The car door panel is an important part of the automotive interior. It is located on the inside of the door and has four points: front, back, left and right.There are usually two or four doors depending on the car system. These parts are collectively referred to as the door panel series.
The car door mold I mentioned is the mold for the left and right door parts of the car. The material is PP+EPDM. The shrinkage is generally 1.011. EPDM rubber is a copolymer of ethylene, propylene and a small amount of non-conjugated diene. It is a type of propylene rubber composed of chemically stable saturated hydrocarbons with only unsaturated double bonds in the side chain. Therefore, it has excellent ozone resistance, heat resistance and weather resistance, and can improve the elasticity of the door panel.
The door panel is an appearance piece, and the outer dimensions are: 880*670.4*105.6mm. Its structural characteristics are as follows:
1. The outer surface is required to be high, no spots or gate marks are allowed, and defects such as shrinkage holes, weld marks, and burrs are not allowed.
2, the door panel is a leather piece, the appearance of the demoulding slope is at least 5 °.
3. The surface of the door panel has high surface finish, complex shape structure, complicated parting line and more inverted buckles. There are 11 inverted buckles on the inner and outer sides of the plastic parts, which makes it difficult to demould.
Tips:
The door mold adopts the demoulding system introduced by “push rod + oblique push block + push block + nitrogen gas spring” and the “straight tube + inclined tube + water well” temperature control system.
Temperature control systems play an important role in the design of automotive parts molds, which have an important impact on the molding cycle and molding quality of plastic parts. Reasonable temperature control has a profound impact on the quality of the plastic parts and shortening the molding cycle. The design of the cooling system for large automotive mold manufacturing should pay attention to the following two points:
1, 3 meters principle. The total length of the cooling waterway should not exceed 3 meters. More than 3M cooling effect is poor. The case where the cooling water is not running after the mold opening should be avoided. In addition, the length of a single cooling passage must take into account the length of the drill bit, the hole is too deep, and the length of the drill bit is not sufficient, otherwise drilling cannot be completed. Straight-through cooling tubes for large automotive parts molds are typically 15 mm in diameter. The design of the fixed mode cooling water passage of the door injection mold should be designed at the same time as the shape of the plastic part, and drilled at both ends.
2, the effect of the palm. Large-scale automotive plastic mold waterway design, and arrange one-way flow of water. The spacing is arranged like a palm, and the distance between the waterways is controlled between 50-60mm.
Key points and difficulties in plastic mold design and manufacturing
1. Production cycle of door panel is relatively short, but procurement time of mold base is long, which brings pressure to design order. It must have rich experience to accumulate procurement work ahead of schedule.
2. Such molds have many inclined tops, mold is ejected, reset is unbalanced, product capacity and inclined top are relatively moved. Therefore, it is necessary to add two return rods, at the same time increase thimble plate screws to prevent product deformation, product side should also be improved by adding measures such as adding a block and strengthening slanting top.
3. Elimination of fusion line. After auto door molding was tested, it was found that sintering line was obvious, and it was solved by improving position of gate and strengthening exhaust.
4. Since speaker net can be discharged after mold is closed, electric discharge machining time is long, so pay attention to relationship between assembly and processing of speaker net.
5. Deviation of template inclined top hole is large, and processing technology must be improved to ensure assembly concentricity.
In recent years, proportion of plastic parts used in automobile production has become larger and larger. At present, interior and exterior parts of automobiles have basically realized plasticization, which plays an important role in reducing weight, saving cost and reducing fuel consumption.
Plastic parts need to be popularized and quality of technology should be improved. Mold as an industrial matrix must be first on to improve itself. As following takes a car door panel as an example to illustrate manufacturing process of plastic injection molding and related design points of plastic injection molding die.
Usually, car has two front and rear doors. According to classification of door holster, it can be divided into with a holster and without holster. According to shape characteristics of door, it can be divided into with a horn net and without horn net. Among them, surface quality requirements of product with a holster are low, and quality of product without a holster is high. For example, surface is not allowed to have a weld line, ejector mart is not allowed, strength requirement is high, and there is no burr.
Understanding Injection Molding Materials for Automotive Parts
Secondly, another way to improve efficiency and decrease defect rate is through getting familiar with the material of your product.
Polypropylene (PP)
Polypropylene is one of the common materials used in making car parts. Due to its resistance to chemicals, UV, and water, it is widely used in interior, engine and exterior parts such as dashboards, radiator and bumpers. It is more stable, easier for molding. Besides, adding fiberglass can increase the strength.
Polyvinyl Chloride (PVC)
Polyvinyl chloride (PVC) is a plastic that can be used to make both hard and soft parts. It is flexible and flame retardant. The auto parts made by PVC include interior panels, and dashboard components. In some cases, you need to use a specially designed screw to avoid corrosion. However, it usually adds plasticizer while manufacturing auto parts, which is harmful to environment. Therefore, there are substitutes such as TPU, ABS, PC or other environmental-friendly material show up.
Polyurethane (PU)
Polyurethane is a soft and high abrasion resistance material. Automotive parts that require a high degree of flexibility, such as foam seats, frequently make use of Polyurethane. The common defects are the surface of products become yellow and not smooth.
The reason why the surface of products become yellow is that the high heating temperature causes scorch. The resulting color will be yellow.
The reason why the surface of products become not smooth is also because high heating temperature, so it has a certain degree of deformation after heating and cooling processes.
Polycarbonate (PC)
Polycarbonate is a rigid, heat resistant, and durable material. In some cases, you need to do screw surface treatment to avoid product black dot. For example, you need to be aware of mold temperature and screw when producing car lights. With high mold temperature and special process of screw, the product surface would be smooth and bright.
Polyamide (Nylon)
Polyamide or Nylon, one of the engineering plastic materials, being wear-resistant material that is used to design bushes and bearings. Fiberglass can be added to strengthen the intensity, which might increase cost.
Acrylonitrile butadiene styrene (ABS)
Acrylonitrile butadiene styrene (ABS) is a common material with high strength, good stiffness and easy for processing and forming, which used in the manufacturing of dashboards and wheel covers. It is a hard and shiny plastic that is resistant to heat and impact damage. Besides, the surface of the processed product is smooth, allowing for the ease of dyeing and electroplating.
Suggested Customized Features of Automotive Injection Molding Machine
The last part, to achieve different purposes, customized requirements is necessary. Based on CLF’s experience, there are customized features of injection molding machines for automotive manufacturers as the suggestions.
Light-weight :
Bigger mold with smaller clamping force or adding fiberglass into material
Productive efficiency :
Multiple manufacture-processing in one machine
Product diversification :
By use of multi-colored/Co-injection injection molding machines
Space-saving :
By use of two-platen injection molding machines
Interior parts including dashboard, roof lining, door handles, center consoles, car mats and dashboard compartments are a fine example of injection molded products.
Aside from normal hardware such as door handles and car mats, some specific automotive parts need a special manufacturing process. For example, dashboard and interior door panels usually need secondary processing. Therefore, the design of injection procedures and cost would be the considerations for your purchasing.
Exterior parts, which are defined as exterior components of the car, such as bumpers, front grilles, step bumpers, headlights, fenders, and even side mirror shields are made using plastic automotive molding.
In this category, most of the manufactures put more focus on the aesthetic of its surface and how to make it light-weight. Beautiful products make product diversification, which leads to high demands of multi-colored/co-injection design of injection molding machines. The trend toward light-weight has also caused adjustments on machine design.
The car door panel is one important part for cars. There are usually two or four doors depending on the car system.
The car door mold we mentioned is the mold for the left and right door parts of the car. The material is PP+EPDM. The shrinkage is generally 1.011. EPDM rubber is a copolymer of ethylene, propylene and a small amount of non-conjugated diene. It is a type of propylene rubber composed of chemically stable saturated hydrocarbons with only unsaturated double bonds in the side chain. Therefore, it has excellent ozone resistance, heat resistance and weather resistance, and can improve the elasticity of the door panel.
Our design team design automotive parts based on clients’ specifications and requirements. Upon completion, we evaluate and test every product design proposal. The analysis process is carried out by design and engineering experts in consultation with the client, which ensures that we deliver precise and high-performing parts. we can share some experience we design plastic injection mold for Car Door Panel Audio Horn Cover if you are interested in it. please leave message here
Actually the Car Door Panel mold design is not difficult when you make the key points clear. we can discuss the door panel mold design with you if you are interested in, and provide some ideas how to design this type of mold.
In consideration of processing problems, the interior water duct of the Car Door Panel Mold maintains a distance of at least 8 mm from pusher holes such as push rods and push blocks.
The length of the cooling water channel is approximately equal, ensuring that the temperature difference between the cooling water inlet and outlet is approximately equal, thus ensuring that the mold temperature is roughly equal.
According to the shape of the plastic part, the Door Panel Mold uses a large-angle oblique hole. Although the drill bit has a side slip phenomenon and is extremely easy to drill, the problem can be solved by milling a platform perpendicular to the inclined hole before drilling.
The door panel is an appearance piece, and the outer dimensions are: 880*670.4*105.6mm. Its structural characteristics are as follows:
1. The outer surface is required to be high, no spots or gate marks are allowed, and defects such as shrinkage holes, weld marks, and burrs are not allowed.
2. The door panel is a leather piece, the appearance of the demoulding slope is at least 5 °.
3. The surface of the door panel has high surface finish, complex shape structure, complicated parting line and more inverted buckles.