By Stuart Croxford
In manufacturing, the type of product and the material used to build it may vary, however the process that product companies use to deliver a high-quality product is universal. A well-planned production audit, outlined by these important five steps, will help ensure a more predictable, overall quality process. Of course, the problems that you encounter during manufacturing often relate to the material and corresponding process that you are using to shape it. Here we will take a closer look at how to ensure that you achieve a high-quality final product based on a very commonly used material, wood.
Wood is one of the oldest materials known to man and has been used for the manufacture of many products from shipbuilding to disposable cutlery.
Previously, wood has not been viewed as an environmentally friendly source of material as, historically, forests have been clear cut to provide this resource. However, responsible manufacturers will now use timber certified under FSC (Forest Stewardship Council) which is only cut from managed woodlands.
It turns out that wood, although beautiful to look at, with its warm tactile feel, is far from the ideal raw material. As it is a “natural product”, its growth and resulting structure, is non-uniform and full of imperfections such as knots. Solid wood is inherently unstable, and when subjected to varying temperatures and humidity, will tend to twist, shrink, split, and warp over time.
To overcome woods inherent instability, a multitude of man-made, engineered boards have been developed. Some of the most common are MDF (medium density fibreboard), chipboard, plywood, and the like. These boards can also be environmentally friendly and economically cost effective as they may be manufactured from lower quality (faster growing) wood or wood waste products like sawdust or wood chips.
These engineered boards, due to their more uniform structure, are inherently more stable than natural wood and certainly a lot less expensive but, they do have their issues. They may be susceptible to water damage and may still be inclined to twist or warp if not manufactured properly.
To help reduce the impact of humidity changes and make products that are aesthetically pleasing, many different finishes can be applied to engineered wood. Liquid coatings such as varnish, stains, paint, and lacquer are commonly used, some of which can be polished to a very high finish, think of the beautiful, lacquered finish on a grand piano (commonly known as Piano finish). However, these liquid coatings are quite slow from a manufacturing perspective and can be costly.
To overcome the cost of liquid coatings, a variety of laminates have been developed for engineered boards. These include foils, vinyls, real wood veneers and hard-wearing melamine. The engineered boards can now take on the appearance of solid wood or alternatively any other look and colour that can be printed onto the laminates themselves. Laminates are usually applied with the help of an adhesive and then subjected to heat and pressure to ensure good adhesion and a flat surface. Vinyl laminates can also be applied to uneven surfaces by heating up the vinyl, allowing it to stretch and subjecting it to a vacuum in a vacuum press to mold the laminate onto the wood.
SureSource has been involved in several of these products, most of which were a very straightforward development and manufacturing exercise, and successfully shipped without any problems.
On one project, however, an indoor wall garden product that incorporated a large flat cabinet door with two window cut outs which was warping (over time) by up to 7mm. The problem was identified through environmental testing at the sample stage so there was no leakage to the market. Initially it was thought that the two cut outs (essentially making the door a “frame”) were the root cause of the problem. However, after further experimentation, the warping remained the same. Further tests were run by SureSource and eventually, by changing the laminates on both sides of the door, changing the adhesive type, and refining the press force and temperature of the laminating process, the problem was resolved. Further heat and humidity testing in a chamber, also confirmed that the new panels were stable through multiple heat and humidity cycles. The customer was always kept appraised of the situation and approved the design changes once the solution had been identified by SureSource and its partner factory. This product is now being shipped without any problems.
When it comes to high quality manufacturing, product companies need to follow well-proven, step by step, product development processes. By implementing a well-planned production audit, inherent design flaws can be identified through the building, and validation testing of sample product. If a problem is identified, a systematic series of experimental sample testing, led by the engineering and quality teams, can be deployed to identify the root cause failure. A proposed solution may then be subjected to multiple rounds of full sample builds and the associated validation testing to prove that the new design and manufacturing process provide a reliable, stable product. Throughout the process, clear and open communication of all elements of the investigation as well as full documentation of test data is critical for success.
If you are out-sourcing your product manufacturing, make sure that your supplier is using a well-proven, detailed and fully documented product development process for all products which they manufacture. You will need to stay fully informed about your program’s progress through weekly tracking reports and video conferences as required. Test data should be collated into formal quality reports as part of a total quality process and shared with you to identify problems or gain your approval to proceed. Finally, comprehensive product validation, function, and performance testing, as well as certification if required, should be conducted to ensure the product fully meets your requirements. For all products, make sure that you sign off on sample production before proceeding to the mass production stage.
This open and transparent way of working with your manufacturer will help ensure the delivery of high-quality, reliable products to you with no surprises.
