Nanjing Julong is good at plastics modification.

Nanjing Julong Science & Technology Co.,LTD

Successful Cases

Case 1

Free-spraying side guard plate by Hainan Drinda Automotive Trim Co., Ltd


The plate appearance looked  not good due to molding gate defects. The gate positions was 70mm deviation from where it should have been.

1.The silver powder was uneven spread at points A and B, thus the surficial color was not in uniform.

2.The obvious welding marks bumped at points A and B simultaneously.


1.The color difference caused by the gate positions, which could not be moved. Was it possible to widen and thicken the gates?

2.The bumped weld marks was definitely related to the welding angles, which were smaller than 135 degrees.


Stage 1 

The engineers thought that gates should be wider and thicker at point A & B, so as to improve the raw material flowing in the local filling process.

Stage 2

The product structure needed changing. The engineers tested the welding angle at point C via the mold flow analysis , correspongdingly thicken 0.3mm per each gate at A & B. The flow direction of the raw material was changed in the filling process.

Stage 3

The molding process was modified. The multi-stage injection molding repaced one-section control. V/P were precisely and timely switched, and silver powder was fast injected into the shallow shade.

Stage 4

Meanwhile the temperature raised to 50°C inside the mold before molding, so as to improve raw material flowing while molding.

Case 2

Front-end frames of GAC


GAC started to design A28 front-end frame since April 2014. Julong and an auto-part manufacturer hepled GAC to do R&D, revision and analyses on the project, as well as put forward the constructive proposals.



1. How to meet GAC's requirments on the strength and deformation of key parts like headlamps, condensers, the lock via mechanical analysis?

2. How to design the standards and formulations of PP LFT?


Stage 1

The three parties divided the work into segments like desgining product structure, selecting materials, making molds and injection molding.

Stage 2

Julong and the auto-part manufacturer did CAE software analysis, put forward constructive proposals and submitted report. The two parties needed to ensure the mechanical strength of front-end frames when they are used anywhere and anytime.

Stage 3

Meanwhile, Julong was responsible for making the standards of material selection and offering proposals,  in order to ensure product quality and production stability.

Stage 4

The auto- part manufacturer was in charge of making molds and injection molding, as well as assemblies and shipments.

The front-end frames have been in mass production since July 2015.


The contents and results CAE analysis






LC1: under 80°C, loading the 150N force on the radiator along X axis



LC2: under 80°C, loading the 300N force on the radiator along Z axis



LC3: under 23°C, loading the 150N force on the headlamp along Z axis



LC4: under 23°C, loading the 5000N force on the lock along Z axis


LC5: under 23°C, ending the mold analysis

Stage 1: 54.39HZ; Stage 2: 93.9HZ

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