Preparation process of seamless aluminum-wood composite decorating part for automotive trim

Abstract

The invention discloses a preparation process of a seamless aluminum-wood composite decorative part for an automotive trim, and relates to the technical field of manufacturing of automotive upholstery through a five-step process of base material compounding, surface treatment, hot press molding, laser etching and in-mold injection molding. According to the preparation process of the seamless aluminum-wood composite decorative part of the automotive trim, the injection molding pressure and the mold temperature are accurately controlled, so that plastic naturally forms rounded R-angle transition in the filling process, sharp edges and corners of a traditional inlaying process are eliminated, visual layers with more stereoscopic impression are created, and in addition, the injection molding melt and the non-woven fabric layer are deeply permeated and combined, so that the production efficiency is improved. And the adhesive force performance is improved, mass production is easy, the difficulty is lower, and the qualification rate is higher.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile interior manufacturing, in particular to a preparation process of a seamless aluminum-wood composite decorative part for automobile interiors. BACKGROUND

[0002] The existing automobile interior decorative parts generally have the problems of material joint gap and discontinuous touch, especially aluminum-wood composite materials. Traditional processes either engrave first and then inlay (complex process), or engrave after composite injection molding (0.5mm gap), which will affect the texture experience of high-end cars. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application provides a preparation process of a seamless aluminum-wood composite decorative part for automobile interiors, which solves the above problems.

[0004] To achieve the above purpose, the present application is implemented by the following technical scheme: a preparation process of a seamless aluminum-wood composite decorative part for automobile interiors, comprising the following steps: S1, substrate composite: composite 0.5±0.05mm wood veneer layer and 0.15mm real aluminum layer through adhesive layer, and composite non-woven fabric layer on the back of the real aluminum layer; S2, surface treatment: polishing the surface of the composite substrate and spraying a color paint layer with a thickness of 15-25μm; S3, hot pressing: hot pressing at 180-220℃ and 5-8MPa pressure to obtain an A-shaped modeling substrate; S4, laser engraving: using a 1064nm wavelength fiber laser to engrave and remove the wood veneer layer at a power of 120-150W to expose the aluminum layer and form a pattern; S5, in-mold injection molding: injecting molten 3mm plastic substrate PC+ABS-GF20 (glass fiber content 20±2%) into the engraved groove under the conditions of mold temperature 80-100℃ and injection pressure 80-120MPa; PC+ABS-GF20 is an alloy made of polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS) by blending modification, and 20% glass fiber is added to enhance the composite material.

[0005] S6, surface protection: spraying polyurethane protective paint to form a 30-50μm transparent protective layer after curing.

[0006] Preferably, the adhesive layer is one of aluminum adhesive paper or wood adhesive paper, the thickness of the aluminum adhesive paper is 0.08±0.01mm, the thickness of the wood adhesive paper is 0.12±0.01mm, and the composite adhesion is ≥8N / cm.

[0007] Preferably, the depth of the laser engraving in step S4 satisfies the following model: ; wherein D is the engraving depth (mm), P is the laser power (W), v is the scanning speed (700-900 mm / s), k is the material ablation coefficient (wood k = 0.33-0.38), and δ is the thermal deformation compensation value (0.02-0.05 mm).

[0008] Preferably, the plastic substrate in step S5 is PC+ABS-GF20 with a melt index of 18-22 g / 10 min, a glass fiber content of 20±2%, an injection molding shrinkage compensation coefficient set to 1.005-1.008, and a three-stage pressure control for injection molding pressure holding: First stage: 90-110 MPa pressure holding for 2-3 s; Second stage: 70-85 MPa pressure holding for 3-4 s; Third stage: 50-65 MPa pressure holding for 5-6 s.

[0009] Preferably, the wood veneer layer is natural wood veneer with a moisture content controlled at 8±1%, and is subjected to plasma pretreatment before hot pressing, with a treatment power of 250-350 W and a treatment time of 60-120 s.

[0010] Preferably, a dynamic deformation compensation system is used in the hot pressing process in step S3, which real-time monitors the mold deformation through a piezoelectric sensor and automatically compensates for a gap of 0.1-0.3 mm, with the compensation amount calculated by the formula: ; wherein C is the compensation amount (mm), α is the material expansion coefficient (wood α = 4.5×10⁻ 6 K⁻¹), R is the curvature radius of the curved surface (mm), and T is the temperature change value (℃).

[0011] Preferably, a CCD visual focus tracking system is used for laser engraving in step S4, which maintains the focus position by the following algorithm: ; wherein is the real-time focus position, is the reference focus, is the focal length compensation coefficient, is the real-time curved surface height, is the reference height.

[0012] Preferably, nano-silicon dioxide particles with a particle size of 30-50 nm are added to the protective paint, with an addition amount of 1-3 wt%, and the pencil hardness of the cured coating is ≥3H and the Taber wear loss is ≤10 mg / 1000 r.

[0013] Preferably, the non-woven fabric layer in step S1 is a phenolic resin-impregnated polyester non-woven fabric with a grammage of 80±5 g / m2, and the resin penetrates into the non-woven fabric by 0.2-0.3 mm during injection molding.

[0014] The present application provides a preparation process of a seamless aluminum-wood composite decorative part for automotive interior. Compared with the prior art, the following beneficial effects are achieved: (1) The process precisely injects molten plastic into the groove of the wood veneer after laser engraving through in-mold injection molding technology, and automatically forms a natural transition fillet using the material shrinkage characteristics, so that the wood-aluminum joint presents a smooth three-dimensional visual effect, and completely eliminates the scratch feeling caused by the 0.5 mm step difference in the traditional process.

[0015] (2) The process combines the depth penetration of the injection melt and the non-woven fabric layer, improves the adhesion performance, and has lower production difficulty and higher qualification rate.

[0016] (3) The process uses a real-time monitoring device to feedback the deformation amount through a piezoelectric sensor, and the control system automatically compensates for a gap of 0.1-0.3 mm to make the curved surface fit perfectly.

[0017] (4) The process establishes a three-dimensional curved surface focal point positioning model based on a CCD vision system to ensure that the engraving depth fluctuation error is small.

[0018] (5) The process adds silicon dioxide particles in the protective paint to improve the hardness and wear resistance. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 The figure is a process flow diagram of the present application; Fig. 2 The figure is a structural diagram of the present application. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0021] Please refer to Figs. 1-2 The embodiments of the present application provide a technical solution: a preparation process of a seamless aluminum-wood composite decorative part for automotive interior, comprising the following steps: S1, raw material preparation: Wood veneer layer: 0.52 mm natural wood veneer, sanded to a surface roughness Ra=1.6 μm Real aluminum layer: 0.15 mm aluminum alloy plate, pretreated as follows: First, the base is washed to remove grease, then anodized, and finally closed; Parameters: oxide film thickness 10 μm, blocking agent temperature 60℃, time 15 min; Adhesive layer: aluminum adhesive paper or wood adhesive paper; Non-woven fabric layer: 80g / m2 polyester non-woven fabric, impregnated with phenolic resin (solid content 45%), bonding pressure 0.5MPa, to enhance and plastic substrate adhesion; Plastic substrate is 3mm PC+ABS-GF20, glass fiber content 20±2%.

[0022] S2, substrate composite: 0.5±0.05mm wood veneer layer and 0.15mm aluminum layer are combined through the adhesive layer, and the non-woven fabric layer is combined on the back of the aluminum layer.

[0023] S3, surface treatment: the surface of the composite substrate is polished, and a 15-25μm thick color paint layer is sprayed, wherein the electrostatic spraying, atomization pressure 0.4MPa, forming air pressure 0.3MPa S4, hot pressing: the composite substrate is placed in a hot press, and is hot pressed and shaped under the action of the hot press at 180-220℃ and a pressure of 5-8MPa to obtain an A-shaped molding substrate.

[0024] Mold parameters: Profile curvature radius R=150mm Compensation mechanism stroke 0-0.5mm Process parameters are as follows:

[0025] The mold deformation is monitored in real time by a piezoelectric sensor, and the compensation amount is calculated by the following formula: ; .

[0026] The deformation amount is fed back by the piezoelectric sensor, and the control system automatically compensates for the gap of 0.1-0.3mm, so that the curvature is exactly S5, laser engraving: Equipment configuration: Laser: IPGYLP-HP-150 fiber laser (1064nm); Scanning galvanometer: Scanlab intelliSCANde20; CCD positioning system: Basler ace2MP; Laser engraving uses a CCD vision focus tracking system, which maintains the focus position by the following algorithm: ; Among them real-time focal position, reference focal position, focal length compensation coefficient, real-time curved surface height, reference height.

[0027] Therefore, a 1064nm wavelength fiber laser is used to engrave and remove the veneer layer at a power of 120-150W to expose the aluminum layer to form a pattern, and a three-dimensional curved surface focal positioning model is established based on a CCD vision system to ensure that the engraving depth fluctuation error is small.

[0028] S6, in-mold injection molding: through an injection molding machine, under the conditions of mold temperature 80-100℃ and injection pressure 80-120MPa, melt 3mm plastic substrate PC+ABS-GF20 (glass fiber content 20±2%) is injected into the laser carving groove; Among them, three-stage pressure control is adopted during injection: First stage: 90-110MPa for 2-3s; Second stage: 70-85MPa for 3-4s; Third stage: 50-65MPa for 5-6s; Then cooled and formed through a cooling process, wherein the injection molding process can make the circumference have a natural R angle through the injection pressure and mold temperature, the visual effect is more three-dimensional, the hand feeling is better without scratching the hand, and the adhesion performance is improved through the deep penetration of the injection melt and the non-woven fabric layer, and the difficulty of mass production is lower and the qualified rate is higher.

[0029] S7, surface protection: polyurethane protective paint with added nano silicon dioxide particles is sprayed to form a 30-50μm transparent protective layer after curing, and the addition of silicon dioxide particles improves the hardness and wear resistance; Spraying parameters: Film thickness: 40±5μm; Curing: 80℃×30min; Leveling: infrared radiation 60℃×3min.

[0030] Therefore, when injecting melt PC+ABS material into the veneer groove area after laser carving, the injection pressure and mold temperature are precisely controlled to make the plastic naturally form a round R angle transition during filling, not only eliminating the sharp edges and corners of traditional inlaying process, but also creating a more three-dimensional visual level, secondly, the deep penetration of the injection melt and the non-woven fabric layer improves the adhesion performance and the difficulty of mass production is lower, and the qualified rate is higher.

[0031] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and illustrative figures, it should be apparent that the scope of the present application is not limited to these specific embodiments.

[0032] While the embodiments of the application have been shown and described herein, it will be understood by those skilled in the art that many changes, modifications, substitutions and alterations to these embodiments can be made without departing from the principles and spirits of the application, and it is intended that the scope of the application be limited solely by the scope of the appended claims and the equivalents thereof.

Claims

1. A process for the preparation of seamless aluminum-wood composite trim for automotive interiors, characterized in that, Comprise the following steps: S1, substrate composite, the veneer layer and the true aluminum layer are compounded through the adhesive layer, the back of the true aluminum layer is compounded with the non-woven fabric layer; S2, surface treatment, polishing the surface of the composite substrate, spraying the color paint layer; S3, hot pressing forming, hot pressing and shaping through the hot press, obtaining the A surface modeling substrate; S4, laser engraving, using a fiber laser to engrave and remove the veneer layer on the veneer layer, exposing the aluminum layer to form a pattern; S5, in-mold injection, then through the cooling process for cooling forming by in-mold injection process, the molten plastic substrate is injected into the engraving groove; S6, surface protection, after forming, spraying polyurethane protective paint, forming a transparent protective layer after curing.

2. A process for the preparation of seamless aluminum-wood composite trim for automotive interiors as claimed in claim 1, wherein: The adhesive layer is one of aluminum adhesive paper or wood adhesive paper.

3. A process for the preparation of seamless aluminum-wood composite trim for automotive interiors as claimed in claim 1 wherein: The depth control of step S4 laser engraving satisfies the following model: ； Wherein D is the engraving depth, P is the laser power, v is the scanning speed, k is the material etching coefficient, and δ is the thermal deformation compensation value.

4. A process for the preparation of seamless aluminum-wood composite trim for automotive interiors as claimed in claim 1 wherein: The plastic substrate of step S5 is PC+ABS-GF20, and the injection pressure is controlled by three stages: First stage: 90-110MPa pressure for 2-3s; Second stage: 70-85MPa pressure for 3-4s; Third stage: 50-65MPa pressure for 5-6s.

5. A process for the preparation of seamless aluminum-wood composite trim for automotive interiors as claimed in claim 1 wherein: The veneer layer is natural wood veneer.

6. A process for the preparation of seamless aluminum-wood composite trim for automotive interiors as claimed in claim 1 wherein: The hot pressing forming process of step S3 adopts dynamic deformation compensation system, which monitors the mold deformation in real time through piezoelectric sensor, automatically compensates the gap, and the compensation amount calculation formula is: ； Wherein C is the compensation amount, α is the material expansion coefficient, R is the curvature radius of the curved surface, and T is the temperature change value.

7. A process for the preparation of seamless aluminum-wood composite trim for automotive interiors as claimed in claim 1 wherein: The laser engraving of step S4 adopts CCD visual focus tracking system, which keeps the focus position through the following algorithm: ； wherein is the real-time focal position, is the reference focal point, is the focal length compensation coefficient, is the real-time surface height, is the reference height.

8. A process for the preparation of seamless aluminum-wood composite trim for automotive interiors as claimed in claim 1 wherein: The protective paint adds nano silicon dioxide particles.

9. A process for the preparation of seamless aluminum-wood composite trim for automotive interiors as claimed in claim 1 wherein: The non-woven fabric layer of step S1 is phenolic resin impregnated polyester non-woven fabric.

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