What is polymer crazing?

Crazing develops when excessive tensile stress is applied to a polymer, leading to microvoid formation in a plane normal to the stress. 8,11,16,26. The voids initiate at microscopic inhomogeneities in the polymer, and are stabilised by fibrils of plastically deformed polymer chains.

Why does crazing happen?

Crazing is caused by the glaze being under too much tension. This tension occurs when the glaze contracts more than the body during cooling. Because glazes are a very thin coating, most will pull apart ar craze under very little tension. Crazing can make foodsafe glazes unsafe and ruin the look of a piece.

What is crazing in coating?

Crazing refers to a network of visual cracks on a coated metallic surface. It occurs due to tension stresses in some glassy thermoplastic polymers. Crazing is propagated in metallic surface regions that experience high tension and leads to the formation of microvoids and small cracks.

What is a craze in a glassy thermoplastic?

Crazing is the phenomenon that produces a network of fine cracks on the surface of a material, for example in a glaze layer. Crazing frequently precedes fracture in some glassy thermoplastic polymers. As it only takes place under tensile stress, the plane of the crazing corresponds to the stress direction.

What does crazing mean?

1 : to make insane or as if insane crazed by pain and fear crazed addicts. 2 : to produce minute cracks on the surface or glaze of crazed glass crazed pottery. 3 obsolete : break, shatter. intransitive verb.

How do you stop crazing?

Crazing can often be eliminated simply by applying a thinner glaze coat. With some glazes, a thinner coat is not an option, but often a slight decrease in glaze thickness will stop crazing.

Does crazing effect value?

The presence of crazing usually diminishes the value of objects but it can depend on the severity of the damage and rarity of the crazed piece.

What causes polycarbonate to craze?

The majority of times you see cracking and crazing in plastics such as Acrylic, Perspex, Plexiglas (PMMA), Polycarbonate (PC) and Ultem (PEI) is due to lack of the correct heat treatment. These such plastics need careful normalising and annealing steps throughout the machining, bonding and polishing process.

Does crazing reduce value?

What causes cracks in plastic?

When force is applied to plastic, it travels along the polymer chains causing molecules to strain to remain in contact. The polymer chains eventually creep toward the pull and deform. This stage is called creep. With force and time, crazing or stress cracking occurs.