There are many, many different elements of plastics design and balancing them can make the difference between the perfect outcome for your product or having to completely head back to the drawing board. Below are some of the key points to consider, at a high level, for designing plastic products and some advice on how to make good choices.
This post is the summary of our new series about the key points of your plastic production. Regularly we will post a new article for each of these key points. Moreover, we propose an alternative to this blog: we can send you directly in your mailbox, 2 days before its release, the content of the post. No need to come back regularly to the blog to check the new release.
There are many kinds of materials to be used on the plastic product, and the commonly used are like ABS、PE、PP、PVC、PA、PC POM and so on. You must choose suitable material according to the selected method of manufacturing. We've discussed some of the materials details in another article.
The different material needs different thickness and it’s very important because the flowability of material is different and the strength is different too. You must consider that the relationship between the flowability of material and manufacturability because it will affect the quality of the product. Incorrectly matching the thickness to the process can cause defects like incompletely filled parts, jetting and sink marks.
You can see the defects that are common problems when the thickness is unsuitable for the material in the pictures below:
In the order: Incomplete Filled Part / Jetting / Sink Mark
3. Draft Angle
In general, each face of the plastic product all need a draft angle for the mold to release easily. The draft angle that we always choose is more between 0.5°to 1°, and you can design different draft angel according to your requirement.
4. Reinforcing Rib
The reinforcing rib design is important to point out, also. The reinforcing rib needs to be designed in the right place not only increase the strength and rigidity but also so the thickness of plastic isn’t too thick. There is another function in that it can avoid to deform of plastic and make the flowability better in some condition (pictured below):
The design of a brace is primarily for fastening between parts, but they can be the pre-drill location of the self-cutting screw or where the metal insert is placed. Each way realizes the purpose of fastening parts. But you must attend three points. First, the height of brace must be fewer 2.5times of the brace diameter. Second, the brace must have several ribs, maybe three or four is good. Third, the height of rib must be lower than the height of the brace. You can see two kinds of brace design in the picture below.
Near-wall Far from a wall
6. Locating Spigot
The locating spigot is used to orient parts for assembly and helps to improve the exterior appearance. There are four kinds (pictured below) :
The purpose of design buckle is to make disassembly and fastening a part easier. For this reason, you must make the buckle with good elasticity and long service life. In general, the height of buckle is range 0.5mm to 1.5mm, so you can design the detail according to requirement.