Pro and cons of using pocket springs in mattresses: a comfort study

Human-centred design asks for wellbeing and comfort of the customer/worker when interacting with a product. The mattress of a bed is a typical product whose relevance in everyday life of people is underevaluated. Fortunately, this behavior is quickly changing and the customer wants to understand the product he/she buys and asks for more comfortable and for scientifically assessed products. In the last few years many researchers and designer have developed ideas and solutions to make the human-sleep as better as possible, introducing new materials and new constructive solution. Nevertheless, some solutions that have a great impact on mattress market, like the pocket spring ones, are based on marketing analysis and not really on scientific principles. The common experience of some manufacturers and users is a decay of comfort performances and a negative feedback about the use of that kind of mattresses after a few times. This study intends to investigate, under a mechanical point of view and using a previously developed comfort assessment method, the interaction among users and pocket spring-based mattresses, in order to understand the effects of this technology on the perceived sleeping (dis)comfort and give some guidelines about the right design choices to create and produce them. A preventive FEM study has been performed in order to correlate the mechanical behavior of the mattress depending on materials and springs’ layout and stiffness. After that, an experimental campaign has been done in order to have an experimental/numerical model that is able to describe the interaction between a body in supine position and the mattress. Finally, an analysis on mechanical parameters of the mattress has been done in order to understand pro and cons of using pocket spring technology and to drive the mattresses’ designer to avoid common design mistakes.