Metal brushed is very common in product , such as widely used in construction, daily necessities, electronic products and other fields. However, due to the high cost of metal brushed products, they are mostly used in mid-to-high-end and above products. Therefore, low-cost plastic parts that are visually similar to metal wire drawing effects are gradually produced. It is not only beautiful, with a metal-like texture, but also has a relatively low cost. Currently, it is more commonly used include portable notebook , tablets, home appliances and electronic products. How to make plastic products have a brushed texture similar to metal? Currently, there are three common methods:
1, injection molding method
Simply put, it is to directly make the wire drawing effect directly on plastic mold (usually on the mother mold kernel). Through injection molding, the surface of the molded plastic products will have a similar wire drawing effect. The general process flow is as follows:
1) Use bronze as the core mold material to process the mold embryo, and use a diamond knife to turn the wire drawing effect on the core mold embryo. Common ones include filaments, short wires, sun pattern , etc. At this time, the core mold embryo is the opposite shape of the mold embryo used to produce plastic products;
2) Put the core copper mold embryo into the electroforming liquid for deposition, and the electroplating solution is generally a nickel solution. The choice of nickel as the electroforming liquid mainly considers the metal characteristics of nickel (nickel, an approximately silver-white, hard, ductile and ferromagnetic metal element, which can be highly polished and corrosion-resistant), which is conducive to the corrosion resistance and mold maintenance of mold kernel during the injection molding process;
3). Generally, the deposition time is long, and it takes more than ten to twenty days. The thickness of the electroplating layer needs to meet the mold design requirements, and generally can reach 10-12mm.
4) Take out the copper core mold and take out the copy of the copper core mold (i.e., the electroplating layer). This copy is the mold kernel used for future production. Of course, it is also necessary to be processed and polished according to the mold design;
5) Place the processed nickel mold kernel in the processed mold steel mold embryo;
6) for injection molding. At this time, the surface of the injection molded product will have a wire drawing effect similar to metal.
The surface of the product after injection molding has the following surface treatments:
1) is directly the color of the plastic material. Dark-colored plastic parts are more likely to have a metal brushed texture similar to the metal brushed texture, and the visual effect is more like the metal brushed effect than the lighter ones;
2) The product is sprayed with metal paint , making the color and brushed plastics visually closer to the metal brushed texture, but it is still a certain difference from real metal brushed wired, such as light feel and insufficient heat transfer speed;
3) vacuum deposition of the product (nickel plating or chrome plating). Since the electroplating layer itself is metal, it is visually very close to metal brushed texture, which is almost comparable to the texture of the real metal brushed effect, at least it is a bit brighter in texture.
Disadvantages or shortcomings of injection molding:
1) If the plastic surface needs to be sprayed, the drawing should be relatively thick, otherwise it will be easily covered by paint; in addition, the thickness of the spray must be controlled, otherwise the drawing will be covered.
2) If vacuum plating is used, the cost of the product will be relatively high;
3) The mold production process is relatively high and the cycle is relatively long;
4) The hardness of nickel is low and it is easy to hit and hurt during mold production, so you must prepare more 3-5 nickel mold kernels in advance to avoid affecting production.
5) If the plastic parts need vacuum plating, large areas, sharp corners, etc. are avoided in design. Generally, the partial decorative parts of the product are brushed.
2, water plating and wire drawing method
Simply put, the plastic product is subjected to wet electroplating (also known as water plating), and then the surface is brushed.
plastic has been electroplating, and its mechanical properties have been greatly improved. For example, the tensile stress, torsional stress and impact stress have increased a lot, and the corrosion resistance is greatly enhanced, and the heat dissipation ability of the plastic can be greatly enhanced. In addition, because plastic electroplating is low in cost and high in production efficiency, plastic electroplating is widely used in electronics, automobiles, household products, etc.However, with the improvement of aesthetic requirements, it is hoped that after plastic plating, it can be made into a similar metal wire drawing effect (such as stainless steel wire drawing effect), so the plastic can be drawn after electroplating.
Since the plastic electroplating layer is relatively thick, it can generally reach 0.08-0.2mm, and sometimes it can reach 0.3mm, so its surface can be thinned and cut. The general process flow is as follows:
1) stress removal : Since there is internal stress after plastic injection molding, in order to reduce the deformation of the product after electroplating, the internal stress of must be removed. Generally, it is soaked in acetone solution;
2) degreasing : In order to ensure uniform contact with the solution during roughening, the grease on the plastic parts must be removed first, and the medium and low temperature alkaline liquid is generally cleaned;
3) roughening : The purpose is to ensure the contact area between the plastic parts and the liquid, generally high chromic acid solution is used;
4) neutralization and reduction of : Remove strong acids, oxides and other impurities remaining on the surface of the plastic part to improve the affinity of the plastic part;
5) pre-precipitation of : In order to attach divalent chromium ions to the surface of the plastic part, prepare for activation;
6) activation of : In order to electroplating metal, a catalytically active metal layer needs to be adsorbed on the surface of the plastic part;
7) reduction of : After activation and cleaning, it is necessary to perform reduction treatment to improve surface activity and accelerate deposition, and at the same time remove activation liquid on the surface. Prevent decomposition caused by bringing it into the electroless plating solution;
8) electroless plating : The purpose is to make the surface of the plastic parts with good conductivity, uniform and continuous plating, and ensure that the circuit can form a loop to ensure the smooth progress of the next step;
9) electroplating : Generally, three metal composite electroplating of copper, nickel and chromium are used to form a surface decorative layer on the plastic surface;
10) wire drawing : Wire the surface, generally thin filaments;
11) spray varnish : Clean and dry after drawing, and then spray the surface with varnish.
electroplated wire drawing parts have many special design requirements in the design, roughly the following points:
1) It is best to use electroplating grade ABS material , which has a butadiene content of 15%~16% and has the best adhesion strength, and it is also relatively cheap;
2) The surface quality of the plastic parts is very high, and electroplating cannot cover up some defects of injection, and it usually makes these defects more obvious. If you can use decorative effects such as leather patterns and knurlings, try to use them, because reducing the reflectivity of the electroplating parts will help cover up possible appearance defects, improve yield, and also help reduce costs;
3) There are several points to pay attention to when designing structures and molds. The appearance should be suitable for electroplating. When designing structures, try to avoid large areas of electroplating and try to avoid sharp corners. When designing the mold, the glue inlet should not be too thin to prevent water from breaking and falling off, prevent tip discharge, pay attention to the decompression slope, reserve exhaust holes, pay attention to the bonding line that affects the appearance and the position of the rubber inlet. At the same time, the mold should be designed to design a fixture or hanging point during electroplating.
4) It is best not to have metal inserts in plastic parts. Due to the different expansion coefficients of the two, when the temperature rises, the electroplating liquid will seep into the gap, which will have a certain impact on the structure of the plastic parts.
5) Small or hollow parts should be designed as one mold and multiple pieces on the mold to save processing time and electroplating time, and also facilitate electroplating fashion and improve production efficiency.
6) To draw the surface, try to be flat as much as possible, otherwise the wire cannot be drawn. Generally, local decorative parts in a product are made of electroplated wire drawing to avoid large areas.
3, gold-stitching transfer method
, simply put, paste a layer of brushed metal film on the plastic. That is, under the high temperature and high pressure of the gold stamping machine , the gold stamping film with a brushed texture is transferred to the surface of the plastic product. A gold stamping film is a hot stamping material made by coating and vacuum evaporation on the film base and adding a layer of metal foil.Domestic gold stamping films are generally 5 layers, base films, layer, detachment layer, dyeing layer, aluminum plating layer and adhesive layer. The specific decomposition is as follows:
1) The base film layer generally uses a 16-pim thick bidirectional stretched polyester film (PET), which has high strength, tensile resistance, high temperature resistance and other properties, and is not easily deformed due to temperature rise.
2) The detachment layer is mainly made of silicone resin , etc. Its main function is to make the color layer, aluminum plating layer and adhesive layer quickly detach from the film and be transferred and bonded to the surface of the object to be stamped.
3) The main components of the dyeing layer are synthetic resin and dyes, which have film-forming properties, heat resistance and transparency. The color layer mainly has two functions: displaying the color and protecting the aluminum-plated pattern (such as brushed textures or patterns) that are stamped on the surface of the article from being oxidized. The colors of the color layer include orange, yellow, gray, red, green, etc. according to needs. The color of the color layer is given a luster after being plated through the aluminum coating, and the color changes to a certain extent. The color of the coating may not necessarily reflect the color after gold stamping, such as yellow is gold after aluminum coating, gray is silver after aluminum coating, etc.
4) The aluminum plating layer is a thin film with a colored layer, etc., placed in a vacuum chamber in a continuous aluminum plating machine. Under a certain vacuum degree, is heated by resistance, melted the aluminum wire and continuously evaporated onto the color layer of the film, forming an aluminum plating layer. The main function is to reflect light, change the color properties of the color layer, and make it appear glossy.
5) The adhesive layer is generally made of fusible thermoplastic resin on the aluminum layer through a coating machine, and then dried to form an adhesive layer. The main function of the adhesive layer is to bond the hot stamping material to the hot object.
Figure: Brushed hot stamping paper
The surface of the product through the hot stamping transfer method has a similar metal brushed texture, which can basically reflect the metal brushed texture visually, but the feel is still a little different. In addition, the gold-stitching transfer method has strict requirements on the surface of the product. Currently, there are more commonly used gold-stitching on boards, flat surfaces or regular curved surfaces. For products with relatively complex shapes, irregular shapes, or rounded corners, the gold-stitching transfer method is basically impossible.
The above three types can all show the effect of metal wire drawing of plastic parts. The specific application must be selected according to actual conditions, such as comprehensive considerations of product requirements, application environment, design requirements, etc.
More tutorials to get
1. Software full set installation package
Proe and Creo full set installation package
2.Creo software basic video tutorial
software basic video tutorial
3.Creo surface basic video tutorial
4.Creo surface practical video tutorial
surface practical video tutorial
5.Creo surface practical video tutorial
surface practical video tutorial
5.Creo surface practical video tutorial 5.Creo surface practical video tutorial
surface practical video tutorial
5.Creo cracked Surface repair video tutorial
Surface repair video tutorial
6.Creo engineering drawing video tutorial
engineering drawing
7. Mobile phone product structure design video tutorial
mobile phone product structure design
8.TWS Bluetooth headset video tutorial
Students who need the above tutorial send a private message to me: Information
