阅读说明：本技术 一种不定向短切纤维增强聚丙烯材料的制备方法 (Preparation method of non-oriented chopped fiber reinforced polypropylene material ) 是由 陈伟鹏 白晓伟 杨磊 杨思敏 顾清波 于 2021-01-19 设计创作，主要内容包括：一种不定向短切纤维增强聚丙烯材料的制备方法,包括如下步骤：步骤一：准确称量聚丙烯、相容剂、抗氧剂、阻燃剂充分混合后通过双螺杆设备熔融挤出,一部分制备出的熔融材料淋膜至特氟龙防粘皮带；步骤二：将专用热塑性玻璃纤维纱短切抛洒沉降铺在树脂膜上；步骤三：将另一部分步骤一得到的熔融材料挤出淋膜至短切玻纤上层；步骤四：通过专用热压浸渍、定型设备,浸渍并冷却定型；步骤五：裁切收卷。本发明制备的产品具有短切玻璃纤维在聚丙烯中均匀分散、纤维长度均匀、力学性能优异,可热复合生产实芯板、作为高强度面皮生产夹芯板直接作为各种木质、钢质板材轻质替代,作为模压材料加热熔融后流动性突出,特别适合复杂异形模压机构件的生产。(A preparation method of a non-directional chopped fiber reinforced polypropylene material comprises the following steps: the method comprises the following steps: accurately weighing polypropylene, a compatilizer, an antioxidant and a flame retardant, fully mixing, melting and extruding through a double-screw device, and laminating a part of prepared molten material to a Teflon anti-sticking belt; step two: spreading the special thermoplastic glass fiber yarns on a resin film in a short-cut throwing and settling manner; step three: extruding and laminating the other part of the molten material obtained in the step one to the upper layer of the chopped glass fiber; step four: dipping and cooling for shaping by special hot-pressing dipping and shaping equipment; step five: and (6) cutting and rolling. The product prepared by the invention has the advantages of uniform dispersion of chopped glass fibers in polypropylene, uniform fiber length and excellent mechanical property, can be used for producing solid core plates by thermal compounding and directly used as light substitutes of various wood and steel plates as sandwich plates produced by high-strength surface skins, has outstanding liquidity after being heated and melted as mould pressing materials, and is particularly suitable for producing complex special-shaped mould pressing machine components.)

1. A preparation method of a non-directional chopped fiber reinforced polypropylene material is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: accurately weighing polypropylene, a compatilizer, an antioxidant and a flame retardant, fully mixing, melting and extruding through a double-screw device, and laminating a part of prepared molten material to a Teflon anti-sticking belt at the running speed of 3-10m/min, wherein the weight of the laminated film per unit area is 50-250 g/square meter;

step two: the special thermoplastic glass fiber yarns are chopped by a chopping device, thrown and settled on a resin film, the chopped length is 3-50mm, and the fiber unit area weight is 100-;

step three: extruding and laminating the other part of the molten material obtained in the step one to the upper layer of the chopped glass fibers, wherein the weight per unit area of the laminated film is 50-250 g/square meter;

step four: dipping and cooling to form sheets with the thickness of 0.15mm-1mm by special hot-pressing dipping and forming equipment, wherein the sheet has the unit area weight of 200 plus 1000 g/square meter;

step five: and cutting and rolling, wherein the rolling width and length are adjusted according to requirements.

2. The method for preparing an unidirectional chopped fiber reinforced polypropylene material as claimed in claim 1, wherein: the adding parts by weight of all the substances in the step one are as follows: 75-94 parts of polypropylene, 1-6 parts of compatilizer, 0.1-1 part of antioxidant and 5-25 parts of flame retardant.

3. The method for preparing a non-oriented chopped fiber reinforced polypropylene material according to claim 1 or 2, wherein:

the melting index of the polypropylene is 10-150g/10 min;

the polypropylene is a mixture of one or two of polypropylene BX3900 or polypropylene BX3920 mixed in any proportion.

4. The method for preparing a non-oriented chopped fiber reinforced polypropylene material according to claim 1 or 2, wherein: the compatilizer is PP grafted maleic anhydride.

5. The method for preparing an unidirectional chopped fiber reinforced polypropylene material as claimed in claim 4, wherein: the compatilizer is a mixture of one or two of PP grafted maleic anhydride 1001 or PP grafted maleic anhydride GPM200A mixed in any proportion.

6. The method for preparing a non-oriented chopped fiber reinforced polypropylene material according to claim 1 or 2, wherein: the antioxidant is hindered phenol antioxidant with high molecular weight.

7. The method for preparing an unidirectional chopped fiber reinforced polypropylene material according to claim 6, wherein: the antioxidant is one or a mixture of two of an antioxidant Irganox1010 and an antioxidant IRGAFOS168 which are mixed according to any proportion.

8. The method for preparing a non-oriented chopped fiber reinforced polypropylene material according to claim 1 or 2, wherein: the flame retardant is a phosphorus-nitrogen flame retardant.

9. The method for preparing an unidirectional chopped fiber reinforced polypropylene material according to claim 8, wherein: the flame retardant is phosphorus-nitrogen flame retardant QB-PN4 or the flame retardant is one or a mixture of two of phosphorus-nitrogen flame retardant Clariant Exolit AP766 mixed in any proportion.

Technical Field

The invention belongs to the field of polypropylene materials, and particularly relates to a preparation method of a non-directional chopped fiber reinforced polypropylene material.

Background

The SMC composite material is subjected to high-temperature one-step compression molding, has the advantages of high mechanical strength, light material weight, corrosion resistance, long service life, high insulating strength, electric arc resistance, flame retardance, good sealing performance, flexible product design, easy large-scale production, safety and attractiveness, has an all-weather protection function, can meet the requirements of various severe environments and places in outdoor engineering projects, overcomes the defects of easy corrosion, short service life, poor heat insulation and preservation performance and the like of outdoor metal equipment boxes, and is widely applied to the fields of telecommunications, electric power, railways and the like. SMC composites, however, suffer from the following drawbacks: 1. toxic volatile substances are discharged in SMC material and product production; 2. the solid waste generated after the product is scrapped cannot be treated 3, the product has higher rigidity, and the product is easy to break after impact.

Disclosure of Invention

The invention provides a preparation method of a non-directional chopped fiber reinforced polypropylene material, which is used for overcoming the defects in the prior art.

The invention is realized by the following technical scheme:

a preparation method of a non-directional chopped fiber reinforced polypropylene material comprises the following steps:

the method comprises the following steps: accurately weighing polypropylene, a compatilizer, an antioxidant and a flame retardant, fully mixing, melting and extruding through a double-screw device, and laminating a part of prepared molten material to a Teflon anti-sticking belt at the running speed of 3-10m/min, wherein the weight of the laminated film per unit area is 50-250 g/square meter;

step two: the special thermoplastic glass fiber yarns are chopped by a chopping device, thrown and settled on a resin film, the chopped length is 3-50mm, and the fiber unit area weight is 100-;

step three: extruding and laminating the other part of the molten material obtained in the step one to the upper layer of the chopped glass fibers, wherein the weight per unit area of the laminated film is 50-250 g/square meter;

step four: dipping and cooling to form sheets with the thickness of 0.15mm-1mm by special hot-pressing dipping and forming equipment, wherein the sheet has the unit area weight of 200 plus 1000 g/square meter;

step five: and cutting and rolling, wherein the rolling width and length are adjusted according to requirements.

The preparation method of the non-oriented chopped fiber reinforced polypropylene material comprises the following steps of: 75-94 parts of polypropylene, 1-6 parts of compatilizer, 0.1-1 part of antioxidant and 5-25 parts of flame retardant.

The preparation method of the non-directional chopped fiber reinforced polypropylene material is characterized in that the melt index of the polypropylene is 10-150g/10 min.

The preparation method of the non-oriented chopped fiber reinforced polypropylene material is characterized in that the polypropylene is a mixture of one or two of polypropylene BX3900 or polypropylene BX3920 mixed in any proportion.

In the preparation method of the non-oriented chopped fiber reinforced polypropylene material, the compatilizer is PP grafted maleic anhydride.

In the preparation method of the non-oriented chopped fiber reinforced polypropylene material, the compatilizer is a mixture of one or two of PP grafted maleic anhydride 1001 or PP grafted maleic anhydride GPM200A mixed in any proportion.

In the preparation method of the non-oriented chopped fiber reinforced polypropylene material, the antioxidant is high molecular weight hindered phenol antioxidant.

In the preparation method of the non-oriented chopped fiber reinforced polypropylene material, the antioxidant is one or a mixture of two of the antioxidant Irganox1010 and the antioxidant IRGAFOS168 which are mixed in any proportion.

In the preparation method of the non-oriented chopped fiber reinforced polypropylene material, the flame retardant is a phosphorus-nitrogen flame retardant.

In the preparation method of the non-oriented chopped fiber reinforced polypropylene material, the flame retardant is the phosphorus-nitrogen flame retardant QB-PN4 or the flame retardant is one or a mixture of two of the phosphorus-nitrogen flame retardants Clariant Exolit AP766 mixed in any proportion.

The invention has the advantages that: the product prepared by the invention has the characteristics of uniform dispersion of chopped glass fibers in polypropylene, uniform fiber length, good interface combination, excellent mechanical property, no release of small molecular volatile matters in the subsequent processing and use processes, good fluidity after heating and the like, can be used for producing solid core plates by thermal compounding and used as high-strength surface skins to produce sandwich plates to be directly used as light substitutes for various wood and steel plates, is used as a die pressing material to be heated and melted and has outstanding fluidity, and is particularly suitable for producing complicated special-shaped die pressing machine components.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic illustration of a product of the present invention;

FIG. 2 is a process flow diagram of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Examples

The method comprises the following steps: accurately weighing polypropylene, a compatilizer, an antioxidant and a flame retardant, fully mixing, melting and extruding through a double-screw device, and laminating a part of prepared molten material to a Teflon anti-sticking belt at the running speed of 5m/min, wherein the weight of the laminated unit area is 150 g/square meter;

step two: the special thermoplastic glass fiber yarns are chopped by a chopping device, thrown and settled on a resin film, the chopped length is 15mm, and the weight per unit area of the fibers is 300 g/square meter;

step three: extruding and laminating the other part of the molten material obtained in the step one to the upper layer of the chopped glass fibers, wherein the weight per unit area of the laminated film is 150 g/square meter;

step four: dipping and cooling to form a sheet with the thickness of 0.5mm by special hot-pressing dipping and forming equipment, wherein the sheet has the weight per unit area of 500 g/square meter;

step five: taking a material with the single weight of 800 g/square meter and the thickness of 4mm as a skin, taking the sheet obtained in the step four as a core material, preheating for 6min at 200 ℃, and putting into a press for pressing the sandwich board.

Comparative example

The material with the weight of 200g per square meter and the thickness of 0.18mm is taken as the skin, the weight per unit area of light GMT is 1650g per square meter, the heat is preheated for 6min at 200 ℃, and the light GMT is put into a press to press the sandwich board.

The performance of the sandwich panels prepared in the examples and the comparative examples was compared, and the results are shown in the table.

Item	Thickness of	Singleweight	Maximum load	Bending strength
					Unit of	mm	g/㎡	N	MPa
Examples	8.5	2100	39.7	7.2
					Comparative example	8.5	2050	29.0	4.9

Watch 1

The data in table one show that the performance of the sandwich panel prepared in example 1 of the present invention is improved by 47% compared with the comparative example, and the sandwich panel has a smooth appearance and can be directly used as a decorative surface.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.