Simulation of the gas-assisted injection molding process used in the process
Part of the carrier path for a mid-term aircraft model
Abstract
Computer Aided Engineering (CAE) Technology) Simulation and experimental studies have been carried out on the cavity filling and gas packaging steps
as part of the carrier path for gas-assisted injection molding. A mid-term aircraft model of the three-dimensional cavity geometry has been proposed using the finite element method for analysis. The lead ball size, distribution of air bubbles and remaining wall thickness were calculated using a commercial simulation software (Moldflow Plastics Insight version 4.1). The predicted results were compared with simulation
and experimental results showing the good prediction ability of the proposed model.
1. Introduction
Nowadays gas-assisted injection molding (gas-assisted injection molding) is not a
Innovative technology hollows out plastic parts for manufacturing industry
And the history of the first patent Dating back to 1978 [1]. However, establishment
as a homogeneous molding process has not yet been achieved
in the polymer industry. This is due to some pitfalls
Intrinsic reasons of gas-assisted injection molding in practical applications
The instability of natural gas, which means a complex relationship
Parameter controlled gas flow and quality
ware. High-efficiency understanding is a
characteristic process, especially for typical
flow phenomena.
There are four different processes to produce gas-assisted injection molded parts:
Short shot process, full shot process, return process and screws
Mold Scalable core[2]. In this work, we examine
The first process is also known as standard gas-assisted injection molding. The shortshot process can be described as a simple three steps:
1. The short rod is initially filled 70-90% with molten polymer
The mold cavity is memory-speed controlled for injection
Modeling machine (Figure 1A).
2. After a brief delay period, the compressed nitrogen core
melts the polymer. Penetrating air leaves a polymer layer on the mold walls, achieving a molded part
with a polymer skin and internal air channels (Fig. 1b). Gas
Penetration which occurs in this step is metering
The main gas penetration. When this step is completed, the mold cavity has been completely filled (Figure 1C).
3. The continuous injection of gas transfers packaging pressure to the polymer. The polymer shrinkage at this stage is offset by the growth of the gas core. Gas Packaging
The pressure remains until all polymer material has solidified.