Engineer Bill Flynn writes in that he has had too many experiences to count with poorly designed products that fail prematurely under normal usage. These products, he writes, typically have no warranty or are out-of-warranty, so no return is possible. Sound familiar?
One example he points to is a non-repairable plastic window frame manufactured by Peachtree . The frames have cracked on three homes he’s owned. View photo.
“The plastic window frame in question is probably a $50.00 item. The manufacturer’s solution is to replace the entire door set (door, door frame and 2 side-lites), at a cost of approximately $2,500, plus removal and installation costs. I spoke to the manufacturer and after being given a very unsatisfactory response, I e-mailed the company. I never received any reply.”
Below is an excerpt of Bill’s e-mail, in which he even offers up a design solution for a replacement kit. If only every customer were so diligent and if only their efforts paid off.
To: email@example.com Date: Jan. 12, 2009
Subject: Long term reliability of plastic injection molded window frames incorporated in your doors & side-litesAttachments: SideLite_Photos_Jan2009.doc; Repair_Kit_Win_Frame_Jan2009.doc
Customer Service Dept.
Please Forward this e-mail to Mr. Dale Rasmussen, Engineering Dept.
Design Engineering Management:
I have owned three new homes in the Ohio-Michigan area in the past 20+ years. These homes were equipped with metal entry doors and metal sidelites that include insulated glass windows. The glass windows are supported by injection molded plastic frames. One frame is installed into the metal door (sandwiched and interlocked between the door skins) and it is not serviceable or removable. The second frame sandwiches the glass plus seals onto the non-removable plastic frame via several steel Philip screws.
The glass, the seals and the removable (interior) frame are replaceable and offered for sale by your distributors and service dept.
In all three cases, the non-removable frames have cracked all the way through their cross section at two vertical locations. During the winter months, the cracks open, up creating a large air-leak path. The crack opens and closes seasonally due to the thermal mismatch between the plastic material and the metal door material (steel).
There is no easy means to replace the damaged non-removable plastic frames, other than replacing the door and the two sidelites. Note that there also is no easy way to replace the sidelites without removing the entire door frame from the house.
It is very obvious, that PeachTree does not perform reliability and thermal analysis prior to releasing a new door design to manufacturing. These are standard engineering tools that every college engineering student must learn to use prior to graduation. I assume that your company has employed degreed engineers to design your products.
Since, the plastic frame is sandwiched between and interlocked into the two metal door skins, the thermal expansion of the two different materials creates large tensile stresses within the weaker plastic material during exposure to cold temperatures. Since, the plastic outgasses and hardens over time and with UV exposure, the stress condition causes a failure in the weakest area. The failure appears as a crack across the vertical section of the plastic frame. Once cracked, the cracks opens and closes as the outside temperature varies.
Looking at a cross section of the design, your engineers did not allow for plastic shrinkage nor add any compensation means to absorb the differences in material expansion.
This problem could be avoided with an expansion compensation device, such as:
1) Use of a closed foam gasket of the appropriate thickness that would separate the metal skins from the plastic frame.
2) Use of reinforced injection molded plastic with chopped or cut E-glass or carbon fibers. The injection reinforced molded plastic material’s thermal coefficient of expansion would be similar to that of the steel door skins. This would greatly reduce the over stress condition and failures.
3) A complete redesign of the window, gasket, plastic frame and door skin interface to permit easily removal and replacement of the plastic frames.
For cracked frames, Peachtree could sell a repair kit, details of which I have included for you here. View detailed drawing and repair kit sketch.
I do not expect a reply. Most manufacturers of commercial products tend to isolate themselves from the end consumer . They believe that the distribution channels, who are totally focused on low cost, are their customers.
Thanks for reading this e-mail. It does not solve my problem, nor does it make me feel any better about American manufacturers and consumers. If we were better educated and more demanding as consumers, we would have better and more reliable products to choose from.