Лако-красочные материалы — производство

A typical cure curve for 100-cP methyl cyanoacrylate is shown in Fig. 5. The speed of cure is influenced by the thickness of the bond, the activity of the surface, and the designed speed of the adhesive.

1. Versatile. There are few materials to which cyanoacrylate will not bond/adhere, even dissimilar materials (polyethylene, polypropylene, and Teflon are some materials that require pretreatment).

2. One-component without solvent, therefore easily dispensed.

3. Economical. A small drop goes a long way. It is important to apply the least amount for maximum strength (see Table 3).

The following equivalents are for application of the adhesive to actual parts.

1 lb = 30,000 bonds 1 in. square and 1 mil thick

1oz= 1,875 bonds 1 in. square and 1 mil thick

2g = 132 bonds 1in. square and 1mil thick

Table 3 Approximate Conversion Chart for Estimating Usea

1 drop = 0.006 g 2 drops = 0.012 g 5 drops = 0.030 g 10 drops = 0.060 g 50 drops = 0.300 g (3 g)

167 drops = 1.00 g 330 drops = 2.00 g 4,666 drops = 1 oz

75,500 drops = 1 lb

aBased on the assumption that 1 drop = 0.006 g.

Cyanoacrylate adhesives have limited gap-filling capability (see Fig. 6). Low — viscosity grades can fill gaps to approximately 2mils, medium viscosity up to 10mils, and high viscosity up to 15 to 20mils. However, note that the speed of cure will be slower and the ultimate strength lower as the gap increases. For example, when the gap is 15 mils it requires 1 h for sufficient handling strength, but with a gap of 1 mil it takes only 10 s. Cure speed can be increased by the use of a chemical accelerator. Moisture and water resistance is limited. Resistance against water, although poor when two rigid parts are bonded, is markedly improved when at least one of the two parts is flexible.