Plastics -There is almost an infinite number of plastic materials 'out there'. We will try to deal here with the common used ones - the property differences and methods of processing. If you are an inventor or developer we can help you with your project.Fit for purpose ?Let's do a fast track sieve test here .........Inside or Outside ?If the product is to be used outdoors then you have some real issues to deal with...UV resistance - in places like the US & Australia this can be really big issue, as compared to countries like the UK where UV is not anywhere near as severe. UV resistance costs $.UV can degrade the colour and the surface of the product. A more specialised plastic and/or coating can overcome this problem but this will come at a cost.TemperatureParticularly if the product is outside what temperature will it be exposed to ?Plastics at lower temperatures will get brittle and the impact resistance will decrease.At higher temperatures the product may wilt under load and discolour and degrade.Fire ResistanceShould the product be resistant to fire ?Does it have to meet a specific regulation ?This feature can very much limit the choice of materials.Chemical ResistanceThere are big variations in chemical resistance of plastics and you should not that as the temperature increases the chemical resistance can reduce. A useful chart for chemical resistance can be found here from Miller Plastics Inc.Physical & Mechanical PropertiesWhat are the extremes of properties for this application ?For example - impact strength, Flexural strength, tensile strength, wear resistance, thermal properties - temperature, coefficient of expansion (which may be different than the material you MAY fix it to) Thermoplastic v's Thermoset PlasticsThe difference between the two is....A thermoset is a material that goes on a one way journey. Usually the application of heat, reaction or catalyst drives a chemical reaction that is not reversible. The material cross links to give a cured polymer that has a three dimensional structure. A thermoplastic softens where heated but does not cure or set. As it gets hotter it can be pumped into a die cavity to form a product and when cooled can be removed from the die. No chemical cross linking occurs. This means the product reprocessed again into another product - recycled - again and again.There are a vast number of variations in the formulation of these materials. Components such as fillers, reinforcements, pigments, light stabilisers, impact modifiers, fire retardants, bends of other resins, are used to tailor a compound to give the sorts of properties required in the end product.Here above is a list of some of the better known thermoplastic and thermosetting resins.
Common Plastic Processes and videosThese are the common processes that are used for plasticsInjection MoldingPellets of plastic are heated and pumped into a die to mould the product, the die is cooled and the part ejected.To show you how this works watch a video ….. click here to view Vacuum FormingA sheet of plastic is heated to a critical temperature and a vacuum is used to suck it down onto a mould. The product is then cooled and trimmed to size.For an explanation, click hereExtrusionHere pellets are heated and pumped through a die to give a continuous shape which is cooled and cut to length. To see a video of this process click hereBlow MoldingThe way to make a plastic bottle - the story of the process in video form is here on YouTubeLaminating with ResinEpoxy laminating - click herePolyester - how to fibreglass - click hereThis should give you a general summary of the subject, talk to us if you want more detail.