2639986

Information

• Patent Grant
• 2639986

• References
• Source

• Patent Number

  2,639,986

• Date Filed

  Not available

• Date Issued

  Tuesday, May 26, 1953
  71 years ago

• CPC

  • D21C3/266 - the same pulping agent being used in all stages

• US Classifications

  • 162 - Paper making and fiber liberation