Continuous improvement programs tend to focus on internally identified opportunities and solutions. After the “low hanging fruit” is plucked, further opportunities are progressively more difficult to identify and solve. Benchmarking provides a way to look for new opportunities and better practices outside of the operation. Benchmarking is a 12-step process, essentially a plan-do-check-act cycle that involves the internal improvement team, as well as outside subject matter experts from suppliers, consultants and peer organizations.
In a focused effort to improve and sustain its Sheet Molding Compound (SMC) operations, Molded Fiber Glass (MFG) embarked on a project in 2006 called Project Hawk to determine and implement industry best practices for compounding SMC with a goal of sustained improvement. MFG led the project and, in the spirit of open innovation, encouraged other companies to join in to benefit the composites industry as a whole.
Sheet molded composites are compression molded high-volume cosmetic and structural parts – mainly for automotive, truck, industrial and watercraft applications – where the SMC is a mixture of polymer resins, inert fillers, fiber reinforcement, initiators, pigments, stabilizers, release agents and thickeners. The manufacture of sheet molding compound is a continuous in-line process. The base components of liquid and solids (paste) are bulk mixed and continuously metered onto the surface of a carrier/barrier film, coating the film surface. One of the paste coated carrier films is then layered with chop fibers. The two carrier webs, paste and fiber are then brought together in a compaction section, where the sandwich-like layered components are kneaded into a homogenous compound sheet. The sheet can then be rolled or festooned into a container and stored in a controlled environment where maturation takes place, on its way to a specified viscosity.
Project Hawk had three phases – benchmarking, implementation and sustainment. We invited many compounders to join us, and several large ones agreed to share best practices with their peers. Including MFG, nine compounding facilities participated in the study.
We generated a list of 82 input items and several output variables related to product uniformity and final quality to the customer. (Input items refer to resources such as raw materials, energy and information that are put into a manufacturing plant to obtain the desired output.) Each compounding facility was rated on these items and variables throughout the benchmarking process. Target areas funneled into seven broad topics:
- General mixing and compounding
- Raw materials
- Paste mixing
- A/B metering
- SMC machine
- Final SMC compounding
- Compounded SMC materials and maturation
In reviewing the benchmarking exercise, we noted that a few facilities had much less output variation than the general population. There was a wide range of capitalization in facilities, but this was not the primary correlator with low variation. The most important point that surfaced was that best practices in both paste production and SMC compounding were data driven and based on sound scientific principles.