What's New » Simple, Low-Cost Yield Control System Proves Its Cost-Saving Capabilities in PVC Powder Extrusion

Simple, Low-Cost Yield Control System Proves Its Cost-Saving Capabilities in PVC Powder Extrusion


Maguire® LineMaster™ System Enabled a High-Volume Producer of PVC Profiles to Increase Output and Consistency While Saving Material and Eliminating Scrap

TAMWORTH, STAFFORDSHIRE, UK, October 9, 2009: A high-precision, easy to operate, low-cost extrusion yield control system enables users of PVC powder-blend to achieve process stability and product consistency by adjusting for variables in raw material and extruder performance, it was announced today by Maguire Europe. The company expects manufacturers of PVC pipe, profiles, and wire and cable to benefit from the system, which is trade-named LineMaster™.

A profile manufacturer in the United Kingdom reports that by installing the LineMaster system on a 500 kg/hr extrusion line, the company produced more on-specification profile at that rate, enhanced quality, saved raw material, shortened times for job setups and changeovers, and virtually eliminated scrap. While the company has asked Maguire not to disclose its identity, it has provided data showing that the process improvements achieved with the LineMaster yield control paid for the investment in the system in less than a month.

The LineMaster system includes control software, connecting devices, and a loss-in weight (LIW) hopper that feeds material into the processing machine. The system is designed to work in concert with the Maguire® Weigh Scale Blender (WSB), a gain-in-weight (GIW) device. “While the blender provides exceedingly precise dosing of material, the LIW hopper generates split-second feedback of actual material consumption by the extruder, updating weight readings every second,” said Chris Crittenden, sales manager. “By adjusting for the variables that affect the rate of this consumption, the LineMaster system automatically ensures that each given length of pipe, profile, or wire insulation contains precisely the same amount of material, which is what yield control is all about.”

Only two or three hours are typically required to install the LineMaster system on an existing extrusion line, minimizing the impact to production and job runs, Crittenden noted. Normally there is 0-10 V connection needed, between the LIW hopper control and the speed control of the drive to be controlled. Once the system is activated, the operator sets the extruder speed, notes when the required throughput (in kg/hr) is achieved, and turns on the “Lock” mode, letting the LineMaster system take control. This procedure does not require specialized personnel.

How the LineMaster™ System Paid for Itself in Less than a Month

Many variables affect the rate at which extruders consume raw material, including the source of the material, storage conditions, density, particle geometry, die and heater conditions, screen packing, and fluctuations in electrical power. In the case of the profile manufacturer in the UK, these variations were especially troublesome owing to the complexity of their products and the close tolerances required. The extrusion line on which the LineMaster system was installed had a twin die producing “back” and “front” segments of the profile that had to be exactly equivalent in weight and dimension.

By adjusting for changes in material consumption caused by the material and extrusion variables, the LineMaster system made it possible to increase product yield by 3 to 4%, in effect saving 15 to 20 kg of raw material per hour at a line speed of 500 kg/hr. Profile strand weight variations were reduced to 3% from a previous norm of 5 to 10%.

Prior to the LineMaster installation, process variations on this production line resulted in inconsistent edges, malformed profiles, and surface blemishes. As a result, monthly scrap generation ranged from 690 to 1,155 kg, according to the customer. After the installation, a five-day test run generated no scrap at all.

As a result of cost savings made possible by these improvements, the profile manufacturer reported, the LineMaster system produced a full return on investment in less than 30 days.


MAGUIRE EUROPE supports a network of distributors throughout Europe, as well as in Africa and the Middle East, with sales and technical support, customer service, and an extensive inventory of Maguire® equipment systems and parts. Maguire Italy, a Padova-based Maguire Europe business unit serving customers through sales agents in five regions of Italy, can be contacted by telephone at 39-049-970-5429 and by email at Robert@Maguire-Europe.com. Maguire Europe is headquartered at Vanguard, Tame Park, Tamworth, Staffordshire B77 5DY, United Kingdom. Tel: 44-1827-265-850. Fax: -855. Email: Paul@maguire-europe.com.

MAGUIRE PRODUCTS, INC., headquartered in Aston, Pennsylvania, U.S.A., is the world’s largest supplier of gravimetric blenders and liquid color pumps and also manufactures loading systems, granulators, dryers, auger feeders, and related equipment and software. Its customers include injection, blow, and rotational molders, extrusion processors, and compounders. Founded in 1977, Maguire operates five manufacturing facilities in Aston and Smithfield, Rhode Island, U.S.A. The company maintains a network of distributors in the Americas and overseas and has two sales and service subsidiaries: Maguire Europe, which supports customers throughout Europe and operates a distribution center in Tamworth, Staffordshire, United Kingdom; and Singapore-based Maguire Asia, serves customers throughout South Asia and the Pacific Rim. Visit the Maguire Products web site: www.maguire.com