An ultra-thin wide-width high-temperature-resistant vacuum bag film and a preparation method thereof

Abstract

The application provides a kind of ultra-thin wide high-temperature-resistant vacuum bag film, the vacuum bag film is multilayer co-extrusion composite film, the multilayer co-extrusion composite film includes outer surface layer, secondary outer surface layer, intermediate layer, secondary inner surface layer and inner surface layer in turn from top to bottom, according to weight fraction, intermediate layer includes 95-98 parts SEBS-g-MAH and 2-5 parts temperature resistant modifier;Outer surface layer and inner surface layer all include 45-60 parts homopolymer PA66, 35-50 parts copolymer PA66, 1-2 parts slip master batch, 1-2 parts temperature resistant modifier, 1-2 parts antistatic agent master batch, 1-2 parts fluorinated material;Outer surface layer additionally adds 2 parts green color master batch;Secondary outer surface layer and secondary inner surface layer all include 45-60 parts homopolymer PA6, 35-50 parts copolymer PA6, 4-8 parts EMA material toughening master batch.The application also discloses its preparation method.The vacuum bag film of the application not only has the advantages of heat stability, low-temperature brittle fracture resistance, high tensile strength, easy peelability, the maximum use temperature can reach 230 DEG C, and its thickness can reach 28-100 μm, width reaches 16 m.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vacuum bag film, in particular to an ultra-thin large-width high-temperature-resistant vacuum bag film and a preparation method thereof. BACKGROUND

[0002] With the improvement of wind turbine technology, large-scale wind turbine capacity has become a development trend, which puts forward higher requirements for the size and temperature resistance of vacuum auxiliary materials. Breaking through the technical barriers of foreign countries, preparing an ultra-thin large-width high-temperature-resistant new vacuum bag film that can meet the vacuum infusion molding process and hot-pressing molding process will have important application prospects in the fields of large-blade wind power manufacturing, aerospace and rail transportation industry chain, and is of great significance to the high-quality development of high-end manufacturing process composite material technology in China.

[0003] CN206048956U "Modified vacuum bag film", by compounding an antioxidant modified polyethylene layer between the two composite layers, the shelf life of the vacuum bag film can be prolonged, the heat aging resistance of the vacuum bag film in the wind power blade forming process is improved, and the obtained vacuum bag film has good toughness and does not become brittle, but the prepared film is not easy to separate from the resin after use.

[0004] CN106009631A discloses a high-temperature-resistant vacuum bag film, which is blow molded by mixing the following materials by weight: homopolymer nylon: 50-75 parts; copolymer nylon: 15-35 parts; elastomer: 2-10 parts; heat stabilizer: 1-4 parts; color masterbatch: 0.2-2 parts. The highest use temperature of the high-temperature-resistant vacuum bag film of the application can reach 215℃, which meets the strength, modulus, and temperature resistance requirements of vacuum bag film in the aerospace field, and guarantees the air tightness requirement of the vacuum bag, but the flexibility of the high-temperature-resistant vacuum bag film of the application needs to be further improved.

[0005] CN110481128A discloses a vacuum bag film with double-sided release function and a preparation method thereof, which is made of PE, Tie, and PA by multi-layer material co-extrusion blow molding, including: PE: 40-65 parts; PA: 30-55 parts; Tie: 2-4 parts; color masterbatch: 0.1-2 parts; other additives: 0.1-2 parts; wherein, PA is a copolymer of PA6 and PA66, PE layer material is a mixture of LDPE and HDPE, the mixing ratio is: HDPE: 15-40 parts; LDPE: 60-85 parts; the interlayer design of multi-layer material is: five-layer co-extrusion PE / Tie / PA / Tie / PE. The application meets the air tightness requirement of the vacuum bag film itself, and also has the isolation function of the isolation film, which can isolate the resin, but the temperature resistance of the vacuum bag film is not enough, and it cannot be used in the field of aerospace.

[0006] CN105038204A discloses a kind of high-temperature-resistant vacuum bag film and its preparation method, which is made of the mixture of PA6 and PA66 or PA66 as base material, and heat stabilizer and slip agent are added as auxiliary agent to make corresponding film.The vacuum bag film obtained by the invention has no curling, melting, rupture and other abnormalities when baked at 170-230 DEG C for 2 hours, the tensile strength is between 75-85 MPa, the breaking rate is greater than 300%, and the highest use temperature can reach 230 DEG C, which meets the molding requirements of most resin systems, far higher than the limitation of existing composite film 120 DEG C, but the extrusion process of the invention is complicated, which is not conducive to industrialization, and the width and thickness are not specified. SUMMARY

[0007] The present application selects materials and optimizes the formula of the vacuum bag film, and designs the structure of multi-layer co-extrusion and interlayer, so that the vacuum bag film has heat stability, low-temperature brittleness resistance, high tensile strength and easy peelability, and can be wide and thin, and the thickness uniformity of the vacuum bag film is ensured.

[0008] To achieve one of the purposes of the present application, the present application provides the following technical solutions:

[0009] In a first aspect, the present application provides a high-temperature-resistant vacuum bag film with ultra-thin and wide width, which is a multi-layer co-extrusion composite film, and the multi-layer co-extrusion composite film comprises, from top to bottom, an outer surface layer, a secondary outer surface layer, a middle layer, a secondary inner surface layer and an inner surface layer.

[0010] According to weight fraction, the middle layer comprises 95-98 parts of SEBS-g-MAH and 2-5 parts of temperature-resistant modifier.

[0011] The outer surface layer and the inner surface layer each comprise 45-60 parts of homopolymer PA66, 35-50 parts of copolymer PA66, 1-2 parts of slip master batch, 1-2 parts of temperature-resistant modifier, 1-2 parts of antistatic agent master batch and 1-2 parts of fluorinated material, and the outer surface layer further comprises 2 parts of green color master batch.

[0012] The secondary outer surface layer and the secondary inner surface layer each comprise 45-60 parts of homopolymer PA6, 35-50 parts of copolymer PA6 and 4-8 parts of EMA material toughening master batch.

[0013] The thickness of the inner surface layer accounts for 12.5%-20% of the thickness of the vacuum bag film; the thickness of the outer surface layer accounts for 12.5%-20% of the thickness of the vacuum bag film; the thickness of the secondary inner surface layer accounts for 12.5%-20% of the thickness of the vacuum bag film; the thickness of the secondary outer surface layer accounts for 12.5%-20% of the thickness of the vacuum bag film; and the thickness of the middle layer accounts for 30%-50% of the thickness of the vacuum bag film.

[0014] The vacuum bag film has a thickness of 28-100 μm, and the film width can reach 16 m.

[0015] In some embodiments, the temperature-resistant modifier is a compound of copper salt and phenolic antioxidant. The temperature-resistant modifier can improve the temperature-resistant performance of the intermediate layer, thereby further improving the temperature-resistant performance of the vacuum bag film. The addition of the temperature-resistant modifier can maintain the chemical stability of the homo-polymer PA66 and co-polymer PA66, so that the long-term heat resistance of the PA66 is good, thereby ensuring the long-term heat resistance of the vacuum bag film.

[0016] In some embodiments, the slip master batch is a compound of erucic acid amide and natural silica.

[0017] In some embodiments, the antistatic agent master batch is a glyceride antistatic agent master batch.

[0018] In some embodiments, the fluorinated material refers to a fluoropolymer; preferably, the fluoropolymer is ethylene trifluoro chloroethylene copolymer.

[0019] In some embodiments, the thickness of the inner surface layer and the outer surface layer is consistent, and the thickness of the secondary inner surface layer and the secondary outer surface layer is consistent.

[0020] In a second aspect, the present application provides a preparation method of an ultra-thin large-width high-temperature-resistant vacuum bag film, which comprises the following steps:

[0021] Step 1) preparing materials according to the weight ratio, and loading the materials of the outer surface layer, the secondary outer surface layer, the intermediate layer, the secondary inner surface layer and the inner surface layer into five hoppers of a spiral plastic extruder;

[0022] Step 2) melting and plasticizing through the spiral plastic extruder, under the action of the pressure in the barrel of the spiral plastic extruder and the forward thrust of the screw, the melt-like materials are transported to the die head of a five-layer co-extrusion film blowing machine, and after being compounded through the die head and blown into a tubular vacuum bag film at the die head, the obtained vacuum bag film is drawn, stretched, folded and wound, to obtain a vacuum bag film product; wherein the screw extrusion temperature of the inner surface layer and the outer surface layer of the screw plastic extruder is 260-280 ℃, the rotation speed is 20-80 rpm, and the extrusion processing pressure is 10-30 Mpa;

[0023] The screw extrusion temperature of the secondary inner surface layer and the secondary outer surface layer of the screw plastic extruder is 255-270 ℃, the rotation speed is 20-80 pm, and the extrusion processing pressure is 10-25 Mpa;

[0024] The screw extrusion temperature of the SEBS-g-MAH layer of the intermediate layer of the screw plastic extruder is 250-265 ℃, the rotation speed is 20-80 rpm, and the extrusion processing pressure is 10-25 Mpa.

[0025] In some embodiments, the screw length-diameter ratio is 28-32:1, preferably 30:1, and the cooperation of the thread structure and the length-diameter ratio enables each material to be fully melted and uniformly mixed by shearing and transporting at high temperature.

[0026] In some embodiments, the die temperature of the film blowing machine of the screw plastic extruder is 250-265 DEG C, the blow-up ratio is 1.4-2.2, and the winding speed is 10-55 m / min.

[0027] Compared with the prior art, the present application has the following beneficial effects:

[0028] The vacuum bag film provided by the present application is a multi-layer co-extrusion composite film. The co-polymer PA66 material of the outer surface layer and the inner surface layer can endow the vacuum bag film with superior mechanical properties such as tensile strength and elongation at break. The homopolymer PA66 contained therein has a short-term heat resistance that is 10 DEG C or more higher than that of the co-polymer PA66. A moderate increase in the proportion of the homopolymer PA66 can improve the short-term heat resistance of the film. In some embodiments, a decrease in the proportion of the homopolymer PA66 will cause the vacuum film to melt and shrink at 230 DEG C, and the temperature resistance cannot reach 230 DEG C. On this basis, the present application further adds a temperature-resistant modifier to the outer surface layer and the inner surface layer to ensure the long-term heat resistance of the outer surface layer and the inner surface layer. The long-term heat resistance focuses more on the durability and stability of the material, while the short-term heat resistance focuses more on the critical point of the material under high-temperature impact or drastic changes. The vacuum bag film provided by the present application takes into account both the long-term heat resistance and the short-term heat resistance. The vacuum bag film prepared by the present application has a maximum use temperature of 230 DEG C. In addition, the addition of other auxiliary agents to the outer surface layer and the inner surface layer of the present application can further improve the easy-peeling performance, flexibility and anti-aging property of the vacuum bag film.

[0029] Further, the vacuum bag film provided by the present application uses homopolymer PA6, co-polymer PA6 and EMA material toughening masterbatch as raw materials for the secondary outer surface layer and the secondary inner surface layer. The PA6 has better impact strength and flex fatigue life, and the effective cooperation of the co-polymer PA6 and the homopolymer PA6 endows the film with better flexibility and impact resistance. The addition of the EMA material toughening masterbatch can further improve the toughness of the material. In addition, the intermediate layer of the present application is a blown film grade maleic anhydride grafted SEBS material with high toughness and temperature resistance. The intermediate layer improves the flexibility of the vacuum bag film. The multi-layer combination of the intermediate layer and the PA material improves the shortcomings of the pure PA film, such as poor toughness and easy brittle cracking when used at low temperature and low humidity. The ultra-thin vacuum bag film prepared has good toughness. In addition, the SEBS grafted with maleic anhydride (SEBS-g-MAH) makes the SEBS have a certain polarity, which can ensure the adhesion of the SEBS with the PA material layer, i.e. the secondary outer surface layer and the secondary inner surface layer. In addition, the temperature-resistant modifier prepared by compounding copper salt and phenolic antioxidant in the intermediate layer significantly improves the heat resistance and stability, thereby ultimately ensuring the high heat stability of the film.

[0030] Finally, the thickness ratio of the intermediate layer SEBS-g-MAH layer plays a key role in the toughness of the vacuum bag film. If the thickness of the intermediate layer SEBS-g-MAH layer is too small, the vacuum bag film with an ultra-thin thickness will cause instability in the film blowing process, and the film will be severely broken. The proportion of SEBS-g-MAH plays a decisive role in whether the vacuum bag film can reach an ultra-thin thickness of 28 μm.

[0031] In addition, the preparation method of the present application can promote the obtained vacuum bag film to have a thickness of 28-100 μm and a width of not less than 16 m, i.e. to obtain an ultra-thin large-width vacuum bag film. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The present application provides an ultra-thin large-width high-temperature-resistant vacuum bag film structure schematic diagram.

[0033] Figure 2 The present application provides a vacuum bag film product form schematic diagram. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present application. If the specific technology or condition is not specified in the embodiments, it is carried out according to the technology or condition described in the literature in the art or according to the product instruction. If the reagent or instrument is not specified by the manufacturer, it is a conventional product that can be obtained from the market.

[0035] TERMS EXPLANATION:

[0036] "PA66" refers to polyamide 66;

[0037] "PA6" refers to polyamide 6;

[0038] "SEBS-g-MAH" refers to a copolymer of styrene block copolymer (styrene / ethylene-butylene / styrene) grafted with maleic anhydride.

[0039] The "smooth master batch" used in the following examples refers to a mixture master batch of 1:1 erucic amide and natural silica with PA as the carrier, and the additive accounts for 5%;

[0040] Glycerol ester antistatic agent master batch: glycerol ester antistatic agent is CJ483A, Dongguan Color Plastic Products Co., Ltd.;

[0041] Fluorinated material refers to fluorine-containing polymer, ethylene chlorotrifluoroethylene copolymer ECTFE, 6014, Sinopec USA;

[0042] “EMA material toughening masterbatch” refers to ethylene methyl acrylate toughening aid, 15024S, DuPont, USA;

[0043] Temperature resistance modifier, namely “copper salt and phenolic compound antioxidant masterbatch” refers to the general copper salt antioxidant and phenolic antioxidant that can be purchased in the market, which is compounded with PA as the carrier according to 1:1, and the antioxidant masterbatch is obtained, and the additive ratio is 5%;

[0044] Green color masterbatch; green masterbatch GN70605, Suzhou Zhuocai New Material Co., Ltd.

[0045] Example 1

[0046] (1) Preparation of materials (all parts are weight parts)

[0047] Preparation of inner and outer layers of PA66:

[0048] Homopolymer PA66: 48 parts, copolymer PA66: 48 parts, slip masterbatch: 1 part, temperature resistance modifier: 1 part, antistatic agent masterbatch: 1 part, fluorinated material: 1 part, and 2 parts of green color masterbatch are additionally added to the outer layer, which is uniformly blended by using a high-speed mixer and then reserved.

[0049] Preparation of inner and outer layers of PA6 (polyamide 6):

[0050] Homopolymer PA6: 48 parts, copolymer PA6: 48 parts, EMA material toughening masterbatch: 4 parts, which is uniformly blended by using a high-speed mixer and then reserved.

[0051] Preparation of SEBS-g-MAH layer:

[0052] SEBS-g-MAH: 98 parts, copper salt and phenolic compound antioxidant masterbatch: 2 parts, which is uniformly blended by using a high-speed mixer and then reserved.

[0053] (2) Preparation process

[0054] The preparation process includes the following steps:

[0055] According to the interlayer structure of the five-layer co-extrusion screw extruder, each layer material is loaded into the hopper of the screw plastic extruder, and is plasticized and melted through the screw plastic extruder. The screw extrusion temperature of the inner surface layer PA66 layer and the outer surface layer PA66 layer is 265℃, the rotation speed is 20rpm, and the extrusion processing pressure is 10Mpa; the screw extrusion temperature of the secondary inner surface layer PA6 layer and the secondary outer surface layer PA6 layer is 260℃, the rotation speed is 20pm, and the extrusion processing pressure is 10Mpa; the screw extrusion temperature of the intermediate layer SEBS-g-MAH layer is 260℃, the rotation speed is 52rpm, and the extrusion processing pressure is 15Mpa; the inner cooling air volume is 10000m 3 / h, the air speed is 10m / s, the outer cooling air volume is 40000m 3 / h, the air speed is 20m / s; the die temperature is 260℃, the blow ratio is 1.5, the film thickness is 40μm, the film width is 14m, and the winding speed is 15m / min.

[0056] As shown in Figure 1 , the thickness of the prepared inner surface layer PA66 layer 1 and the outer surface layer PA66 layer 5 accounts for 15% of the thickness of the vacuum bag film, the thickness of the inner surface layer PA6 layer 2 and the secondary outer surface layer PA6 layer 4 accounts for 15% of the thickness of the vacuum bag film, and the thickness of the intermediate layer SEBS-g-MAH layer 3 accounts for 40% of the thickness of the vacuum bag film.

[0057] Example 2

[0058] (1) Preparation of materials (all parts are weight parts)

[0059] Preparation of inner surface layer PA66 layer and outer surface layer PA66 layer material:

[0060] Homopolymer PA66: 56 parts, copolymer PA66: 40 parts, slip master batch: 1 part, temperature resistance modifier: 1 part, antistatic agent master batch: 1 part, fluorinated material: 1 part, 2 parts of green color master batch are additionally added to the outer surface layer, and the high mixer is used for blending uniformly and standby.

[0061] Preparation of secondary inner surface layer PA6 layer and secondary outer surface layer PA6 layer material:

[0062] Homopolymer PA6: 56 parts, copolymer PA6: 38 parts, EMA material toughening master batch: 6 parts, and the high mixer is used for blending uniformly and standby.

[0063] Preparation of intermediate layer SEBS-g-MAH layer material:

[0064] SEBS-g-MAH: 98 parts, copper salt and phenolic compound compounded antioxidant master batch: 2 parts, and the high mixer is used for blending uniformly and standby.

[0065] (2) Preparation process

[0066] The preparation process comprises the following steps:

[0067] According to the interlayer structure of the five-layer co-extrusion screw extruder, each layer of material is loaded into each hopper of the screw plastic extruder and is plasticized and melted through the screw plastic extruder. The screw extrusion temperature of the inner surface layer PA66 layer and the outer surface layer PA66 layer is 270 DEG C, the rotating speed is 20 rpm, and the extrusion processing pressure is 15 Mpa; the screw extrusion temperature of the secondary inner surface layer PA6 layer and the secondary outer surface layer PA6 layer is 260 DEG C, the rotating speed is 15 pm, and the extrusion processing pressure is 10 Mpa; the screw extrusion temperature of the intermediate layer SEBS-g-MAH layer is 260 DEG C, the rotating speed is 30 rpm, and the extrusion processing pressure is 12 Mpa; the inner cooling air volume is 10000 m 3 / h, the air speed is 10 m / s, the outer cooling air volume is 40000 m 3 / h, the air speed is 20 m / s; the die temperature is 260 DEG C, the blow ratio is 1.6, the film thickness is 28 μm, the film width is 16 m, and the winding speed is 22 m / min.

[0068] The thickness of the prepared inner surface layer PA66 layer 1 and the outer surface layer PA66 layer 5 accounts for 20% of the thickness of the vacuum bag film, the thickness of the inner surface layer PA6 layer 2 and the secondary outer surface layer PA6 layer 4 accounts for 15% of the thickness of the vacuum bag film, and the thickness of the intermediate layer SEBS-g-MAH layer 3 accounts for 30% of the thickness of the vacuum bag film.

[0069] Example 3

[0070] (1) Preparation of materials (all parts are weight parts)

[0071] Preparation of the inner surface layer PA66 layer and the outer surface layer PA66 layer material:

[0072] Homopolymer PA66: 57 parts, copolymer PA66: 38 parts, slip master batch: 1 part, temperature resistance modifier: 1 part, antistatic agent master batch: 1 part, fluorinated material: 2 parts, 2 parts of green color master batch are additionally added to the outer surface layer, and the high mixer is used for blending to obtain a uniform material.

[0073] Preparation of the secondary inner surface layer PA6 layer and the secondary outer surface layer PA6 layer material:

[0074] Homopolymer PA6: 54 parts, copolymer PA6: 38 parts, EMA material toughening master batch: 8 parts, and the high mixer is used for blending to obtain a uniform material.

[0075] Preparation of the intermediate layer SEBS-g-MAH layer material:

[0076] SEBS-g-MAH: 97 parts, copper salt and phenolic compound compounded antioxidant master batch: 3 parts, and the high mixer is used for blending to obtain a uniform material.

[0077] (2) Preparation process

[0078] The preparation process comprises the following steps:

[0079] According to the five-layer co-extrusion screw extruder interlayer structure, each layer of material is loaded into the hopper of the screw plastic extruder, and is plasticized and melted through the screw plastic extruder. The screw extrusion temperature of the inner surface layer PA66 layer and the outer surface layer PA66 layer is 273℃, the rotation speed is 20rpm, and the extrusion processing pressure is 17Mpa; the screw extrusion temperature of the secondary inner surface layer PA6 layer and the secondary outer surface layer PA6 layer is 258℃, the rotation speed is 15pm, and the extrusion processing pressure is 11Mpa; the screw extrusion temperature of the intermediate layer SEBS-g-MAH layer is 260℃, the rotation speed is 30rpm, and the extrusion processing pressure is 12Mpa; the inner cooling air volume is 10000m 3 / h, the air speed is 10m / s, the outer cooling air volume is 40000m 3 / h, the air speed is 20m / s; the die temperature is 265℃, the blow ratio is 1.6, the film thickness is 28μm, the film width is 16m, and the winding speed is 22m / min.

[0080] The thickness of the prepared inner surface layer PA66 layer 1 and the outer surface layer PA66 layer 5 accounts for 20% of the thickness of the vacuum bag film, the thickness of the inner surface layer PA6 layer 2 and the secondary outer surface layer PA6 layer 4 accounts for 15% of the thickness of the vacuum bag film, and the thickness of the intermediate layer SEBS-g-MAH layer 3 accounts for 30% of the thickness of the vacuum bag film.

[0081] Example 4

[0082] (1) Prepare the material (all parts are weight parts)

[0083] Preparation of the inner surface layer PA66 layer and the outer surface layer PA66 layer material:

[0084] Homopolymer PA66: 57 parts, copolymer PA66: 38 parts, slip master batch: 1 part, temperature resistance modifier: 1 part, antistatic agent master batch: 1 part, fluorinated material: 2 parts, 2 parts of green color master batch are additionally added to the outer surface layer, and the high mixer is used for blending uniformly and standby.

[0085] Preparation of the secondary inner surface layer PA6 layer and the secondary outer surface layer PA6 layer material:

[0086] Homopolymer PA6: 54 parts, copolymer PA6: 38 parts, EMA material toughening master batch: 8 parts, and the high mixer is used for blending uniformly and standby.

[0087] Preparation of the intermediate layer SEBS-g-MAH layer material:

[0088] SEBS-g-MAH: 97 parts, copper salt and phenolic compound compounded antioxidant master batch: 3 parts, and the high mixer is used for blending uniformly and standby.

[0089] (2) Preparation process

[0090] The preparation process comprises the following steps:

[0091] According to the interlayer structure of the five-layer co-extrusion screw extruder, each layer of material is loaded into the hopper of the screw plastic extruder and plasticized and melted through the screw plastic extruder. The screw extrusion temperature of the inner surface layer PA66 layer and the outer surface layer PA66 layer is 273°C, the rotation speed is 46 rpm, and the extrusion processing pressure is 30 Mpa; the screw extrusion temperature of the secondary inner surface layer PA6 layer and the secondary outer surface layer PA6 layer is 258°C, the rotation speed is 35 pm, and the extrusion processing pressure is 22 Mpa; the screw extrusion temperature of the intermediate layer SEBS-g-MAH layer is 260°C, the rotation speed is 69 rpm, and the extrusion processing pressure is 25 Mpa; the inner cooling air volume is 10000 m 3 / h, the air speed is 10 m / s, the outer cooling air volume is 40000 m 3 / h, the air speed is 20 m / s; the die temperature is 265°C, the blow ratio is 1.6, the film thickness is 65 μm, the film width is 16 m, and the winding speed is 22 m / min.

[0092] The thickness of the inner surface layer PA66 layer 1 and the outer surface layer PA66 layer 5 accounts for 20% of the thickness of the vacuum bag film, the thickness of the inner surface layer PA6 layer 2 and the secondary outer surface layer PA6 layer 4 accounts for 15% of the thickness of the vacuum bag film, and the thickness of the intermediate layer SEBS-g-MAH layer 3 accounts for 30% of the thickness of the vacuum bag film.

[0093] Example 5

[0094] (1) Preparation of materials (all parts are by weight)

[0095] Preparation of inner surface layer PA66 layer and outer surface layer PA66 layer material:

[0096] Homopolymer PA66: 48 parts, copolymer PA66: 48 parts, slip master batch (erucamide: natural silica = 1:1): 1 part, temperature resistance modifier: 1 part, antistatic agent master batch: 1 part, fluorinated material: 1 part, 2 parts of green color master batch are additionally added to the outer surface layer, and the mixture is uniformly blended by using a high-speed mixer and then reserved.

[0097] Preparation of secondary inner surface layer PA6 layer and secondary outer surface layer PA6 layer material:

[0098] Homopolymer PA6: 46 parts, copolymer PA6: 46 parts, EMA material toughening master batch: 8 parts, and the mixture is uniformly blended by using a high-speed mixer and then reserved.

[0099] Preparation of intermediate layer SEBS-g-MAH layer material:

[0100] SEBS-g-MAH: 98 parts, copper salt and phenolic compound compounded antioxidant masterbatch: 2 parts, use high mixer to blend uniformly and reserve.

[0101] (2) Preparation process

[0102] The preparation process comprises the following steps:

[0103] According to the interlayer structure of the five-layer co-extrusion screw extruder, the materials of each layer are loaded into the hoppers of the screw plastic extruder respectively, and then plasticized and melted by the screw plastic extruder. The screw extrusion temperature of the inner and outer surface layers of PA66 is 265℃, the rotation speed is 20rpm, and the extrusion processing pressure is 10Mpa; the screw extrusion temperature of the secondary inner and outer surface layers of PA6 is 260℃, the rotation speed is 20pm, and the extrusion processing pressure is 10Mpa; the screw extrusion temperature of the middle layer of SEBS-g-MAH is 260℃, the rotation speed is 38rpm, and the extrusion processing pressure is 12Mpa; the inner cooling air volume is 10000m 3 / h, the air speed is 10m / s, the outer cooling air volume is 40000m 3 / h, the air speed is 20m / s; the die temperature is 260℃, the blow ratio is 1.4, the film thickness is 29μm, the film width is 12m, and the winding speed is 22m / min.

[0104] The thickness of the inner surface layer of PA66 layer 1 and the outer surface layer of PA66 layer 5 accounts for 17% of the thickness of the vacuum bag film, the thickness of the inner surface layer of PA6 layer 2 and the outer surface layer of PA6 layer 4 accounts for 17% of the thickness of the vacuum bag film, and the thickness of the middle layer of SEBS-g-MAH layer 3 accounts for 32% of the thickness of the vacuum bag film.

[0105] Comparative Example 1

[0106] (1) Preparation of materials (all parts are weight parts)

[0107] Preparation of inner surface layer of PA66 and outer surface layer of PA66:

[0108] Homopolymer PA66: 38 parts, copolymer PA66: 57 parts, slip masterbatch (erucamide: natural silica = 1:1): 1 part, temperature resistance modifier: 1 part, antistatic agent masterbatch: 1 part, fluorinated material: 1 part, 2 parts of green color masterbatch are additionally added to the outer surface layer, and the mixture is uniformly blended by using a high-speed mixer and then reserved.

[0109] Preparation of secondary inner surface layer of PA6 and secondary outer surface layer of PA6:

[0110] Homopolymer PA6: 54 parts, copolymer PA6: 38 parts, EMA material toughening masterbatch: 8 parts, use high mixer to blend uniformly and reserve.

[0111] Preparation of the middle layer SEBS-g-MAH layer material:

[0112] SEBS-g-MAH: 97 parts, copper salt and phenolic compound compounded antioxidant masterbatch: 3 parts, and then uniformly blended with a high-speed mixer for standby.

[0113] (2) Preparation process

[0114] The preparation process includes the following steps:

[0115] According to the five-layer co-extrusion screw extruder interlayer structure, the materials of each layer are respectively loaded into the hoppers of the screw plastic extruder for plasticizing and melting. The screw extrusion temperature of the inner and outer surface layers PA66 is 265°C, the rotation speed is 20 rpm, and the extrusion processing pressure is 15 MPa; the screw extrusion temperature of the secondary inner and outer surface layers PA6 is 260°C, the rotation speed is 30 rpm, and the extrusion processing pressure is 12 MPa; the screw extrusion temperature of the middle layer SEBS-g-MAH is 260°C, the rotation speed is 38 rpm, and the extrusion processing pressure is 12 MPa; the inner cooling air volume is 10000 m 3 / h, the air speed is 10 m / s, the outer cooling air volume is 40000 m 3 / h, the air speed is 20 m / s; the die temperature is 265°C, the blow ratio is 1.6, the film thickness is 28 μm, the film width is 16 m, and the winding speed is 22 m / min.

[0116] The thickness of the inner surface layer PA66 layer 1 and the outer surface layer PA66 layer 5 accounts for 20% of the thickness of the vacuum bag film, the thickness of the inner surface layer PA6 layer 2 and the secondary outer surface layer PA6 layer 4 accounts for 15% of the thickness of the vacuum bag film, and the thickness of the middle layer SEBS-g-MAH layer 3 accounts for 30% of the thickness of the vacuum bag film.

[0117] Comparative Example 2

[0118] (1) Preparation of materials (all parts are by weight)

[0119] Preparation of the inner surface layer PA66 layer and the outer surface layer PA66 layer material:

[0120] Homopolymer PA66: 48 parts, copolymer PA66: 48 parts, slip masterbatch (erucamide: natural silica = 1:1): 1 part, temperature resistance modifier: 1 part, antistatic agent masterbatch: 1 part, fluorinated material: 1 part, and 2 parts of green color masterbatch are additionally added to the outer surface layer, and then uniformly blended with a high-speed mixer for standby.

[0121] Preparation of the secondary inner surface layer PA6 layer and the secondary outer surface layer PA6 layer material:

[0122] Homopolymer PA6: 48 parts, copolymer PA6: 48 parts, EMA material toughening masterbatch: 4 parts, use high mixer to blend uniformly and reserve.

[0123] Intermediate layer SEBS-g-MAH layer material preparation:

[0124] SEBS-g-MAH: 98 parts, copper salt and phenolic compound antioxidant masterbatch: 3 parts, use high mixer to blend uniformly and reserve.

[0125] (2) Preparation process

[0126] The preparation process includes the following steps:

[0127] According to the five-layer co-extrusion screw extruder interlayer structure, the materials of each layer are loaded into the hoppers of the screw plastic extruder respectively, and then plasticized and melted through the screw plastic extruder. The screw extrusion temperature of the inner and outer surface PA66 layers is 265℃, the rotation speed is 20rpm, and the extrusion processing pressure is 10Mpa; the screw extrusion temperature of the secondary inner and outer surface PA6 layers is 260℃, the rotation speed is 20pm, and the extrusion processing pressure is 10Mpa; the screw extrusion temperature of the intermediate layer SEBS-g-MAH layer is 260℃, the rotation speed is 20rpm, and the extrusion processing pressure is 6Mpa; the inner cooling air volume is 10000m 3 / h, the air speed is 10m / s, the outer cooling air volume is 40000m 3 / h, the air speed is 20m / s; the die temperature is 260℃, the blow ratio is 1.5, the film thickness is 40μm, and the winding speed is 15m / min.

[0128] The thickness of the inner surface PA66 layer 1 and the outer surface PA66 layer 5 accounts for 20% of the thickness of the vacuum bag film, the thickness of the inner surface PA6 layer 2 and the secondary outer surface PA6 layer 4 accounts for 20% of the thickness of the vacuum bag film, and the thickness of the intermediate layer SEBS-g-MAH layer 3 accounts for 20% of the thickness of the vacuum bag film.

[0129] Comparative Example 3

[0130] This comparative example is basically the same as Example 2, the only difference is that no temperature-resistant modifier is added in the formula of each layer of raw materials, and finally a vacuum bag film is obtained.

[0131] The properties of the vacuum bag films obtained in Examples 1-5 and Comparative Examples 1-3 are tested, and the results are shown in Table 1 below.

[0132] Table 1

[0133]

[0134]

[0135] From the above examples, comparative examples and performance tables, it can be seen that the highest use temperature of the present application can reach 230°C, the thinnest film thickness can reach 28pm, the widest film can reach 16m, the tensile strength, elongation at break, water vapor transmission and oxygen transmission can all meet the technical requirements; the content of homopolymer PA66 in comparative example 1 is only 38 parts, because the short-term heat resistance of homopolymer PA66 is higher than that of copolymer PA66 by more than 10°C, the content of homopolymer PA66 in this comparative example is lower than the required range, so the vacuum bag film has already melted and shrunk at 230°C, and the temperature resistance cannot reach 230°C; in comparative example 2, the content of SEBS-g-MAH layer in the middle layer is only 20% of the thickness of the vacuum bag film, which is lower than the required range, and cannot effectively improve the toughness of the vacuum bag film, resulting in unstable blowing process of the vacuum bag film and serious film breakage, which shows that the content of SEBS-g-MAH plays a key role in whether the vacuum bag film can reach the thickness of 28pm.

[0136] Example 6

[0137] As shown in Figure 2 , the vacuum bag films obtained in examples 1-5 are subjected to traction stretching and folding and winding, the 16m wide vacuum bag film is converted into a 4m folded width vacuum bag film for winding, and the vacuum bag film products are respectively made into sheet (SHT) 101, center fold (CF) 102, flat tube (LFT) 103, gusset flat tube (GT) 104, gusset (G) 105, for easy storage and customer selection.

[0138] The above examples only describe the preferred embodiments of the present application, and do not limit the scope of the present application, and those skilled in the art can make various modifications and improvements to the technical solutions of the present application without departing from the design spirit of the present application, which shall fall within the protection scope determined by the claims of the present application.

Claims

1. A high-temperature resistant vacuum bag film with ultra-thin and wide width, characterized in that, The vacuum bag film is a multilayer co-extruded composite film, which, from top to bottom, includes an outer layer, a second outer layer, an intermediate layer, a second inner layer, and an inner layer. The intermediate layer comprises 95-98 parts of SEBS-g-MAH and 2-5 parts of temperature-resistant modifier by weight. Both the outer and inner outer layers comprise 45-60 parts of homopolymer PA66, 35-50 parts of copolymer PA66, 1-2 parts of slip masterbatch, 1-2 parts of temperature-resistant modifier, 1-2 parts of antistatic agent masterbatch, and 1-2 parts of fluorinated material. The outer layer also comprises 2 parts of green color masterbatch. Both the secondary outer surface layer and the secondary inner surface layer comprise 45-60 parts of homopolymer PA6, 35-50 parts of copolymer PA6, and 4-8 parts of toughening masterbatch of EMA material. The thickness of the inner surface layer accounts for 12.5% ​​to 20% of the thickness of the vacuum bag film; the thickness of the outer surface layer accounts for 12.5% ​​to 20% of the thickness of the vacuum bag film; the thickness of the second inner surface layer accounts for 12.5% ​​to 20% of the thickness of the vacuum bag film; the thickness of the second outer surface layer accounts for 12.5% ​​to 20% of the thickness of the vacuum bag film; the thickness of the vacuum bag film is 28 to 100 μm, the film width is 12 m, 14 m or 16 m, and the temperature resistance is 230℃; the temperature resistance modifier is a compound of copper salt and phenolic antioxidant.

2. The ultra-thin, wide-format, high-temperature resistant vacuum bag film according to claim 1, characterized in that, The slip masterbatch is a compound of erucamide and natural silica.

3. The ultra-thin, wide-format, high-temperature resistant vacuum bag film according to claim 1, characterized in that, The antistatic agent masterbatch is a glycerol ester-based antistatic agent masterbatch.

4. The ultra-thin, wide-format, high-temperature resistant vacuum bag film according to claim 1, characterized in that, The fluorinated material mentioned refers to a fluorinated polymer.

5. The ultra-thin, wide-format, high-temperature resistant vacuum bag film according to claim 4, characterized in that, The fluoropolymer is an ethylene-chlorotrifluoroethylene copolymer.

6. The ultra-thin, wide-format, high-temperature resistant vacuum bag film according to claim 1, characterized in that, The inner and outer layers have the same thickness, and the secondary inner and secondary outer layers have the same thickness.

7. The method for preparing the vacuum bag film according to any one of claims 1 to 6, characterized in that, The preparation method includes the following steps: Step 1) Prepare the materials according to the weight ratio, and load the materials of the outer surface layer, the second outer surface layer, the middle layer, the second inner surface layer and the inner surface layer into the five hoppers of the screw plastic extruder respectively; Step 2) After plasticizing and melting in the screw plastic extruder, the molten material is transported to the die head of the five-layer co-extrusion blown film machine under the pressure inside the barrel of the screw plastic extruder and the forward thrust of the screw. After being compounded by the die head and blown into a tubular vacuum bag film at the die, the obtained vacuum bag film is stretched, folded and rolled up to obtain the vacuum bag film product. The inner and outer screw extrusion temperatures of the screw plastic extruder are 260℃~280℃, the rotation speed is 20~80rpm, and the extrusion processing pressure is 10~30Mpa. The screw extrusion temperature of the inner and outer surfaces of the screw plastic extruder is 255℃~270℃, the speed is 20~80rpm, and the extrusion processing pressure is 10~25Mpa; The intermediate SEBS-g-MAH layer of the screw plastic extruder has an extrusion temperature of 250℃~265℃, a rotation speed of 20~80rpm, and an extrusion processing pressure of 10~25Mpa.

8. The method for preparing the vacuum bag film according to claim 7, characterized in that, The screw has a length-to-diameter ratio of 28 to 32:

1. Through the combination of the thread structure and the length-to-diameter ratio, the materials are fully melted and mixed evenly at high temperatures through shearing and transport.

9. The method for preparing the vacuum bag film according to claim 7, characterized in that, The length-to-diameter ratio of the screw is 30:

1.

10. The method for preparing the vacuum bag film according to claim 7, characterized in that, The die temperature of the blown film extruder of the screw plastic extruder is 250℃-265℃.

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