By Seva，WayKen Project Manager
Vacuum casting is also called urethane casting, which is similar to injection molding. In general, will use silicon mold, and use CNC machining or 3D printing for the master pattern. Such soft mold has the advantage of short lead-time, more economy, and is available with rigid or flexible material. Besides, the material color can be adjusted, and the parts have better surface quality. It’s a good technology for prototyping and low volume production.
How to choose casting material for your projects
Urethane materials can be rigid, elastic, transparent, and in a variety of colors. The designer or engineer can choose the best casting material for their project.
– Aesthetic requirements: appearance texture, color, transparent or not, what result they want to achieve.
– Use environment: Do the parts need to be within the low or high temperature? Do the parts need to be in an environment with ultraviolet light? The casting material option needs to cover these considerations.
– Functional requirements: For example, if the parts need good sealing and flexibility, you can choose a casting material that is similar to rubber. The parts with requirements of good strength can use casting material that is similar to ABS material.
3 common urethane casting material
1. Hei-cast 8150
This material is of the Japanese brand and is a common, economical urethane casting material, which is comparable in strength and impact resistance to ABS, a thermoplastic polymer.
This casting material is rigid and durable, can be a good option for the enclosure of most products, such as consumer electronics, toys, equipment, etc.
The color of the casting material can be adjusted for products with a color scheme or for prototypes with various colors. And because the color is not only on the surface, there is no worry about the color falling off, and it does not affect the surface texture.
In addition, due to the UV radiation list of polyurethane castable materials, if the product is to be used outdoors, it needs to be coated with UV protection.
This French brand casting material is transparent, which is similar to PMMA material. It is a good option for most transparent optical components, such as light guides, lenses, or other optical parts. If using this material during silicon tooling, which needs to be in a vacuum environment, to avoid bubbles, so as affect the cosmetic appearance. Besides, this casting material can also adjust the color.
For example, a part with two colors requirement but wants to be made in one piece, not separately.
At this time, the transparent casting material can be used to adjust the color. First, casting the opaque part and then the transparent part (to avoid that if casting the opaque part later, the material will flow to the transparent part, thus affecting the appearance), to obtain the overall effect.
In addition, it can also be used to imitate the injection material with a diffusion function. Through the preliminary test, a certain proportion of diffusion powder is added to the casting material and the color is adjusted to obtain diffusion function.
The casting material is flexible and the hardness can be adjusted within a certain range.
This urethanes material is similar to rubber and has many mechanical properties.
Like good impact resistance and flexibility, it can be used for projects such as rubber handles and skins, cladding, buttons and keyboards, cable connectors, and even rubber boots.
Products with the hardness of 50 Shore A and below provide high tensile strength, toughness, and flexibility, while 60 to 80 Shore A products are ideal for wear-resistant parts and fixtures with some flexibility.
Urethane casting: a good option for low volume production
For most projects, urethane casting can shorten production time, reduce mold costs, and allow flexibility in material selection to meet project requirements. No matter it is a rigid material with high strength, or a transparent optical part, or a flexible material with high tensile strength, it can be achieved all these results.
Of course, if you have no idea how to choose, choose Wayken, a reliable manufacturer, we can reduce the burden, provide professional manufacturing suggestions. If you have an upcoming or ongoing similar project, don’t hesitate to contact us.