How to improve product feel and texture through mold design?

一, Structural optimization: shaping product aesthetics through precision design
1. Art of parting line and demolding slope
The parting line is the seam line generated when the mold is closed, and its position directly affects the integrity of the product appearance. The design of high-end electronic product casings often hides the parting line on the side or bottom, and hides the mold traces through CNC machining. For example, the Apple MacBook case adopts a one-piece molding process, with the parting line hidden at the pivot and anodized surface treatment to achieve visual invisibility. The design of demolding slope needs to balance demolding convenience and product form: the demolding slope of smooth surfaces should be ≥ 0.5 °, the rough textured surface should be>1.5 °, and the slope of the outer surface of deep cavity structures should be greater than that of the inner surface to prevent uneven wall thickness caused by core misalignment during injection molding.
2. Rounded transition and stress dispersion
Sharp edges not only affect the tactile sensation, but also lead to product cracking due to stress concentration. Car interior design generally adopts rounded corners of R0.5mm or more, which not only improves grip comfort, but also extends mold life through uniform stress distribution. A high-end car brand dashboard mold reduced surface stress by 40% by changing the right angle transition to a gradient arc, while reducing weld marks during injection molding and improving surface glossiness by 2 levels.
3. Strengthen reinforcement and wall thickness control
The thickness of the reinforcing ribs should be strictly controlled between 50% and 70% of the product wall thickness. Excessive thickness can cause surface shrinkage, while insufficient thickness can affect structural strength. A certain smart home brand optimized the layout of the reinforcement ribs in the remote control mold, reducing the wall thickness from 3.2mm to 2.5mm. Combined with a reinforcement rib design with a thickness of 0.8mm, the product weight was reduced by 23% and the injection molding cycle was shortened by 15% while ensuring grip comfort.
二, Surface treatment: Creating a tactile feast with micro craftsmanship
1. Surface texture replication technology for molds
By using EDM (electric discharge machining) or laser engraving to create micro textures on the surface of the mold cavity, it is possible to achieve effects such as skin texture, sanding, diamond cutting, etc. on the surface of the product. The back cover mold of a certain mobile phone brand adopts a laser engraving process with a precision of 0.01mm, forming a nano level concave convex structure on the surface of the mold, so that the friction coefficient of the product surface is precisely controlled between 0.3-0.4, which is both anti slip and fingerprint free.
2. Nitriding treatment and coating technology
The surface treatment of molds directly affects the surface quality of products. Nitriding treatment can increase the surface hardness of the mold to HV1000 or above, significantly improving wear resistance, and is suitable for the production of high gloss mirror products. A certain cosmetic packaging mold uses FCVA vacuum coating diamond film technology to form a superhard coating with a thickness of 0.5 μ m on the surface of the mold, resulting in a surface glossiness of over 90GU and continuous production of 100000 molds without scratches.
3. Precision control of polishing process
The polishing grade of the mold directly affects the surface roughness of the product. The car headlight mold needs to meet the # 12000 mesh mirror polishing standard, with a surface roughness Ra<0.01 μ m to ensure a light transmittance of>90%. A certain optical lens mold adopts magnetorheological polishing technology, which controls the flow of polishing solution through a magnetic field to achieve nanoscale surface accuracy, increasing the product's transmittance to 92% and controlling the edge distortion rate within 0.1%.
三, Material selection: Achieving long-lasting texture through performance matching
1. Targeted selection of mold steel
The performance requirements for mold steel vary significantly among different products
High gloss product: Made of H13/2344 steel, with a hardness of HRC52 after deep cryogenic treatment, it has excellent high temperature resistance and is suitable for producing high gloss components such as automotive instrument panels.
Wear resistant products: Made of S136H steel, processed by vacuum quenching, with a hardness of HRC48-52, suitable for producing components such as gears that require long-term friction.
Corrosion environment: 316L stainless steel molds are treated with PVD coating and have a salt spray resistance test of over 1000 hours, making them suitable for producing medical device casings.
2. Application of new composite materials
A certain drone brand has reduced product weight by 60% and increased surface hardness by 3 levels by using carbon fiber reinforced PEEK molds. This mold requires the use of a five axis linkage machining center, combined with electrode machining with a precision of 0.05mm, to ensure the accuracy control of the composite material flow channel.
3. Balance between lightweight and strength
The design of automotive interior mold needs to balance weight reduction and safety: The dashboard bracket mold of a new energy vehicle model uses aluminum magnesium alloy substrate, which reduces weight by 35% through topology optimization design. At the same time, the strength is improved by adding 0.3% scandium element, making the product pass the C-NCAP collision test requirements.
四, Digital technology: Empowering texture upgrade with intelligent design
1. CAE simulation optimization
By simulating the flow state of plastic melt in the mold cavity using Moldflow software, defects such as weld lines and air pockets can be detected in advance. A certain household appliance brand reduced the number of weld marks on the air conditioning panel mold from 8 to 2 through simulation optimization, and improved the surface glossiness uniformity by 40%.
2. Rapid iteration of 3D printing molds
Metal 3D printing technology has shortened the mold development cycle by 60%. A certain consumer electronics brand has successfully completed the entire process from design to sample within 72 hours through 3D printing trial production of molds. The surface roughness Ra is less than 0.8 μ m, meeting the requirements of high gloss products.
3. Intelligent sensor integration
A high-end mold embeds pressure sensors inside the core to monitor real-time injection pressure distribution. Through AI algorithms, process parameters are automatically adjusted to stabilize product dimensional accuracy within ± 0.02mm and reduce surface shrinkage to below 0.3%.