scholarly journals Development of a novel color inhomogeneity test method for injection molded parts

2014 ◽  
Vol 37 ◽  
pp. 112-116 ◽  
Author(s):  
L. Zsíros ◽  
A. Suplicz ◽  
G. Romhány ◽  
T. Tábi ◽  
J.G. Kovács
Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 943
Author(s):  
Eva Gleichweit ◽  
Christian Baumgartner ◽  
Reinhard Diethardt ◽  
Alexander Murer ◽  
Werner Sallegger ◽  
...  

Reliable bonding of microstructured polymer parts is one of the major challenges in industrial fabrication of microfluidic devices. In the present work, the effects of a UV/ozone surface activation on the bonding process were investigated for the combination of a commonly used thermoplastic cyclic olefin copolymer (COC) with an elastomeric COC (eCOC) as a new thermoplastic elastomer material. Bonding was studied using two-component injection molded parts of COC and eCOC, together with microfluidic COC chips. Surface activation and bonding process parameters were optimized and bond strengths were characterized by the wedge test method. The results showed that strong bonding of this polymer materials combination can be achieved at temperatures significantly below the bulk glass transition temperature of COC.


2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110169
Author(s):  
Liu Hong ◽  
Jiang Zheqi ◽  
Pan Danqi

Nondestructive test method for residual stress in a structural member is always an important research subject, as a new technique for measuring residual stress loading measuring method needs to consummate for the convenience of engineering. The paper proves that nondestructive test loading measuring method is effective and accurate when compared with the result from hole-drilling method. Taking the measurement of residual stress of injection-molded part in automotive lamp as example, the residual stresses in the surface of injection-molded parts of automotive lamp measured by the two methods are very close based on the two measuring results. It shows that loading measuring method, a new method is used to measure the residual stress, has enough accuracy and credibility when it is used to measure the residual stress of complicated injection-molded part. It provides a basis for popularization and application of loading measuring method in engineering. The paper discusses the basic principles of loading measuring method and detailed procedure of the measurement of residual stress by loading measuring method; it gives out some advices to reduce the test errors.


2006 ◽  
Vol 326-328 ◽  
pp. 187-190
Author(s):  
Jong Sun Kim ◽  
Chul Jin Hwang ◽  
Kyung Hwan Yoon

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i) the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of both methods came from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. The comparison between two methods is demonstrated for the same sample of which retardation is up to 850 nm.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2523
Author(s):  
Franciszek Pawlak ◽  
Miguel Aldas ◽  
Francisco Parres ◽  
Juan López-Martínez ◽  
Marina Patricia Arrieta

Poly(lactic acid) (PLA) was plasticized with maleinized linseed oil (MLO) and further reinforced with sheep wool fibers recovered from the dairy industry. The wool fibers were firstly functionalized with 1 and 2.5 phr of tris(2-methoxyethoxy)(vinyl) (TVS) silane coupling agent and were further used in 1, 5, and 10 phr to reinforce the PLA/MLO matrix. Then, the composite materials were processed by extrusion, followed by injection-molding processes. The mechanical, thermal, microstructural, and surface properties were assessed. While the addition of untreated wool fibers to the plasticized PLA/MLO matrix caused a general decrease in the mechanical properties, the TVS treatment was able to slightly compensate for such mechanical losses. Additionally, a shift in cold crystallization and a decrease in the degree of crystallization were observed due to the fiber silane modification. The microstructural analysis confirmed enhanced interaction between silane-modified fibers and the polymeric matrix. The inclusion of the fiber into the PLA/MLO matrix made the obtained material more hydrophobic, while the yellowish color of the material increased with the fiber content.


2001 ◽  
Vol 2 (4) ◽  
pp. 203-211 ◽  
Author(s):  
Young Il Kwon ◽  
Tae Jin Kang ◽  
Kwansoo Chung ◽  
Jae Ryoun Youn

Author(s):  
Kurt Beiter ◽  
Kosuke Ishii ◽  
Lee Hornberger

Abstract This paper describes the development of geometry-based indices that predict sink mark depth in injection molded parts. Plastic part designers need such indices to incorporate manufacturability concerns at the conceptual stage of design. These indices apply to several form features so engineers do not have to check different design rules for each geometry element. First, we propose a geometry-based sink index that can be used to predict sink mark depth as a function of process conditions such as packing pressure. Next, we explain how this relationship is identified through experiments. We also describe HyperDesign/Plastics, a Macintosh-based design aid that incorporates the sink index.


1996 ◽  
Vol 17 (5) ◽  
pp. 649-655 ◽  
Author(s):  
Deborah F. Mielewski ◽  
Nitin R. Anturkar ◽  
David R. Bauer

2018 ◽  
Vol 62 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Dániel Török ◽  
József Gábor Kovács

In all fields of industry it is important to produce parts with good quality. Injection molded parts usually have to meet strict requirements technically and aesthetically. The aim of the measurements presented in our paper is to investigate the aesthetic appearance, such as surface color homogeneity, of injection molded parts. It depends on several factors, the raw material, the colorants, the injection molding machine and the processing parameters. In this project we investigated the effects of the injection molding machine on surface color homogeneity. We focused on injection molding screw tips and investigated five screw tips with different geometries. We produced flat specimens colored with a masterbatch and investigated color homogeneity. To evaluate the color homogeneity of the specimens, we used digital image analysis software developed by us. After that we measured the plastication rate and the melt temperature of the polymer melt because mixing depends on these factors. Our results showed that the screw tips (dynamic mixers) can improve surface color homogeneity but they cause an increase in melt temperature and a decrease in the plastication rate.


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