Splay is a term used in the manufacture of

injection molded plastics Injection moulding (U.S. spelling: injection molding) is a manufacturing process for producing parts by injecting molten material into a Molding (process), mould, or mold. Injection moulding can be performed with a host of materials mainly incl ...

to refer to off-colored streaking along the surface of a molded part. A cosmetic defect, it is often silvery in color and is sometimes called 'silver streak's. The most common cause of splay is moisture, which is caught in the resin inside the injection molding machine during the heating process. The moisture turns to steam when heated in the barrel of the machine, and become tiny gas bubbles that streak across the plastic as injection occurs. This causes the silvery pattern, or streaks, to appear on the surface of the plastic. Splay can be avoided by keeping moisture out of plastics and injection molding machines. Non-

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance ...

plastics that do not absorb moisture are less likely to suffer from splay. Mold leaks, improper drying of materials, incorrect material throughput, and non-functional dryers are other causes of moisture-related splay. Other causes of splay are sheer and heat.

References

{{material-stub Plastics