scholarly journals Use of a Holistic Design and Manufacturing Approach to Implement Optimized Additively Manufactured Mould Inserts for the Production of Injection-Moulded Thermoplastics

2020 ◽  
Vol 4 (4) ◽  
pp. 100
Author(s):  
Loucas Papadakis ◽  
Stelios Avraam ◽  
Demetris Photiou ◽  
Simona Masurtschak ◽  
Juan Carlos Pereira Falcón

Injection moulding is one the most familiar processes for manufacturing of plastic parts by injecting molten thermoplastic polymers into a metallic mould. The cycle time of this process consists of the phases of injection, packing, cooling, and ejection of the final product. Shortening of cycle time is a key consideration to increase productivity. Therefore, in this manuscript the adoption of additively manufactured mould inserts with conformal cooling channels by means of selective laser melting (SLM) with the aim to reduce process cycles is presented. The design and manufacture of a mould insert with conformal cooling channels for producing pressure fitting thermoplastic parts is described. Numerical analysis of the injection process and simulation of shape distortions after SLM were conducted providing useful results for the design and manufacture of the mould insert. The results of the numerical analyses are compared with experimental 3D geometrical data of the additively manufactured mould insert. Temperature measurements during the real injection moulding process demonstrating promising findings. The adoption of the introduced method for the series production of injection moulded thermoplastics proves a shortening of cycle times of up to 32% and a final product shape quality improvement of up to 77% when using mould inserts with conformal cooling channels over the conventional mould inserts.

2016 ◽  
Vol 700 ◽  
pp. 31-41
Author(s):  
Z. Shayfull ◽  
S. Sharif ◽  
Azlan Mohd Zain ◽  
S.M. Nasir ◽  
R. Mohd Saad

Warpage is a common issue in an injection moulding process due to non-uniform temperature variation causing differential shrinkage on the moulded parts. In designing moulds for injection molding process, it is very difficult to achieve efficient cooling with uniform thermal distribution. Most of researchers focus on an optimisation of processing parameters to improve the warpage. However, the conformal cooling channels have advantages with the uniform distance between center of cooling channels and mould surfaces in order to get a better thermal distribution thus reducing the warpage. This paper presents the Milled Grooved Square Shape (MGSS) conformal cooling channels which provide more uniform in cooling and have a bigger effective cooling surface area cross sectional area and comparing to circular and others type of cooling channels with similar cross section. A case study on front panel housing is investigated and the possibility of fabrication the conformal cooling channels on hard tooling for injection moulding process which is easier to design, fabricate and assemble compared to other method are presented. The performance designs of straight drilled are compared to the two types of MGSS conformal cooling channels by using Autodesk Moldflow Insight (AMI) 2012. The analyses show that the both types of MGSS conformal cooling channel suggested can provide a more uniform thermal distribution and able to reduce the warpage on the molded part compared to the straight drilled cooling channels.


2017 ◽  
Vol 882 ◽  
pp. 23-27
Author(s):  
Ros Atikah Abdul Kadir ◽  
Nor Hafiez Mohamad Nor ◽  
Istikamah Subuki ◽  
Muhammad Hussain Ismail

This paper highlights the influence of titanium hydride particle on the rheological behaviour of nickel-titanium feedstock used in the metal injection process. The ratio of 50at% nickel and 50at% titanium hydride with 2 different powder loadings (65.5vol% and 67.5vol%) were investigated. A Rosand RH2000 capillary rheometer was used to determine the flow behaviour of feedstocks. The feedstocks were characterized at different temperature ranging from 150°C and 170°C and shear rate ranging from 50/s and 4442.63/s. The results showed on pseudo-elastic behaviour flow of NiTi feedstock which is suitable for injection moulding process.


2015 ◽  
Vol 761 ◽  
pp. 8-11 ◽  
Author(s):  
Mohd Amran ◽  
Siti Salmah ◽  
Raja Izamshah ◽  
Mohd Shahir ◽  
Mohd Amri ◽  
...  

Warpage deflection is one of the common pitfalls in plastic injection moulding which is always affected the quality and accuracy of the plastic products. It occurs due to the influences of mould temperature during injection moulding process and it is related to the number of cooling system existed in the mould. Therefore, this paper studies the effect of cooling channels on warpage of dumbbell plastic part having different number of cooling channel using Moldflow software. Warpage analysis was run using four and eight cooling channels. Parameters involved in this study are injection time, packing time, melt temperature and mould temperature. The result of warpage from simulation analysis was projected on the graphic having different colour which is presented the actual value of warpage. It is found from warpage simulation result that the maximum warpage for four cooling channels is 1.283mm and the maximum warpage for eight cooling channels is 1.280mm. It shows that the increasing of the number of cooling channel from four to eight channels in the injection mould reduces the warpage deflection about 0.2%. Thus, the result shows that the number of cooling system in the mould plays an important role on the quality of plastic part during injection moulding process.


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