Plastic surface treatment is to form a layer with some or more special properties on the surface of material through physical or chemical methods. Surface treatment can improve appearance, texture and function of product.

In-mold decoration technology (IMD) is a molding method in which a diaphragm with a printed pattern is placed into a metal mold, molding resin is injected into metal mold to join diaphragm, so that printed diaphragm and resin are integrated and solidified into a finished product.
IMD includes IML (no stretching, small curved surface), IMF (high stretch products, 3D), and IMR (surface film is removed, leaving only ink on the surface). Currently, IML and IMF are collectively referred to as IML in industry.

 

IMR technical features:
(1) Exquisite decorative graphics and logos are embedded and will not disappear due to friction or chemical corrosion;
(2) Graphics, text, logos and color designs can be changed at any time without changing mold;
(3) For three-dimensional shape products, printing accuracy is accurate, with an error of ±0.05mm;
(4) It can provide graphics, text, logo backlighting and high light transmittance window effects;
(5) Function buttons have even bumps, good feel, and a service life of more than 1 million times;
(6) Three-dimensional changes can increase designers’ freedom in product design;
(7) Composite molding processing achieves seamless effect.

Spraying is a coating method that uses a spray tool such as a spray gun to atomize paint and then spray it on workpiece to be coated. Process flow is as follows: injection molding → primer → drying → topcoat → drying.
Advantage:
(1) Rich colors;
(2) Processing in a liquid environment can achieve surface treatment of complex structures;
(3) Process is mature and can be mass-produced;
(4) It has unique transparency and high gloss.
Shortcoming:

(1) Cost is too high and low-cost positioning products are not suitable for this process;

(2) Process is relatively complex and yield rate is low.

NCVM, also known as discontinuous coating technology or non-conductive electroplating technology, uses thin films such as metal and insulating compounds to be plated, utilizes discontinuous characteristics of each phase to obtain a product with a final appearance that has a metallic texture and does not affect wireless communication transmission effect.
NCVM can be applied to various plastic materials, such as PC, PC/ABS, ABS, PMMA, PA, etc. It is more in line with green environmental protection requirements of production process. It is an alternative technology for chromium-free electroplating products and is suitable for all plastics that require surface treatment. products, especially suitable for 3C products with signal transceiver.
Technical features:
(1) Manufactured product is non-conductive and can pass high-voltage test of tens of thousands of volts with a high-voltage meter without conduction or breakdown;
(2) Surface of produced product has a metallic texture and can achieve translucency control.

Electroplating allows plastics to obtain metallic-effect surfaces with higher yields and lower costs. Similar to physical vapor deposition (PVD), PVD is a physical principle, and electroplating is chemical plating, which is mainly divided into vacuum electroplating and water electroplating.

 

Advantage:
(1) Weight reduction;
(2) Comprehensive cost savings;
(3) Fewer processing steps;
(4) Simulated metal parts.
Shortcoming:
(1) Including metal inserts that cannot be changed during molding process;
(2) Molding parts larger than 200 square inches is much more difficult than die casting;
(3) There is a fire risk when electroplated plastic is used in certain types of household appliances.

Plastic parts printing is a process that prints desired pattern on the surface of plastic parts through pad printing, screen printing, transfer printing and other methods.
Pad printing: It is an indirect recessable rubber head printing technology. Designed pattern is first etched on printing plate, etching plate is coated with ink, and then most of ink is transferred to printed object through silicone head.
Screen printing: It is a main printing method in stencil printing. Printing plate is mesh-shaped. During printing, ink on printing plate leaks from through holes of plate to substrate under squeeze of squeegee. Usually wire mesh is made of nylon, polyester, silk or metal mesh.
Transfer printing includes water transfer printing and heat transfer printing.
Water transfer printing is a type of printing that uses water pressure to hydrolyze polymers on transfer paper/plastic films with colored patterns. Thermal transfer printing is a technology that prints patterns or patterns on heat-resistant adhesive paper, then prints pattern or pattern of ink layer onto finished material through heating and pressure.

Laser engraving, also called laser engraving or laser marking, is a surface treatment process that uses optical principles. It is similar to screen printing and pad printing. Laser engraving can be used to type or pattern on the surface of product.
Technical features:
(1) Wide range, safe and reliable;
(2) Accurate, meticulous, safe and fast;
(3) Low cost, conservation and environmental protection.

 

Biting is a process that uses chemicals such as concentrated sulfuric acid to corrode inside of plastic molding mold to form patterns such as snakes, etching, plowing, etc. After plastic is molded through mold, surface will have corresponding patterns.
Process flow: Mold receiving→Sandblasting→Chemical cleaning (pickling)→Decals→Applying bitumen powder→Heating→Loading samples→Dry paint→Chemical etching→Chemical cleaning→Sandblasting→Quality inspection.
Technical features:
(1) Improve visual effect and feel of product;
(2) Anti-slip;
(3) Increase surface area to facilitate heat dissipation;
(4) Easy to demould and easy to form.