BMC composite material, production method and application thereof

Abstract

The invention provides a BMC composite material as well as a production method and application thereof. The BMC composite material comprises the following raw materials in parts by weight: 40-50% of recycled short glass fiber powder, 20-25% of recycled thermosetting resin powder, 15-20% of unsaturated resin, 5-8% of styrene, 10-15% of calcium carbonate, 0.2-0.4% of a curing agent and 0.4-0.6% of an internal release agent. According to the invention, the ratio of recycled materials is up to about 60-70%, so that the utilization rate of process waste materials is greatly improved; through a cross-linking reaction, unsaturated resin and recycled short glass fiber powder form a framework-filling structure, so that the bearing performance of the BMC composite material is enhanced; a solvent-free modification process is adopted, so that chemical pollution is avoided, and environmental friendliness is improved; the reclaimed materials are used for replacing new materials, so that the cost of production materials is greatly reduced, and meanwhile, the disposal cost of hazardous wastes is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material preparation, in particular to a BMC composite material. Background Art

[0002] Since thermosetting waste is difficult to treat, its molecular chains are cross-linked and solidified, and cannot be recycled through traditional heating and softening. In addition, traditional modification processes have limitations. Some technologies attempt to modify thermosetting resins with chemical solvents, but these require the use of strong acids or organic solvents, which result in high costs and secondary pollution. Therefore, existing technologies mostly use incineration or landfill to treat thermosetting waste, causing environmental pollution and waste of resources.

[0003] Based on the above reasons, currently bulk molding compounds (BMC) are mostly prepared from new materials, with a very small proportion of recycled materials added, and are mainly made from ordinary plastic scraps, resulting in a low resource utilization rate. Summary of the Invention

[0004] The purpose of the present invention is to provide a BMC composite material, a production method and its application, so as to solve the current problems of difficulty in treating thermosetting waste and low resource utilization of BMC composite materials.

[0005] To solve the above problems, the present invention first provides a BMC composite material, comprising the following raw materials in parts by weight: 40-50% recycled short glass fiber powder, 20-25% recycled thermosetting resin powder, 15-20% unsaturated resin, 5-8% styrene, 10-15% calcium carbonate, 0.2-0.4% curing agent, and 0.4-0.6% internal release agent.

[0006] Furthermore, the curing agent is tert-butyl perbenzoate.

[0007] Furthermore, the method comprises the following raw materials in parts by weight: 40% recycled short glass fiber powder, 20% recycled thermosetting resin powder, 20% unsaturated resin, 6.5% styrene, 12.5% ​​calcium carbonate, 0.4% curing agent, 0.53% internal release agent, and 0.07% pigment paste.

[0008] The present invention also provides a method for producing a BMC composite material as described in the above technical solution, comprising the following steps: fully stirring an unsaturated resin and styrene to form a matrix resin; kneading and mixing the mixture with recycled short glass fiber powder, recycled thermosetting resin powder, calcium carbonate, a curing agent, and an internal release agent; placing the mixture in a mold and compression molding it at 140-150° C. and 5 MPa; wherein the modification process is achieved by initiating styrene cross-linking peroxide.

[0009] Furthermore, the kneading and mixing speed is 300-800 r / min, the time is 1-3 hours, and the negative pressure environment is maintained.

[0010] The present invention also provides an application of the BMC composite material as described in any one of the above technical solutions for preparing manhole covers.

[0011] According to a BMC composite material, production method and application provided by the present invention, the proportion of recycled materials is as high as about 60-70%, which greatly improves the utilization rate of process waste; and through a cross-linking reaction, the unsaturated resin and the recycled short glass fiber powder form a "skeleton-filler" structure, thereby enhancing the load-bearing performance of the BMC composite material; the solvent-free modification process avoids chemical pollution and improves environmental protection; the use of recycled materials instead of new materials greatly reduces the cost of production materials and reduces the cost of hazardous waste disposal. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0013] Figure 1 This is the cross-linking reaction chemical formula for the BMC composite material production process provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0014] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0015] Example 1 BMC composite material

[0016] To address the current difficulties in handling thermosetting waste and the low resource utilization of BMC composite materials, this embodiment provides a BMC composite material that can effectively utilize recycled materials, such as resin and glass fiber materials recovered from waste circuit boards, thereby greatly improving resource utilization.

[0017] The raw material ratio (weight percentage) of BMC composite material is:

[0018] Recycled components: 40-50% recycled short glass fiber powder, 20-25% recycled thermosetting resin powder;

[0019] Matrix components: unsaturated resin 15-20%, styrene 5-8%;

[0020] Additives: calcium carbonate 10-15%, curing agent 0.2-0.4%, internal release agent 0.4-0.6%.

[0021] Among them, t-butyl perbenzoate is preferably used as the curing agent, and a suitable proportion of pigment paste can be added as needed to adjust the color.

[0022] Example 2 BMC composite material

[0023] The raw material ratio (weight percentage) of the BMC composite material provided in this embodiment is:

[0024] Recycled short glass fiber powder 40%, recycled thermosetting resin powder 20%, unsaturated resin 20%, styrene 6.5%, calcium carbonate 12.5%, curing agent 0.4%, internal release agent 0.53%, pigment paste 0.07%.

[0025] Example 3 BMC composite material production method

[0026] In traditional processes, resin powder and short glass fiber powder recovered from the crushing of waste circuit boards are generally considered by those skilled in the art to be thermosetting plastic waste that cannot be directly reused. However, by adding the auxiliary materials of the present invention and undergoing a cross-linking reaction, and then high-temperature pressing, a strong BMC material can be made, breaking the perception that "waste is useless". The specific production method is as follows:

[0027] Prepare raw materials according to the ingredient ratio of Example 1 or 2;

[0028] Stirring: fully stir the unsaturated resin and styrene in a disperser to form a matrix resin, for example, stirring at 600 r / min for 2 hours. The stirring parameters can be adjusted as needed;

[0029] Kneading and forming: put the base resin and other raw materials into the kneader to form a uniform mass, preferably stirring at 500r / min for 1.5h;

[0030] Compression molding: the mass is weighed and placed into the mold, and pressed at 160°C and 8MPa for 15 minutes. After molding, the product is taken out of the mold and can be blown clean with a high-pressure air gun.

[0031] The product is cooled naturally to room temperature, and preferably the edges and corners are manually deburred, and the finished BMC composite material is obtained after packaging.

[0032] In the production process of this embodiment, styrene is used as a cross-linking agent and a peroxide curing agent (tert-butyl perbenzoate is used in this embodiment) is used as an initiator. The free radicals released by the peroxide can simultaneously open the double bonds in the unsaturated resin molecules and the styrene molecules; the resin molecules are simply divided into "~~C=C~~", so the styrene and the resin after the double bonds are opened are mainly as shown in the following table. The cross-linking reaction process of styrene and resin is as follows: Figure 1 shown.

[0033]

[0034] Example 4 Application of BMC composite materials

[0035] The BMC composite materials provided in Examples 1 and 2, as well as the BMC composite material prepared according to the production method of Example 3, can be used to produce manhole cover products.

[0036] The performance test of the BMC composite manhole cover produced by the formula of Example 2 and the production method of Example 3 was carried out. The test contents are as follows:

[0037] This test is based on the CJ / T121-2000 standard and uses the RJG-1-Z-600 manhole cover to test its load-bearing performance. Among them, the numbering adopts the provisions in the industry standard: the numbering of the recycled resin composite manhole cover consists of four parts: product code (RJG) structural type, single layer (1), double layer (2); load-bearing level: light (Q), general (P), heavy (Z); main parameters: nominal diameter of the circular manhole cover (mm).

[0038] 1. Test basis and standard requirements

[0039] Load-bearing grade: Heavy (Z), corresponding to test load 240kN, allowable residual deformation ≤D / 500 (≤1.2mm when D=600mm).

[0040] Testing equipment: hydraulic press (loading capacity ≥ 360kN, force measurement error ≤ ± 3%);

[0041] Rigid spacer (diameter 356mm±1mm, thickness ≥40mm);

[0042] Rubber gasket (thickness 6-10mm, plane size consistent with the pad).

[0043] 2. Test methods and steps

[0044] Sample pretreatment:

[0045] Take 3 sets of RJG-1-Z-600 manhole covers and place them in an environment of 23±2℃ for 48 hours to ensure stable performance.

[0046] Load the test program:

[0047] Step 1: 2 / 3 test load cycle loading: load to 160 kN (240 kN × 2 / 3) at a speed of 2 kN / s, hold for 1 min, then unload, repeat 5 times;

[0048] The center deformation of the manhole cover before the first loading and after the fifth unloading was measured, and the residual deformation was calculated.

[0049] Step 2: Load the full test load to 240 kN at the same speed, maintain for 5 minutes and then unload;

[0050] Check whether there are cracks on the surface of the manhole cover and support, and record the load-displacement curve.

[0051] Deformation measurement:

[0052] A displacement sensor with an accuracy of 0.01mm is used to measure the vertical displacement of the center of the manhole cover relative to the support.

[0053] 3. Test Results

[0054] The standard requirements of the test items and the average values ​​of the three groups of test data are as follows:

[0055]

[0056] In addition, an additional overload test was carried out: when loaded to 392kN, the residual deformation was 1.5mm (still less than D / 400), and the manhole cover did not crack, indicating a safety factor of 2.8 times.

[0057] The present invention provides a BMC composite material, production method, and application. Using thermosetting resin powder and short glass fiber powder recovered from waste circuit boards as primary raw materials, with the recycled content reaching up to 70%, the material is compounded with unsaturated resin, styrene, and additives. Through a solvent-free peroxide-induced crosslinking process with styrene, the thermosetting waste is repurposed. This material can be used in the manufacture of manhole covers, addressing the low recycled content and difficulty in utilizing thermosetting waste from existing BMC materials.

[0058] The present invention greatly improves the utilization rate of process waste, and through cross-linking reaction, the unsaturated resin and recycled short glass fiber powder form a "skeleton-filler" structure, thereby enhancing the load-bearing performance of the BMC composite material; the solvent-free modification process avoids chemical pollution and improves environmental protection; the use of recycled materials instead of new materials greatly reduces the cost of production materials and reduces the cost of hazardous waste disposal.

[0059] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

[0060] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0061] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0062] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A BMC composite material, characterized in that: It includes the following raw materials in parts by weight: Recycled short glass fiber powder 40-50%, recycled thermosetting resin powder 20-25%, unsaturated resin 15-20%, styrene 5-8%, calcium carbonate 10-15%, curing agent 0.2-0.4%, internal release agent 0.4-0.6%.

2. The BMC composite material according to claim 1, characterized in that: The curing agent is tert-butyl perbenzoate.

3. The BMC composite material according to claim 2, characterized in that: It includes the following raw materials in parts by weight: Recycled short glass fiber powder 40%, recycled thermosetting resin powder 20%, unsaturated resin 20%, styrene 6.5%, calcium carbonate 12.5%, curing agent 0.4%, internal release agent 0.53%, pigment paste 0.07%.

4. A method for producing a BMC composite material according to any one of claims 1 to 3, characterized in that: The following steps are involved: The unsaturated resin and styrene are fully stirred to form a base resin; Knead and mix with recycled short glass fiber powder, recycled thermosetting resin powder, calcium carbonate, curing agent and internal release agent; Put the mixed material into the mold and press it into shape at 140-150℃ and 5MPa; The modification process is initiated by styrene cross-linking peroxide.

5. The method for producing the BMC composite material according to claim 4, characterized in that: The kneading and mixing process is carried out at a rotation speed of 300-800 r / min for 1-3 hours, and a negative pressure environment is maintained.

6. An application of the BMC composite material according to any one of claims 1 to 3, characterized in that: Used for preparing manhole covers.

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