STRUCTURE TECHNOLOGY

Adhesion – Adhesion refers to the sum of all forces which occur at the interfaces between two substrates, e.g. a sur-face to be bonded and a pressure- sensitive adhesive. The measurable bond strength of adhesion results from the combination of these physical interactions and the energy dissipation from the pressure-sensitive adhesive’s viscoelastic properties.  

A particular form of adhesion is the tack, which determines whether an adhesive mass can quickly wet a surface with which it comes into contact with virtually no pressure. But the tack does not ultimately correlate with the actual bond strength of a pressure- sensitive adhesive. Pressure sensitive adhesives with a low tack are capable of withstanding high stresses when high final adhesive strength and/or high shear strength are formed. Therefore, the thumb test (or even fin- ger tack) is not suitable for drawing conclusions about the bond strength of a pressure sensitive adhesive. 

Cohesion – For the adhesive bond to stay intact, sufficient cohesion (internal strength) of the pressure-sensitive adhesive is required. The cohesion of a pressure-sensitive adhesive describes the elastic behaviour of the adhesive, which in turn has an impact on the shear strength or restoring forces of a bond. 

Adhesive strength – Adhesive strength is described by the interplay of adhesion and cohesion, i.e. only through a certain combination of adhesion and internal strength is an adhesive bond able to withstand the stresses that act on it. 

Surface tension and energy – In order to achieve sufficient contact points for the formation of high adhe- sion forces, the pressure-sensitive adhesive must be able to sufficiently wet the substrate to be bonded. Wetting largely depends on the surface tension or energy of the substrate and the pressure-sensitive adhesive. 

A pressure-sensitive adhesive is generally able to wet-out a substrate if the substrate’s surface energy is greater than or equal to that of the adhesive. The higher the wet-out, the more contact points are available to form a bond between two surfaces. As a first indication one can use a water droplet to differentiate between high and low surface energy substrates. If the droplet forms a film, this points to a high surface energy. On the other hand, if it stays a droplet or drips off, it points to a lower surface energy than water. In this case, bonding to the substrate may be difficult. More accurate results are achieved with so-called test inks, which are also available in pen form. The surface energy is given in mN/m, dyn/cm or sometimes also in mJ/m2, whereby: 1 mN/m = 1 dyn/cm. The boundary between low-energy and high energy surfaces is usually drawn in the range of a surface energy of 36 – 38 mN/m. Therefore, the bondability for surface tensions above this range is usually problem-free, whereas at values below this range a pretreat- ment of the surface to be bonded should be considered. 

Initial and ultimate peel adhesion – Due to the viscoelastic character of an adhesive tape the peel adhesion increases over time. The time needed to achieve the ultimate peel adhesion strongly depends on factors such as the type of adhesive mass, tempera- ture, contact pressure and substrate. This behavior is described as the initial and ultimate peel adhesion. The figure on the right shows, both synthetic and natural rubber pressure sensitive adhesives require less time to reach the ultimate peel adhesion than acrylic-based pressure sensitive adhesives. As a rule of thumb, it takes 72 hours to achieve the ultimate peel adhesion of acrylic adhesives. With the use of a bonding agent (adhesion promoter) the time needed to achieve the ultimate peel adhesion is typically reduced.  Higher temperatures also significantly reduce the time needed to achieve the ultimate peel adhesion. At lower processing temperatures, a much longer time is once again required to achieve the ultimate peel adhesion.  

Product structure – All adhesive tapes consist essentially of a backing material and at least one self-adhesive layer of adhesive. The product structures shown on the right are typical for single-sided and double-sided adhesive tapes.  The adhesive and backing materials are adapted to the specific application requirements of each adhesive tape solution. Examples of adhesive masses are acrylics, natural rubber and synthetic rubber. Examples of backings are film, paper, tissue and foam. In order to help you choose the appropriate adhesive tape, we offer product ranges for the various fields of application. These include, for example, adhesive tapes for surface protection, masking, bundling and permanent bonding in the automotive, electronics, construction or furniture industries.

APPLICATION

• Primary electrical insulation
• Harnessing
• Protection for low and medium voltage cables splices
• Typically engineered for the professional requirements of telecom and electricity boards
• Automotive electrical wire harness wrapping

PRODUCT BENEFITS

Some of the features and benefits of using RUBAN-NOIR 

Extreme Duty Polyvinyl Chloride Soft Tape are:

• Excellent resistance to abrasion, corrosion, moisture
• High dielectric strength and mechanical protection
• Excellent conformability
• Suitable for indoor and outdoor applications
• Provides higher voltage break-down and mechanical protection

PRODUCT PROPERTIES

• Branding: EMAAR ENERGY
• Color: Clear, Black, Blue, Red, Yellow…
• TCVN 2284-78:
  • Thickness: 0.17 mm, 0.19 mm, 0.25 mm
  • Length: 10m, 20 m, 30 m, 50 m, 80 m
  • Width: 15 mm, 18 mm, 20 mm, 25 mm, 30 mm, 45 mm
  • Minimum Breaking Strength: 27 N/cm to 49,4 N/cm
  • Elongation @ break point: ≥ 160%
  • Adhesion strength to steel: 2,4 N/cm to 4,1 N/cm
  • Adhesion strength to back: 2,4 N/cm to 4,1 N/cm
  • Dielectric @ dry: ≥ 7 kV/mm
  • Dielectric @ wet: ≥ 6,3 kV/mm Heat resistance 100ºC within 4 hours: Passed
  • Insulation resistance: ≥ 2,4 x 109 Ω
  • Flammability: Pass (burn stop @ < 3,1s) 

RECOMMENDATIONS

Care should be taken to avoid direct contact between the tape and petroleum-type solvents and oils. Oils may affect the electrical properties of the tape.

The rolls should be stored flat on their cut edges in the original packaging. The product must be protected from dust, heat, moisture, direct sunlight and solvent fumes. Storage temperature between +10°C and +25°C.

Under these conditions, the storage life of the tape in a temperate climate will be at least five years.