Polymer Processing

What is polymer processing?

Polymer processing of thermoplastics commonly relies on heat, friction, shear forces, and pressure to shape or mold polymers into desired products. Some of the common processes are as follows:

1. Extrusion: A process that employs a heated barrel to melt and extrude polymers into products of desired profiles. Once the process is initiated, the majority of the heat is generated internally through frictional heating. This internal heat generation overcomes issues with plastic having a relatively low thermal conductivity. Often extrusion is a preceding process to any shape-forming process. Different variations of extrusion include
• Profile extrusion
• Blow film extrusion
2. Injection molding: A net shape-forming process that forms products by injecting molten polymer into a mold.
3. Compression Molding: A process that uses compressive pressure along with heat to mold objects.
4. Blow molding: A process that uses premolded shapes that are further blown into shapes with hot air to form hollow containers.
5. Rotational molding: A process that relies on heat to melt the polymer and coat the inside of the mold that holds the resin.

What are bioplastics?

Bioplastics are polymeric materials derived from renewable resources such as agricultural crops and materials, most notably from corn and sugarcane. Some well-known examples are starch plastics and polylactic acid (PLA) that are derived from corn starch and fermentation of sugars from corn starch, respectively. Other examples include protein plastics that utilize the naturally occurring plant protein as the polymer, vegetable oil-based resins that are synthesized from plant fatty acids as monomers, and petroleum-derived bioplastics that are biodegradable.

More on biobased products

What is the meaning of biorenewable, compostable, and biodegradable?

Biorenewable is a term used to identify materials that are derived from a renewable feedstock. These materials are often biodegradable, but some are nonbiodegradable.

Compostable is a term used to identify materials that will biodegrade under controlled aerobic composting conditions.

Biodegradable is a term used to identify materials that biodegrade when exposed to the environment. These materials can be derived either from biorenewable or petroleum feedstock.

What are the differences in manufacturing with bioplastics?

Bioplastics can be processed with existing polymer-processing technology/processes. Bioplastics typically process at lower temperatures with respect to petroleum plastics. In addition, these plastics are typically sensitive to moisture during processing. Often, high relative humidity conditions during processing deteriorate the final properties of the product.

What can CIRAS do for my company?

CIRAS can help your company with various polymer-processing and manufacturing challenges:

• Short term technical assistance for immediate problems
• Identifying opportunities to integrate biobased materials to suit current product specification and facilitate changeover
• Material and product characterization and testing

What is my next step?

Polymer Processing assistance is offered based on availability and capability of resources and staff.  Contact this staff member to see what CIRAS can do for you.

Shankar Srinivasan

515-290-6702

srigshan@iastate.edu