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Solutions for Problems With Gels

Can Ampacet Help You Solve Problems With Gels?

Ampacet’s world-class analytical services can help plastics converters identify the type of gels found in their product and the location of the gel in a coex design. Ampacet offers a variety of products that can  be used to significantly reduce most gel problems.  However, it is important to note that the proper identification of the gel source is critical in a decision process involving any kind of counteraction. If the wrong counteraction is applied, the gel problem can intensify. The source of gels is generally  from one of the following areas:

Degraded or Cross-Linked Polymer

  • Source: Cross-linked polymer that results in inconsistent surface characteristics and/or variation in optical properties.
  • Causes: Factors such as: high heat exposure, high shear,  long residence time, insufficient A/O package, etc.
  • Solution: To solve this problem, use lower processing  temperatures, A/O package, higher throughput, less aggressive screw design, etc.

 

Improperly Distributed Resin or Concentrate (often called “un-melt”)  

  • Description: Often referred to as un-melted resin or un-melted concentrate.
  • Causes: Viscosity variations and/or processing conditions.
  • Solution: Modification to the processing conditions can often solve the problem (higher back pressure, mixing screw design, tighter screen pack, temperature profile adjustment). Modifications  to the concentrate include smaller pellets, lower concentration & carrier resin adjustments.

 

Poor Dispersion Quality

  • Cause: Insufficient energy applied during concentrate production.
  • Result: Surface and optical properties will be effected,  opacity reduced.
  • Solution: The concentrate supplier must alter its process and or raw materials (adjustments to the process will not solve this problem).
  • Also Consider: Are you using the right concentrate for the job? If yes, try a different concentrate lot.

In addition to gel identification tools, Ampacet has the capability to run suspect materials on commercial scale line equipment to verify if the problem is equipment or material related. For example, if the occurrence of the problem is linear, it generally suggests that the problem is equipment related. In order to verify this theory, a follow-up run on a separate piece of equipment is necessary. This is where Ampacet can help. Ampacet has access to equipment that includes both co-extrusion and monolayer film configurations, in addition to a diverse line of molding equipment for our injection and blow molding customers.

Ampacet offers a variety of products that can help eliminate gel problems.