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.
AR (alumina red): This is a reddish / maroon colored alumina oxide material, which can vary in purity from 80% to 97%. The Yuasa YM-85C material is 85% purity and is utilized for the ceramic component of the bearing roller guides.
AW (alumina white): This is a white or off-white colored alumina oxide ceramic. Alumina ceramic is naturally colorless, so color may be added to differentiate the ceramic purity (as is the case with Yuasa ceramics), or for visual contrast to make it easier to see running yarn on a ceramic surface since the yarn is often white as well. Our products designated “AW” can vary from 90% to 99% purity. Yuasa white alumina is offered for specific items as 92% purity (YM-92CW) or 99.7% purity (YM-99CW).
T (titania): This is a tan or yellowish brown colored titania ceramic (Titanium Dioxide). Titania was one of the earlier materials used as a yarn guide in the textile industry. This material can be well polished and can be more delicate to certain yarns than alumina, although it also tends to wear faster and fracture more easily than alumina due to its larger micro-crystal particulate size. Titania is not available in as many complex shapes as alumina ceramic, and is most often used for eyelets.
TC (titania conductive): This is a dark gray or blue-gray titania ceramic material that has been fired with an additive to cause it to be electrically conductive. This is often used in applications with yarn where static build-up is a concern (for example, w/fiberglass yarn).
PCS (polycrystalline sapphire): This is a material developed by Yuasa (YM-9999) for specific applications requiring the highest purity alumina oxide ceramic available. This material is not frequently sold due to its cost, as the refining and firing of this ceramic must be done in a controlled environment. Only certain shapes and sizes of limited size can be achieved with this material, and due to this cost of this material only those guides which Yuasa regularly manufacturers from this material can be offered.
Porcelain is a material which was historically used in the textile industry but has since been largely replaced by the use of titania and alumina ceramics. Eldon Specialties no longer carries an active inventory of yarn guides made from porcelain material. Porcelain guides are not polished, but have a glazed surface (glass coating). When this coating is worn through, the underlying base material porcelain is very abrasive.
Surface Finishes
Normal Polish:
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.
Diamond Polish:
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.
Matte Finish:
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.
