Low-smoke low-toxicity coal mine plastic whole-core flame-retardant conveying belt and preparation method thereof
Patent Information
- Application Number
- CN202610494725.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-15
- Publication Date
- 2026-10-27
AI Technical Summary
Traditional solid-core flame-retardant plastic conveyor belts are prone to delamination and debonding under high load, alternating hot and cold, or humid environments. When burning, they produce thick black smoke, which seriously affects visibility in coal mines and hinders escape and rescue.
It adopts a three-layer composite structure of plastic core, core paste layer and capping adhesive. The outer surface of the plastic core is provided with triangular grooves and four-cornered pyramidal through holes. The core paste layer passes through the four-cornered pyramidal through holes. Combined with a highly efficient flame retardant system such as zinc phosphomolybdate and zinc borate, plant secretions and peony seed oil are used to reduce combustion smoke and toxicity.
It significantly improves interlayer bonding strength, reduces delamination and degumming, has a short open flame burning time and a short flameless burning time, produces little smoke and has low toxicity during combustion, meets the safety standards for flame-retardant conveyor belts used in coal mines, and reduces the risk of smoke asphyxiation and poisoning in fires.
Smart Images
Figure CN122402986A8_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of flame-retardant conveyor belt technology, specifically relating to a low-smoke, low-toxicity plastic solid-core flame-retardant conveyor belt for coal mines and its preparation method. Background Technology
[0002] Traditional plastic cores and core paste, as well as core paste and capping adhesive, are mostly in simple physical contact or bonding. Under long-term high-load operation, alternating hot and cold environments, or humid conditions, peeling, delamination, or debonding can easily occur between the layers. When delamination occurs between the layers, the conveyor belt becomes loose. If a fire breaks out, it will accelerate combustion and produce thick black smoke. In the confined and narrow space of a coal mine, the smoke will spread rapidly, causing a sharp drop in visibility and severely hindering personnel escape and rescue command. Summary of the Invention
[0003] The purpose of this invention is to provide a low-smoke, low-toxicity plastic solid-core flame-retardant conveyor belt for coal mines and its preparation method in order to solve the above-mentioned problems.
[0004] The present invention achieves the above objectives through the following technical solutions:
[0005] This invention provides a low-smoke, low-toxicity plastic solid core flame-retardant conveyor belt for coal mines. The plastic solid core flame-retardant conveyor belt uses a plastic solid core as the central skeleton. A core paste layer is attached to the surface of the plastic solid core. After the core paste layer is formed, a cover rubber is applied to obtain the plastic solid core flame-retardant conveyor belt. The cover rubber serves to increase wear resistance and seal the plastic solid core and the core paste layer.
[0006] The plastic core is obtained by heating and melting plastic resin particles, injecting the melt into a mold, and then demolding it after cooling.
[0007] The thickness of the plastic core is 8-15mm, the thickness of the core paste layer is 12-20mm, and the thickness of the capping adhesive is 5-10mm.
[0008] By weight, the core paste layer is prepared by extruding and cooling the core paste compound. The core paste compound comprises 30-35 parts of polyvinyl chloride paste resin, 20-25 parts of zinc phosphomolybdate, 6-11 parts of microcrystalline wax, 1-3 parts of antioxidant KY-405, 5-10 parts of peony seed oil, 12-16 parts of decabromodiphenyl ether and 1-3 parts of phosphite.
[0009] By weight, the materials used to prepare the capping adhesive include 25-40 parts of PVC suspension resin, 75-85 parts of nitrile rubber powder, 5-8 parts of amphibole powder, 10-15 parts of zinc borate, 1-3 parts of sulfur, 15-25 parts of zinc phosphomolybdate, 0.5-2.5 parts of antioxidant KY-405, 1-5 parts of glyceryl monostearate, 1-2 parts of phosphite, and 5-15 parts of plant secretions.
[0010] As a further optimization of the present invention, the outer surface of the plastic core is provided with triangular grooves, the triangular grooves are arranged at equal intervals, and a four-cornered pyramidal through hole is opened between every two triangular grooves. The opening of the four-cornered pyramidal through hole is larger at the top and smaller at the bottom, and the core paste layer passes through the four-cornered pyramidal through hole.
[0011] As a further optimization of the present invention, a circular ring is provided inside the four-cornered pyramidal through hole, and the circular ring plays a role in stabilizing the shape of the four-cornered pyramidal through hole.
[0012] As a further optimization of the present invention, the preparation process of plant secretions is as follows: (i) wash the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle, remove the surface soil, and air dry the surface moisture; (ii) straighten and bundle the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle after air drying the surface moisture; (iii) cut off the front end, tilt the cut end downwards so that the secretion drips, and after 2 minutes, make a horizontal cut again 3 cm above the cut end, repeating this process until the bundle is completely cut, and collect the secretion.
[0013] As a further optimization of the present invention, the mass ratio of *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, *Taraxacum mongolicum*, and *Sonchus oleraceus* is 1:1:0.3:0.5:1.2.
[0014] As a further optimization of the present invention, the plastic resin particles are nylon 6 resin granules.
[0015] As a further optimization of the present invention, the preparation process of the core paste is as follows: (i) Zinc phosphomolybdate, microcrystalline wax, antioxidant KY-405 and decabromodiphenyl ether are dried in a forced-air drying oven at 80-100℃ for 2-4 hours, put into a mixer and stir at 550r / min for 2-5min, add peony seed oil and stir at 60r / min for 5-8min to obtain a mixed paste; (ii) Polyvinyl chloride paste resin is added to the mixed paste at 45℃ and stirred at 60r / min for 15-20min, add phosphite and stir at 60r / min for 15-20min to obtain the core paste.
[0016] As a further optimization of the present invention, the preparation process of the capping adhesive is as follows: (i) At 120°C, PVC suspension resin is added with amphibole powder and zinc borate at a stirring speed of 35 r / min and stirred for 10 min. Zinc phosphomolybdate and antioxidant KY-405 are added at a stirring speed of 25 r / min and stirred for 10 min. The mixture is stirred at 15 r / min for 10 min to obtain the base adhesive. Glyceryl monostearate and phosphite are added and placed in a planetary mixer. When the temperature drops to 40-50°C, nitrile rubber powder and plant secretion liquid are added and stirred at 25 r / min for 45-60 min. Sulfur is added and stirred at 1200-1500 r / min for 45-60 min to obtain the capping adhesive.
[0017] This invention also provides a method for preparing a low-smoke, low-toxicity plastic solid-core flame-retardant conveyor belt for coal mines, comprising the following steps:
[0018] S1, the core paste material is extruded and bonded to the outside of the plastic core by an extruder at an extrusion die temperature of 160-170℃, an extrusion pressure of 10-15MPa, and a traction speed of 0.3-0.8m / min to obtain a plastic core with an attached core paste layer.
[0019] S2, the capping rubber is extruded and bonded to the outside of the plastic core with the core paste layer by an extruder, at an extrusion die temperature of 160-170℃, an extrusion pressure of 15-20MPa, and a traction speed of 0.5-1.2m / min, to obtain a plastic core flame-retardant conveyor belt.
[0020] The beneficial effects of this invention are as follows: This invention adopts a three-layer composite structure of plastic core, core paste layer, and cover rubber. The outer surface of the plastic core is provided with triangular grooves and four-cornered pyramidal through holes. The core paste layer can penetrate the four-cornered pyramidal through holes, so that the core paste layer and the plastic core form a mechanical interlocking and anchoring structure, which significantly improves the interlayer bonding force and avoids problems such as delamination, degumming, and bulging during use, resulting in stronger structural stability. The core paste layer and cover rubber are compounded with a highly efficient flame retardant system such as zinc phosphomolybdate, zinc borate, and decabromodiphenyl ether, which work synergistically to exert a flame retardant effect, resulting in a short open flame burning time, a short flameless burning time, and strong self-extinguishing property, meeting the stringent safety standards for flame-retardant conveyor belts used in coal mines. The environmentally friendly components such as plant secretions and peony seed oil result in low smoke output, low specific optical density, and low toxicity index of combustion products during combustion, significantly reducing the risk of smoke asphyxiation and poisoning in fires, making it more suitable for confined spaces such as underground coal mines. Attached Figure Description
[0021] Figure 1 This is a three-dimensional schematic diagram of the plastic core in Embodiments 1-2 of the present invention;
[0022] Figure 2 This is a schematic diagram of the plastic core in Embodiments 1-2 of the present invention;
[0023] Figure 3 This is a three-dimensional schematic diagram of the plastic core in Comparative Example 2 of the present invention;
[0024] Figure 4 This is a three-dimensional schematic diagram of the plastic core in Comparative Example 3 of the present invention. Detailed Implementation
[0025] The present application will now be described in further detail. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0026] Unless otherwise specified, all methods used in this invention are conventional methods known to those skilled in the art, and all reagents and materials used are commercially available products.
[0027] Example 1
[0028] like Figure 1-2 The plastic solid core flame-retardant conveyor belt uses a plastic solid core as its central skeleton. A core paste layer is attached to the surface of the plastic solid core. After the core paste layer is formed, a cover rubber is applied to obtain the plastic solid core flame-retardant conveyor belt. The cover rubber increases wear resistance and seals the plastic solid core and the core paste layer. The plastic solid core is obtained by heating and melting plastic resin granules (nylon 6 resin granules), injecting the melt into a mold, and then demolding after cooling. The thickness of the plastic solid core is 8mm, the thickness of the core paste layer is 12mm, and the thickness of the cover rubber is 5mm. The outer surface of the plastic solid core has triangular grooves arranged at equal intervals. A quadrangular pyramidal through hole is formed between every two triangular grooves. The opening of the quadrangular pyramidal through hole is wider at the top and narrower at the bottom. The core paste layer passes through the quadrangular pyramidal through hole. A circular ring is provided inside the quadrangular pyramidal through hole to stabilize its shape. The plastic solid core has arc-shaped outer edges on both sides.
[0029] The preparation process of plant secretions is as follows: (i) Wash the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle (the mass ratio of *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle is 1:1:0.3:0.5:1.2) to remove the surface soil and air dry the surface moisture; (ii) Straighten and bundle the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle after air drying the surface moisture; (iii) Cut off the front end, tilt the cut end downwards so that the secretion drips, and after 2 minutes, make a horizontal cut again 3 cm above the cut end. Repeat this process until the bundle is completely cut and collect the secretion.
[0030] The preparation process of the core paste is as follows: (i) 20 parts of zinc phosphomolybdate, 6 parts of microcrystalline wax, 1 part of antioxidant KY-405 and 12 parts of decabromodiphenyl ether are dried in a forced-air drying oven at 80°C for 2 hours, put into a mixer and stir at 550r / min for 2min, add 5 parts of peony seed oil and stir at 60r / min for 5min to obtain a mixed paste; (ii) 30 parts of polyvinyl chloride paste resin are added to the mixed paste at 45°C and stirred at 60r / min for 15min, add 1 part of phosphite and stir at 60r / min for 15min to obtain the core paste.
[0031] The preparation process of the capping adhesive is as follows: (I) At 120℃, 25 parts of PVC suspension resin are stirred at 35r / min with 5 parts of amphibole powder and 10 parts of zinc borate for 10min. At 25r / min, 15 parts of zinc phosphomolybdate and 0.5 parts of antioxidant KY-405 are stirred for 10min. After stirring at 15r / min for 10min, the base adhesive is obtained. 1 part of glyceryl monostearate and 1 part of phosphite are added and placed in a planetary mixer. When the temperature drops to 40℃, 75 parts of nitrile rubber powder and 5 parts of plant secretion liquid are added and stirred at 25r / min for 45min. 1 part of sulfur is added and stirred at 1200r / min for 45min to obtain the capping adhesive.
[0032] The core paste is extruded and bonded to the outside of the plastic core using an extruder at an extrusion die temperature of 160°C, an extrusion pressure of 10 MPa, and a traction speed of 0.3 m / min to obtain a plastic core with an attached core paste layer.
[0033] The capping adhesive is extruded and bonded to the outside of the plastic core with the core paste layer by an extruder. The extrusion die temperature is 160℃, the extrusion pressure is 15MPa, and the traction speed is 0.5m / min to obtain a plastic core flame-retardant conveyor belt.
[0034] Example 2
[0035] like Figure 1-2The plastic solid core flame-retardant conveyor belt uses a plastic solid core as its central skeleton. A core paste layer is attached to the surface of the plastic solid core. After the core paste layer is formed, a cover rubber is applied to obtain the plastic solid core flame-retardant conveyor belt. The cover rubber increases wear resistance and seals the plastic solid core and the core paste layer. The plastic solid core is obtained by heating and melting plastic resin granules (nylon 6 resin granules), injecting the melt into a mold, and then demolding after cooling. The thickness of the plastic solid core is 12mm, the thickness of the core paste layer is 16mm, and the thickness of the cover rubber is 8mm. The outer surface of the plastic solid core has triangular grooves arranged at equal intervals. A quadrangular pyramidal through hole is formed between every two triangular grooves. The opening of the quadrangular pyramidal through hole is wider at the top and narrower at the bottom. The core paste layer passes through the quadrangular pyramidal through hole. A circular ring is provided inside the quadrangular pyramidal through hole to stabilize its shape. The plastic solid core has arc-shaped outer edges on both sides.
[0036] The preparation process of plant secretions is as follows: (i) Wash the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle (the mass ratio of *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle is 1:1:0.3:0.5:1.2) to remove the surface soil and air dry the surface moisture; (ii) Straighten and bundle the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle after air drying the surface moisture; (iii) Cut off the front end, tilt the cut end downwards so that the secretion drips, and after 2 minutes, make a horizontal cut again 3 cm above the cut end. Repeat this process until the bundle is completely cut and collect the secretion.
[0037] The preparation process of the core paste is as follows: (I) 22 parts of zinc phosphomolybdate, 8 parts of microcrystalline wax, 2 parts of antioxidant KY-405 and 14 parts of decabromodiphenyl ether are dried in a forced-air drying oven at 90°C for 3 hours, put into a mixer and stir at 550r / min for 4min, add 8 parts of peony seed oil and stir at 60r / min for 6min to obtain a mixed paste; (II) 32 parts of polyvinyl chloride paste resin are added to the mixed paste at 45°C and stirred at 60r / min for 18min, add 2 parts of phosphite and stir at 60r / min for 18min to obtain the core paste.
[0038] The preparation process of the capping adhesive is as follows: (I) At 120℃, 35 parts of PVC suspension resin are mixed with 6 parts of amphibole powder and 12 parts of zinc borate at a stirring speed of 35r / min and stirred for 10min. At a stirring speed of 25r / min, 20 parts of zinc phosphomolybdate and 2 parts of antioxidant KY-405 are added and stirred for 10min. The mixture is stirred at 15r / min for 10min to obtain the base rubber. 3 parts of glyceryl monostearate and 2 parts of phosphite are added and placed in a planetary mixer. The temperature is lowered to 45℃ and 80 parts of nitrile rubber powder and 10 parts of plant secretion liquid are added and stirred at 25r / min for 55min. 2 parts of sulfur are added and stirred at 1350r / min for 55min to obtain the capping adhesive.
[0039] The core paste is extruded and bonded to the outside of the plastic core using an extruder at an extrusion die temperature of 165°C, an extrusion pressure of 12MPa, and a traction speed of 0.5m / min to obtain a plastic core with an attached core paste layer.
[0040] The capping adhesive is extruded and bonded to the outside of the plastic core with the core paste layer by an extruder. The extrusion die temperature is 165℃, the extrusion pressure is 18MPa, and the traction speed is 0.8m / min to obtain a plastic core flame-retardant conveyor belt.
[0041] Example 3
[0042] like Figure 1-2 The plastic solid core flame-retardant conveyor belt uses a plastic solid core as its central skeleton. A core paste layer is attached to the surface of the plastic solid core. After the core paste layer is formed, a cover rubber is applied to obtain the plastic solid core flame-retardant conveyor belt. The cover rubber increases wear resistance and seals the plastic solid core and the core paste layer. The plastic solid core is obtained by heating and melting plastic resin granules (nylon 6 resin granules), injecting the melt into a mold, and then demolding after cooling. The thickness of the plastic solid core is 15mm, the thickness of the core paste layer is 20mm, and the thickness of the cover rubber is 10mm. The outer surface of the plastic solid core has triangular grooves arranged at equal intervals. A quadrangular pyramidal through hole is formed between every two triangular grooves. The opening of the quadrangular pyramidal through hole is wider at the top and narrower at the bottom. The core paste layer passes through the quadrangular pyramidal through hole. A circular ring is provided inside the quadrangular pyramidal through hole to stabilize its shape. The plastic solid core has arc-shaped outer edges on both sides.
[0043] The preparation process of plant secretions is as follows: (i) Wash the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle (the mass ratio of *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle is 1:1:0.3:0.5:1.2) to remove the surface soil and air dry the surface moisture; (ii) Straighten and bundle the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle after air drying the surface moisture; (iii) Cut off the front end, tilt the cut end downwards so that the secretion drips, and after 2 minutes, make a horizontal cut again 3 cm above the cut end. Repeat this process until the bundle is completely cut and collect the secretion.
[0044] The preparation process of the core paste is as follows: (I) 25 parts of zinc phosphomolybdate, 11 parts of microcrystalline wax, 3 parts of antioxidant KY-405 and 16 parts of decabromodiphenyl ether are dried in a forced-air drying oven at 100°C for 4 hours, put into a mixer and stir at 550r / min for 5min, add 10 parts of peony seed oil and stir at 60r / min for 8min to obtain a mixed paste; (II) 35 parts of polyvinyl chloride paste resin are added to the mixed paste at 45°C and stirred at 60r / min for 20min, add 3 parts of phosphite and stir at 60r / min for 20min to obtain the core paste.
[0045] The preparation process of the capping adhesive is as follows: (I) At 120℃, 40 parts of PVC suspension resin are stirred at 35r / min with 8 parts of amphibole powder and 15 parts of zinc borate for 10min. Then, 25 parts of zinc phosphomolybdate and 2.5 parts of antioxidant KY-405 are stirred at 25r / min for 10min. The mixture is stirred at 15r / min for 10min to obtain the base adhesive. 5 parts of glyceryl monostearate and 2 parts of phosphite are added and placed in a planetary mixer. When the temperature drops to 50℃, 85 parts of nitrile rubber powder and 15 parts of plant secretion liquid are added and stirred at 25r / min for 60min. 3 parts of sulfur are added and stirred at 1500r / min for 60min to obtain the capping adhesive.
[0046] The core paste is extruded and bonded to the outside of the plastic core using an extruder at an extrusion die temperature of 170°C, an extrusion pressure of 15MPa, and a traction speed of 0.8m / min to obtain a plastic core with an attached core paste layer.
[0047] The capping adhesive is extruded and bonded to the outside of the plastic core with the core paste layer by an extruder. The extrusion die temperature is 170℃, the extrusion pressure is 20MPa, and the traction speed is 1.2m / min to obtain a plastic core flame-retardant conveyor belt.
[0048] Comparative Example 1
[0049] like Figure 1-2The plastic solid core flame-retardant conveyor belt uses a plastic solid core as its central skeleton. A core paste layer is attached to the surface of the plastic solid core. After the core paste layer is formed, a cover rubber is applied to obtain the plastic solid core flame-retardant conveyor belt. The cover rubber increases wear resistance and seals the plastic solid core and the core paste layer. The plastic solid core is obtained by heating and melting plastic resin granules (nylon 6 resin granules), injecting the melt into a mold, and then demolding after cooling. The thickness of the plastic solid core is 12mm, the thickness of the core paste layer is 16mm, and the thickness of the cover rubber is 8mm. The outer surface of the plastic solid core has triangular grooves arranged at equal intervals. A quadrangular pyramidal through hole is formed between every two triangular grooves. The opening of the quadrangular pyramidal through hole is wider at the top and narrower at the bottom. The core paste layer passes through the quadrangular pyramidal through hole. A circular ring is provided inside the quadrangular pyramidal through hole to stabilize its shape. The plastic solid core has arc-shaped outer edges on both sides.
[0050] The preparation process of the core paste is as follows: (I) 22 parts of zinc phosphomolybdate, 8 parts of microcrystalline wax, 2 parts of antioxidant KY-405 and 14 parts of decabromodiphenyl ether are dried in a forced-air drying oven at 90°C for 3 hours, put into a mixer and stir at 550r / min for 4min, add 8 parts of peony seed oil and stir at 60r / min for 6min to obtain a mixed paste; (II) 32 parts of polyvinyl chloride paste resin are added to the mixed paste at 45°C and stirred at 60r / min for 18min, add 2 parts of phosphite and stir at 60r / min for 18min to obtain the core paste.
[0051] The preparation process of the capping adhesive is as follows: (I) At 120℃, 35 parts of PVC suspension resin are mixed with 6 parts of amphibole powder and 12 parts of zinc borate at a stirring speed of 35r / min and stirred for 10min. At a stirring speed of 25r / min, 20 parts of zinc phosphomolybdate and 2 parts of antioxidant KY-405 are added and stirred for 10min. The mixture is stirred at 15r / min for 10min to obtain the base rubber compound. 3 parts of glyceryl monostearate and 2 parts of phosphite are added and placed in a planetary mixer. The temperature is lowered to 45℃ and 90 parts of nitrile rubber powder are added and stirred at 25r / min for 55min. 2 parts of sulfur are added and stirred at 1350r / min for 55min to obtain the capping adhesive.
[0052] The core paste is extruded and bonded to the outside of the plastic core using an extruder at an extrusion die temperature of 165°C, an extrusion pressure of 12MPa, and a traction speed of 0.5m / min to obtain a plastic core with an attached core paste layer.
[0053] The capping adhesive is extruded and bonded to the outside of the plastic core with the core paste layer by an extruder. The extrusion die temperature is 165℃, the extrusion pressure is 18MPa, and the traction speed is 0.8m / min to obtain a plastic core flame-retardant conveyor belt.
[0054] Comparative Example 2
[0055] like Figure 3 The plastic solid core flame-retardant conveyor belt uses a plastic solid core as its central skeleton. A core paste layer is attached to the surface of the plastic solid core. After the core paste layer is formed, a cover rubber is applied to obtain the plastic solid core flame-retardant conveyor belt. The cover rubber serves to increase wear resistance and seal the plastic solid core and the core paste layer. The plastic solid core is obtained by heating and melting plastic resin granules (the plastic resin granules are nylon 6 resin granules), injecting the melt into a mold, and demolding after cooling. The thickness of the plastic solid core is 12mm, the thickness of the core paste layer is 16mm, and the thickness of the cover rubber is 8mm. The outer surface of the plastic solid core is provided with triangular grooves, which are equidistantly arranged. A four-corner pyramidal through hole is opened between every two triangular grooves. The opening of the four-corner pyramidal through hole is larger at the top and smaller at the bottom. The core paste layer passes through the four-corner pyramidal through hole. The two sides of the plastic solid core are provided with arc-shaped outer edges.
[0056] The preparation process of plant secretions is as follows: (i) Wash the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle (the mass ratio of *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle is 1:1:0.3:0.5:1.2) to remove the surface soil and air dry the surface moisture; (ii) Straighten and bundle the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle after air drying the surface moisture; (iii) Cut off the front end, tilt the cut end downwards so that the secretion drips, and after 2 minutes, make a horizontal cut again 3 cm above the cut end. Repeat this process until the bundle is completely cut and collect the secretion.
[0057] The preparation process of the core paste is as follows: (I) 22 parts of zinc phosphomolybdate, 8 parts of microcrystalline wax, 2 parts of antioxidant KY-405 and 14 parts of decabromodiphenyl ether are dried in a forced-air drying oven at 90°C for 3 hours, put into a mixer and stir at 550r / min for 4min, add 8 parts of peony seed oil and stir at 60r / min for 6min to obtain a mixed paste; (II) 32 parts of polyvinyl chloride paste resin are added to the mixed paste at 45°C and stirred at 60r / min for 18min, add 2 parts of phosphite and stir at 60r / min for 18min to obtain the core paste.
[0058] The preparation process of the capping adhesive is as follows: (I) At 120℃, 35 parts of PVC suspension resin are mixed with 6 parts of amphibole powder and 12 parts of zinc borate at a stirring speed of 35r / min and stirred for 10min. At a stirring speed of 25r / min, 20 parts of zinc phosphomolybdate and 2 parts of antioxidant KY-405 are added and stirred for 10min. The mixture is stirred at 15r / min for 10min to obtain the base rubber. 3 parts of glyceryl monostearate and 2 parts of phosphite are added and placed in a planetary mixer. The temperature is lowered to 45℃ and 80 parts of nitrile rubber powder and 10 parts of plant secretion liquid are added and stirred at 25r / min for 55min. 2 parts of sulfur are added and stirred at 1350r / min for 55min to obtain the capping adhesive.
[0059] The core paste is extruded and bonded to the outside of the plastic core using an extruder at an extrusion die temperature of 165°C, an extrusion pressure of 12MPa, and a traction speed of 0.5m / min to obtain a plastic core with an attached core paste layer.
[0060] The capping adhesive is extruded and bonded to the outside of the plastic core with the core paste layer by an extruder. The extrusion die temperature is 165℃, the extrusion pressure is 18MPa, and the traction speed is 0.8m / min to obtain a plastic core flame-retardant conveyor belt.
[0061] Comparative Example 3
[0062] like Figure 4 The plastic solid core flame-retardant conveyor belt uses a plastic solid core as its central skeleton. A core paste layer is attached to the surface of the plastic solid core. After the core paste layer is formed, a cover rubber is applied to obtain the plastic solid core flame-retardant conveyor belt. The cover rubber increases wear resistance and seals the plastic solid core and the core paste layer. The plastic solid core is obtained by heating and melting plastic resin granules (nylon 6 resin granules), injecting the melt into a mold, and then demolding after cooling. The thickness of the plastic solid core is 12mm, the thickness of the core paste layer is 16mm, and the thickness of the cover rubber is 8mm. The outer surface of the plastic solid core has triangular grooves arranged at equal intervals. A quadrangular pyramidal through hole is formed between every two triangular grooves. The opening of the quadrangular pyramidal through hole is wider at the top and narrower at the bottom. The core paste layer passes through the quadrangular pyramidal through hole. A circular ring is provided inside the quadrangular pyramidal through hole to stabilize its shape. The plastic solid core has arc-shaped outer edges on both sides.
[0063] The preparation process of plant secretions is as follows: (i) Wash the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle (the mass ratio of *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle is 1:1:0.3:0.5:1.2) to remove the surface soil and air dry the surface moisture; (ii) Straighten and bundle the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle after air drying the surface moisture; (iii) Cut off the front end, tilt the cut end downwards so that the secretion drips, and after 2 minutes, make a horizontal cut again 3 cm above the cut end. Repeat this process until the bundle is completely cut and collect the secretion.
[0064] The preparation process of the core paste is as follows: (I) 22 parts of zinc phosphomolybdate, 8 parts of microcrystalline wax, 2 parts of antioxidant KY-405 and 14 parts of decabromodiphenyl ether are dried in a forced-air drying oven at 90°C for 3 hours, put into a mixer and stir at 550r / min for 4min, add 8 parts of peony seed oil and stir at 60r / min for 6min to obtain a mixed paste; (II) 32 parts of polyvinyl chloride paste resin are added to the mixed paste at 45°C and stirred at 60r / min for 18min, add 2 parts of phosphite and stir at 60r / min for 18min to obtain the core paste.
[0065] The preparation process of the capping adhesive is as follows: (I) At 120℃, 35 parts of PVC suspension resin are mixed with 6 parts of amphibole powder and 12 parts of zinc borate at a stirring speed of 35r / min and stirred for 10min. At a stirring speed of 25r / min, 20 parts of zinc phosphomolybdate and 2 parts of antioxidant KY-405 are added and stirred for 10min. The mixture is stirred at 15r / min for 10min to obtain the base rubber. 3 parts of glyceryl monostearate and 2 parts of phosphite are added and placed in a planetary mixer. The temperature is lowered to 45℃ and 80 parts of nitrile rubber powder and 10 parts of plant secretion liquid are added and stirred at 25r / min for 55min. 2 parts of sulfur are added and stirred at 1350r / min for 55min to obtain the capping adhesive.
[0066] The core paste is extruded and bonded to the outside of the plastic core using an extruder at an extrusion die temperature of 165°C, an extrusion pressure of 12MPa, and a traction speed of 0.5m / min to obtain a plastic core with an attached core paste layer.
[0067] The capping adhesive is extruded and bonded to the outside of the plastic core with the core paste layer by an extruder. The extrusion die temperature is 165℃, the extrusion pressure is 18MPa, and the traction speed is 0.8m / min to obtain a plastic core flame-retardant conveyor belt.
[0068] Performance testing
[0069] According to MT / T668-2019 "Flame-retardant steel wire rope core conveyor belts, flame-retardant fabric solid core conveyor belts and flame-retardant plastic solid core conveyor belts for coal mines", the performance of the plastic solid core flame-retardant conveyor belts prepared by the methods of Examples 1-3 and Comparative Examples 1-3 was tested, and the test results are shown in Table 1.
[0070] Table 1
[0071] As can be seen from Table 1, Examples 1-3 of the present invention are generally superior to Comparative Examples 1-3 in terms of tensile strength, dimensional stability (low elongation) and flame retardant performance; among them, Example 2 has the best overall performance: the highest tensile strength (790 N / mm), the lowest elongation (2%), and the shortest open flame and flameless combustion time (2.0 s). This shows that the technical solution of the present invention can simultaneously improve the mechanical properties and flame retardant safety performance of the material, and has obvious technical advantages.
[0072] The smoke performance of the solid plastic flame-retardant conveyor belts prepared by the methods of Examples 1-3 and Comparative Example 1 was tested according to GB / T8323.2-2008, and the test results are shown in Table 2. The lethal toxicity of the solid plastic flame-retardant conveyor belts prepared by the methods of Examples 1-3 and Comparative Example 1 was evaluated according to GB / T8323.2-2008, and the evaluation results are shown in Table 2.
[0073] Table 2
[0074] As can be seen from Table 2, Examples 1-3 are significantly better than Comparative Example 1 in terms of smoke density, exhibiting excellent low-smoke characteristics; the toxicity index of combustion products in Examples 1-3 is lower than that in Comparative Example 1, demonstrating superior flame retardancy, environmental friendliness, and safety; the technical solution of this invention enables the plastic solid-core flame-retardant conveyor belt to simultaneously possess the advantages of low smoke, low toxicity, and high safety, with overall performance significantly superior to Comparative Example 1.
[0075] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.
Claims
1. A low-smoke, low-toxicity, solid-core flame-retardant plastic conveyor belt for coal mines, characterized in that, The solid plastic flame-retardant conveyor belt uses a solid plastic core as the central skeleton. A core paste layer is attached to the surface of the solid plastic core. After the core paste layer is formed, a cover rubber is applied to obtain the solid plastic flame-retardant conveyor belt. The cover rubber serves to increase wear resistance and seal the solid plastic core and the core paste layer. The plastic core is obtained by heating and melting plastic resin particles, injecting the melt into a mold, and then demolding it after cooling. The thickness of the plastic core is 8-15mm, the thickness of the core paste layer is 12-20mm, and the thickness of the capping adhesive is 5-10mm. By weight, the core paste layer is prepared by extruding and cooling the core paste compound. The core paste compound comprises 30-35 parts of polyvinyl chloride paste resin, 20-25 parts of zinc phosphomolybdate, 6-11 parts of microcrystalline wax, 1-3 parts of antioxidant KY-405, 5-10 parts of peony seed oil, 12-16 parts of decabromodiphenyl ether and 1-3 parts of phosphite. By weight, the materials used to prepare the capping adhesive include 25-40 parts of PVC suspension resin, 75-85 parts of nitrile rubber powder, 5-8 parts of amphibole powder, 10-15 parts of zinc borate, 1-3 parts of sulfur, 15-25 parts of zinc phosphomolybdate, 0.5-2.5 parts of antioxidant KY-405, 1-5 parts of glyceryl monostearate, 1-2 parts of phosphite, and 5-15 parts of plant secretions.
2. The low-smoke, low-toxicity, solid-core flame-retardant plastic conveyor belt for coal mines according to claim 1, characterized in that, The outer surface of the plastic core is provided with triangular grooves, which are arranged at equal intervals. A quadrangular pyramidal through hole is opened between every two triangular grooves. The opening of the quadrangular pyramidal through hole is larger at the top and smaller at the bottom. The core paste layer passes through the quadrangular pyramidal through hole.
3. The low-smoke, low-toxicity, solid-core flame-retardant plastic conveyor belt for coal mines according to claim 1, characterized in that, A circular ring is provided inside the quadrangular pyramidal through hole, which serves to stabilize the shape of the quadrangular pyramidal through hole.
4. The low-smoke, low-toxicity, solid-core flame-retardant plastic conveyor belt for coal mines according to claim 1, characterized in that, The plastic core has arc-shaped outer edges on both sides.
5. The low-smoke, low-toxicity, solid-core flame-retardant plastic conveyor belt for coal mines according to claim 1, characterized in that, The preparation process of the plant secretions is as follows: (i) Wash the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle to remove the surface soil and air dry the surface moisture; (ii) Straighten and bundle the *Euphorbia humifusa*, *Euphorbia humifusa*, *Cynanchum paniculatum*, dandelion, and sow thistle after air drying the surface moisture; (iii) Cut off the front end, tilt the cut end downwards so that the secretions drip down, and after 2 minutes, make a horizontal cut again 3 cm above the cut end, repeating this process until the bundle is completely cut, and collect the secretions.
6. The low-smoke, low-toxicity, solid-core flame-retardant plastic conveyor belt for coal mines according to claim 5, characterized in that, The mass ratio of the following herbs is 1:1:0.3:0.5:1.2: Euphorbia hirta, Asclepiadum, Taraxacum mongolicum, and Sow thistle.
7. The low-smoke, low-toxicity, solid-core flame-retardant plastic conveyor belt for coal mines according to claim 1, characterized in that, The plastic resin granules are nylon 6 resin granules.
8. The low-smoke, low-toxicity, solid-core flame-retardant plastic conveyor belt for coal mines according to claim 1, characterized in that, The preparation process of the core paste is as follows: (i) Zinc phosphomolybdate, microcrystalline wax, antioxidant KY-405 and decabromodiphenyl ether are dried in a forced-air drying oven at 80-100℃ for 2-4 hours, put into a mixer and stir at 550r / min for 2-5min, add peony seed oil and stir at 60r / min for 5-8min to obtain a mixed paste; (ii) Polyvinyl chloride paste resin is added to the mixed paste at 45℃ and stirred at 60r / min for 15-20min, add phosphite and stir at 60r / min for 15-20min to obtain a core paste.
9. A low-smoke, low-toxicity, solid-core flame-retardant plastic conveyor belt for coal mines according to claim 1, characterized in that, The preparation process of the capping adhesive is as follows: (i) At 120°C, PVC suspension resin is stirred for 10 minutes with amphibole powder and zinc borate at a stirring speed of 35 r / min, zinc phosphomolybdate and antioxidant KY-405 are stirred for 10 minutes at a stirring speed of 25 r / min, and the mixture is stirred for 10 minutes at a stirring speed of 15 r / min to obtain the base adhesive. Glyceryl monostearate and phosphite are added, and the mixture is placed in a planetary mixer. When the temperature drops to 40-50°C, nitrile rubber powder and plant secretion liquid are added and stirred at a stirring speed of 25 r / min for 45-60 minutes. Sulfur is added and stirred at a stirring speed of 1200-1500 r / min for 45-60 minutes to obtain the capping adhesive.
10. A method for preparing a low-smoke, low-toxicity, solid-core flame-retardant plastic conveyor belt for coal mines as described in any one of claims 1-9, characterized in that, Includes the following steps: S1, the core paste material is extruded and bonded to the outside of the plastic core by an extruder at an extrusion die temperature of 160-170℃, an extrusion pressure of 10-15MPa, and a traction speed of 0.3-0.8m / min to obtain a plastic core with an attached core paste layer. S2, the capping rubber is extruded and bonded to the outside of the plastic core with the core paste layer by an extruder, at an extrusion die temperature of 160-170℃, an extrusion pressure of 15-20MPa, and a traction speed of 0.5-1.2m / min, to obtain a plastic core flame-retardant conveyor belt.