A Proposed Technique to Acquire Cavity Pressure Using a Surface Strain Sensor During Injection-Compression Molding

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Wei-Sheng Guan ◽  
Han-Xiong Huang
Keyword(s):  
Critical Time ◽  
Pressure Profile ◽  
Compression Molding ◽  
Surface Strain ◽  
Cavity Surface ◽  
Mold Surface ◽  
Cavity Pressure ◽  
Large Area ◽  
Part Surface ◽  
Injection Compression Molding

A new technique was proposed and experimentally verified for the cavity pressure acquisition in the injection-compression molding (ICM). The surface strain of the fixed mold half and the cavity pressure were monitored simultaneously during ICM. In the compression stage, a directly proportional relationship between the cavity pressure and mold surface strain was found and determined via the regression analysis. By taking the advantage of this relationship, the cavity pressure profile with high accuracy was indirectly obtained from the nondestructive measurement of the mold surface strain. Moreover, the mold surface strain profile could indicate the part weight or thickness and the critical time when the part surface lost contact with the cavity surface in a large area. The monitoring of the mold surface strain could serve as an interesting alternative to the direct monitoring of the cavity pressure with respect to process and part quality control for ICM.

A Model for the Flow of a Chopped Fiber Reinforced Polymer Compound in Compression Molding

1986 ◽  
Vol 53 (2) ◽  
pp. 361-371 ◽  
Author(s):  
M. R. Barone ◽  
D. A. Caulk
Keyword(s):  
Normal Component ◽  
Compression Molding ◽  
Fiber Reinforced Polymer ◽  
Cavity Surface ◽  
Mold Surface ◽  
Two Dimensional ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Stress Resultant ◽  
Polymer Compound

The flow of a chopped fiber reinforced polymer compound in compression molding is modelled as a two-dimensional membrane-like sheet which extends uniformly through the cavity thickness with slip at the mold surface. The model is consistent with both the kinematic mechanisms observed in actual flow and the three-dimensional anisotropy caused by the arrangement of fibers in the sheet. The material resistance to extension is expressed in a constitutive equation for the two-dimensional stress resultant formed by integrating the planar stress components through the thickness of the cavity. This stress resultant is assumed to be a linear function of the corresponding planar rate of deformation in the molding compound. Through a mechanism of fiber-resin interaction, the material resistance to extension can be characterized by a single scalar function of the transverse temperature distribution. Three alternatives are considered for the friction response at the cavity surface: (i) constant magnitude, (ii) proportional to the relative velocity (hydrodynamic), and (iii) proportional to the normal component of the stress vector (Coulomb). These three assumptions are compared by considering their general implications on the flow-front progression. The latter two are examined in some detail for thin charges in which the material resistance to extension is negligible compared to the effect of friction. Analytical solutions for an elliptical charge are obtained for both hydrodynamic and Coulomb friction. By comparing these solutions with experimental results, we conclude that the hydrodynamic model for the friction response is the best of the three proposed alternatives.

Numerical Simulation and Process Optimization of a 3D Thin-Walled Polymeric Part Using Injection Compression Molding

2021 ◽  
Vol 36 (4) ◽  
pp. 459-467
Author(s):  
D. Sönmez ◽  
A. A. Eker
Keyword(s):  
Numerical Simulation ◽  
Injection Molding ◽  
Process Parameters ◽  
Compression Molding ◽  
Injection Molding Process ◽  
Mold Surface ◽  
Clamping Force ◽  
Molding Process ◽  
Thin Walled ◽  
Injection Compression Molding

Abstract Injection compression molding (ICM) is a hybrid injection molding process for manufacturing polymer products with high precision and surface accuracy. In this study, a 3D flow simulation was employed for ICM and injection molding (IM) processes. Initially, the process parameters of IM and ICM were discussed based on the numerical simulations. The IM and ICM processes were compared via numerical simulation by using CAE tools of Moldflow software. The effect of process parameters of mold surface temperature, melting temperature, compression force and injection time on clamping force and pressure at the injection location of molded 3D BJ998MO Polypropylene (MFI 100) part was investigated by Taguchi analysis. In conclusion, it was found that the ICM has a relatively lower filling pressure than ICM, which results in reduced clamping force for producing a 3D thin-walled polymeric part.

Study on Optical Properties of Microstructure of Lightguiding Plate for Micro Injection Molding and Micro Injection-Compression Molding

2006 ◽  
Vol 505-507 ◽  
pp. 229-234 ◽  
Author(s):  
Yung Kang Shen ◽  
H.J. Chang ◽  
C.T. Lin
Keyword(s):  
Optical Properties ◽  
Injection Molding ◽  
Digital Camera ◽  
Mold Temperature ◽  
Compression Molding ◽  
Micro Injection Molding ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Injection Compression Molding ◽  
Better Than

The purpose of this paper presents the optical properties of microstructure of lightguiding plate for micro injection molding (MIM) and micro injection-compression molding (MICM). The lightguiding plate is applied on LCD of two inch of digital camera. Its radius of microstructure is from 100μm to 300μm by linearity expansion. The material of lightguiding plate uses the PMMA plastic. This paper uses the luminance distribution to make a comparison between MIM and MICM for the optical properties of lightguiding plate. The important parameters of process for optical properties are the mold temperature, melt temperature and packing pressure in micro injection molding. The important parameters of process for optical properties are the compression distance, mold temperature and compression speed in micro injection-compression molding. The process of micro injection-compression molding is better than micro injection molding for optical properties.

A Theoretical Analysis on Resin Injection/Compression Molding

2007 ◽  
Vol 334-335 ◽  
pp. 209-212 ◽  
Author(s):  
Akbar Shojaei ◽  
A. Spah
Keyword(s):  
Analytical Solutions ◽  
Mold Filling ◽  
Compression Molding ◽  
Fiber Content ◽  
Flow Front ◽  
Transfer Molding ◽  
Unidirectional Flow ◽  
Resin Injection ◽  
Filling Time ◽  
Injection Compression Molding

In the present investigation, mold filling process of resin injection/compression molding (RI/CM) is compared with resin transfer molding (RTM) for simple mold geometry. To do this, analytical solutions are obtained for RI/CM in unidirectional flow. Based on the analytical solutions, flow front progression and pressure distribution are compared with RTM at different fiber content. The results indicate that the RI/CM reduces the mold filling time significantly, particularly for composite parts with higher fiber content.

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