GB2247168A

GB2247168A - Non-slip plastics mat and process for its manufacture

Info

Publication number: GB2247168A
Application number: GB9116921A
Authority: GB
Inventors: Jurgen Holzapfel
Original assignee: Gebrueder Holzapfel GmbH and Co KG
Current assignee: Gebrueder Holzapfel GmbH and Co KG
Priority date: 1990-08-09
Filing date: 1991-08-06
Publication date: 1992-02-26
Anticipated expiration: 2011-08-06
Also published as: FR2665624B1; GB9116921D0; GB2247168B; CH684679A5; FR2665624A1

Description

NON-SLIP PLASTIC MAT AND PROCESS FOR ITS MANUFACTURE The invention

concerns a non-slip plastic mat and a process for its manufacture In particular the invention concerns a flexible plastic mat, which can be used as an inlay for bathtubs, shower stalls and the like, which features on its upper side in the using position a pebbled, structured surface and which on its underside in the using position is provided with suction cups that prevent the plastic mat as per the invention from slipping on a smooth surface.

The invention also concerns a process for the manufacture of such a flexible, non-slip mat made of one or more different plastic materials.

Bathtub or shower inlays and neck cushions with pebble-t -pe structured surfaces and with suction cups on the underside are known from DE-GM 80 29 732.

Inlays of this tce prevent s-ipping i a tub in a satisfactory manner There is no information to be gathered from DE-GM 3029 732 about the metcnc CL attachinc the suction cups to the underside of the inlay, cther than that attaching is carried out in the usual manner.

In DE-G M,7 21 240, a massage or cleaning mat specially for laying down in bathtubs is described, which is also provided with suckers on the undersi de which in use serve as an adhesion agent to affix the mat to a base such as the bottom of a bathtub There is no indication to be gathered from this publication about the method of attaching the suckers to the underside of the mat.

DE-OS 30 20 961 discloses a bathtub inlay that consists of several thermal layers joined to one another by welding.

Suction cups joined to a base rolled material by welding, for instance, provide for attaching the bathtub inlay to the bottom of the bathtub Thermal welding of the suction cups to the base rolled material of such a bathtub inlay requires a separate step in the manufacture of such an inlay This is decidedly expensive and increases undesirably the costs of such an inlay.

In DE-GM 946 837 a bathtub inlay made of soft plastic, moisture-repellent materials is described, which also features suction cups on its underside for attaching it to a smooth tub bottom The cups are either firmly fixed to the inlay or are detachable and can be buttoned on to the inlay in the form preferred This solution, however, has the disadvantage that, due to frequent mechanical strain or a momentarily occurring mechanical strain, the mat openings into which the suction cups are to be buttoned tear, thus preventing the bathtub inlay from being firmly attached to the base Apart from that, the process for manufacturing the bathtub inlays described is technically very complicated.

An inlay for shower and bathroom fixtures in the forn of a mat-type product featuring detachable suction cups for fixing it to a base is also described in DE-PS 24 14 294 The mat consists of a flat net-type body with openings and is coated with plastic to which detachable suction cups are affixed This bathmat just like the one previously described has the disadvantage that upon sudden mechanical stress on the mat the suction cups can become partially or competely loosened from the body and/or the underside of the mat with the result that there is no guarantee of a safe connection between the mat and the base.

DE-PS 33 03 993 refers to a flexible inlay for bathtubs, shower stalls and the like, which is made of foamed plastic with suction cups on the underside, whereby the suction cups consisting of at least slightly foamed plastic v are joined individually to the foamed layer of the inlay.

The foamed layer of the inlay and the suction cups individually joined to it feature an airtight skin made of a non-foamed plastic corresponding to the foamed plastic material One disadvantage of this solution is that the foaming is not adequate in that form in the step of the foaming of the inlay and the suction cups in dividually joined to it This makes the item too heavy and too stiff to meet the requirements for use Apart from this, the manufacture of such an item is so expensive that the product cannot be sold at a price that is still marketable.

Furthermore, the manufacturing process outlined permits too little latitude for attractive styling of the surface, eg with colouringe and/or printing.

The concern of the present invention was to eliminate the state of the art disadvantages mentioned The invention is intended to make it possible to provide non-sl ip plastic mats that are simple and inexpensive to manufacture and featuring on their underside firmly atzached suctioron cups for affixing the plastic mat on to a smooth base.

It is the purpose of the process suitable for the production of these mats to make it possible to guarantee that the suction cups are affixed securely, in simple steps, to the underside of the mats in the using position At the same time, the raw material for the mats shall be capable of being drawn off from a roll and fed through a mould, in which the suction cups are formed, affixed to the underside of the mat at the same time, and the mat contour cut.

This is achieved with a non-slip mat made of one or more flexible, thermoplastic high polymer material(s) compatible with one another, with a non-slip upper side and suction cups on the underside, and with the particular feature that the suction cups are injected on to the underside of the prefabricated mat.

The invention also concerns a process for the manufacture of such a non-slip plastic mat with the characteristic that the prefabricated material of the mat, which at least on the underside consists of a flexible, thermoplastic high polymer material A, is fed in roll form to a mould, in which the suction cups-made of a compatible material B in thermoplastic state are injected on to the underside of the roll segment under plastification conditions, and that the roll segment being fed in is simultaneously cut to the desired shape of the plastic mat.

The non-slip mat as per the invention consists of one or more flexible, thermoplastic high polymer material(s), compatible with one another Such materials are known from the above-named state of the art and include, for example, polyolefinss such as polyethylene and polypropylene, acrylatep-olymerssuch as pol-yacrylate and povlymethacrylate, polyvinyl chloride, polystyene, po 01 yamide, polyurethane, and also thermoplas 4 ically processed elastomers (EVA), and copolymers, such polymers as rubber-modifi-ed polyolefin, lPP/EFDH (polyropylene / ethyiene-propylene-diene terpolymer)I Tn certain cases pocyblends are also suitable for non-sl Ip plastic mats as per the invention Appropriate plasticizers and additives can be added to the said high polymer materials, which improve their properties with regard to flexibility and resistance to heat and chemicals (in particular alkalis) etc in the desired manner.

For the non-slip mats as per the inven tion it is possible to laminate or combine various polymers to a layer lattice.

This can be particularly advantageous when a certain structure is to be put on to the surface of the mat in order to ensure resistance against slipping of the feet.

There are no limitations with regard to such laminates - except as to their compatibility with one another.

The non-slip mat as per the invention normally features a strongly structured surface on the upper side, eg in the form of pebbling or embossing On the underside, as will be described in the following in detail, suction cups are injected on in order to be able to affix the mat firmly to a suitable base eg the surface of a bathtub or shower stall.

In one popular version the mat may also feature slits or holes that make it easier for the water to run through or flow off These holes are so arranged that they do not adversely affect in any undesirable manner the stability or the tensile strength of the mat.

According to one aspect of the invention the high polymer materials, of which at least the underside of the mat and the suction cups consist, are so chosen that they fuse together This means, both here and in the following description and in the claims, that under processing conditions (pressure, temperature) the polymer materia(s) will melt in a narrow temperature range and mix together in the form of a common fusion When the fusion cools, a solid emerges that possesses equally good if not better mechanical properties when compared to unmixed polymers, and which unites the two parts of the mats as per the invention (underside and suction cups) firmly with each other.

One of the specialities of the invention is that the suction cups of the non-slip plastic mat consist of an unfoamed high polymer material and at least the underside of the mat consists of the same material as the suction cups, the latter material however being foamed This version in particular gives a special guarantee that, upon joining the suction cups to the underside of the mat in the following procedural steps described in detail under high pressure and at high temperature, a fusion takes place, and vz r this leads to a stable join between the suction cups and the mat This stable join is of particular benefit to the non-slip properties of the mat.

Some examples of high polymer materials that as per the invention are particularly preferred because of their advantageous properties and their durability are polyolefins such as polyethylene and polypropylene and their copolymers and their mixtures In one such case, therefore, the suction cups, for example, would consist of one of the said polyolefins, a copolymer or a mixture thereof, eg a polyolefin such as polypropylene-with a thermoplastic elastomer such as EPDM (ethylene-propylene diene-terpolymer), whereas at least the underside of the mat, preferably the whole mat, consists of rolled material made of polyethylene or polypropylene and possibly EPDM, which contain the usual additives to impart the desired characteristics.

Another polymer suitable for the invention and also with advantages in its use is polyvinylchloride in this case, the rolled material normally consists of a soft PVC foamed rolled material that can be used with or without supports.

The suction cups also consist of soft PVC and are injected on to the underside of the rolled material in the procedure described in detail in the following.

For the upper side of the mat at least, as far as a foamed polymer can be used, the regular solid expanding agents are used, which are mixed with the polymer and then, in what is in fact normal procedure, exposed to a high temperature to swell or foam the polymer The procedures for forming such foamed polymers are as such known to the state of the art and require no further explanation here.

According to a further aspect of the invention the high polymer material, out of which at least the underside of the mat if not the whole mat consists, and the high polymer material, out of which the suction cups consist, are joined together by an adhesive or primer 48 This is then of particular advantage if the polymers used have a chemically different composition and/or differ greatly with regard to their physical properties Suitable adhesives depending on the polymers used are known from the state of the art and include polyurethanes and acrylate polymers such as acrylic acid and methacrylic acid polymers, their esters and their copolymers In another popular version a primer is used in such a way that it is already applied to the rolled material which is fed to the mould, or is applied to the rolled material immediately before the entry of the rolled material into the mould.

Of course, the poy-mers of the mat material as well as those of he material for the suction cups may contain additives that mocdi fy their properties These too are described in detail in the relevant state of the art and include colouring substances, stabilisers and agents to increase resistance %o chemicals, in particular resistance to alkalis A detailed list will be dispensed with in this case too.

The process as per the invention will be explained in detail as follows and with reference to the figures, viz:

I Figure 1 shows a non-slip mat as per the invention, whereby the reference number 1 designates the body of the mat and 2 the suction cups; the mat is shown in figure 1 lying with the suction cups ( 2) upwards, thus showing precisely the opposite position to that of the non-slip plastic mat as per the invention when in use; Figure 2 shows in the using position a cross-section of the non-slip plastic mat as per the invention, whereby the actual body of the mat ( 1) is shown upwards and the suction cups 2 downwards; Figure 3 shows equipment with which the non-slip plastic mat as per the invention can be manufactured; and Figure ' shows a cross-section of Dar% of the equipment shown in figure 3, namely the actual moulding equipment with the feed roll for the rolled goods, the extruder for feeding the polymer granulate and the moulding equipment.

The process as per the invention is characterized by the fact that the prefabricated material of the mat, which at least on the underside consists of a flexible, thermoplastic, high polymer material A, is fed in roll form to a mould ( 4, 33), in which the suction cups ( 2), made of a compatible material B, are injected in a thermoplastic state on to the underside of the roll segment ( 43) under plastification conditions, and that at the same time the fed-in roll segment ( 43) is cut to the desired shape of the plastic mat.

It is preferable to perform the process in several steps.

in the first step the process as per the invention for the manufacture of a non-slip plastic mat, as described above, the prefabricated material of the mat is fed in roll form to a mould ( 4, 33) of the equipment ( 3) To this purpose, for example, the prefabricated mat material is wound up on to a roll ( 31), ( 41) and consists of one or more of the polymers already described in more detail above.

According to one aspect of the invention already described, at least the side of the mat that will later be the underside of the product as per the invention consists of a flexible, thermoplastic, high polymer material A As per the invention it is possible for the whole mat to consist of this material A It is, however, equally possible that one or more la-ers of the mat consist of another polymer ma Lerial as described above and only the underside of the mat of the flexible, thermoplastic, high polymer material A.

mhis material ("roll'ed material") is fed from the roller ( 31), ( 41) preferab ' by way of guide rollers ( 32), ( 42) to the moulding equipment ( 4, 33) In so doing, usually so much material is drawn into the moulding equipment ( 4, 33) as can be processed in one step, ie shaped, fitted with suction cups ( 2), cut and if required also profiled and sealed at the developing edges.

In the process step running parallel to the step of feeding the prefabricated rolled goods, a preferably thermoplastic high polymer material B is also fed to the moulding equipment ( 4, 33) in the customary manner This is selected according to one aspect of the invention so that it can fuse together with the high polymer material A This was described above in detail.

Filling in the high polymer material B is performed, for example, via a plastification unit ( 35), ( 44) fitted with a funnel ( 34) The high polymer material B referred to, usually in the form of pellets, granulate or the like, is fed into the funnel ( 34) and flows from there by force of gravity into the preferably heatable plastification unit ( 35), ( 44) where, under heat, a perpetual screw ( 45) kneads the material and feeds it in the direction of the negative moulds ( 46), ( 47) of the moulding equipment ( 4, 33).

Processing the polymer material B in the plastification unit ( 35), ( 44) is carried out in a manner in fact known to the state of the art Additives such as plasticizers, colouring substances or the like can be added at this processing step to the high polymer materal B if desired, which are mixed intimately with the polymer by kneading, thus affecting its properties in the desired manner - depending on the additive.

At the end of the screw operation of the plastification unit ( 35), ( 44) there is a negative mould ( 46) featuring the dies ( 461) corresponding to the subsequent suction cups ( 2) The melted polymer is injected into these moulds The dies ( 461) corresponding to the suction cups are situated in the mould ( 46) of the moulding equipment ( 33) opposite the underside of roll segment ( 43) that was fed in in the processing step described above.

I 10 I I ii IL I 1 I When the two halves of the mould ( 46) and ( 47) of the moulding equipment ( 4, 33) are pressed together, they contain in the cavity created in the centre a roll segment ( 43) that was fed in in the first process step In the next step of the process the suction cups ( 2) formed in the plastification step are injected on to the underside of the roll segments ( 43) under plastification conditions.

Temperatures are used for this that lie within the range of the melting point or the melting points of the polymersuction cups 2 used and which are also dependent individually on the polymers used in each case It is essential to use such temperatures as are useful to the creation of a common melting of the two high polymer materials A and B in accordance with the aspect of the invention described above The suction cups ( 2) formed by the extrusion in the corresponding dies ( 461) are fixed irmly at high pressure on to the underside of the roll segments ( 43) In this way, and in an efficient, economical, and safe manner, the suction cups ( 2) are firmly attached to the underside of the mat material, which later gives a high safety factor to the non-slip plastic mat as per the invention.

At the same time as the step of injecting the suction cups ( 2) under plastification conditions to the underside of the roll segments ( 43) of the plastic mat the mat is cut into the desired form Thus a further process step in setting the desired mat size can easily be omitted.

A popular version of the invention process requires that at least for the underside of the mat and the suction cups ( 2) thermoplastic high polymer materials are chosen, which are made from a monomer corresponding to the same basic monomer type This advantageous version of the process makes it possible according to one aspect of the invention to use high polymer materials A and B that can fuse together, thus leading to a firm fusion between the suction cups ( 2) and the underside of the mat thanks to the similar properties of the materials concerned.

An even more popular version consists in choosing polymer materials made from the same monomer Polymers that can be used for this are in particular those whose maxima of molecular weight distribution lie in the same mass or figure range.

Even more popular is the procedure of choosing equal polymers (A = B), of which the unfoamed high polymer material is used for the suction cups ( 2), the foamed high polymer material however for the body of the mat, at least however for its underside In this connection the usual expanding agents and those known from the state of the art are used.

For the purposes of the invention the procedure of using soft PVC or a polyolefin as high polymer materials has proved especially advantageous Special mention should be made of the polyolefins polyethylene and polypropylene.

Especially popular for the suction cups, also good for using with rolled goods, these are modified with other polymer materials, such as EPDM (ethylene-propylene-diene- terpolymers) These and also the other usable high polymer materials can contain the usual additives such as plasticizers, colorants or the like in order to modify their properties in a manner appropriate to the application.

For the purposes of the invention the invention-related process for high polymer materials is used, whereby the body of the mat or at least its underside consists of a PVC foam foil and the suction cups ( 2) of soft PVC Rubber- modified polyolefin, especially polypropylene is also suitable for the body of the mat and for the suction cups ( 2) polyolefins such as polyethylene, polypropylene or their copolymers or appropriately rubber modified polyolefins and/or their compounds according to specifications given above For exampie, PP/EPDM (polypopylene/ethylene-ropylne-diene-terpblyers) are used for the rolled material and for the suction cups.

The temperatures used for the plastification and subsequent injecting of the suction cups to the underside of the mat should not exceed or only slightly exceed the melting points of the polymers so as not to bring about a breakdown of the polymer(s) Usually, depending on the polymer used in each case temperatures are used which lie only slightly above if at all the melting range of the polymer(s).

Usually by means of the invention-related procedure the suction cups ( 2) adhere securely and firmly to the underside of the mat since for both parts of the mat high polymer materials are used, which can undergo fusion together and combine exceedingly well upon cooling.

This situation is shown in detail in figure 4 After the suction cups have been injected on to the underside of the roll segment ( 43) the second negative mould ( 47) of the moulding equipment ( 4, 33) separates from the first negative mould ( 46) driven by the opening and closing mechanism ( 36) of the moulding equipment ( 4, 33), and the appropriate ready, cut roll segment ( 43) is released and if necessary further processed in the following manner.

Conforming to a further aspect of the invention, when using for example certain polymers differing greatly in their chemical and/or physical properties or for especially secure joins between the underside of the mat and the suction cups, to promote adhesion between the underside of the mat and the suction cups, adhesion promoters, or primers, may be used Popular examples of such primers are polyurethane and acrylate primer, as already described above These ought to ensure an improvement in the adhesion between the underside of the mat and the suction cups and also join polymers, whose chemical and/or physical properties prevent a stable fusion between the polymers at least of the underside of the mat and the suction cups In a further, especially popular version one of the said primers ( 48) is used in such a way that it is applied already to the rolled material being fed to the moulding equipment or immediately after the entry of the rolled material into the moulding equipment.

Another popular version conforming to the invention is to provide holes in the non-slip plastic mat that allow water to flow or run through These are inserted before or after the step whereby the suction cups are injected on to the underside of the mat.

in a final procedure, which can also be carried out with special equipment in the moulding equipment, however also seperately from it, the edges of the mat or also if necessary the edges of the additionally supplied holes to allow the water to run through, upon being heated at the same time, can be pressed together and sealed so as to prevent water getting into the foam structure of the body of the mats Moreover, this step stops the edges from fraying and thus wearing quickly upon use.

Claims

1 A non-slip mat comprising one or more flexible, thermoplastic high polymer materials compatible with one another, with a non-slip upper surface and suction cups on the underface, characterized in that the suction cups are injected moulded on to the underface of the prefabricated mat.

2 A mat in accordance with claim 1, wherein the high polymer materials, comprising at least the underface of the mat and the suction cups, are selected such that they are capable of being fused together.

3 A mat in accordance with claim 1 or claim 2, wherein the high polymer materials consist of the same basic type of monomer.

4 A mat in accordance with any one of claims 1 to 3, wherein the high polymer materials consist of the same monomer.

A mat in accordance with any one of claims 1 to 4, wherein the suction cups and at least the underside of the mat consist of the same high polymer material, the suction cups being of unfoamed polymer and at least the underside of the mat being of foamed polymer.

6 A mat in accordance with any one of claims 1 to 5, wherein the high polymer material is polyvinylchloride or a polyolefin.

7 A mat in accordance with claim 6, wherein the high polymer material for the suction cups, and preferably for the mat, comprises a polyolefin, in particular polypropylene, and a thermoplastics elastomer, in particular EPDM.

8 A mat in accordance with claim 1, wherein the underface of the mat and the suction cups, are bonded together by an adhesion agent (primer).

/7- 9 A process for the manufacture of a non-slip plastic mat according to any one of claims 1 to 8, characterized in that the prefabricated material of the mat, which consists, at least on the underface, of flexible, thermoplastic, high polymer material A, is fed in roll form to moulding equipment, ( 4, 33), in which the suction cups ( 2) made of a compatible material B are injection moulded in a thermoplastic state on to the underside of the roll segment ( 43) under plastification conditions, and at the same time the fed-in roll segment ( 43) is cut to the desired shape of the plastic mat.

A process according to claim 9, characterized in that the high polymer materials A and B are selected in such a way that they can undergo fusion together upon heating under injection moulding conditions.

11 A process according to claim 9 or claim 10, wherein for at least the underface of the mat and the suction cups thermoplastic materials are chosen, which consist of the same basic type of monomer, preferably from the same monomer, even more preferably from a foamed high polymer material A and an unfoamed high polymer material B, where A and B are the same polymer.

12 A process according to any one of claims 9 to 11, wherein the high polymer materials A and B are selected from PVC or a polyolefin, preferably polypropylene.

13 A process according to claim 12, wherein high polymer material B is soft PVC, and high polymer material A is PVC foam foil.

14 A process according to claim 12, wherein a polyolefin, in particular polypropylene, optionally rubber-modified is used as high polymer material A, and a rubber-modified polyolefin, in particular polypropylene, preferably PP/EPDM, is used as high polymer material B. t 8- A process according to claim 9, wherein an adhesive promotor or primer is used for the promotion of adhesion between the polymers of at least of the underface of the mat and the suction cups.

16 A process according to claim 15, wherein the adhesion promotor or primer is a polyurethane or acrylate primer.

17 A process according to any one of claims 9, 15 and 16, wherein the roll of polymer material being fed to the moulding equipment ( 4, 33) is pre-treated with primer, or primer is applied to the rolled polymer material immediately before the entry into the moulding equipment ( 4, 33).

18 A process according to any one of claims 9 to 17, wherein holes are provided in the mat to let water flow or run through.

19 A process according to any one of claims 9 to 18, wherein the mat edges are heat sealed under pressure.

Published 1992 at The Patent Office Concept Hou Cardt S Road Newport Gwent NP 9 IRH Further copies may be obtained from a Branch Unit 6 Nine Mile Point Cwmfelinfach Crnss Kev f WD 7 W 7 Te my 7 b eo btaine f V LWUL Uple X techniques Ita St Mary crav Kent.

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