The use of polypropylene has been implemented over the years for non traditional applications including auto parts, blender casings, etc. due to the use of mineral reinforcements i.e. Calcium Carbonate, Talc and Glass Fiber. As a result of these reinforcements in addition to PP numerous advantages, Polypropylene has become a good alternative to replace engineering materials such as nylon, ABS and acetal.

The following are some of the advantages observed when using Reinforced Polypropylene:

The above advantages will depend on the mineral reinforcement type and percentage of a given reference. The following graphics show the comparative behavior of the different mechanical properties and the three main types of reinforcement.

Prior to establishing which of the available options is the most suitable, it is important to analyze the prevailing property required by the piece to be manufactured or replaced, e.g. flexural modulus (rigidity), gardner impact, or izod impact (failure propagation) as well as shrinkage, density, etc.

The following Table shows the reinforced PP contraction vs. that of some thermoplastics. This is an important issue to be considered when selecting a particular reference as it may affect a given type of adjustment between pieces or a new mould design.

As you can see, Comai materials include Calcium Carbonate reinforced Polypropylene which in addition to its increased rigidity and impact has the highest thermal conductivity – 2.6 [W/M°K] – vs 0.45 or 0.2 for high density Polyethylene or Polypropylene respectively. This property will help reducing cycle times by allowing a faster heat liberation which results in increased productivity. Propilco and Comai Technical Departments will gladly provide any technical assistance so that you can make the best decision regarding new products or the replacement of an existing material.