Abstract
High performance clear TPE products
are developed to replace silicone and PVC in
various medical and personnel care applications.
These are high clarity TPEs with high tensile and
tear properties. They retain mechanical
properties and dimensional stability after hours
of testing in boiling water and repeated
dishwasher cleaning cycles. These TPEs have
good processability. They can be used in FDA
and USP required applications.
Background
Silicone and PVC are widely used in
medical and personnel care products requiring
clarity . Silicone has excellent high temperature
performance and chemical resistance. However,
silicone is very expensive material. PVC is a
low cost material with wide processing window
exhibiting ocessing friendly together with high
temperature properties. However, there is a
growing recycling concern over PVC especially
in Europe.
Styrene Block Copolymer (SBC) is a
TPE that combine the processing characteristic
of thermoplastics and physical properties of
vulcanized rubbers. SBC compounds offer good
economics and formulation flexibility meeting
the end use performance requirements. Since the
introduction of styrene block copolymer four
decades ago, newer molecules with varied
chemistry have been introduced to the market.
Some of them have FDA and USP approval.
This paper concentrates on SBC
compounds, which are intended for applications
where silicone and PVC are presently specified
offering improved economics over silicone and
alleviating the recyclability concerns of PVC.
We will first discuss the important design
parameters that affect the clarity and properties
of the TPE compounds. Specific examples will
be highlighted to provide performance attributes