Rethinking the Combined Process of Injection Molding and Polyurethane Overmolding

        Multicomponent plastic concept

        This combined process not only requires competence in the fields of injection molding machines, polyurethane systems and mold technology, but automation and various materials also play a crucial role
.
Yizumi and Frimo chose SAR as their automation equipment partner, polyamide specialist Akro-Plastic and PUR specialist Rühl Puromer as raw material partners
.
Thilo Stier, director of sales and innovation at Akro-Plastic, emphasizes: “The perfect product can only be created if all raw materials are matched to each other, and emphasizes: “When choosing the right thermoplastic, it is necessary to be strict to ensure minimal deformation of the material, because The process allows for only small tolerances; in addition, a material must be found that will bond well to the polyurethane
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Timing in the production process also matters, so amorphous polyamides adhere better than crystalline polyamides
.
"

        After testing different formulations, Yizumi finally chose Akro-Plastic's 20% glass fiber reinforced polyamide Akromid B3 GF20 2 RM-DNaturl(4164)
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On the PUR side, Puroclear from Rühl was used
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Dr.
Ingo Kleba, Managing Director of Rühl Puromer, introduced today's production with PUR to the visitors to the Frimo Technology Open Day: "A topic of current interest is the surface treatment of parts by spraying polyurethane materials on them, both It can be made transparent or colored; in addition, the foil can be changed almost infinitely in design and the combination of function and light, gloss, suitability for daily use and scratch resistance of the surface are getting better and better
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"The decisive factor for the efficiency of the PUR coating process, especially when combined with the injection moulding process, is the excellent self-separation of modern Puroclear systems, which makes it unnecessary to use other common external release agents or special moulds," he explained.
paint," he continued
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He is particularly proud of the self-healing properties of the PUR formulation: "If a scratch appears on the surface, it disappears within a few hours at room temperature
.
"

        Integrated additive manufacturing process

        Additive manufacturing processes can also be seamlessly integrated into this production process
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At the Frimo Technology Open Day, the additive manufacturing unit printed a layer of reinforcement structure on the engine cover using the FLM process; the material is a carbon fiber reinforced polyamide Akromid B3 ICF 30 9 AM black (7451) pellets
.
According to Thilo Stier, "Because the carbon fibers are preferentially aligned in the direction of application, extremely high strength is possible here
.
"

        All in all, the solution presented at the Frimo Technology Center shows that the combined process of injection molding and polyurethane overmolding requires competitiveness in different fields
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In addition to injection molding machines, polyurethane material suppliers, additive manufacturing and automation, mold technology and the corresponding materials each play a decisive role
.
"Yizumi and technology partners from different fields combine different technologies into an integrated process in an intelligent, modular way
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Only when all fields are perfectly coordinated can the creation of The perfect product
," concludes Benjamin Wessling, project manager for polymer applications in Yizumi, Germany
.