To ensure the consistency throughout the resulting batch of material, the blending process is utilized to mix multiple batches of the same polymer type together. The blender used in this process can usually hold between 5 to 18 tons of reground plastic.
When the material are fed into the blender, a vertical rotating screw will augers it to the top of the blender, where it then sprays from the top of the screw before being further dispersed and mixed by the foils inside of the machine. This blending process continues until a uniform mix of product is attained. Following are the three stages of blending:
Pre-Blending
When reground feed-stocks are purchased, materials are blended before being put into production.
This pre-blending process allows a test of a representative sample of the product to ensure it is not contaminated with different polymer types and also to obtain the physical properties for that batch of feedstock.
Blending
When the technical-center has formulated which materials will provide the required specification for a product from the sample, they are blended together.
The purpose of blending at this stage is again to create a uniform cluster of feedstock that will produce a consistent quality compound. Without this uniformity, adjustment of the settings of your molding equipment maybe needed, which will reduce cycle times, increase scrap rates and potentially affect the quality of the final product.
Post-Blending
Post-blending is really a post-production process that occurs when there are minor fluctuations through the batch of finished compound. These fluctuations could cause variations in physical properties or color of the resulting product. As a result, different parts of the batch will be again blended together to obtain a more consistent product.
Once the material is blended, further quality assurance checks are performed to ensure that the compound meets the required specification and quality criteria.
[Courtesy of: Taiwan Industrial Machinery Professional.]
Section I: Introduction
Section II: Present (YOU ARE CURRENTLY IN THIS SECTION)
Section III: Future
Complete Table of Contents
Reference