Anisotropic Fibers
This is part of a guide to the identification of particles seen in samples of free particles.
This file includes all anisotropic particles that have approximately parallel sides and are at least five times as long as they are wide.
Smooth Fibers with no Internal or External Features
These particles are generally extruded polymers without rutile inclusions or Insect and Spider silks.
Click here for more images of Synthetic Fibers.
Click here for more images of Insect Silks.
Smooth Fibers with no External Features but with small (micrometer or less) filler (rutile).
These particles are generally extruded polymers with rutile particles added to enhance the color of the fiber.
Fibers with External Barbs or Scales
These fibers include mammalian hair, insect hair, feather barbules, and plant hair.
Mammals

Click here for more images of Mammalian Hair.
Insect Hair
Click here for more images of Insect Hair.
Feather Barbules
Click here for more images of Feather Barbules.
Fibers with Internal Cells or internal Voids
These particles tend to be plant fibers, plant hairs, animal hairs, insect hairs, or fungal structures.
(Click here for
more images of Plant Fibers.)
(Click here for
more images of Plant hairs.)
(Click here for
more images of Mammal hairs.)
(Click here for
more images of Insect Hairs.)
Aspergillus Conidiophore
Fibers with Striations Parallel to Length
These particles tend to be mineral fibers, insect silks, or man-made plastic fibers though some plant
fibers may also fall into this category.
(Click here for
more images of Fibrous Minerals.)
(Click here for
more images of Clothing Fiber.)
Aspergillus Conidiophore
Fibers with Striations at an Angle to Length
These structures may also be called nodes and occur in many plant fibers but may also occur in some man-made plastic fibers.
Fibers with Tapered Terminations
These fibers may grow tapered ends, like hairs of plants and animals, or may plastically deform and taper prior to final break. Paper fibers
also tend to have tapered ends.
Fibers with Broomed Ends
These fibers tend to be fibers that consist of bundles of parallel finer fibers referred to as fibrils. They include some plant fibers, mammalian
hair, some natural mineral fibers, and some soft polymers that form zones of stress-aligned fibrils when under load (i.e. polypropylene).
Fibers that Keep Dividing into Finer Fibers Parallel to Length
These fibers tend to be mineral fibers, including those identified as asbestos.
(Click here for
more images of Fibrous Minerals.)
|