AP (alumina pink): This is a pink colored alumina oxide material, which is often in the range of 95 to 99.7% purity. This material is durable and has excellent wear resistance to most yarns. For certain items made by Yuasa, this material (Yuasa YM-99C) can be offered with engineered surface finishes for optimal performance (see note on the Ceramic Finishes tab concerning surface finishes). Alumina oxide ceramics have been a successful material within the textile industry for decades, and are used in many ceramic designs.
Nearly all ceramic guides we offer are polished to some degree – this is necessary as the fired ceramic often has a rough and pitted surface which is abrasive. Normal polished ceramic is suitable for most general applications.
Some ceramic surfaces are polished to a greater extent – this is what we call “Diamond Polished” is distinguished by “DP” as a suffix of the part number. Not all items are available with this surface finish, and this process does result in a higher price for the guide. Diamond polished surfaces are possible on alumina and titania ceramic, and are ideal for use with twisted or textured yarn.
Some ceramics are considered to be matte finish (part number suffix: ’MF’) when in an unpolished state, but in the case of higher purity alumina ceramics by Yuasa (YM-99C material) the matte finish is the result of subsequent firing to grow the ceramic crystals after normal polishing. This microscopically results in a smoother matte finish, often nicknamed the ‘orange peel’ finish that is ideal for use with flat untwisted yarns. Matte finish is only available on specific items made by Yuasa, in alumina oxide material. (Matte finish surfaces on titania ceramic are easily worn away and are not durable).
Ceramic Coating: (Not available)
There are some guides available in the textile industry which are made by coating a metal guide with a ceramic coating. Eldon Specialties does not offer guides of this nature. Although ceramic coated guides offer an ideal combination of wear resistance with fracture resistance, there is a risk of fracture to the coating and this can lead to yarn damage which is not detected until after it is further processed into a product. For this reason, Eldon does not offer ceramic coated guides.