A quality control system for a good diaper manufacturer requires at least five levels of operations in order to achieve proper administration of total quality. Each system must operate in a closed loop with constant feedback to the production area, in combination with a continuous improvement program with set goals:
1) In-Line Visual Inspection System: This includes automatic vision systems and manual in-line visual inspections. Most inspections can be done automatically with a digital imaging equipment; as many as 24 individual items in every single diaper can be inspected automatically. These systems can catch must common diaper defects, such as missing or skewed tapes, frontal tape position, skewed elastic waste foam, pad integrity issues, bad cut leg trims and leg cuff placement, among many others; there are a few things that are not visible to the camera, such as hot melt glue spray and internal lateral tape folding, among others, all these require human interaction and direct feedback to the operator. An inkjet printer is very helpful in order to add a code to each diaper made to track potential diaper complaints. An operator logbook is also a must in each diaper line. In order to be able to trace a raw material defect, the date coding needs to be clear and readable.
2) Internal Quality Laboratory: This includes laboratory facilities for testing raw materials as well as finished products. All raw materials must comply with specifications defined by the certificate of analysis previously negotiated with the suppliers. Laboratory personnel have to follow very precise standardized work instructions to make sure the diaper complies with all requirements, including total liquid holding capacity, rewet, speed of absorption, backsheet pin-hole, hot melt temperature ageing, elastomeric retractile forces and lateral tapes peel and shear forces, among others. All information needs to be tracked for future reference for potential consumer complaints. If you want a complete benchmark reference to understand how your diaper compares with a reference product in the market, we can do this for you. Please click here: Laboratory Services
3) External Audit Program: An independent quality audit needs to be in place to make sure that diapers taken randomly from the warehouse comply with the Quality Manual and a quality value is obtained. This is the best way to make sure that overall quality keeps improving. A system to translate minor and major diaper defects found during the audit must be in place in order to obtain a number that represents the quality level of the factory and that is statistically representative of all the diapers made in the factory. A process control audit should also be in place to make sure that the diaper machine operators run their equipment in a standard acceptable way. This is also an excellent tool to reduce down time. One way to do an independent audit is to hire an external laboratory to compare results with the internal laboratory every quarter or at least twice per year.
4)Consumer Feedback: This can be implemented with a Toll Free telephone number, the defective diaper is collected for in-lab analysis and a replacement is given to the consumer. A good tracking system which requires the printing of a code in each diaper is an excellent tool to help identify process and raw material problems. Statistical analysis of each diaper complaint is the best way to define priorities for the factory in order to improve quality and reduce complaints. Another way to get feedback is direct interviews of major diaper distributors.
5) Infant Test Center: This is the location where babies are using diapers made from your factory under a controlled environment. Here factory trained technicians can learn about ways to improve diaper fit and reduce leakage. It is probably the best tool for research and development, as it gives you the chance to test diaper improvements before they go to the market. A day care center is an excellent choice to set up this system; in exchange for use of free diapers, most parents will agree to have their babies test diapers from the factory.