DE-102024003686-A1 - Staircase renovation step with optimized edge joint and milling shape for preparing the underside of an SPC panel for direct heating of the milling groove and edge to obtain a staircase renovation step made of SPC material.

DE102024003686A1DE 102024003686 A1DE102024003686 A1DE 102024003686A1DE-102024003686-A1

Abstract

A carrier board for stair renovation is provided with at least one groove on its inner surface to form the respective step. The groove is rounded at its apex, or has a semicircular or lens-shaped profile, and is cut into the carrier material only to a depth that leaves 2 mm of the carrier material to stabilize the resulting edges. Two grooves are milled parallel to each other on the carrier board, one on the right and one on the left. After the material is bent at a 90° angle in the area of these grooves, a renovation double step is created. By creating rounded V-shaped grooves, directly heating these groove areas while simultaneously cooling the surrounding areas, and bending the groove areas with the remaining carrier material and the decorative layer, a stable double step is created. This minimizes waste and yields two steps that can be installed on-site onto existing stair treads. If more than two grooves of this surface structure are made parallel in the bending area of the stair tread, each of these grooves only supports a partial bend of the base plate up to the 180° angle being reached. The stresses that arise in the material due to the bending process are thus minimized, so that cracking or breaking of the stair tread is largely avoided.

Inventors

Sven Hoffmann
Sascha Limpek

Assignees

HAFA TREPPEN GMBH

Dates

Publication Date: 20260513
Application Date: 20241111

Claims (12)

A renovation step made of SPC carrier material with a decorative surface coating such as vinyl, which is used for stair renovation, characterized in that the material thinning necessary for its chamfering on the inside of the carrier board is formed by means of at least one groove with a rounded apex extending through at least a partial area of the carrier board.
Thinning of a support plate running in a line for a stair renovation step after Claim 1 , wherein the groove-shaped thinning extends through the base material of the carrier plate in a V-shape with a rounded apex, semicircular or lenticular shape,
Groove-shaped thinning according to one of the preceding claims, characterized in that the groove-shaped thinning does not remove at least 2 mm of the carrier layer or the decorative layer.
Groove-shaped thinning in a support plate for a stair tread according to one of the preceding claims, wherein the groove-shaped thinning is interrupted by at least one web extending transversely to the groove.
Groove-shaped thinning in a carrier plate for a stair tread according to Claim 1 until 3 , wherein the groove-shaped thinning is interrupted by at least one, but at most 8, webs running transversely to the groove.
Groove-shaped thinning of a support plate for a stair tread according to one of the preceding Claims 1 until 3 , wherein the apex of the milling head is rounded off by at least 2 mm at its tip.
Groove-shaped thinning of the support plate for a stair tread according to Claim 1 until 3 , where the radius of the rounding at the apex of the milling head is at least R 4.
Renovation stair tread with rounded apex of the groove in the area of the chamfer.
A method for manufacturing a renovation stair tread by thermal forming according to one of the preceding claims, comprising the steps of: a) creating a groove, rounded at its apex, into the surface of the back of a support plate b) bending the groove-bearing side of the support plate, wherein the area of the bend is partially heated to 130 to 140 degrees Celsius for 64-68 seconds and the edge areas of the groove are simultaneously cooled to a constant 17-24 degrees Celsius.
Procedure according to Claim 9 , where step b) is carried out in an ambient temperature range of 16 to 25 °C.
Procedure according to Claim 9 , wherein the groove is produced with a milling head with a rounded head of radii R 4 to R 6.
Procedure according to Claim 9 , whereby the rounded groove cuts into the carrier layer only up to 2 mm before its connection with the adjacent decorative layer.

Description

The invention relates to a stair renovation step made of stone-powder composite core material, with or without a decorative surface coating. The invention relates to the milling required on the underside of the stairs to allow the stone-powder composite panels to be bent to form stair renovation steps. DESCRIPTION Technical field The present invention relates to a special stair renovation step used for the renovation of existing stairs, particularly worn, old, or unsightly ones. In this process, at least one chamfer is formed from a base plate of the material forming the new stair tread surface, enabling the creation of the corresponding stair tread. The base material of the carrier plate from which the stair renovation step is formed can consist of wood, wood fiberboard (HDF or MDF), plastics, or mixtures thereof. Such plates are typically provided with a decorative tread surface made of plastic such as laminate, vinyl, or composite materials. Another particularly durable carrier plate material is a stone powder composite (SPC) material, in which the carrier plate is formed from a plastic mixture containing stone powder/stone flour. Here, too, the tread surface is provided with special decorative finishes to better blend visually into the surroundings of the stairs being renovated (hallways, landings, handrails, etc.). Before the area of the support plate to be bent is shaped under heat according to the dimensions of the individually manufactured stair tread or according to a grid pattern, the bending point must be prepared accordingly. Such manufacturing processes are established as state of the art and are described, for example, in the patent specification. US 2023/0020659 A1 or from the German utility model 20 2023 000 633.3 known. To maintain stability at the bending point/front edge during the bending process, a portion of the core material is bent along with the core material, according to the invention. For this purpose, a portion of the core material is removed from the back of the SPC panel, leaving a portion intact. It has been found that a specific milling shape must be selected for this partial removal of the core material to prevent the remaining material, particularly the decorative surface material, from tearing during bending and to avoid production defects. Depending on the building's requirements, a wide variety of stair tread designs can be provided and renovated. Besides the classic rectangular or square treads, trapezoidal, triangular, quadrilateral, and pentagonal tread shapes are available for non-straight or spiral staircases. STATE OF THE ART To renovate old, unsightly, and worn staircases, standard renovation treads are applied to the existing steps. These treads are made from wood-based materials such as HDF/MDF core boards, which are coated with a decorative finish. This method allows staircases to be renovated with the same decor as adjacent areas such as landings, hallways, and rooms. The decorative layers of the flooring and the renovation elements can be identical. This prevents any discrepancies in decor and creates a uniform appearance between the staircase and the surrounding design. Special connectors (tongue-and-groove joints) ensure a smooth transition from the stair landing to the landing and the stairwell. Standard renovation elements made of wood-based materials are sensitive to moisture, flammable, and have a relatively low material density, which can lead to limited durability. Although many stair panels available on the market are made from low-swelling core materials and are therefore generally low-swelling, moisture penetration into the stair, or exposure to moisture, especially over the long term in consistently high humidity, can lead to swelling of the core panel and deformation of the newly installed renovation stair. Consequently, these stair panels are only suitable for use in dry interior spaces and largely dry environments without elevated humidity. The renovation stair panels are offered with various decorative surface coatings such as CPL, laminate, or PVC vinyl. The production processes for bonding the surfaces to the core material and then manufacturing a renovation stair panel using a postforming process are complex and require high-quality workmanship. The adhesive bonds are also susceptible to failure and can deteriorate prematurely if there are problems with one of the adhesives used, variations between batches of adhesives, or if the processing instructions are not followed precisely. Any minor change in the base material or auxiliary materials used (e.g., batch variations in the adhesive or due to a change of supplier) can negatively affect the molding process of the stage or the durability of the molded stage. Material deviations often necessitate new, extensive tests and long-term tests, particularly of the adhesive bonds. This is required. The so-called postforming process therefore harbors a multitude of potential sources of error. To sta