Process for scrapless forming of plastic articles

In a process for forming articles from a powder of a thermoplastic resinous polymer wherein the powder in an amount sufficient to produce the article is compressed at a temperature below the melt temperature of the powder into a briquette containing polymer particles and having green strength and the briquette having been maintained at a temperature in the range from about the alpha transition temperature to less than the melt temperature of the polymer for a time sufficient to effect sintering of the polymer particles of the briquette is forged into an article of fused polymer;

• the improvement which comprises compacting the powder with vibratory energy for a time in the range from about 0.008 to about 45 seconds, using a compaction pressure in the range from about 40 to about 60,000 psi, a frequency in the range from about 1 to about 25,000 cycles per second and a temperature within the range from ambient up to temperatures below the melting point of the polymer to form the briquette.

In a process for forming articles from a powder of a thermoplastic resinous polymer wherein the powder in an amount sufficient to produce the article is compressed at a temperature below the melt temperature of the powder into a briquette containing polymer particles and having green strength and the briquette having been maintained at a temperature in the range from about the alpha transition temperature to less than the melt temperature of the polymer for a time sufficient to effect sintering of the polymer particles of the briquette is forged with a forging apparatus into an article of fused polymer wherein lubrication is provided between the contacting surfaces of the briquette and the forging apparatus;

• the improvement which comprises compacting the powder with vibratory energy to form the briquette having a percent compaction of at least about 85 percent.