As a key material for improving the appearance quality of plastic products, plastic polishing paste has the core function of improving the surface microstructure through physical or chemical effects, thereby significantly improving the glossiness. The actual effect is affected by multiple factors such as plastic substrate, plastic polishing paste ingredients, and operating process. The specific improvement needs to be analyzed in combination with actual cases and scientific principles.
Plastic polishing paste removes tiny scratches and oxide layers on the surface through the mechanical action of abrasive particles, and uses lubricants and surfactants to fill surface pits to form a smooth mirror surface. For example, Germany's Reipo clean plastic polishing paste combines high-efficiency abrasive particles with lubricating grease to repair minor damage to materials such as acrylic and PC, and improve glossiness by 30%-50%.
The molecular structure and hardness of different plastics lead to different polishing effects. Hard plastics (such as ABS and PC) have tight molecular chains, and the glossiness is significantly improved after polishing, reaching 80-90 gloss units (GU); while soft plastics (such as PP and PE) are prone to elastic deformation, and the glossiness is improved by about 20-40 GU. In addition, the gloss improvement of recycled plastics after polishing is limited due to the high amount of impurities and rough surface.
The abrasive particle size and lubricant type in the plastic polishing paste directly affect the gloss. Fine-grained abrasives (such as 1-5μm) can achieve high-precision polishing, but the efficiency is low; coarse-grained abrasives (such as 10-20μm) can quickly remove scratches, but are prone to residual micro-pits. Experiments show that plastic polishing paste containing lubricants such as polyether and high-grade aliphatic hydrocarbons can increase the gloss of polypropylene products from 50 GU to 75 GU.
The polishing pressure, speed and time must match the hardness of the plastic. For example, when polishing hard plastics, the pressure is controlled at 0.5-1 MPa and the speed is 2000-3000 r/min to avoid excessive wear; while soft plastics need to reduce the pressure to 0.2-0.5 MPa and extend the polishing time to 5-10 minutes. Improper operation may cause surface burns or uneven gloss.
The industry usually uses a 60° angle gloss meter for measurement. Take the new PC board as an example: the gloss before polishing is about 60 GU, and after polishing it can reach 85-90 GU, an increase of 40%-50%. For aged and yellowed plastic parts, polishing can restore 70%-80% of the original gloss, but it cannot completely restore transparency.
The durability of the gloss after polishing depends on the surface protective layer. For plastics without protective film, the gloss may drop by 20%-30% due to friction and oxidation within 1-3 months; after coating with UV-curing coating or nano self-cleaning coating, the gloss can be maintained for more than 1 year.
In the field of automotive interiors, plastic polishing paste can increase the gloss of plastic parts of the instrument panel from 70 GU to 90 GU, meeting the VDA 270 standard; in 3C electronic products, the gloss of the mobile phone shell can reach more than 95 GU after polishing, meeting the requirements of brands such as Apple and Samsung. These cases verify the key role of plastic polishing paste in improving product competitiveness.
Plastic polishing paste can improve the surface gloss by 20%-50%, the specific extent depends on the plastic substrate, plastic polishing paste composition and operation process. Through scientific selection and standardized operation, the dual optimization of gloss and wear resistance can be achieved to meet the high standards of appearance quality of plastic products in different industries.
