Tuning and control of dimensional consistency in molded products

Kazmer, David O.; Lotti, Cybele; Bretas, Rosário Elida Suman; Zhu, Lei

doi:10.1002/adv.20007

Cited by 7 publications

(2 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, the part weight is commonly used as an estimator of part qualities such as short shot, flash and dimensional consistency. 5 Second, statistical analysis, conducted for part dimensions, indicated nearly identical results to those herein presented for part weights.…”

Section: Resultssupporting

confidence: 66%

Validation of moulding consistency with a self-regulating melt pressure valve

Kazmer¹,

Kudchadkar²,

Nageri³

2004

Plastics, Rubber and Composites

View full text Add to dashboard Cite

Net shape manufacturing of plastic products through injection moulding, extrusion and other polymer forming processes has been limited by a lack of observability and controllability of the state of the polymer melt. For this reason, a self-regulating melt pressure valve has been developed that utilizes a valve pin to adjust the juncture loss to balance a provided control force with the force exerted by the melt pressure on an exposed surface of the valve pin. Since the valve pin position is adjusted in accordance with natural laws, an open-loop control system design is feasible without the need for any instrumentation or process feedback for closed-loop control. The process capability of a hot-runner injection moulding process with two self-regulating melt pressure valves is validated with respect to part weight consistency. A resolution four fractional factorial design characterized the main effects for conventional hot-runner injection moulding and injection moulding with the self-regulating valve operated in both open and closedloop control schemes. It was observed that the self-regulating valve operating in an open-loop control mode reduced the sensitivity of the part weight to changes in the moulding process by 73% compared with conventional injection moulding; short-term part-to-part variation was also reduced by 60%. While it might be expected that closed-loop control would provide even greater results, the relatively slow response of the pneumatic control valve actually tended to induce process variation compared with the open-loop control of the self-regulating valve.

show abstract

Section: Resultssupporting

confidence: 66%

Validation of moulding consistency with a self-regulating melt pressure valve

Kazmer¹,

Kudchadkar²,

Nageri³

2004

Plastics, Rubber and Composites

View full text Add to dashboard Cite

show abstract

“…However, such method has some limitations, for instance there is no 1:1 mapping between part weight and part quality features. The use of an indirect key part characteristic may also lead to the loss of the causality between the process variable and the part quality characteristic [3]. This control method has also limitations when there are opposite defects affecting weight simultaneously, e.g., flash and voids.…”

Section: Introductionmentioning

confidence: 99%

Inspection model and correlation functions to assist in the correction of qualitative defects of injected parts

Chaves

Vizán

Márquez

et al. 2010

Polymer Engineering & Sci

View full text Add to dashboard Cite

To perform quality inspection in the injection process is a complex task due to high number of defects that could occur in an injected part and the high number of process parameters that could produce them. Injection defects, in particular qualitative ones, are not a clear reference to determine correct process parameter value setting to produce good quality parts. Research results show that the occurrence of each injection defect could be caused by specific parameters with values above or below an optimal one. Although this information is a guide for the defect correction, the effective correction of qualitative defects with parameter modifications is very complex. This is due to the problems that arise when transforming a qualitative defect into a quantitative inspection. This article shows an inspection model to assist the qualitative defect intensity classification using defect behavior tendency curves. These curves have been deduced from generic analytical relationships established between injection defects and injection process parameters. Conducted tests allow validating the approach and its initial effectiveness.

show abstract

Literature Review and Research Objectives

Moayyedian

2018

Intelligent Optimization of Mold Design and Process Parameters in Injection Molding

View full text Add to dashboard Cite

Tuning and control of dimensional consistency in molded products

Cited by 7 publications

References 15 publications

Validation of moulding consistency with a self-regulating melt pressure valve

Validation of moulding consistency with a self-regulating melt pressure valve

Inspection model and correlation functions to assist in the correction of qualitative defects of injected parts

Literature Review and Research Objectives

Contact Info

Product

Resources

About