The Importance Of Plastic Product Design
Plastic products occupy a very important position in the entire manufacturing industry, their molds account for almost 40% of the entire mold industry, and their advantages are also very obvious. However, the design of plastic products has their own unique requirements and rules. It must be completed by professional designer. Based on decades of experience in the plastic molding industry.
Advantages Of FMS Plastic Product Design
FMS product designers have unique advantages in the design of plastic products, at first, Our experience in injection molding simulation analysis and injection mold design benefits our plastic product design. secondly, We are located in the most concentrated area of injection mold making and injection molding production in the world. it allows us to access all kinds of mold makers and injection molding companies, and expose us to new designs and molding techniques. these also benefit our plastic product designers, Our service is professional, efficient，honest, good quality but not expensive
The Style Of Plastic Product
Injection molded plastic products can be designed to provide good looking products that consumers want to buy at no additional cost over boring products that have no sales appeal. To do this, you need the right product concept, the right people, and the right tools. Almost all of the new products on the market today are designed using industrial strength solid modeling CAD systems with good surface modeling capabilities such as UGNX. Our experience in UGNX surface modeling gives us the skills and tools we need to create competitively priced parts designed for economical injection molding
Just the right tools are not enough to create good looking parts. A designer with a sense of style who is working with an strong look concept is required to deliver a product look that will sell. Our experience in creating attractive plastic parts in UGNX can help you turn the idea of a good product into the physical reality of a well-designed plastic product.
Productive Design
Parts made of plastic must be “designed for production” than any other material. Almost everyone can design a plastic product to a certain extent, but in order to do it well, in addition to the “conventional” design skills, you need to understand the injection molding process and the function of the injection mold. We have previously provided our customers with the services of our injection mold design, and we have a deeper understanding of injection molds and injection molding issues. This knowledge, combined with our UGNX and FEA stress analysis capabilities, provides us with a powerful background in the design of plastic products
The importance of plastic stress analysis
The structural characteristics of plastic are very different from those metals, which is no longer news. But even a common term like stress, the meaning of a plastic part is very different from the meaning of a metal part. The real question is how do these different material properties affect the design process?
Plastics are considered to be a low cost material, but in reality they are quite expensive from a unit volume or load bearing point of view. Due to the high speed of the injection molding process, the cost of plastic parts is low. With this in mind, 100% of plastic products are not always the best way to get the most cost-effective products.
Plastics are generally good at handling intermittent loads, but they are permanently deformed even at low long-term loads. Often, a reasonable amount of plastic can not be added to overcome this characteristic in the design, so adding a small amount of load bearing metal parts to the main plastic design will result in a better product.
Getting great results from plastic injection molding requires a respect for the properties of thermoforming plastic resins and how they behave inside of a mold tool. Using good design practices at the beginning of the product development cycle will help you to avoid common pitfalls and will improve the look and performance of your parts. you always are some suggestions for the most common causes of defects in plastic injected molded parts and how to avoid them for our next project. thanks you so much!
Designing uniform wall thickness is essential to controlling the distribution of heat within the part during molding.
To get the best results, follow these design tips for wall thickness. Be careful to note the type of plastic being molded, which may effect the rate of shrinkage in the mold.
Adjacent walls should be equal in thickness wherever possible, but should in no case differ more than ~50%
Long wall sections should be supported with ribs or gussets, instead of making them thicker for strength
There should be a draft angle of 1 degree for every 2 cm in wall height
Walls should have a slight radius at their base to relieve stress which can cause cracking or deformation
Material and Thickness are very important when designing a plastic product
Depending on (1) how the product works, (2) the environment it will be in and (3) the preference of the designer, a material should be selected. These materials change how the part feels, looks and operates. Some are flexible, some are rigid, some are strong, some are brittle. The type of material chosen will often have a significant effect on the design of the part. Some support ribs may need to be removed or added, walls may need to be thicker or thinner, etc.
The plastic product design process offers many versatile solutions and unique benefits, but it’s a practice that depends on the strength of its design. The injection molding part design must be developed to maximize the efficiency inherent in high-volume molding. Plastic product and mould design, tool building, plastic material selection, and Injection molding manufacturing process are the four key factors that go into making a high-quality plastic injection molded part. During both the injection and cooling stages of the manufacturing process.
There are some differences between plastic product design and other product design. Here I would like to share some experience about plastic product design:
1. Wall thickness
Thin walls are advisable in plastic manufacturing for shorter cycle times and being able to produce more plastic part designs in shorter production lead time. Thinner walls also makes the cooling process faster. Ideal wall thickness from 0.08″ (2mm) to 0.16″ (4mm), but thin wall injection molding can go as thin as 0.02″ (0.5mm).
However, wall thickness also depends on the type of plastic material being used. Here are the recommended wall thickness for various plastic materials; ABS resin is between 0.045 and 0.140 inches, Acrylic is at 0.025 –0.150, Liquid crystal polymer at 0.030 -0.120, Nylon at 0.030–0.115, Polycarbonate at 0.040 – 0.150, Polyester at 0.025 –0.125 and Polypropylene at 0.025– 0.150.
2. Ribs
Adding ribs helps increase the bending stiffness due to the increased moment of inertia. This is a suggested option instead of adding thickness to the wall. Here are recommendations with ribs in plastic production;
Rib’s thickness should not be more than 60% of the nominal thickness value.
Height should be three times lower than the wall thickness.
Draft angle is at 25 degrees.
The ribs position must be perpendicular to the axis where the bending occurs.
Corners of the attachment points must be rounded instead of having them pointed.
3. Bosses
Bosses are layers wherein fasteners are attached and threaded inserts are located. Recommended specifications for bosses are the following;
Bosses’ wall thickness should not be more than 60% of the main wall.
Base radius should be at least 25% thickness of the main wall.
Bosses should be supported by ribs connecting to walls adjacent from their position or gussets at the bottom the mold design.
Ribs should be used to isolate bosses in corners of the design.
Plastic product designer’s Services include dynamic, linear and non-linear analyses, consulting, CAD development and design and prototyping.
Plastic Part design could become tricky and compromises and trade-offs usually lead to failures. Automotive OEM’s will mainly use plastic material in cosmetic components and some other non-load carrying components.
Main features of plastic part design would include:
Good Knowledge of Material Database – There are many sources of data available for 100’s of plastic material types and grades in the market. But very few would provide complete understanding of material properties. When select the plastic materials, temperature and time variation of strength should be considered, as it could significantly lead to development of creep & fatigue.
Type of Loading & Application – Short term cyclic loading or long term constant load. In both cases, the maximum allowable stresses are going to be significantly lesser than the tensile strength of material. The environmental exposure of the part can also decide the life of the part as it degrades on coming in contact with chemicals, UV rays, sunlight and temperature.
Part Design Features – Many factors like ribs, notches, wall thickness, holes can contribute to stress concentration & residual stresses in the part. Thus careful consideration of part features should be done in order to optimize the stress lines within the part. For example, any abrupt change in wall thickness may lead to high stress concentration and thus reduce strength of the part.
Process Induced issues – process control parameters like cooling time, heating temperature, poor material mixing, poor part design leading to improper material flow can significantly affect the structural characteristics & quality of the part.
Basically, the manufacturer try to cut costs by compromising on either of these factors which should be taken care by the product engineering team of the automotive company.
When designing with plastic, our goal is to achieve a technically accurate design that works well and can effectively reduce manufacturing costs. Following these basic techniques will help achieve these goals and speed up the design process.
Today’s high-performance plastics bring many benefits to the design table, which was previously thought to be only available on metal. The first is durability. Over time, today’s high performance plastics have proven to be much stronger than metals in many applications. Every imaginable industry, from plumbing, medical and aerospace, now has hundreds of applications, and previously designed metal parts are converted into plastic.