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Zero waste wings for sanitary napkins

2012-09-20T04:48:34+00:00

At first look sanitary napkins seem all very similar. They are all made of a central chassis, usually straight or slightly contoured, and a pair of "wings" to position the product on the user's underwear.

State of the art design wants the full product cut from a single web. The outcome is 30% of your material goes in trim. Is it possible to find another way to produce it and save all that raw materials? Of course the answer is yes. Other manufacturers found a solutions and now their patents are on the way to expire.

How to innovate your sanitary napkin design?

Many types of sanitary napkins exist on the market. But all of them can be divided in 2 big categories: “shaped” and “winged”. The latter is the most appreciated by women because they are equipped with lateral tabs, commonly called "wings", that help the positioning of the product on the underwear and protect the underwear itself from the contact with body fluids that might not be immediately absorbed by the sanitary napkin.

The wings extend from the longitudinal sides of the sanitary napkin and can be attached to the underwear folding them on the external part of the garment, thus enveloping completely or partially the part of the underwear on the opposite side of the sanitary napkin.

Generally these wings are integrally formed by one or more layers constituting the sanitary napkin itself, and particularly by the union of the lateral edges of the inner material and the outer material.

A mechanical cut, usually of rotary type, is used to shape outer profile from a single web although consisting of multiple materials laminate.

This very standard process has a major drawback: material scrap.

The waste is in some cases from 20 to 40% of the total material used, due to the fact that the wings are present only in the central part of the product. This results obviously in a very significant cost.

Among other drawbacks there is also the fact that the tool for cutting the profile is closely connected to the profile itself. In fact, being the outline rather complex to be drawn, the cutting tool is generally delicate, expensive and must be replaced periodically when worn out. This represents a cost since the replacement of the tool, which involves a machine stoppage, is often long, even in case of product change over on the same production line, and is often not a simple activity.

To produce sanitary napkins of different sizes or with a different wing design is mandatory to stop the machine and replace the cutting tool according to the new product profile, and this results in an increase of production costs. Moreover the strict link between tool profile and product leads to an important cost increase of the whole production line because for each product size it will be needed at least 2-3 tools to keep line running with spare tools while worn tools are regrinding.

It is more and more common develop alternatives processes to save as more material as possible. According these new methods wings are manufactured from a separate web and attached to the main product body in a later stage along the process. In this way you can shape wings reducing to zero (or almost to) material trim.

A new smashing technology can be applied to production of sanitary napkins in order to further simplify the whole process and reduce capital investments. It consists of the following steps:

- cutting at least one sheet of suitable material in order to form the absorbent product wings, with a non-rectilinear profile in such a way as to create, on a single web, two identical specular sequence of wings;

- putting alongside the two wings sequences in phase so that said profiles look specular, thus forming a sequence of pairs of opposed and symmetrical wings sequences;

- linking pairs of opposed wings with a release paper;

- cutting said web along a transversal line in order to isolate a pair of opposite wings including release paper patch;

- transferring the wing pair and release paper patch to absorbent product central structure for a following seam.

The manufacturing process according to this system here described allows the significant reduction of the scrap material, in particular for the production of the wings, resulting therefore less expensive.

But the process above described, providing phases (in particular cutting) simplified compared to standard processes, significantly reduces the complexity of the production equipment. Some patents are present around this construction. Take care to design it properly or acquire a valid license.

Sanitary Napkins Patents in USA

2012-08-20T20:58:10+00:00

Each bag of sanitary napkins in US has printed a list of patent that are relevant to that product. In order to make a list of the most "important" patents related to sanitary napkins we carried out a short review among some shops in US.

We spotted the most famous brand, some second brand or private label product as well and took note of each patent listed on them. What we collected is a nice list, hereunder enclosed, showing some trends in the market.

Manufacturers try to protect specifically

- wings design and features like shape, stretchability or simply way of folding them

- core structure using new materials (eg foam) or a specific combination of already known layers.

- raw materials to obtain better performances or improved fit like soft topsheet or stretchable ply

- printings on some specific webs

- added value packagings

Having a review of all of them allow you to understand what is the state of the art of sanitary napkins in USA and be prepared in case you are thinking to start selling a product here.

Let us know your doubts and request specific survey.

US patent No

4.892.534 Nonwoven web useful as a bodyside liner for an absorption article

4.950.264 Thin, flexible sanitary napkin

5.009.653 Thin, flexible sanitary napkin

5.147.343 Absorbent products containing hydrogels with ability to swell against pressure

5.147.345 High efficiency absorbent articles for incontinence management

5.260.345 Absorbent foam materials for aqueous body fluids and absorbent articles containing such materials

5.268.224 Absorbent foam materials for aqueous body fluids and absorbent articles containing such materials

5.318.554 High efficiency absorbent articles for incontinence management

5.331.015 Absorbent foam materials for aqueous body fluids and absorbent articles containing such materials

5.354.400 Method of making absorbent article having flaps and zones of differential extensibility

5.387.207 Thin-unit-wet absorbent foam materials for aqueous body fluids and process for making same

5.389.094 Absorbent article having flaps and zones of differential extensibility

5.413.568 Refastenable adhesive fastening systems for individually packaged disposable absorbent articles

5.462.166 Package seal for individually packaged sanitary napkins

5.518.801 Web materials exhibiting elastic-like behavior

5.520.875 Process for producing a surfactant treated, formed, polymeric web

5.569.231 Trisection sanitary napkin

5.620.430 Absorbent article having flaps and zones of differential extensibility

5.628.097 Method for selectively aperturing a nonwoven web

5.652.194 Process for making thin-until-wet absorbent foam materials for aqueous body fluids

5.795.344 ABSORBENT ARTICLE WITH PROTECTION CHANNEL

5.800.654 Method of making sanitary napkin having improved flap disposition and means for maintaining the flap therein

5.817.704 Heterogeneous foam materials

5.856.366 Process for making heterogeneous foam materials

5.869.171 Heterogeneous foam materials

5.916.661 Selectively apertured nonwoven web

5.968.029 Web materials exhibiting elastic-like behavior

6.087.551 Multi-denier non-woven fabric for disposable absorbent products

6.117.523 Absorbent article with comfortable and rapid acquisition topshee

6.139.912 Method for intermittent application of particulate material

6.204.298 Processes for the rapid preparation of foam materials from high internal phase emulsions at high temperatures and pressures

6.207.724 Foam materials and high internal phase emulsions made using oxidatively stable emulsifiers

6.231.555 Absorbent article having improved integrity and acquisition

6.362.243 Method for production of porous cross-linked polymer

6.362.244 Method for degassification of high internal phase emulsion components

6.365.642 Rapid preparation of foam materials from high internal phase emulsions

6.369.121 Rapid preparation of foam materials from high internal phase emulsions

6.395.792 Method for production of porous cross-linked poymer

6.444.716 Foam materials and high internal phase emulsions made using oxidatively stable emulsifiers

6.525.106 Method for continuous curing of hipe into hipe foams

6.601.705 Package containing a window and performance charcteristic indicator

6.649.665 Method for production of porous cross-linked polymer material

6.750.263 Method for production of porous cross-linked polymer

7.163.528 Absorbent article

7.185.761 Package containing a window and a performance characteristic indicato

7.241.280 Absorbent article having perception of depth

7.270.651 Absorbent article

7.306.582 Absorbent article

7.311.696 Absorbent article