Nonmetallic Fatty Chemicals as Internal Mold Release Agents in Polymers

Percell, Kim; Walp, Leonard; Tomlinson, Harry

doi:10.1201/9781420027327.ch72

Cited by 1 publication

(2 citation statements)

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“…The modification of the mold surface in order to decrease the adhesion between the mold and the molded plastic component is one approach to reduce the ejection force. An established method is to apply release agents such as waxes, soaps, or silicones onto the mold in order to reduce the sticking of adherent polymers, hence reducing the ejection force and removing the injected part without any damage [8,9]. However, the release agents are non-permanent and only effective for eight to ten injection molding cycles [9].…”

Section: Introductionmentioning

confidence: 99%

“…An established method is to apply release agents such as waxes, soaps, or silicones onto the mold in order to reduce the sticking of adherent polymers, hence reducing the ejection force and removing the injected part without any damage [8,9]. However, the release agents are non-permanent and only effective for eight to ten injection molding cycles [9]. Another approach is to deposit a permanent film with a hydrophobic behavior onto the mold.…”

Section: Introductionmentioning

confidence: 99%

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Reduction of Ejection Forces in Injection Molding by Applying Mechanically Post-Treated CrN and CrAlN PVD Films

Tillmann

Stangier

Dias

et al. 2019

JMMP

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In injection molding, the reduction of ejection forces is a process relevant aspect to improve the production rates. For this purpose, CrN and CrAlN films were sputtered on cylindrical and quadratic AISI H11 cores of an injection mold in order to investigate their influence on the resulting ejection forces to demold polypropylene test components. Within this context, the ejection forces of the PVD coated cores were compared to those of uncoated cores made of AISI H11. For both the cylindrical and quadratic cores, the as-deposited CrN and CrAlN films exhibit higher ejection forces than the uncoated cores due to the increase of the roughness profile after sputtering. It is known that the ejection forces are directly related to the surface roughness. In order to ensure comparable surface conditions to the uncoated surfaces, and to demonstrate the potential of PVD coated mold surfaces when reducing the ejection forces, the coated surfaces were mechanically post-treated to obtain a similar roughness profile as the uncoated cores. The combination of a PVD deposition and post-treatment ensures a significant reduction of the ejection forces by 22.6% and 23.7% for both core geometries.

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Section: Introductionmentioning

confidence: 99%