Maximising product quality of LLDPE tape extrusion

Impact Solutions regularly works with clients on various products.  Recently we helped a client maximise product quality in LLDPE tape extrusion

Polypropylene (PP), in the form of extruded and stretched tape/fibre, is a key product in the manufacture of carpets and artificial grass matting. Because of the need for large quantities of stretched tape/fibre, the manufacturing process involves high speed extrusion using multifilament lines.  Consistency of resin supply and reliability of process equipment is crucial to sustain efficient and continuous production of high quality finished product.

Against this background, Impact led an audit of a stretched tape manufacturing facility to identify the critical process parameters which had led to multiple line breakdowns, resulting in wasted materials and costly downtime. The audit began with a typical Ishikawa root cause analysis leading to an investigation of resins used and their processing properties, the sensitivity of production to extrusion line parameters and the effect of the variability of post extruder equipment settings on the number of line breaks. Statistical process control (SPC) was used wherever possible to give quantitative definition and to set control limits for parameters such as resin melt flow rate, melt temperature, oven entry
temperature and heat set temperature.

This rigorous approach allowed Impact to establish which of the material and process parameters were predominantly responsible for line breaks in the extrusion process. Tighter control limits, increased vigilance and better maintenance were implemented to tackle this aspect.

Resin batch sensitivity was found to be a strong contributory factor and improved QC methods were put in place to identify and select the more tolerant batches for high speed production. Alternative approaches were taken with the remaining batches (typically <10%) including different process parameters and use in other products. Overall this work led to > 90% reduction in line breakage, significantly increasing the facility’s output and productivity.

To learn more on the complete Impact solution and to arrange a confidential on-site meeting, please contact us.

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