Study of a polymer ejector design and manufacturing approach for a mobile air conditioning

Beran, Tobias; Hübel, Johannes; Maertens, Robert; Reuter, Steffen; Gärtner, Jan; Köhler, Jürgen; Koch, Thomas

doi:10.1016/j.ijrefrig.2021.01.023

Cited by 11 publications

(5 citation statements)

References 30 publications

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“…In general, Scheffler [48] concludes that the plasticizing torque for thermosetting molding compounds is influenced by multiple factors, but has a strong correlation to the backflow during the injection phase. Several authors [49,50] used the injection work W Plast , which is the integral of the plasticizing power P Plast , as a measure for the total energy input into the polymer during the plasticization phase, see Equation (6).…”

Section: Data Acquisition During the Injection Molding Processmentioning

confidence: 99%

“…Typical applications for phenolic molding compounds that are established in the state of the art are oil pump housings, intake manifolds, valve blocks [ 4 , 5 ], and other small automotive parts, for example in the air condition systems [ 6 ] or turbochargers [ 7 ]. In these applications, the beneficial properties of the phenolic resin, such as high heat resistance, chemical resistance, and an overall excellent dimensional accuracy and stability come into play.…”

Section: Introductionmentioning

confidence: 99%

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Development of an Injection Molding Process for Long Glass Fiber-Reinforced Phenolic Resins

et al. 2022

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Glass fiber-reinforced phenolic resins are well suited to substitute aluminum die-cast materials. They meet the high thermomechanical and chemical demands that are typically found in combustion engine and electric drive train applications. An injection molding process development for further improving their mechanical properties by increasing the glass fiber length in the molded part was conducted. A novel screw mixing element was developed to improve the homogenization of the long fibers in the phenolic resin. The process operation with the mixing element is a balance between the desired mixing action, an undesired preliminary curing of the phenolic resin, and the reduction of the fiber length. The highest mixing energy input leads to a reduction of the initial fiber length L0 = 5000 μm to a weighted average fiber length of Lp = 571 μm in the molded part. This is an improvement over Lp = 285 μm for a short fiber-reinforced resin under comparable processing conditions. The mechanical characterization shows that for the long fiber-reinforced materials, the benefit of the increased homogeneity outweighs the disadvantages of the reduced fiber length. This is evident from the increase in tensile strength from σm = 21 MPa to σm = 57 MPa between the lowest and the highest mixing energy input parameter settings.

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Section: Data Acquisition During the Injection Molding Processmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Development of an Injection Molding Process for Long Glass Fiber-Reinforced Phenolic Resins

et al. 2022

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“…The total power input into the material is the sum of the mechanical power input P Mech , the power required for temperature and enthalpy change between the extruder inlet and outlet (P Heat and P Enthalpy ), and the power used to increase the material pressure P Pressure [14] P tot = P Mech + P Heat + P Enthalpy + P Pressure (1) With the extruder speed ω, the extruder torque M Extr , the mass throughput Q, the enthalpy difference ∆H, the pressure difference ∆p, and the material density ρ, Equation (1) becomes…”

Section: Compounding Of Phenolic Molding Compoundsmentioning

confidence: 99%

“…Composite parts manufactured from fiber-reinforced phenolic molding compounds have a high maximum operating temperature, an excellent chemical resistance, and a very good dimensional accuracy. These characteristics enable their application in the direct vicinity of internal combustion engines [1][2][3][4]. Recent developments have proven that phenolic molding compounds can successfully be used in electric motors for traction applications [5].…”

Section: Introductionmentioning

confidence: 99%

Compounding of Short Fiber Reinforced Phenolic Resin by Using Specific Mechanical Energy Input as a Process Control Parameter

et al. 2021

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For a newly developed thermoset injection molding process, glass fiber-reinforced phenolic molding compounds with fiber contents between 0 wt% and 60 wt% were compounded. To achieve a comparable remaining heat of the reaction in all compound formulations, the specific mechanical energy input (SME) during the twin-screw extruder compounding process was used as a control parameter. By adjusting the extruder screw speed and the material throughput, a constant SME into the resin was targeted. Validation measurements using differential scanning calorimetry showed that the remaining heat of the reaction was higher for the molding compounds with low glass fiber contents. It was concluded that the SME was not the only influencing factor on the resin crosslinking progress during the compounding. The material temperature and the residence time changed with the screw speed and throughput, and most likely influenced the curing. However, the SME was one of the major influence factors, and can serve as an at-line control parameter for reactive compounding processes. The mechanical characterization of the test specimens revealed a linear improvement in tensile strength up to a fiber content of 40–50 wt%. The unnotched Charpy impact strength at a 0° orientation reached a plateau at fiber fractions of approximately 45 wt%.

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“…Currently, addictive manufacturing of polymers is moving more and more towards manufacturing applications, allowing more competitive parts and a more flexible process [25]. However, even traditional polymer parts for the automotive industry have been the target of some studies trying to improve their mechanical properties [26] by redesigning the manufacturing process itself, as presented by Beran et al [27]. In the current work, the part remains the same, but the process is improved through automated systems.…”

Section: Introductionmentioning

confidence: 96%

A Novel Automated System for the Handling of Car Seat Wires on Plastic Over-Injection Molding Machines

et al. 2021

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The structure of car seats is becoming increasingly complex, with mixing of wire conformation and plastic injection. The plastic over-molding process implies some labor, which can be reduced if novel solutions are applied in this manufacturing area. The handling of the wires used in car seats is the main problem identified in the process, wasting time both in the feeding and in the extraction of the molds used in the wire over-molding process. However, these machines are usually extremely compact and the free space around them is too short. In classic molding injection machines, there are just two half-molds, the female, and the male. In the over-molding process of wires used in car seats, three half-molds are used in order to increase the cycle time. Thus, to solve this problem, the classic robotic solutions are not appliable due to lack of space and elevated cost. This work describes the development of an automated solution able to handle the wires in both the feeding and the extracting phases of the production cycle, avoiding the traditional labor costs associated with this type of machine. Departing from an industrial need, the developed novel solution is described in detail and can be successfully adapted to other situations of low added-value products where it is needed to increase the productivity and competitiveness of the product. The system developed uses mechanical and pneumatic solutions which, combined, can be used to solve the identified problem, occupying a restricted space and requiring a small budget. This solution can be translated into guidelines that will allow the analysis of situations where the same system can be applied.

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Study of a polymer ejector design and manufacturing approach for a mobile air conditioning

Cited by 11 publications

References 30 publications

Development of an Injection Molding Process for Long Glass Fiber-Reinforced Phenolic Resins

Development of an Injection Molding Process for Long Glass Fiber-Reinforced Phenolic Resins

Compounding of Short Fiber Reinforced Phenolic Resin by Using Specific Mechanical Energy Input as a Process Control Parameter

A Novel Automated System for the Handling of Car Seat Wires on Plastic Over-Injection Molding Machines

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