What processes can be used for cosmetic injection molding packaging?

 

 

When choosing cosmetics, consumers are often attracted by the product packaging. To enhance their market competitiveness, manufacturers focus on the surface finish of cosmetic packaging. Nowadays, the surface finishes for cosmetic packaging are incredibly diverse, including common finishes like gradient colors, bright gold, matte, silver plating, and textured surfaces. These processes enhance the color, appearance, and feel of cosmetic injection molding packaging, making it more textured and aesthetically pleasing. So how are these effects achieved? Below, HUIWEN Plastics will explain the processes that can be used for cosmetic injection molding packaging.

The manufacturing process of cosmetic packaging mainly consists of two processes: coloring and printing.

 

I. Coloring Processes

 

Electroplating Aluminum: An aluminum exterior layer wrapped around an inner plastic layer.

 

Electroplating (UV): Produces a brighter color compared to spray painting.

 

Spray Painting: Produces a matte color compared to electroplating.

 

**Inner Bottle External Spray:** Spraying is done on the outside of the inner bottle. Visually, there's a noticeable gap between the inner and outer bottles, and the sprayed area is small when viewed from the side.

 

**Outer Bottle Internal Spray:** Spraying is done on the inside of the outer bottle. Visually, the area appears larger, but it's smaller when viewed from a vertical plane, and there's no gap between the inner and outer bottles.

 

**Brushed Gold/Silver Coating:** This is actually a single film; close inspection reveals seams on the bottle surface.

 

**Secondary Oxidation:** Injection molding manufacturers perform a secondary oxidation process on the existing oxide layer, achieving a glossy surface with matte patterns or a matte surface with glossy patterns. Often used for logos.

 

**Injection Molding Color:** Color powder is added to the raw material during injection molding. This process is relatively inexpensive. Pearl powder can also be added. Adding tapioca starch will turn transparent PET opaque.

 

**II. Printing Processes:**

 

**Screen Printing:** The printed effect has a noticeable raised texture because it's a single layer of ink.

 

** Screen printing on regular-shaped bottles (cylindrical) can be completed in one go. For irregularly shaped bottles, each print is charged separately, and the color is also charged separately. There are two types of inks: self-drying ink and UV ink.

 

Screen Printing 3

 

Hot Stamping: A thin layer of paper is stamped onto the surface, so it doesn't have the raised texture of screen printing.

 

Hot stamping should not be done directly on PE and PP materials. Heat transfer printing is required first, or you can use good hot stamping foil.

 

Water Transfer Printing: This is an irregular printing process done in water, resulting in inconsistent patterns, and it is more expensive.

 

2

Heat Transfer Printing: Heat transfer printing is mostly used for high-volume, complex printing products. It involves applying a film to the surface and is relatively expensive.

 

Offset Printing: Mostly used for aluminum-plastic flexible tubes and all-plastic flexible tubes. If using colored flexible tubes to print white, screen printing is required. Offset printing will show the base color showing through. Sometimes a glossy or matte film is applied to the surface of the tube.