Part I.  Industry Challenges

1.1  Requirements in High-Temperature Industrial Environments

In industries such as electronics manufacturing, high-temperature spray coating & curing, automotive harness processing, and industrial production lines, masking tapes and harness-fixing tapes face extremely stringent requirements. Under sustained high-temperature baking, hot-air circulation, and thermal radiation conditions, products must maintain dimensional stability with zero adhesive bleed-out, zero displacement, and zero residue upon removal — delivering both structural integrity and surface cleanliness.

1.2  Shortfalls of Conventional Materials

Conventional SIS-based and standard hot melt adhesive systems suffer from insufficient heat resistance and cohesive strength. Under elevated temperatures, high melt flowability and poor creep resistance lead to tape shrinkage, edge lifting, adhesive bleed-out, and bonding shift. Residual adhesive after removal significantly increases cleaning labor costs and reduces production yield.

1.3  The Core Performance Contradiction in Conventional SIS

The industry has long faced an unresolved trade-off:

● High-styrene SIS offers superior heat resistance and cohesion, but excessive stiffness causes die-cutting issues — stringing, blade sticking, and unclean cut edges.

● High-diblock SIS provides good die-cuttability, but poor heat resistance and low cohesion lead to deformation and flow at elevated temperatures.

No conventional grade can simultaneously satisfy high-temperature stability and precision die-cutting without residue. The grade described below was developed precisely to resolve this contradiction.

 

Part II.  How the Custom SIS Achieves Its Performance Balance

2.1  High Styrene Content — High Cohesion, High Heat Resistance, Low Flow

A styrene hard-segment content of approximately 30% significantly increases the physical crosslink density and structural rigidity of the polymer, delivering tensile strength of ≥17 MPa and exceptional cohesion. Combined with a low melt flow index, the material exhibits outstanding resistance to flow and creep at elevated temperatures — maintaining stable adhesive layer structure with zero bleed-out, deformation, or displacement, and excellent long-term dimensional stability.

2.2  High Diblock Content — Precise Brittle Fracture for Clean Die-Cutting

A diblock content of approximately 30% — rarely achieved in the industry — breaks the long-standing barrier that high-heat-resistant materials cannot be cleanly die-cut. While retaining high cohesion and heat resistance, the elevated diblock ratio imparts a controlled brittle-fracture characteristic: cut edges are clean and flat with no stringing or blade-sticking, and removal from work surfaces leaves zero residue.

2.3  The 1:1 Golden Ratio — Resolving Multiple Competing Properties

By engineering a 1:1 balance between styrene content and diblock content, this grade simultaneously eliminates the traditional contradiction of 'high cohesion = difficult die-cutting' versus 'easy die-cutting = poor heat resistance.' The result is a single material that delivers high hardness, high strength, low flow, high heat resistance, easy die-cutting, and zero residue — far exceeding the overall performance of standard general-purpose SIS grades.

 

Part III.  Target Applications & Substitution Value

3.1  Primary Application Scenarios

This grade is optimized for the following applications:

● High-temperature masking tapes — electronics thermal curing, spray coating protection, PCB assembly

● Automotive harness tapes — high-temperature wire bundling and fixation in engine bays and body assemblies

● Industrial process tapes — masking in powder coating, anodizing, and precision painting lines

● Specialty modification — heat-resistant modification of engineering plastics and asphalt systems, improving thermal stability and structural strength

3.2  Import Substitution Value

This grade is a direct replacement for imported low-flow, high-heat-resistance specialty SIS grades, eliminating high cost, long lead times, and supply instability. It matches or exceeds the physicochemical performance of imported counterparts, making it the preferred domestic solution for premium high-temperature adhesive and specialty modification applications.