Renault D41 1108 Material Specification - Test Procedure

The “Renault D41 1108 Material specification - Test procedure” standard, developed by the French automobile company Renault, includes procedures for the following types of materials:

• Body shop material (adhesives, sealants and similar)
• Paint shop material (sealer, UBC and similar)
• Trim workshop material (gluing, sealing and the like)

The purpose of this test method is adhesive and binder characterization of crosslinkable, gelable or self-drying materials in the body shop, paint shop or trim shop (sealant, bonding, UBC, setting material and similar).

When performing this procedure, in principle, a parallel-sided adhesive bond is applied between two supports and baked if necessary. The test piece is subjected to tensile-shear stress under time and temperature conditions specified by normative documents. The bond is characterized by the type of stress and rupture (adhesive or bonding).

The primary material used in these tests includes:

• The material of the supports is defined in the normative documents, and their geometry in the annex to this standard (Annex A). The surface is prepared according to the indicators specified in the normative documents.
• The oil set is made of polytetrafluoroethylene (PTFE) with a thickness of 0,2 mm, 2 mm, 5 mm or any other thickness specified in normative documents.
• The shim set consists of aluminum or steel of equal thickness to the supports + clamping or realignment jaws.
• It consists of a 4 mm screw assembly, associated washers and nuts or any other device used to block the PTFE shim between the supports.
• A tensioning machine is a machine that has a self-tightening jaw, a dynamometer, and the following features:
  • The moving jaw speed is set at 10 mm/min plus/min 2 mm/min.
  • It has a load scale of 10 to 1 000 daN depending on the type of product inspected.
• Spatula or preferably a piece of equipment used for product extrusion.
• Knife.
• The ventilation oven is used to bake the product if necessary. Its atmosphere can be adjusted up to 250 degrees plus/minus 2 degrees according to the curing condition specified in the normative document.
• The conditioned room is conditioned to a temperature of 23 degrees plus/minus 2 degrees and a relative humidity of 50 percent plus/minus 5 percent.
• Special apparatus (glass supports)
• Product for degreasing supports (excluding regreased layer), (e.g. heptane).
• Crosslinkable, gelatinous or self-drying material.

The test is repeated three times per curing or drying condition.

The geometry of the adhesive joint depends on the product to be inspected. Unless specific instructions are given, the thickness specified in the normative documents is:

• Procedure A: 0,2 mm (with 12,5 mm plus/minus 0,5 mm overlap) for bonding products
• Procedure B: 2 mm (with 20 mm plus/minus 0,5 mm overlap) for products with lower mechanical properties
• Procedure C: 2 mm (with 12,5 mm plus/minus 0,5 mm overlap) for thin shop bonded products
• Procedure D: 5 mm (with 12,5 mm plus/minus 0,5 mm overlap) for glazing products

Each test piece is prepared as follows:

• The receiver bracket, screws and shims are positioned as shown in the standard insert.
• To prevent air bubbles from forming at the joint, the required amount of product is placed between two wedges using a spatula or preferably an extruder. The placed bead should be round or triangular in shape and there should always be an excess after mating.
• The assembled support is placed in place, the product is pressed until it comes into contact with the shims to obtain a slight overhang over the entire gluing width, taking care that the supports are still parallel.
• Washers and nuts are installed and then the assembly is locked with medium force.

The test piece thus obtained and held in a horizontal position is baked or dried for the periods specified in the normative documents. After drying or cooling, the nuts are unscrewed and the screws and shims are removed by sliding. After resting for 24 hours in the conditioned room or after being subjected to one of the aging processes specified in the normative documents, the test pieces are cleaned with a knife from lateral adhesive overflows due to slight flow or swelling during baking or drying.

The shear strength test is carried out at room temperature or at any other temperature specified in normative documents according to the following procedure:

• The test piece is fixed vertically and centred between the jaws of the dynamometer, with a distance of 50 mm between them and the connection edges. If suitable (realignment) jaws are not available, a shim is placed on the connection side between the jaw and the support. For example, a 1 mm shim is used for 0,2 mm thick supports and 1,2 mm connections.
• The test piece is pulled until it breaks.
• The force “F” corresponding to the rupture is read on the dial or recorder.
• All broken test pieces are retained.

Among the numerous tests, measurements, analyses and evaluation studies that our organization has carried out for businesses in various sectors, it also provides testing services defined in the “Renault D41 1108 Material properties - Test procedure” standard with its trained and expert staff and advanced technological equipment.