E-cigarettes, as personal consumer products, have their appearance as a key factor reflecting product quality and features, and attracting consumer groups. In a market where functional differences are minimal and product homogenization is significant, creating a unique appearance becomes a critical strategy for manufacturers to craft distinctive product identities. E-cigarette casings made from plastic, aluminum alloys, and other materials can undergo various decorative processes to enhance their aesthetic appeal and texture. Let’s explore these processes:
Plastic Surface Treatment
To become a widely accepted product, plastic items must not only be functional but also boast a dazzling and unique appearance. Sometimes, it’s necessary to convey corporate product information and brand messages through graphic means, requiring product decoration.
Decorative treatments for injection-molded parts can generally be divided into four categories based on the stage of the processing sequence:
- Direct processing during injection molding, primarily utilizing materials, molds, and injection molding machines to process the product’s appearance;
- Indirect processing during injection molding, mainly mold-in compound processing, such as In-Mold Decoration (IMD), In-Mold Labeling (IML), In-Mold Rolling (IMR) processes;
- Direct surface processing after injection molding, directly applying coatings, printing, etc., on the product surface, such as spraying, plating, digital printing;
- Indirect processing after injection molding, using carriers like films to transfer pre-made patterns onto the product surface, such as transfer printing, coating.
Now, let’s delve into these common injection molding decoration techniques:
1. Laser Engraving Mold Surface Texture
Traditional mold surface texture processing uses etching, known as “exposing” in Hong Kong and “biting” in Taiwan. This involves using chemicals like concentrated sulfuric acid to etch the interior of plastic molding molds, creating patterns. Traditional chemical etching offers only standard textures, lacking personalization and struggling with many textures.
Laser texture processing, a relatively new technique, can create up to 30-50 levels of texture patterns, providing more layered and finer surface quality. It offers unparalleled design possibilities for different materials and sizes.
2. Multi-Color Molding
Multi-color, multi-material injection-molded products are made from two or more colors of materials or different materials through one or more channels. They are molded without allowing the materials to penetrate each other, merging different materials in one molding process to create personalized function or color combinations.
3. High-Gloss Seamless Injection Molding
This technique employs rapid temperature change mold technology for dynamic temperature control, improving melt flow, reducing injection pressure, and enhancing molding processes. Dynamic temperature changes effectively prevent the formation of a condensed layer by the melt at the cavity wall, eliminating defects and achieving a high-gloss surface effect.
4. IML In-Mold Decoration
IML involves placing pre-printed and die-cut decorative film materials into the injection mold, then injecting resin behind the ink layer of the forming film, merging the resin and film into a solid form. IML offers durable, scratch-resistant, and fade-resistant finishes. It has been widely applied in e-cigarette products by companies like McWell and Green Sound.
5. Water Transfer Printing
This printing technique uses water pressure to apply colored patterns from transfer paper/plastic film through polymer hydrolysis. It involves laying specially treated film with the desired color pattern onto water, transferring the pattern evenly onto the product surface. The process results in a unique visual effect after applying a transparent protective coating.
Aluminum Alloy Surface Treatment
Aluminum alloy surface treatments include sandblasting, brushing, anodic oxidation, micro-arc oxidation, and laser engraving. Let’s examine these:
1. Gradient Anodizing
Achieved by controlling the dyeing time in the dye bath after anodization to create a gradient effect. Anodizing forms an oxide layer on the metal surface, with dyes entering the molecular gaps of the oxide layer during dyeing. Controlling the dyeing time allows for more dye absorption and deeper color. Gradient anodizing has been successfully applied to smartphones and can be applied to aluminum e-cigarette components.
2. Sandblasting Anodizing
This process involves using purified compressed air to spray dry sand or other abrasives onto the aluminum surface before anodizing, removing surface defects and achieving a uniform, matte finish.
3. Laser Engraved Logos and Nameplates
Laser engraving uses laser radiation to etch characters onto material surfaces, offering durability and precision. The finished products are aesthetically pleasing and highly accurate, avoiding issues like edge fraying or character deformation common in screen printing.