Production process of forest waste fiber-based automobile interior panel

Abstract

The application provides a production process of a forest waste fiber-based automobile interior panel and belongs to the technical field of fiberboard processing. Fiber milk slurry is sprayed into a grinding chamber of a hot grinder, forest waste fibers and residual fiber milk slurry are uniformly mixed, and paraffin with 40-50% of mass percentage of p-t-butyl phenol formaldehyde resin after heating, melting, dissolving and dispersing is dissolved and dispersed, urea-formaldehyde resin glue contains 1-2% of mass percentage of zinc oxide. Compared with conventional fiberboards, vulcanizing agent p-t-butyl phenol formaldehyde resin and activator zinc oxide are crosslinked through subsequent vulcanization pre-pressing, curing and hot pressing, the strength of the fiberboard is improved, the use amount of urea-formaldehyde resin glue and the formaldehyde release amount are reduced, the static bending strength, internal bonding strength, surface bonding strength and water absorption thickness expansion rate of the fiberboard are high, the formaldehyde release amount is low, the raw material sources are wide, the cost is low, the forest waste fibers of landscaping and forestry can be treated, and the application is green and environment-friendly.

Description

Technical Field

[0001] This invention belongs to the field of fiberboard processing technology, and in particular to a production process for automotive interior panels based on waste forest fiber. Background Technology

[0002] my country possesses abundant forest fiber resources that can be used as raw materials for bioethanol. The annual output of forestry waste (logging residues, timber residues, and processing residues) alone reaches 133 million tons, most of which is discarded or incinerated. If half of this waste were converted into bioethanol, it could replace 21% of gasoline consumption. Furthermore, my country's fast-growing plantation resources also have significant development potential. Currently, my country produces approximately 20-40 million tons annually of garden plant residues generated from natural shedding or artificial pruning, including common branches and shrub pruning materials, and the problem of their disposal is becoming increasingly prominent. Those skilled in the art urgently need to develop a production process for forest waste fiber-based automotive interior panels to meet current usage needs and performance requirements. Summary of the Invention

[0003] To address the aforementioned problems, this invention aims to provide a production process for automotive interior trim panels based on waste forest fibers.

[0004] This invention is achieved through the following technical solution:

[0005] A production process for automotive interior trim panels based on forest waste fiber, comprising the steps of chipping, screening to obtain wood chips of a predetermined size, drying after gluing, sorting, laying, and cooling, sanding, edge sawing, and stacking after slitting, is characterized by further comprising the following steps: (1) preparing residual fiber emulsion slurry from garden greening ground cover plant residues by crushing and pulping; (2) hot grinding and waxing process (this process is carried out after the screening step): executing the hot grinding process parameters, spraying the fiber emulsion slurry obtained in the previous step into the grinding chamber of the hot grinding mill through a metering pump, and obtaining forest waste fiber from the wood chips of a predetermined size through the hot grinding of the hot grinding mill, the forest waste fiber and residual fiber After the emulsion is evenly mixed, it is sprayed out to obtain mixed wood fibers; and when the total hot grinding time reaches 50% to 60%, the heated and melted paraffin containing 40% to 50% by mass of p-tert-butylphenol formaldehyde resin is directly sprayed into the grinding chamber of the hot grinding machine through a metering pump, and hot grinding continues until the total hot grinding time is reached; (3) Applying adhesive: then apply urea-formaldehyde resin adhesive containing 1% to 2% by mass of zinc oxide to the obtained mixed wood fibers in the spray pipe of the hot grinding machine, and enter the drying process; (4) After the slab is laid and formed, it is vulcanized, pre-pressed, cured and hot-pressed, and then cut; the above process is carried out after the laying step. After cutting, it is cooled, sanded, sawed, and stacked.

[0006] Furthermore, in step (3) of the adhesive application process, the amount of urea-formaldehyde resin adhesive applied is controlled within the range of 8% to 10% by weight of oven-dried urea-formaldehyde resin adhesive to oven-dried mixed wood fiber.

[0007] Furthermore, the predetermined size of the wood chips in step (2) is 20-30mm × 10-20mm × 5-10mm.

[0008] Furthermore, the mixed wood fiber obtained in step (3) accounts for 70% to 80% of the mass of the oven-dried mixed wood fiber.

[0009] Ground cover plants in landscaping refer to low-growing plants used in landscaping that can cover the ground, including herbaceous and woody plants such as dwarf shrubs, creeping or semi-climbing shrubs, and vines. Because of their small overall size, their fibrous slurry can be obtained through simple crushing and pulping.

[0010] In daily production and quality inspection, it was unexpectedly discovered that a certain batch of fiberboard products exhibited superior overall performance compared to conventionally produced fiberboard products, with high surface bonding strength, low formaldehyde release, high internal bonding strength, and low water absorption thickness swelling rate. This performance improvement, while fluctuating, received positive feedback and evaluation from downstream customers. However, this performance improvement was not stable and did not recur in subsequent production. Therefore, a comprehensive investigation was conducted, examining the production process, employee operating parameters, and equipment. It was found that the main reason for the performance improvement was the unexpected introduction of additional batches of landscaping plant residues (waste) into the wood raw materials. These landscaping plant residues came from branches and twigs pruned from trees and shrubs, and the improvement was particularly pronounced when they were waste materials from Euonymus, vines, and dandelion roots. During processing, these residues showed a sticky, grayish-white appearance and exhibited a certain degree of adhesion.

[0011] Furthermore, the landscaping ground cover plant residues are one or more of the following: Euonymus remnants, Aristolochia remnants, and Taraxacum remnants. Euonymus is an evergreen plant and belongs to the shrub family. Euonymus, Aristolochia remnants, and Taraxacum are relatively common in Anhui Province and have a strong ability to adapt to their environment. After landscaping maintenance and further processing, a large number of stems and roots are discarded, mainly abandoned in wastelands or used as fuel.

[0012] Furthermore, the process parameters of the hot grinding mill in step (2) are set as follows: discharge temperature 60-65℃, hot grinding mill pressure 7.2-8 bar, preheating silo temperature 80-90℃, cooking pressure 7.5-8 bar, cooking time 130-160 s, cooking temperature 140-145℃, preheating silo material level 75%-80%, feed screw speed 47-50 rpm, discharge screw speed 65-75 rpm, discharge valve opening 50%-70%, pressure difference 0.2-0.3 MPa, and total hot grinding time 3-5 min.

[0013] The pressure difference between the grinding chamber pressure and the cooking tank pressure is called the pressure differential.

[0014] Furthermore, in step (2), the paraffin is 58# fully refined paraffin, and the amount added is 0.5% to 0.6% of the oven-dried mixed wood fiber.

[0015] Furthermore, the vulcanization pre-pressing in step (4) is as follows: pre-pressing pressure 1.5~1.8MPa, vulcanization pre-pressing temperature 160~170℃, pre-pressing time 25~30s / mm. The curing hot pressing process is as follows: high pressure 1.6~2.2MPa, heat transfer section pressure 0.3~0.6MPa, thickness setting pressure 0.8~1.0MPa, hot pressing temperature 200~220℃, hot pressing time 25~30s / mm.

[0016] Furthermore, the solid content of the remaining fiber emulsion slurry in step (4) is 50% to 60%.

[0017] Furthermore, the moisture content of the slab formed in step (4) is 8% to 9%.

[0018] The beneficial effects of this invention are:

[0019] This invention discloses a forest waste fiber-based automotive interior panel. The process involves crushing and pulping landscaping plant residues to prepare a fiber emulsion. This emulsion is then injected into the grinding chamber of a thermomill using metering pumps, where the forest waste fibers and the fiber emulsion are uniformly mixed. Further mixing is then performed with paraffin wax containing dissolved and dispersed p-tert-butylphenol formaldehyde resin, and the urea-formaldehyde resin adhesive contains 1%–2% zinc oxide by weight. Compared to conventional fiberboard, this method utilizes some lower-cost raw materials. The residues of landscaping ground cover plants, along with zinc oxide and p-tert-butylphenol formaldehyde resin, produce a latex slurry containing latex components, which have a certain adhesive effect. Through a vulcanizing agent on the tert-butylphenol formaldehyde resin and the activator zinc oxide, as well as subsequent vulcanization pre-pressing, curing, and hot pressing, the latex is cross-linked. This not only improves the strength of the fiberboard but also reduces the amount of urea-formaldehyde resin used and formaldehyde release. Furthermore, the p-tert-butylphenol formaldehyde resin can be uniformly dissolved in paraffin wax, eliminating the need for additional processing equipment; the technology can be improved on existing production lines. Meanwhile, the residues of landscaping ground cover plants such as Euonymus provide both wood fiber and latex components during the production process, achieving efficient conversion and high-value utilization. The wood fiber serves as the base material for fiberboard and as a bonding component to improve its strength. Zinc oxide can improve the vulcanization of the latex components and enhance the bonding effect of the fiberboard. Tests have shown that fiberboard has high static bending strength, high internal bond strength, high surface bond strength, low water absorption thickness expansion rate, low formaldehyde release, and a wide range of raw material sources, resulting in low cost. It can also absorb waste fibers from landscaping and forestry, making it green and environmentally friendly. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of the production process of automotive interior trim panels based on waste forest fibers; Figure 2 This is a photograph of the actual automotive interior trim panel based on waste forest fiber obtained in Example 1. Detailed Implementation

[0021] The present invention is illustrated below with specific embodiments, but these are not intended to limit the scope of the invention. Example 1

[0022] Raw materials and equipment:

[0023] Raw materials: X268 flip-plate cooler, X269 and X267 cooling plate conveyor; BSG2613VGD two-frame sander, BSG2713VGD four-frame sander, BSG2713VXXD four-frame sander, BX2110 drum chipper, Andritz48 hot mill; Gaoqiao Petrochemical 58# fully refined paraffin wax; landscaping ground cover plant residues are dandelion root residues from Yu Guanziyu in Neixiang, Nanyang (approximately 90 yuan / ton); purchased from Gaotai Township, Funan County, waste hardwood branches with a moisture content of 35%, free from decay and deterioration, free from sand, mud, snow, and other foreign matter (encasing the raw materials), free from disease, rot, insects, and other pests, with a small end diameter not less than 4cm, a large end diameter not greater than 16cm, and an average length of 100cm. Jiaxiang Jiatai Chemical's JTHG010 urea-formaldehyde resin glue conforms to GB / T 14732-2017 standard, with a free formaldehyde content of <0.1% and a solid content of 50%, and is a milky white liquid; Fuyang Hongli Chemical's Type I zinc oxide; and Fuyang Hangmo's P9402 p-tert-butylphenol formaldehyde resin.

[0024] The residue from processing dandelion roots is crushed and pulped to prepare a residue fiber emulsion. The solid content of the residue fiber emulsion is 50%, the average length of the residue fibers is 1 mm, and the length-to-width ratio is 40.

[0025] A production process for automotive interior trim panels based on waste forest fibers includes the following steps: chipping, screening to obtain wood chips of a predetermined size, hot grinding, waxing, gluing, drying after gluing, sorting, laying, cooling after slitting, sanding, edge sawing, and stacking.

[0026] The predetermined size of the wood chips is 20mm × 10mm × 5mm; the application amount of urea-formaldehyde resin adhesive is controlled within the range of 8% by weight of oven-dry urea-formaldehyde resin adhesive to oven-dry mixed wood fibers; the hot grinding and waxing process (performed after the screening step) is as follows: the hot grinding process parameters are set as follows: discharge temperature 60℃, hot grinding pressure 7.2 bar, preheating hopper temperature 8℃, cooking pressure 7.5 bar, cooking time 130s, cooking temperature 140℃, preheating hopper material level 75%, feed screw speed 47 rpm, discharge screw speed 65 rpm, discharge valve opening 50%, and pressure difference 0.2 MPa; the fiber emulsion obtained in the previous step is injected into the grinding chamber of the hot grinding mill through a metering pump. The wood chips of the predetermined size are processed by the hot grinding mill to obtain forest waste fibers. After the forest waste fibers and the remaining fiber emulsion are evenly mixed, they are sprayed out to obtain mixed wood fibers. The mixed wood fiber consists of 70% oven-dried forest waste fiber by weight; and when the total hot grinding time reaches 50%, paraffin wax, which has been heated and melted and contains 40% by weight of p-tert-butylphenol formaldehyde resin, is directly injected into the grinding chamber of the hot mill through a metering pump, and hot grinding continues until the total hot grinding time is reached. The amount of paraffin wax added is 0.5% of the oven-dried mixed wood fiber; sizing: then the obtained mixed wood fiber is sizing in the spray pipe of the hot mill. A urea-formaldehyde resin adhesive containing 1% zinc oxide by mass is applied and then dried. After the slab is laid and formed, it undergoes vulcanization pre-pressing, curing hot pressing, and then slitting. The vulcanization pre-pressing process is as follows: pre-pressing pressure 1.5MPa, vulcanization pre-pressing temperature 160℃, pre-pressing time 25s / mm. The curing hot pressing process is as follows: high pressure 1.6MPa, heat transfer section pressure 0.3MPa, thickness setting pressure 0.8MPa, hot pressing temperature 200℃, hot pressing time 25s / mm.

[0027] Specifically, such as Figure 1 As shown, the entire process of manufacturing automotive interior panels based on waste forest fibers includes the following four major stages.

[0028] I. Material Preparation Section:

[0029] The process consists of two parts: chipping and screening. Chipping: To ensure the specifications and quality of the processed wood chips, the moisture content of the raw branches and twigs is 35%. For branches and twigs with lower moisture content, a humidification treatment is applied to bring the moisture content to 35% before chipping. Timber is transported from the raw material yard to the raw material platform by loader trucks, and then fed into the chipper by a loader for processing (wood chip specifications: length × width × height: 20mm × 10mm × 5mm). The chipped wood chips are then conveyed to the wood chip silo for storage by a belt conveyor. Screening: The wood chips in the silo are discharged quantitatively via a screw conveyor and then conveyed to the wood chip screening machine for screening. Large, substandard pieces of wood are returned to the chipper for further processing; excessively fine bark and debris are sent to the waste shed for use as fuel in the heating center.

[0030] II. Fiber Preparation Section:

[0031] The fiber preparation section mainly includes three parts: hot grinding, sizing and drying, and sorting. Hot grinding: Prepared wood chip raw materials are transported to the main workshop via a closed conveyor pipeline. The wood chips enter the wood chip preheating silo via a belt conveyor. The preheated wood chips are continuously and evenly fed into a vertical steam generator for cooking and softening treatment via a vibrating discharge device and a wood plug screw feeder. The steam generator is equipped with a new type of gamma-ray level gauge to control the wood chip level and cooking time. The softened wood chips are then fed into the grinding chamber of the hot grinding mill via a feeder and screw conveyor for fiber separation. Simultaneously, heated and melted paraffin wax containing 40% by weight of p-tert-butylphenol formaldehyde resin is directly sprayed into the grinding chamber of the hot grinding mill via a metering pump. The paraffin wax adheres evenly to the fiber surface and effectively lubricates the grinding disc. The ground fibers are then fed into the fiber drying system via a continuous screw discharge valve.

[0032] Sizing and Drying: The sizing fibers discharged from the thermomill have a high moisture content, making them unsuitable for pneumatic conveying and uniform laying. Therefore, the fibers must be dried. Drying the fibers to a moisture content of 8% is necessary to meet the requirements of subsequent processes such as pneumatic conveying, laying, and hot pressing. The thermo-milled fibers are fed into the dryer through a fiber discharge pipe, while the prepared urea-formaldehyde resin is simultaneously pumped into the thermomill discharge pipe using a metering pump. The materials are mixed under moving conditions, with the air duct operating at a wind speed of 24 m / s. After 6 seconds, the moisture content is reduced to 8% (the entire sizing and mixing process takes place in a closed pipeline). The heating medium for the dryer is a mixture of high-temperature flue gas from the thermal energy center and a makeup air blower. The high-temperature flue gas (340℃) from the thermal energy center, after being dusted by a multi-tube dust collector, mixes with air in the mixing chamber before entering the drying pipeline and directly contacting the material. Flash drying is achieved during the pipeline transport process using hot airflow. At the end of the drying pipeline, the fibers and humid air are separated by a cyclone separator, and the fibers are dried to the required moisture content. The drying cyclone outlet reaches 65℃, and the dried fibers enter the fiber sorting machine for sorting. The drying system is equipped with a moisture content meter, spark detection, fire extinguishing, and temperature control devices, and the entire system is automatically controlled by a PLC system. Sorting: The dried fibers enter the fiber sorting machine. Under the action of the sorting machine, qualified fibers are sent to the fiber bin at the top of the laying machine for storage via a secondary air conveying system, while unqualified fiber clumps are removed by gravity and sent to the energy center for combustion as fuel.

[0033] III. Sheet metal forming section:

[0034] The slab forming section mainly includes two parts: paving and pre-pressing.

[0035] Laying and Pre-compression: A rotary feeder is installed at the bottom of the dry fiber silo. Fibers fed by the feeder continuously enter the storage silo of the BP3313 laying machine. The fiber wood is then conveyed forward by the conveyor belt at the bottom of the silo to the discharge port, where it is forcibly thrown by throwing rollers, providing a uniform and continuous flow of material to the laying head. Under the action of a set of inclined throwing rollers at the laying head, the material flow falls evenly onto the conveyor belt, forming slabs. These slabs are then conveyed by the forming belt to the pre-compressor. After pre-compression, the slabs are inspected by a metal detector before being fed into a continuous flat-press hot press for hot pressing. Unqualified slabs are broken up by a slab recycling device and then sent to the fiber silo of the laying machine for recycling by a pneumatic conveyor. Hot Pressing: Qualified pre-compressed slabs are fed into the feed port of the continuous flat-press by a retractable conveyor belt and enter the press under the clamping of upper and lower steel belts.

[0036] IV. The post-processing of the boards mainly includes five parts: board cutting, cooling, sanding, edge sawing, and inspection. Board cutting: After the continuous raw boards come out of the hot press, they are inspected by a thickness measuring and weighing system. Boards that pass inspection are cut into specific specifications by a transverse saw (SJ21D) before proceeding to the next process. Cooling: Boards that pass cutting enter a cooling machine for cooling. After natural cooling and stacking, they are automatically stacked and sent to an intermediate warehouse for storage.

[0037] Sanding: After two days of stacking, the rough boards are fed into the sanding line by an automated stacking system. This project plans to use a 2+4+4 ten-rack combination process. After coarse, medium, and fine sanding, the boards meet the thickness requirements. Edge Sawing: The sanded boards undergo SC15 edge sawing to meet product dimensional requirements. Inspection and Grading: The finished sanded boards enter the inspection and grading section. Boards that fail inspection are sent to the thermal energy center as fuel. Qualified boards are graded, stacked, and then transported to the finished product warehouse by forklift. Product specifications are 2440mm × 1220mm × 1mm.

[0038] Product performance: Density 0.94 g / cm³ 3 Moisture content 4.7%; internal density deviation -2.0%, +1.4; static bending strength 50.4MPa; elastic modulus 4843MPa; internal bond strength 1.69MPa, surface bond strength 2.36MPa, water absorption thickness swelling rate 22.0%, formaldehyde release 4.9mg / 100g.

[0039] Comparative Example 1

[0040] Compared to Example 1, this comparative example omits the residual fiber emulsion slurry, p-tert-butylphenol formaldehyde resin, and zinc oxide during the hot grinding process. That is, the paraffin does not contain P9402 resin, the urea-formaldehyde resin glue does not contain zinc oxide, and the fiberboard is a conventional fiberboard made from pure forest waste hardwood branches.

[0041] Product performance: Density 0.94 g / cm³ 3 Moisture content 4.6%; internal density deviation -2.1%, +1.5; static bending strength 48.3MPa; elastic modulus 4641MPa; internal bond strength 1.54MPa, surface bond strength 2.30MPa, water absorption thickness swelling rate 24.0%, formaldehyde release 12.9mg / 100g. Example 2

[0042] The equipment is the same as in Example 1. The raw material, garden and landscaping ground cover plant residue, is a mixture of Euonymus remnants and Tremella remnants in a 1:1 mass ratio (100 yuan / t). Gaoqiao Petrochemical 58# fully refined paraffin wax; purchased from waste hardwood branches and twigs in Gaotai Township, Funan County, with a moisture content of 40%, free from decay and deterioration, and free from sand, mud, ice, snow, or other foreign matter (encasing the raw material), free from disease, rot, insect infestation, and other pests. The small end diameter must not be less than 4cm, the large end diameter must not be greater than 16cm, and the average length is 100cm. Jiaxiang Jiatai Chemical's JTHG010 urea-formaldehyde resin glue conforms to GB / T 14732-2017 standard, with a free formaldehyde content of <0.1% and a solid content of 50%, a milky white liquid; containing Shanjinhua Type I zinc oxide; Fuyang Hangmo P9401 p-tert-butylphenol formaldehyde resin.

[0043] The residues of Euonymus alatus from Funan Kaiyuan Green Company and the residues of Tremella fuciformis from Funan Linsenyuan Green Company were mixed in a 1:1 ratio and then crushed and pulped to prepare a residue fiber emulsion. The solid content of the residue fiber emulsion was 60%.

[0044] A production process for automotive interior trim panels based on waste forest fibers includes the following steps: chipping, screening to obtain wood chips of a predetermined size, hot grinding, waxing, gluing, drying after gluing, sorting, laying, cooling after slitting, sanding, edge sawing, and stacking.

[0045] The predetermined size of the wood chips is 30mm×20mm×10mm; the application amount of urea-formaldehyde resin adhesive is controlled within the range of 10% by weight of oven-dry urea-formaldehyde resin adhesive to oven-dry mixed wood fibers; the hot grinding and waxing process (performed after the screening step) is as follows: the hot grinding process parameters are set as follows: discharge temperature 65℃, hot grinding pressure 8bar, preheating hopper temperature 90℃, cooking pressure 8bar, cooking time 160s, cooking temperature 145℃, preheating hopper material level 80%, feed screw speed 50rpm, discharge screw speed 75rpm, discharge valve opening 70%, pressure difference 0.3MPa, and total hot grinding time 5min; the fiber emulsion obtained in the previous step is sprayed into the grinding chamber of the hot grinding mill through a metering pump. The wood chips of the predetermined size are processed by the hot grinding mill to obtain forest waste fibers. The forest waste fibers and the remaining fiber emulsion are uniformly mixed and then sprayed out to obtain mixed wood fibers; mixed wood fibers The oven-dried forest waste fiber accounts for 80% of the oven-dried mixed wood fiber mass; and when the total hot grinding time reaches 60%, the heated and melted paraffin wax, which contains 50% by mass of p-tert-butylphenol formaldehyde resin, is directly injected into the grinding chamber of the hot mill through a metering pump, and hot grinding continues until the total hot grinding time is reached. The amount of paraffin wax added is 0.6% of the oven-dried mixed wood fiber; sizing: then, the obtained mixed wood fiber is sizing with an oxidizing agent containing 2% by mass in the spray pipe of the hot mill. Zinc-based urea-formaldehyde resin adhesive enters the drying process; after being laid to form a slab, it undergoes vulcanization pre-pressing, curing hot pressing, and then slitting. The vulcanization pre-pressing process is as follows: pre-pressing pressure 1.8MPa, vulcanization pre-pressing temperature 170℃, pre-pressing time 30s / mm. The curing hot pressing process is as follows: high pressure 2.2MPa, heat transfer section pressure 0.6MPa, thickness setting pressure 1.0MPa, hot pressing temperature 220℃, hot pressing time 30s / mm. The product specifications are 2440mm×1220mm×1mm.

[0046] Product performance: Density 0.94 g / cm³ 3 Moisture content 4.8%; internal density deviation -2.0%, +1.4; static bending strength 50.7MPa; elastic modulus 4898MPa; internal bond strength 1.77MPa, surface bond strength 2.45MPa, water absorption thickness swelling rate 21.3%, formaldehyde release 4.8mg / 100g.

[0047] Note: Moisture content determination shall be performed according to the method specified in 4.3 of GB / T17657-2013. Static bending strength and modulus of elasticity determination shall be performed according to the method specified in 4.7 of GB / T17657-2013, and specimen balancing treatment shall be performed. If the specimen does not fail, the maximum load-bearing capacity shall be used as Fmax for static bending strength calculation. Internal bond strength determination shall be performed according to the method specified in 4.11 of GB / T17657-2013, and specimen balancing treatment shall be performed. Surface bond strength determination shall be performed according to the test method specified in 6.9 of GB / T11718-2021, and specimen balancing treatment shall be performed. Water absorption thickness swelling rate determination shall be performed according to the method 1 for water absorption swelling rate determination specified in 4.4 of GB / T17657-2013, requiring an immersion time of 24 hours, and the measurement after immersion shall be completed within 10 minutes. The water absorption rate was determined according to the 24-hour water absorption rate test method specified in section 4.6 of GB / T17657-2013. The formaldehyde emission rate was determined according to the formaldehyde emission rate test method specified in GB18580-2017.

Claims

1. A production process for automotive interior trim panels based on waste forest fibers, characterized in that, excluding the steps of chipping, screening to obtain wood chips of predetermined sizes, drying after gluing, sorting, laying, and cooling, sanding, edge sawing, and stacking after slitting, the process further includes: It also includes the following steps: (1) The residual plant residues of landscaping are crushed and pulped to prepare residual fiber emulsion slurry; the residual plant residues of landscaping are one or more of Euonymus japonicus residues, vine residues, and dandelion residues; (2) Hot grinding and waxing process: the hot grinding process parameters are executed, and the residual fiber emulsion slurry obtained in the previous step is sprayed into the grinding chamber of the hot grinding machine through a metering pump. Wood chips of a predetermined size are obtained by hot grinding of forest waste fibers in the hot grinding machine. The forest waste fibers and residual fiber emulsion slurry are evenly mixed and then passed through the hot grinding machine. The mixture of wood fibers is sprayed out; and when the total hot grinding time reaches 50% to 60%, the heated and melted paraffin containing 40% to 50% by mass of p-tert-butylphenol formaldehyde resin is directly sprayed into the grinding chamber of the hot grinding mill through a metering pump, and the hot grinding continues until the total hot grinding time is reached; the hot grinding process parameters of step (2) are set as follows: discharge temperature 60 to 65°C, hot grinding mill pressure 7.2 to 8 bar, preheating silo temperature 80 to 90°C, and cooking pressure 7.5 to 8 bar. bar, cooking time 130-160s, cooking temperature 140-145℃, preheated silo level 75%-80%, feed screw speed 47-50rpm, discharge screw speed 65-75rpm, discharge valve opening 50%-70%, pressure difference 0.2-0.3MPa, total hot grinding time 3-5min; (3) Glue application: Then apply urea-formaldehyde resin adhesive containing 1%-2% zinc oxide by mass to the obtained mixed wood fiber in the spray pipe of the hot grinding mill, and enter the drying process. Sequence; (4) After the slab is laid and formed, it is then vulcanized and pre-pressed, and then slit after curing and hot pressing; The vulcanization pre-pressing in step (4) is: pre-pressing pressure 1.5~1.8MPa, vulcanization pre-pressing temperature 160~170℃, pre-pressing time 25~30s / mm, and curing and hot pressing process is: high pressure 1.6~2.2MPa, heat transfer section pressure 0.3~0.6MPa, thickness pressure 0.8~1.0MPa, hot pressing temperature 200~220℃, and hot pressing time 25~30s / mm.

2. The production process of a forest waste fiber-based automotive interior panel according to claim 1, characterized in that, In step (3), the amount of urea-formaldehyde resin adhesive applied is within the range of 8% to 10% by weight of the oven-dried urea-formaldehyde resin adhesive to the oven-dried mixed wood fiber.

3. The production process of a forest waste fiber-based automotive interior panel according to claim 1, characterized in that, The predetermined size of the wood chips in step (2) is (20-30) mm × (10-20) mm × (5-10) mm.

4. The production process of a forest waste fiber-based automotive interior panel according to claim 1, characterized in that, In step (3), the oven-dried forest waste fiber in the mixed wood fiber accounts for 70% to 80% of the oven-dried mixed wood fiber mass.

5. The production process of a forest waste fiber-based automotive interior panel according to claim 1, characterized in that, In step (2), the paraffin is 58# fully refined paraffin, and the amount added is 0.5% to 0.6% of the oven-dried mixed wood fiber.

6. The production process of a forest waste fiber-based automotive interior panel according to claim 1, characterized in that, The solid content of the remaining fiber emulsion slurry in step (4) is 50% to 60%.

7. The production process of a forest waste fiber-based automotive interior panel according to claim 1, characterized in that, The moisture content of the slab formed after step (4) is laid is 8% to 9%.

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