Three factors of poor gloss of injection molded parts

Many injection molding factories will encounter similar problems. There is no problem with the product quality, but the glossiness of the product is not up to standard, which eventually leads to the rejection of the injection molded parts. In addition to the problems of the plastic itself, there are also problems such as injection mold, production, design, etc


1. In the injection molding production process

There are several options to try, which can be changed by adjusting mold temperature, feed / hold pressure, fill rate, and material temperature. In most cases, these adjustments will not have a significant impact and will reduce the process window of the whole production, thus increasing the possibility of other problems. Therefore, it is best to find the most robust process for the part and maintain the surface finish of the cavity mold.

2. In terms of injection mold

When dealing with the problem of gloss, do not change the surface finish of die steel at the first step. On the contrary, it is necessary to adjust the process parameters to change the glossiness of the product. Lower mold temperature, colder melt, lower feeding / holding pressure and lower filling speed may make your plastic parts glossier. The reason for this is that the plastic is not copied into the micro details of the surface finish of the die steel due to the lower die temperature and the lower pressure applied.

On the contrary, the higher the injection mold and melt temperature, the higher the feeding / holding pressure, and the faster the filling speed, the darker the luster of your parts will be. The influence of melt temperature is not as great as the filling speed, because the influence of filling speed and the resulting shear force on material viscosity is much greater.

On the other hand, if the surface gloss of the product is too high, it can be considered to reduce the surface gloss of the die steel surface or sandblasting in the mold cavity. Both methods create small pits in the steel, increasing the surface area, which allows the injection molding to absorb more light and thus appear to darken your parts.

3. In the design of injection molding products

Another major cause of gloss problem is the design of the product, especially the position where the wall thickness of the product changes. When the wall thickness changes, it is difficult to maintain the uniform gloss of the parts. Due to the difference of flow patterns, the thinner wall section will not be under too much plastic material pressure, and the result is that the glossiness of the area will be higher.

Inadequate exhaust will also produce inconsistent surface gloss. Depending on the material and process, insufficient exhaust will cause dark spots and bright spots.

The above three points are important factors affecting the glossiness of injection molding products. As long as the injection molding manufacturers consider these problems in place before producing products, they can avoid the problem of glossiness of injection molded products.



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]


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