16 kg is greater than or equal to 9 g / 10 min; the compound flame retardant comprises tetrabromobisphenol S bis (2, 3-dibromopropyl) ether, antimony trioxide and hydroquinone bis (diphenyl phosphate), and the filler is at least one of talcum powder, barium sulfate and wollastonite. Through specific types of polyethylene, the polyolefin flexibilizer, the compound flame retardant and the filler, excellent flame retardance and toughness can be obtained.

The invention belongs to the technical field of high-voltage cross-linked polyethylene compositions, and particularly relates to a water-tree-resistant cross-linked polyethylene insulating composition for a high-voltage direct-current submarine cable and a preparation method and application of the water-tree-resistant cross-linked polyethylene insulating composition. The insulating composition comprises the following components in parts by weight: 80-120 parts of low-density polyethylene resin with a melt index of 1.9-2.1 g / 10min; 0.2 to 0.3 part of a composite antioxidant; 1.25 to 1.85 parts of a composite cross-linking agent; 0.2 to 0.3 part of a scorch inhibitor; 8-12 parts of a water-inhibiting master batch; wherein the water-inhibiting master batch is prepared from 80 to 120 parts of composite polyolefin resin, 6 to 9 parts of composite water-inhibiting agent, 3.6 to 5.4 parts of maleic anhydride graft and 0.15 to 0.25 part of antioxidant; the composite water inhibitor comprises polyethylene glycol and oleamide in a mass ratio of (8-12): 1. The insulation composition can inhibit insulation scorching and resist insulation water tree growth, and is high in gel content, high in extrusion cabling speed and stable in production process.

The invention relates to the technical field of material performance detection, in particular to a rapid testing method for thermal aging failure of an oil and gas pipeline anticorrosive coating material, which comprises the following steps: testing oxidation induction time t of a sample; respectively carrying out thermal aging with different time lengths at 150 DEG C, measuring and calculating A (tri) / A (on) and a melt index change rate, establishing a linear equation of the A (tri) / A (on), and calculating A '(tri) / A' (on) corresponding to 35% of the melt index change rate; carrying out thermo-oxidative aging on the sample at different time lengths, measuring and calculating A (tri) / A (on), and obtaining aging time t'according to A '(tri) / A' (on); carrying out oxidation induction time test on the thermally aged material to obtain a rate coefficient k; and calculating the aging time corresponding to the material failure critical point. The test method provided by the invention can rapidly characterize the thermal aging failure critical point of the anticorrosive coating material, and provides a scientific basis for development of the material.

The invention discloses a continuous foaming composite process for a pearl wool coiled material and a waste gas recovery system thereof, and belongs to the technical field of pearl wool processing. Aiming at the problems of low efficiency and waste gas pollution of a traditional intermittent process, the process realizes continuous production through raw material selection (the melt index of LDPE is 1.0-2.5 g / 10min), drying and mixing pretreatment, melting and plasticizing through a twin-screw extruder, injection of foaming agents such as butane under the pressure of 8-12MPa, extrusion foaming at a die head of 140-160 DEG C and combination of air-cooling and water-cooling shaping. The compounding link comprises multiple processes such as hot pressing and co-extrusion to adapt to different base materials, after-treatment is conducted through trimming, taper tension coiling and standing stress release, the product density fluctuation is + / -3%, and the peel strength is larger than or equal to 3 N / cm. According to the waste gas recovery system, negative pressure collection is conducted through a closed gas collecting hood, indirect cooling and alkali liquor spraying pretreatment are conducted, activated carbon adsorption concentration and catalytic combustion purification are conducted, the VOCs removal rate is larger than or equal to 98%, the emission concentration is smaller than or equal to 50 mg / m < 3 >, and efficient production and environmental protection benefits are achieved.

The invention provides a modified engineering plastic melt index real-time monitoring method which comprises the following steps: determining a melt index difference value of adjacent monitoring points by acquiring a melt index value of each section of an extrusion production line; obtaining the number of shearing cycles of the extrusion production line, identifying the fiber shearing damage degree of each section according to the melt index difference and the number of shearing cycles to obtain fiber damage distribution, and determining the fiber fracture position according to the fiber damage distribution; the melt index difference value corresponding to the fiber fracture position is analyzed by obtaining the melt index of the fiber fracture position, and the monitoring point interval is dynamically adjusted through the melt index difference value; and obtaining the melt index value and the fiber shortening amplitude after the interval adjustment of the monitoring points, and comparing the melt index change and the fiber length loss of each monitoring point to obtain the corresponding distribution of the fiber shortening amplitude and the melt index value.

The invention relates to the technical field of polymer compositions, and discloses a fiber microcrack self-healing composition with a shape memory characteristic, which comprises modified polyester containing thermally reversible dynamic covalent bonds and an asymmetric polyether-polyester block copolymer interface regulator, the melt index ratio of the interface regulating agent to the modified polyester is 1.8-3.2, and the interface regulating agent is distributed on the periphery of the modified polyester to form a core-shell microdomain. By utilizing the rheological gradient among the components, the interface regulating agent forms a low-viscosity flowing layer when the matrix shrinks; and the modified polyester is restrained to directionally migrate towards the tip of the fiber microcrack, so that active closing and densification filling of the crack area are realized, micro holes in the repaired area are eliminated, and the mechanical continuity of the composition in a dynamic environment is kept.

This invention proposes a catalyst component, catalyst, and their applications for olefin polymerization, belonging to the field of olefin polymerization technology. The catalyst component contains products obtained from the reaction of a magnesium source, a titanium source, and an internal electron donor, wherein the internal electron donor comprises furan compounds and diether compounds. The catalyst of this invention exhibits high hydrogen sensitivity and stereoregulation, with a good balance between the two. The molecular weight distribution of the prepared low melt index polymer is broader than that of the high melt index polymer, and the catalyst component of this invention does not contain phthalate compounds (plasticizers).

The invention discloses a parameter control method, device and equipment for an injection molding machine and a storage medium, and relates to the technical field of injection molding machine parameter control. The method comprises the following steps: firstly, acquiring surrounding environment temperature, material melt index and viscosity of the injection molding machine, determining three types of environment temperature adjustment amounts in combination with corresponding reference thresholds, and performing weighted correction to obtain a target environment temperature and performing control; meanwhile, pressure and flow velocity adjustment amount is determined according to the melt index and viscosity, the initial pressure and flow velocity are subjected to weighted correction to obtain second pressure and flow velocity, the injection molding pressure is controlled by combining the equipment health degree index, and compensation adjustment amount is calculated when the health degree is insufficient to obtain third pressure through weighted correction. In combination with product image detection, the flow velocity is corrected according to a notch or burr type first defect value to obtain a third flow velocity, and the pressure maintaining duration is corrected according to a surface depression type second defect value to obtain a second pressure maintaining duration; the defective rate is counted through preset duration, when the defective rate reaches the standard, the parameter optimization coefficient is adjusted according to the decreasing amplitude and the threshold value, and each weight is dynamically optimized. The method improves the product quality.

A polyethylene copolymer may comprise about 90 wt % to about 99.99 wt % ethylene and about 0.01 wt % to about 10 wt % an alpha-olefin that is not ethylene, wherein the polyethylene has: a density of about 0.930 g / cm3 to about 0.955 g / cm3, a melt flow index (2.16 kg at 190°° C.) of about 10 g / 10 min to about 50 g / 10 min, a melt flow index ratio (MIR) of about 15 to about 25, a weight average molecular weight to number average molecular weight ratio (Mw / Mn) of about 2 to about 4, a wt % of TREF elution at 90° C. and less of about 10 wt % to about 80 wt %, and a wt % of TREF elution at 95° C. and greater of about 3 wt % or more. Said polyethylene may be especially well-suited for making bicomponent fibers, which may be useful producing in nonwoven fabrics.

The invention belongs to the technical field of cable materials and preparation thereof, and discloses a high-melt-index fire-resistant cable body and a preparation method thereof.The cable body takes modified polyolefin as a matrix, and through in-situ grafting of phosphorus-containing and nitrogen-containing functional monomers, the melt fluidity of a polymer is remarkably improved; and the surface-functionalized nano-micron synergistic composite flame-retardant filler is introduced, so that efficient dispersion and synergistic interaction are realized. During preparation, the modified matrix and the composite filler are integrally extruded and molded in a twin-screw extruder to obtain a cable body with excellent fire-resistant retentivity and mechanical and electrical properties; compared with the prior art, the processing performance and the fire resistance of the material are both considered, the preparation process is simple and convenient, the energy consumption can be greatly reduced, and the fire resistance requirements in building and industrial scenes are met.

The invention discloses an accurate temperature control method and system for regeneration and recovery of injection molding products, and relates to the field of temperature control. The method comprises the following steps: analyzing regenerated plastic components in real time through a near-infrared spectrometer, and obtaining a melt index, a thermal stability parameter and a glass transition temperature; establishing a melt apparent viscosity-temperature-shear rate three-dimensional response curved surface model in combination with a rheology theory; the method comprises the following steps: acquiring temperature gradient and pressure data by utilizing a multi-sensor network deployed in each module of a double-screw extruder, calculating an actual shear rate and melt apparent viscosity, and comparing the actual shear rate and melt apparent viscosity with theoretical values to trigger a PID (Proportion Integration Differentiation) neural network to predict temperature fluctuation so as to carry out differential temperature compensation on a feeding section and a melting section; and after each batch of production, model parameters are optimized by adopting a least square method, so that closed-loop intelligent regulation and control in the processing process of the regenerated plastic are realized. The method has the advantages that through the three-dimensional model, the PID neural network differential temperature control is combined, the temperature control problem of the regenerated plastic is solved, the quality stability of products is improved, and the waste rate is reduced.

The present invention relates to oriented, multilayer polyethylene films. In one aspect, a biaxially oriented, multilayer polyethylene film comprises: at least one inner layer comprising: (1) a polyethylene-based composition that comprises: (a) at least 97% by weight, based on the total weight of the polyethylene-based composition, of one or more polyethylenes having a density between 0.926 g / cm3 to 0.970 g / cm3 and a melt index (I2) between 0.1 to 10 g / 10 min; (b) 20 to 5000 ppm, based on the total weight of the polyethylene-based composition of a sorbitol acetal derivative comprising the structure of formula (I): wherein R1-R5 comprise the same or different moieties chosen from hydrogen and a C1-C3 alkyl.

A polyolefin bonding adhesive film includes a support base layer and a bonding adhesive layer formed on a side surface of the support base layer by co-extrusion. The support base layer is a polypropylene film. The bonding adhesive layer is formed of a first polyolefin copolymer modified by maleic anhydride. The first polyolefin copolymer is formed by copolymerization of at least two kinds of C2 to C4 olefin molecules, a first graft ratio of the maleic anhydride grafted onto the first polyolefin copolymer is between 0.5% and 5%, and a first melt index of the first polyolefin copolymer is between 3 g / 10 min and 5 g / 10 min.

The present invention relates to a polyolefin polymer, and a system and method for polymerizing same, the polymer having a density of 0.868 to 0.897 g / cm3, a melt flow index (MIE, 190°C with a load of 2.16 kg) of 0.1 g / 10 min to 20.0 g / 10 min, a PDI of 1 to 5, a number average molecular weight (Mn) of 20,000 to 70,000 g / mol, a weight average molecular weight (Mw) of 50,000 to 150,000 g / mol, and two or more melting temperatures (Tm).

This disclosure relates to ethylene interpolymer products comprising a Melt Flow-Intrinsic Viscosity Index value, MFIVI, of from ≥0.05 to ≤0.80; a first derivative of a melt flow distribution function, formula (I) at a loading of 4000 g, of from ≥−1.85 to ≤−1.51; a sum of unsaturation, SUMU, from ≥0.047 to ≤0.100 unsaturations per 100 carbon atoms; and a residual QC catalytic metal of from ≥0.03 to ≤5 ppm of hafnium. Ethylene interpolymer products comprise at least two ethylene interpolymers. Ethylene interpolymer products are characterized by a melt index (I2) from 0.3 to 500 dg / minute, a density from 0.855 to 0.975 g / cc and from 0 to 25 mole percent of one or more a-olefins. Ethylene interpolymer products have polydispersity, Mw / Mn, from 1.7 to 25; and CDBI50 values from 1% to 98%. These ethylene interpolymer products have utility in flexible as well as rigid applications.

The invention relates to the technical field of high polymer materials, in particular to a polyethylene flame-retardant master batch and a production process thereof. The polyethylene flame-retardant master batch is prepared from the following raw materials in parts by weight: 50 to 60 parts of polyethylene, 10 to 20 parts of hydroxymethyl phosphinic acid, 15 to 20 parts of HDPE-g-MAH, 0.8 to 1.5 parts of an initiator, 1 to 2 parts of an antioxidant and 3 to 6 parts of functional particles. The polyethylene is selected from high-density polyethylene, and the melt index of the polyethylene is 7-20g / 10min under the conditions of 190 DEG C and 2.16 kg; the polyethylene flame-retardant master batch produced by the invention not only can effectively enhance the flame retardant property of a polyethylene product, but also can effectively improve the anti-aging property of the polyethylene product; and the service life of the polyethylene product is prolonged to a certain extent while the quality of the polyethylene product is ensured.

Disclosed herein is a blown film comprising at least 50 wt.% of a polyethylene composition comprising the reaction product of ethylene and optionally, one or more alpha-olefin comonomers, wherein the polyethylene composition is characterized by the following properties: a melt index, I2, of from 0.1 to 2 g / 10 min; a density of from 0.940 to 0.970 g / cm³; a melt flow ratio, I10 / I2, of from 5.5 to 7.2; and a molecular weight distribution (Mw / Mn) of from 2.2 to 3.5.

The invention relates to a polypropylene material as well as a preparation method and application thereof. The polypropylene material comprises the following components: co-polypropylene, the co-polypropylene comprises a continuous phase formed by a homo-polypropylene chain segment and a rubber phase formed by an ethylene-propylene copolymer chain segment; the isotacticity of the homo-polypropylene chain segment is 98 to 99 percent; the mass percentage content of the rubber phase in the co-polypropylene is 10-15%; the mass percentage content of the ethylene unit in the rubber phase is 20-40%; the melt index of the polypropylene material is 60 to 100g / 10min. Through component design, the polypropylene material provided by the invention has the characteristics of high melt index, high modulus and high impact resistance, and can meet the application requirements of large thin-wall workpieces.

This invention provides a halogen-free flame-retardant foamed composite board and its preparation method. The halogen-free flame-retardant foamed composite board includes a top layer, an intermediate layer, and a bottom layer stacked together. The three-layer sandwich structure is configured, and the composition of the materials in each layer is defined. Specifically, a specific amount of foaming agent is added to the material of the intermediate layer, and the melt index of the first polycarbonate is defined as 6–21 cm⁻¹. 3 / 10min, the melt index of the second polycarbonate is 5-9cm. 3 The process involves adding flame retardants and anti-aging agents to all three layers of material, resulting in a halogen-free flame-retardant foamed composite board that combines high tensile strength, low density, and excellent flame retardant properties. Furthermore, the low bromine and chlorine content contributes to its environmentally friendly characteristics.

The present invention relates to a hinged assembly comprising a polyethylene composition comprising-a high density polyethylene (HDPE) having a density in the range of 950 to 960 kg / m3, measured according to ISO 1183, a melt flow index in the range of 5 to 40 g / 10 min, measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190 DEG C, a weight average molecular weight Mw, measured by size exclusion chromatography, in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0 to 10.0; and-a linear low density polyethylene (LLDPE) having a density in the range of 920 to 940 kg / m3, measured according to ISO 1183, a melt flow index in the range of 1 to 20 g / 10 min, measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190 DEG C, a weight average molecular weight Mw, measured by size exclusion chromatography, in the range of 40,000 to 120,000 g / mol, and a molecular weight distribution Mw / Mn in the range of 3 to 7; wherein the polyethylene composition has an overall density, measured according to ISO 1183, in the range of 935 to 950 kg / m3 and an overall melt flow index, measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190 DEG C, of 5 to 30 g / 10 min; wherein the amount of HDPE is in the range of from 30 to 70% by weight of the total amount of HDPE and LLDPE, and wherein the amount of LLDPE is in the range of from 30 to 70% by weight of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100% by weight of the polyethylene composition.

The invention provides a shoe material particle based on a vinyl polyolefin elastomer material, a preparation method of the shoe material particle and a shoe foaming material, and belongs to the technical field of polyolefin and polymer compositions. Comprising the following components in parts by weight: 100 parts of vinyl polyolefin elastomer, 0.1-2 parts of an initiator, 0.01-0.1 part of an antioxidant and 0.01-0.1 part of a lubricant, wherein the vinyl polyolefin elastomer is a polyolefin elastomer obtained through polymerization reaction by taking ethylene as a single raw material, the melt index is 3-10 g / 10 min, the branching degree is 70-130 branched chains / 1000 carbons, the weight-average molecular weight is 77000-52.1 ten thousand, the molecular weight distribution is 1.0-2.0, the density is 0.860-0.9 g / cm < 3 >, and the melting point is 55-65 DEG C; and the initiator is a peroxide initiator.

The utility model discloses a melt index tester which comprises a tester main body, the outer wall of a charging barrel is in sliding sleeve connection with the tester main body, a heating coil for heating the charging barrel is arranged in the tester main body, the bottom of the charging barrel is connected with a mold outlet, a piston assembly is arranged in the charging barrel, and the piston assembly is arranged in the charging barrel. The piston assembly is used for extruding molten materials in the charging barrel to be discharged, the fixed lantern ring fixedly sleeves the top of the outer wall of the charging barrel, the fixed lantern ring is slidably clamped to the top of the tester main body, and the handle assembly is arranged on the side of the fixed lantern ring. According to the utility model, the tester main body, the charging barrel, the fixed lantern ring, the piston assembly and the handle assembly are matched for use, under the action of the handle, the limiting block and the locking rod, the stability of the connecting plate and the fixed lantern ring mounted on the tester main body can be ensured, the locking rod is driven by the handle to be separated from the limiting block, and the charging barrel can be directly taken out; and therefore, the charging barrel is detached and cleaned.

This invention relates to the field of polymer materials technology, specifically disclosing the application of low melt flow index (MFI) polyoxymethylene (POM) in improving the spinning performance of POM. Using heteropolyacids as catalysts, and controlling the polymerization temperature and the amount of heteropolyacid catalyst added, low MFI POM with a melt flow index of 0.1 g / 10 min to 2.5 g / 10 min was prepared. After compounding this low MFI POM with a heat-stabilizing agent in a certain proportion, it was blended with general-purpose POM and extruded into granules. Unexpectedly, the thermal stability of the POM was significantly improved, and it also exhibited moderate rheological properties. When applied to the melt spinning process, the spinnability of the POM was significantly improved. Compared with the POM without the addition of this low MFI, the draw ratio increased by approximately 1.4 times, and the tensile strength of the POM fiber reached 6–8 g / d, a maximum increase of approximately 1.4 times. The yield and strength of the finished fiber product were significantly improved.

The present disclosure relates to a polymer blend (I) comprising: A) a first polyethylene component in a wt.% A amount from 5 to 80 wt.%, having a density DA from 0.926 to 0.945 g / cm3, a Melt Index MIE from 0.1 to 3 g / 10 min and Mw / Mn of 7 or greater; B) a second polyethylene component in a wt.% B amount from 5 to 80 wt.%, having a density DB from 0.949 to 0.965 g / cm3, a Melt Index MIF from 5 to 28 g / 10 min. and a ratio MIF / MIP from 5 to 10.5; C) a third polyethylene component in a wt.% C amount from 10 to 40 wt.%, having a density DC from 0.949 to 0.965 g / cm3, a Melt Index MIF from 10 to 40 g / 10 min. and a ratio MIF / MIP from 11 to 30; wherein the wt.% A of the first polyethylene component A), the wt.% B of second polyethylene component B) and the wt.% C of third polyethylene component C) are with respect to the overall weight of A) + B) + C).

This invention discloses a thermoplastic elastomer composition, its preparation method, and its applications. The thermoplastic elastomer composition of this invention comprises the following components: PP resin I, SEBS, TPV, glass fiber powder, paraffin oil, antioxidant, and light stabilizer; wherein, the PP resin I conforms to ISO 1133-1-2011 standard, with a melt index of 80–130 g / 10 min at 230°C and 2.16 kg; the SEBS has a weight-average molecular weight of 80,000–160,000; and the TPV comprises PP resin II and EPDM. The thermoplastic elastomer composition of this invention combines PP resin with a specific melt index, SEBS with a specific weight-average molecular weight, and TPV, resulting in a thermoplastic elastomer composition that possesses both high fluidity and low gloss, as well as excellent high-temperature resistance.

A multilayer film suitable for manufacturing a stretch hood used to secure palletized goods during shipment and transport. The multilayer film comprises at least three layers and includes a first layer comprising a linear low density polyethylene resin having a melt index within the range of 0.20 and 0.60 dg / min and a density within the range of 0.910 to 0.914 g / cm3, a second layer comprising a linear low density polyethylene resin having a melt index within the range of 0.20 and 0.60 dg / min and a density within the range of 0.910 to 0.914 g / cm3, and at least one intermediate layer in between the first and second layers, the intermediate layer or layers including a linear low density polyethylene resin having a fractional melt index and a thermoplastic polyolefin having a melt index within the range of 0.30 and 0.70 dg / 10 min and a density within the range of 0.870 to 0.890 g / cm. The multilayer film having a total thickness between 4.85 and 6.7 mils and a density between 0.909 and 0.913 g / cm3. A stretch hood fabricated from such multilayer film exhibits exceptionally high holding force and, provides robust stability when utilized on palletized goods during transport. A method of manufacture of such multilayer film is also provided.

The application belongs to the technical field of precision casting, and particularly relates to a high-viscosity and high-strength precision casting adhesive wax and a preparation method thereof. The adhesive wax comprises the following components: 30-40 parts of paraffin wax, 16-24 parts of microcrystalline wax, 25-30 parts of petroleum resin, 8-14 parts of rosin resin, 5-10 parts of EVA, 2-5 parts of LDPE and 0.1-2 parts of additives; wherein the LDPE is composed of two kinds of LDPE with different melt indexes. By introducing the petroleum resin, rosin resin, ethylene-vinyl acetate copolymer (EVA) and low-density polyethylene (LDPE) into the paraffin wax and microcrystalline wax base system, and controlling the proportion between the resin system and the polyolefin reinforcing system, the adhesive wax has high viscosity and hardness at 100 DEG C, and the bending strength is improved. Thus, the comprehensive performance of the adhesive wax is achieved, i.e., the adhesive wax is not easy to sag at high temperature, is not easy to be pressed at room temperature, and is not easy to crack under stress.