Method of monitoring the quality of a mattress
The invention pertains to a method of monitoring the quality of a mattress during its lifetime, wherein the mattress is an assembly of multiple separate parts, wherein the parts are mechanically interconnected, the method comprising during its lifetime, assessing at least one property of the mattress, determining whether or not the property meets a predetermined specification, and when the property does not meet the predetermined specification, identifying a part of the said multiple separate parts that corresponds to the property, removing the identified part from the assembly and optionally replacing the removed part with a replacement part, wherein the mattress that is monitored is manufactured by forming the mechanical interconnection with an adhesive, which adhesive has a first order phase-transition temperature between 80° C. and 180° C., at which temperature the adhesive undergoes a solid-liquid transition, and wherein before the said removing of the identified part, the adhesive with which this part is interconnected with other parts in the assembly is heated to a temperature above its phase-transition temperature, whereafter the identified part is grasped and pulled out of the assembly. The invention also pertains to a method of manufacturing a mattress suitable for use in this monitoring method.
1. A method of monitoring quality of a mattress during a lifetime of the mattress, the method comprising:
(a) providing a mattress comprised of an assembly of multiple separate parts which are mechanically interconnected with an adhesive having a first order phase-transition temperature at which the adhesive undergoes solid-liquid transition of between 80° C. and 180° C.,
(b) assessing during the lifetime of the mattress at least one property of the mattress,
(c) determining whether or not the property assessed according to step (b) meets a predetermined specification, and when the property does not meet the predetermined specification, identifying a part of the multiple separate parts that corresponds to the property as a defective part to be removed from the mattress,
(d) heating the adhesive interconnecting the identified defective part with any other parts of the assembly above the first order phase-transition thereof so as to disconnect the identified defective part from any other parts of the assembly, and thereafter
(e) removing the disconnected identified defective part from the assembly by grasping and pulling the disconnected identified defective part out of the assembly.
2. The method according to claim 1 , wherein the assembly comprises a first layer having length and width dimensions that correspond to length and width dimensions of the mattress, and wherein the first layer is a support layer comprising a collection of contiguous pocketed springs, wherein each pair of two contiguous pocketed springs are mechanically interconnected by the adhesive.
3. The method according to claim 1 , wherein the assembly comprises two stacked layers having length and width dimensions that correspond to length and width dimensions of the mattress, and wherein the two stacked layers have a different composition and different rigidity, and wherein the two stacked layers are mechanically interconnected by an intermediate layer of the adhesive.
4. The method according to claim 3 , wherein a second layer of the two stacked layers is an upholstery layer.
5. The method according to claim 4 , wherein the upholstery layer comprises a three-dimensional reticulated material.
6. The method according to claim 5 , wherein the reticulated material is connected directly to the first layer with the adhesive.
7. The method according to claim 1 , wherein the adhesive has a first-order transition temperature between 100° C. and 160° C.
8. The method according to claim 1 , wherein the adhesive has a first-order transition temperature between 130° C. and 150° C.
9. The method according to claim 1 , wherein the adhesive comprises at least 50% by weight of a polymer selected from the group consisting of polyurethane, polycarbonate, polyester, mixtures thereof and copolymers thereof.
10. The method according to claim 1 , wherein the adhesive comprises at least 50% by weight of a polyester.
11. The method according to claim 1 , wherein the assembly of multiple separate parts comprises two or more parts that are made of a polyester polymer.
12. The method according to claim 1 , wherein step (a) comprises:
(a1) providing a first layer of contiguous pocketed springs, wherein pockets of the pocketed springs are interconnected by adhering the pockets together with the adhesive having the first order phase-transition temperature between 80° C. and 180° C., and
(a2) connecting an overlaying upholstery layer to the first layer by adhering the upholstery layer to the first layer with the adhesive applied in step (a1) or with another adhesive that has a first order phase-transition temperature between 80° C. and 180° C. at which temperature the another adhesive undergoes a solid-liquid transition.
13. The method according to claim 12 , wherein the upholstery layer comprises a three-dimensional reticulated material.
14. The method according to claim 12 , wherein the adhesive has a first-order transition temperature between 100° C. and 160° C.
15. The method according to claim 12 , wherein the adhesive comprises at least 50% by weight of a polymer selected from the group consisting of polyurethane, polycarbonate, polyester, mixtures thereof and copolymers thereof.
16. The method according to claim 12 , wherein the adhesive comprises at least 50% by weight of a polyester.
17. The method according to claim 12 , wherein the pockets, the overlaying upholstery layer and the adhesive are made of a polyester polymer.
18. A mattress obtained by the method according to claim 12 .
19. The method according to claim 12 , wherein the adhesive has a first-order transition temperature between 120° C. and 150° C.
20. The method according to claim 1 , further comprising the step of:
(f) replacing the removed defective part with a replacement part.