PLASTIC MATERIAL AND A METHOD FOR MAKING THE SAME

Abstract: A material to be used as an impact-absorbing, warming, flotation, padding, or similar material (1), comprising a plastic-based basic substance, particularly a cellular plastic, with holes to reduce its sweatiness or for other purposes. According to the invention, the holes (2) have at least one cut (3), to permit the hole/cut to be spread. The interior (2) of the holes, which has been cut away but has remained in place, can be easily detached by spreading the material, when the cutaway part will drop out by itself, or with the aid of a suitable mechanical operation, such as blowing with compressed air.

Description: Plastic material and a method for making the same The present invention relates to a plastic material and a method for making the same. The plastic material is particularly a cellular plastic, for example, a closed- cell plastic, from which various paddings, impact absorbers, or flotation materials and similar are made. Attempts have been made particularly to make materials intended for the above purposes breathable, either by slitting them, as disclosed in Finnish patent applica- tion 972210 or by perforating them. Holes are made conventionally at suitable distances according to a regular pattern in a sheet-like material of suitable thickness. A serious drawback in making perforated materials in that, while the annular cut required by the desired hole can certainly be easily made in many different ways, it is extremely difficult to remove the cut piece to open the hole. This is naturally mainly due to the material, which 'grips' the cut-away piece of material, tending to hold it in place. The holes have therefore had to be opened by practically manual cleaning. Obviously, modern production cannot afford manual work, if an automa- ted system is possible. The present invention is intended to improve both the product and its method of manufacture. Thus, according to the invention, a product is achieved, which is less sweaty than before, with perforations that can be easily cleaned by means of the method according to the invention. The benefits and advantages referred to above and others are achieved in the manner stated in the characterizing section of the accompanying Claims. The invention is described in greater detail with reference to the accompanying drawings, in which Figure 1 shows a material according to the invention after suitable cuts have been made in it and Figure 2 shows the same material in a state in which the cut-away inner parts of the holes are being removed. Figures 1 and 2 are self-explanatory. Annular cuts, the interiors 2 of which form cylindrical pieces that must be removed to form a hole, are stamped or otherwise made in a sheet-like material 1. Of course, the shape of the piece to be removed can be some other than that of the circular hole shown. According to the invention, removal is assisted by making a cut 3 on at least one side of hole 2 being formed, though if desired a cut can be made on both sides of the hole. Figure 2 shows how cut 3 is opened by spreading material 1 to the sides, providing free space for the cutaway interior 2 of the hole, which can be easily removed by shaking or, for example, using compressed air. When the material is being spread, interior 2 may drop out with no mechanical assistance at all. However, its electrical properties may make it cling to the edge of spread cut 3, from which it can be easily detached by, for instance, using compressed air. It is obvious that the said method and material can be applied to many non-rigid basic materials, in which similar problems appear. However, cellular plastic appears to be the most usually manufactured of such materials, so that the need to develop the method and product is greatest in connection with it. It is obvious that the invention can be varied in many ways. For example, the hole to be formed can in principle be any shape whatever. If it is wished to use the method to form decorative holes, it will work quite as well as for round holes. Cuts 3 may be on either or both sides of the holes and may run in a direction other than the longitudinal direction of the piece of material. In they run transversely, stret- ching must take place longitudinally. Slanting cuts 3 will function in the said manner without difficulty. A product manufactured according to the invention is suitable for any use, in which, for example, it comes in contact with or close to the skin, when its sweatiness will become an important factor. Breathability can be improved by using slits in addition to perforations.

Claims: Claims 1. A material (1) to be used as an impact-absorbing, warming, flotation, padding, or similar material, and comprising a plastic-based basic substance, particularly cellular plastic, and holes to reduce its sweatiness or for other purposes, characterized in that the holes (2) to be formed also include at least one cut (3) to permit the hole/cut to be spread. 2. A material according to Claim 1 , characterized in that each hole (2) includes two cuts (3) starting from either side of it. 3. A material according to Claim 1 , characterized in that the cuts (3) run in essentially one direction and start from the holes (2) in essentially opposite directions. 4. A material according to Claim 1 , characterized in that the holes (2) are round or of a desired shape. 5. A method for making an impact-absorbing, warming, flotation, padding, or similar material (1), comprising a plastic-based basic substance, particularly cellular plastic, with holes to reduce its sweatiness or for other purposes, characterized in that at least one cut (3) is made in the material, in connection with or after the stamping or other manufacture of the holes (2), to permit the hole/cut to be spread. 6. A method according to Claim 5, characterized in that during the manufacture of the holes, the cutaway interior (2) of the hole is removed by spreading the material, when the cut/hole will open and release its grip on the cutaway interior. 7. A method according to Claim 6, characterized in that the cutaway interior of the holes is finally detached by mechanical shaking, by blowing with compressed air, or in another suitable manner.

Inventors: LAAKSONEN KARI, LAAKSONEN, KARI
Applicants: FAGERDALA TUOTANTO OY, LAAKSONEN KARI, LAAKSONEN, KARI
Application year: 2000
Main classification: A47C7
IPC codes: A47C21