Scrap rates for the injection moulding industry are easy to calculate, but often painful to believe – it is simply the difference in weight between how much plastic you buy in, and the total weight of parts delivered. Typically this is as much as 10%, although when questioned about scrap rates companies reported to us the figures they wanted to talk about – such as “customer reject rates” of 4.5ppm or their “production reject rate” where we heard of 0.001%.  These figures are just self-congratulatory and distorted.

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