{"id":215,"date":"2015-11-10T13:18:58","date_gmt":"2015-11-10T13:18:58","guid":{"rendered":"http:\/\/www.plastikcity.co.uk\/blog\/?p=215"},"modified":"2020-08-25T14:22:05","modified_gmt":"2020-08-25T14:22:05","slug":"specific-gravity-not-that-specific-at-all-ignore-this-blog-at-your-peril","status":"publish","type":"post","link":"https:\/\/www.plastikcity.co.uk\/blog\/specific-gravity-not-that-specific-at-all-ignore-this-blog-at-your-peril\/","title":{"rendered":"Specific Gravity – Not that Specific at all. Ignore this blog at your peril!"},"content":{"rendered":"

The definition of \u2018Specific\u2019 is clearly defined or identified<\/em> or a<\/em> precise detail<\/em>.\u00a0 Unfortunately, when it comes to specific gravities for polymers, this definition doesn\u2019t always hold true, so in reality you may just be ‘sticking your finger in the air’………<\/strong><\/p>\n

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This is because the standard way of quoting a particular material\u2019s s.g. is in its solid state, but most of us are in the business of melting plastic. In some cases, the shift in material density when moving from the solid to the molten state can be as high as 20%.<\/p>\n

\u00a0At the bottom of this Blog we provide you with the tools you will need to avoid making costly mistakes.<\/em><\/h5>\n

Using the wrong source of information for the s.g. of a particular material might not sound that much of a big deal, but I have known of instances where a moulder has quoted for a job, only to later find he can\u2019t actually handle it because his machine doesn\u2019t have sufficient shot weight.\u00a0 In one extreme case, a company placed an order for a new machine based on incorrect information.<\/p>\n

So what\u2019s the problem?\u00a0 <\/strong>We aren\u2019t talking about the slight differences between specific grades of a material, although you should always take care when dealing with filled materials.<\/p>\n