Sink marks in injection molding are a common problem in plastics processing that can affect both the appearance and functionality of parts. But did you know that there is a natural solution to prevent these surface defects? In this article, you will learn how sink marks occur and how innovative materials from Golden Compound that contain natural fibers derived from sunflower seed hulls can help. We will also show you how you can save additional material and cost by using foaming in the manufacturing process.
What are sink marks and how do they arise?
Sink marks occur when the material cools and shrinks unevenly during the injection molding process. Especially in thick-walled areas, unsightly sink marks can appear on the surface. This occurs because the material shrinks more on the inside while the surface cools and solidifies faster.
The most common causes are
- Insufficient pressure of the material
- Cooling down too quickly
- Incorrect component geometry
- Use of materials with high shrinkage
Blowholes not only impair the visual appearance of a product, but can also affect its structural integrity - a risk that must be avoided.
The solution: materials with natural fibers from Golden Compound
We offer an innovative solution to permanently prevent sink marks. Our materials contain natural fibers made from sunflower seed hulls that have unique physical properties. These fibers swell as soon as they are incorporated into the material. This swelling behavior compensates for shrinkage in the component, preventing sink marks.
This natural fiber reinforcement offers several advantages:
- Improved surface finish: Fibers fill the voids created by shrinkage, eliminating sink marks.
- Sustainability: Using natural fibers made from sunflower hulls is environmentally friendly and helps reduce the use of fossil fuels.
- Mechanical Stability: In addition to preventing sink marks, the fibers provide additional stability and strength to components.
- Uniqueness: Fibers have a unique look and feel.
Material savings by foaming in the injection molding process
Another advantage of our compounds is that they can be processed using the foaming method. During the injection molding process, blowing agents are added to the compound, resulting in foaming during the injection molding process. This process saves material without compromising the stability of the part or creating voids. The result is lighter parts, which is particularly beneficial in industries such as automotive and packaging.
By combining the swellable natural fiber with the foaming process, companies can not only save money, but also more efficiently meet their sustainability goals.
Sink marks in injection molding no longer have to be a thing of the past. Sink marks are a thing of the past with Golden Compound's natural fiber reinforced materials. The sunflower seed hull fibers provide uniform material distribution, eliminating sink marks while reducing material consumption. The addition of the foaming process makes your production not only more efficient, but also more sustainable.
Focus on quality, sustainability and cost efficiency by discovering the benefits of Golden Compound materials for your production!
