Low glossiness means that the surface is dark and dull, and the transparency of transparent products is low. There are many reasons for poor glossiness. Generally, the surface gloss defects of products can be divided into three types: plastic mold failure, improper forming conditions and improper use of raw materials.


Injection Mold Failure


Because the surface of plastic parts is the reappearance of the cavity surface of plastic mold, if there are scratches, corrosion, micro-holes and other defects on the surface of plastic mold, it will be copied on the surface of plastic parts, resulting in bad gloss. If the surface of the cavity is oily and moist, the surface of the plastic parts will be darker. Therefore, the surface of the cavity of the plastic mould should have a good smoothness. The surface of the die cavity must be kept clean and oil and water stains should be removed in time. The type and amount of release agent should be appropriate.


The temperature of plastic mould also has a great influence on the surface quality of plastic parts. Generally, different types of plastics have different surface glossiness under different temperature conditions, and injection mould temperature can not be too high or too low, which may lead to poor glossiness.


In addition, the plastic mold demoulding slope is too small, the thickness of the cross-section changes abruptly, the ribs are too thick and the gate and runner cross-section is too small, the shearing effect of the gating system is too large, the plastic mold exhaust bad and other faults will affect the surface quality of the plastic parts, resulting in poor surface gloss.


Improper use of raw materials


Inadequate raw materials can also lead to poor surface gloss of plastic parts.


Reasons: The excessive moisture content in the forming material and the condensation of volatile components in the cavity wall and the forming process of the plastic mould lead to the poor surface gloss of the plastic parts. Processing method: raw materials should be pre-dried.


The discoloration of raw materials or colorants results in poor gloss. High temperature resistant raw materials and colorants should be used.


The fluidity of raw materials is too poor, the surface of plastic parts is not compact, and the gloss is poor. Replace resin with better fluidity or add appropriate amount of lubricant and increase processing temperature.


When magazines are mixed in raw materials, new materials should be replaced in time.


Improper forming conditions


If the injection speed is too fast or too slow, the injection pressure is too low, the holding time is too short, the supercharger pressure is not enough, the nozzle hole is too small or the temperature is too low, the dispersion of fiber reinforced plastics is too poor, the cylinder temperature is too low, the melt plasticizes poorly, and the supply is insufficient, these conditions may lead to poor surface gloss of plastic parts. For the reasons, we should analyze the specific reasons, and then make corresponding adjustments.


About JasonMould Industrial Company Limited

Jasonmould is a China mold maker of plastic molds- injection mold, die casting moulds, plastic blow molding, rotational molding, medical plastic injection molding, two shot plastic injection molding, insert molding, overmolding, metal injection molding, micro injection molding, powder injection molding, ceramic injection molding, liquid injection molding, husky injection molding, household mold, casting mold, die mold tool, custom molds, china moulds, rapid prototyping tooling, plastic prototyping tooling, punch press tooling, die and tooling for mobile/ cell phone parts, automotive parts, vacuum cleaners, rechargeable tools, telephones, copiers, computers, multimedia speakers, and many other electronic products and household appliances. And also a plastic product manufacturer, mold manufacturer China– plastic parts, plastic water tank, plastic balls, plastic containers, plastic buckle, plastic anchor, plastic hanger, plastic spoon, plastic pipe fitting, plastic tumble, plastic tableware, plastic cups, plastic bottles, plastic tray, plastic cosmetic container, plastic case, plastic food container, plastic chairs, plastic caps, plastic cap closure, plastic tubes, plastic water pipes, plastic knobs, plastic tubing, plastic utility boxes, plastic racks and so on.

Person: James Yuan
Company: JasonMould Industrial Company Limited
Add:  LongGang Village,LongXi Town,BoLuo County,HuiZhou City,GuangDong Province, China
Tel: 86-752-6682869
Email: [email protected]