Plastic injection molding is a good high volume production method. All too often, these parts start to look the same even though they are made by different companies. How can you make your parts stand out from the competition? One answer is to use texture on your parts. What is texture? Texture is a change in the surface of the mold that breaks up the smooth surface with different types and sizes features. Features can be bumps, sharp cut, sand-like pits or any number of other types of geometry. This is one of the final steps when finishing a plastic injection mold. Texture can enhance the value of a plastic part if done with careful consideration.
Texture often helps provide a grip or reduce the gloss of the finished part. These functions can enhance the appeal and usability of the product. In this article let us start looking at seven different reasons to have texture on a part. I will discuss each of these so you can see the what value texture may have on your next project.
One of the most cited reasons for texture is to provide grip. Texture is commonly used to provide more grip especially on tools and controls. Smooth plastic can be slippery, especially when wet. Texture can create edges where the grip will be more positive. Texture can also serve as a visual communication tool. By placing texture in certain areas you can tell the user where the part is meant to be grasped. Texture can complement larger features such as nubs and serrations.
Texture tends to break up light and reduce gloss. Depending on the application, some parts should have a matte appearance. Putting texture on a surface breaks it up the surface which scatters light reflected. Good quality texture makes parts look professional and less like cheap plastic.
When using glass or other filler in plastic, texture can be used to hide the filler from being seen on the surface. In some parts it is undesirable for the filler in the plastic to come to the surface. In many cases this can be mitigated by using the correct process or by using less filler. When this is not the case, texture can help by allowing the glass to flow to the surface only in small areas which are camouflaged by the texture.
Often in plastic parts, ribs are used to make a part stronger without much added weight. Sometimes using ribs results in sink marks appearing on the outside which detract from the quality of the product. Especially when a part is designed with thick ribs, texture can hide the resulting sink marks. By breaking up the surface, the divot formed by the sinking of the material is less noticeable.
Another reason to use texture is to hide parting lines. On smooth surfaces, parting lines show up easily because they break the otherwise smooth surface. With texture, the parting line is easier to hide because it does not stand out as much. In some cases, parting lines look like cracks which the customer could mistake for a broken part. Most manufacture find ways to make sure the customers do make that kind of mistake.
One of the more artistic uses of texture makes the plastic appear to be wood, leather or other material. This type of texture is particularly desirable when trying to cut costs by making more expensive parts out of plastic. While texture may not hide everything, good texture may be enough to look like the original material. Even if it is recognizable as plastic, many customers will appreciated that it does not look like every other plastic part out there.
To preserve the look of your product, texture can hide minor damage. On items that are likely to scratch or dent, texture can help cover up minor imperfections. This can keep the product looking new longer and enhance the reputation of the product.
Now that we have discussed what texture is used for, let us look at how texture is made. Textured features can be produced by methods like acid etch, abrasive blasting, laser or by hand. Laser and hand methods allow for the most flexibility in that they can create a wide variety of texture from simulated wood to custom texture. Blasting and acid etch produce more uniform looking textures which are better for reducing gloss.
Before the next plastic mold project you undertake, look at these factors to help you get an edge on your competition and give you at nicer product.