Technical Data on PE Film Dedicated to Solvent-Free Lamination

PE film blown with SF solvent-free dedicated anti-block and slip masterbatch is suitable for curing solvent-free laminated products at relatively high temperatures (e.g., 40°C), effectively solving the industry-wide phenomenon of increased coefficient of friction in PE solvent-free lamination. The test data are as follows:

[Multiple solvent-free adhesives in the industry were used for testing at different coating weights under relatively high curing conditions, and relatively ideal COF results were obtained in all cases, sufficient to cover different application conditions, demonstrating the technical versatility of the solution.]

Test Data 1

Film blowing: PE28μ; the corona layer and middle layer use low-slip pellets; heat seal layer formula: Carter 0274, Sekco 0220KJ and Dow 5401J at 1/3 each, +3.0 SF anti-block and slip masterbatch.

Solvent-free lamination: VMPPET/PE28μ, a certain domestic solvent-free adhesive 1#, adhesive coating weight 1.8 g/m2, cured at 40°C for 24 h. The COF of the laminated film is shown in Table 1.

Table 1 COF data of the laminated film

VMPPET/PE28μ

Solvent-free dedicated formula

PE base film, Us/Ud

0.2/0.193

0.175/0.163

After curing, Us/Ud

0.279/0.232

0.567/0.509

Switching to a certain domestic solvent-free adhesive 2#, adhesive coating weight 1.5 g/m2, cured at 40°C for 24 h. The COF of the laminated film is shown in Table 2.

Table 2 COF data of the laminated film

VMPPET/PE28μ

Coefficient of friction, Us/Ud

PE base film (tested 18 days after film blowing)

0.175/0.164

Tested immediately after 24 h curing

0.258/0.224

Tested after one day

0.237/0.229

Tested after seven days

0.181/0.175

Using a certain solvent-free adhesive with the largest market share among well-known domestic brands, adhesive coating weight 1.65 g/m2, the COF data after curing at 40°C for 24 h and 48 h are shown in Tables 3 and 4.

Table 3 COF data of the laminated film

Lamination structure: PA15μ/PE28μ

Coefficient of friction, Us/Ud

PE28µ base film

0.175/0.177

Solvent-free laminated film (PA/PE28µ) after curing at 40°C for 25 h (room temperature 25°C)

0.225/0.236

0.213/0.216, 0.216/0.217

0.249/0.227, 0.224/0.225

Table 4 COF data of the laminated film

Lamination structure: PA15μ/PE28μ

Coefficient of friction, Us/Ud

PE28µ base film

0.175/0.177

Solvent-free laminated film (PA/PE28µ) after curing at 40°C for 48 h

(room temperature 25°C)

0.266/0.247

0.230/0.219, 0.243/0.215

0.231/0.216, 0.230/0.220

Stored for 20 days

0.215/0.210, 0.213/0.208

It can be seen that this product performs well in solvent-free lamination of ultra-thin PE even under relatively harsh process conditions.

Test Data 2

Film blowing: PE45μ; the corona layer and middle layer use low-slip pellets; the heat seal layer uses medium-slip pellets +2.5% SF solvent-free dedicated anti-block and slip masterbatch.

Solvent-free lamination: PET12μ/PE45μ, a certain foreign-brand solvent-free adhesive 4#, adhesive coating weight 1.2 g/m2 (estimated based on a transfer roller speed of 55%), cured at 40°C for 24 hours. The COF of the laminated film is shown in Table 5.

Table 5 COF data of the laminated film

PET12/PE45μ

Coefficient of friction, Us/Ud

Solvent-free formula

Conventional formula 1#

Conventional formula 2#

COF of PE base film

0.17/0.176

0.171/0.179

Tested after 24 h curing

0.237/0.229

0.368/0.357

0.460/0.472

Tested after one day

0.245/0.206

0.407/0.417

0.422/0.412

The strength tests of the solvent-free formula PE laminated film are as follows:

① Peel strength (N/15mm), TD: 4.45; MD: 3.35, 3.28

② Heat seal strength (N/15mm), MD: 43.46, 37.26

Using a certain solvent-free adhesive with the largest market share among well-known domestic brands, adhesive coating weight 1.65 g/m2, the COF data after curing at 40°C for 24 h and 48 h are shown in Tables 6 and 7.

Table 6 COF data of the laminated film

Lamination structure: PA15μ/PE45μ

Coefficient of friction, Us/Ud

PE45µ base film

0.182/0.186

Solvent-free laminated film (PA/PE45µ) after curing at 40°C for 25 h (room temperature 25°C)

0.230/0.227

0.250/0.229, 0.257/0.232

0.229/0.224, 0.219/0.221

Table 7 COF data of the laminated film

Lamination structure: PA15μ/PE45μ

Coefficient of friction, Us/Ud

PE45µ base film

0.182/0.186

Solvent-free laminated film (PA/PE45µ) after curing at 40°C for 48 h (room temperature 25°C)

0.219/0.209, 0.217/0.210

0.240/0.226, 0.230/0.222

0.203/0.209, 0.220/0.210

Stored for 20 days

0.234/0.216, 0.212/0.212

Test Data 3

Film blowing: PE65μ; the corona layer and middle layer use low-slip pellets; the heat seal layer uses medium-slip pellets +2.0% SF solvent-free dedicated anti-block and slip masterbatch.

Using a certain solvent-free adhesive with the largest market share among well-known domestic brands (model WD8118), adhesive coating weight 1.65 g/m2, the COF data after curing at 40°C for 24 h and 48 h are shown in Tables 8 and 9.

Table 8 COF data of the laminated film

Lamination structure: PA15μ/PE45μ

Coefficient of friction, Us/Ud

PE65µ base film

0.177/0.184

Solvent-free laminated film (PA/PE65µ) after curing at 40°C for 25 h (room temperature 25°C)

0.260/0.233

0.232/0.216

0.215/0.211, 0.225/0.215

Table 9 COF data of the laminated film

Lamination structure: PA15μ/PE45μ

Coefficient of friction, Us/Ud

PE65µ base film

0.177/0.184

Solvent-free laminated film (PA/PE65µ) after curing at 40°C for 48 h (room temperature 25°C)

0.239/0.228

0.222/0.214, 0.224/0.217

0.217/0.207, 0.214/0.204

Stored for 20 days

0.1930.181, 0.189/0.184

5.3 Technical Features

5.3.1 The COF of the PE base film is 0.15-0.2, providing good slip performance but not excessive slip, which is conducive to solvent-free lamination winding.

Note: It should be distinguished from ordinary polyethylene films with added conventional slip and anti-block agents; the slip of the base film is not necessarily related to the slip of the solvent-free laminated film.

5.3.2 After solvent-free lamination, the COF of the PE base film increases only slightly, and the anti-block and slip properties are good. After curing is completed, the COF drops to a stable equilibrium state within 2-3 days, without significant fluctuation.

Note: Ordinary polyethylene films with added conventional slip and anti-block agents have very good slip before solvent-free lamination, but under test conditions of a relatively higher curing temperature (e.g., 40°C) or a larger adhesive coating weight, the COF increases abnormally and the performance is unstable.

5.3.4 For dry lamination products, the additives will not migrate to the corona surface and cause poor peel strength, and good anti-block and slip properties are achieved one day after curing is completed, making it versatile for both dry lamination and solvent-free lamination.

Note: When ordinary polyethylene films with excessive conventional slip and anti-block agents are used in dry lamination, poor peel strength usually occurs, with obvious quality risks.