닐스 로고

• 목록
• 답변
• 글쓰기
• 게시판 리스트 옵션
  • 수정
  • 삭제

The thermal conditions applied during polymer manufacturing plays a fundamental role in shaping its mechanical and chemical characteristics. When polymers are subjected to high temperatures during manufacturing processes such as extrusion, injection molding, or thermoforming, they are exposed to thermal energy that can cause irreversible polymer reactions. If the temperature is beyond the material’s limit or the material is held at elevated temperatures for too long, chemical deterioration becomes inevitable. This degradation often appears as molecular fragmentation, where the long polymer chains undergo cleavage into low-mass units. As a result, the material may experience reduced tensile and impact resistance, become brittle, or exhibit yellowing or browning.

Thermal stability varies significantly across polymer families. For example, HDPE, LDPE, or LLDPE can tolerate higher processing temperatures compared to polyvinyl chloride, which degrades prematurely at moderate heat and may emit toxic fumes such as HCl. Even within the single polymer type, formulation components like antioxidants, UV inhibitors, or lubricants can significantly alter thermal resistance. Without proper thermal stabilizers, some polymers may break down prematurely under temperatures deemed non-damaging.

Chemical breakdown may remain undetected at first. In some cases, the material seems unaffected upon cooling, but after prolonged exposure, especially when exposed to sunlight, the weakened structure becomes apparent. This latent degradation can lead to safety incidents or regulatory violations in critical applications like medical devices or automotive parts.

To prevent thermal damage, manufacturers must optimize heating and cooling cycles. This includes calibrating extruder zones and تولید کننده کامپاند پلیمری cavity heat settings, limiting exposure duration above threshold levels, and applying controlled quenching methods. Monitoring the melt flow index before and after processing can also provide quantitative indicators of molecular damage.

Ultimately, processing temperature is a critical parameter that must be customized per material grade. Insufficient heat can lead to poor flow and incomplete molding, but Excessive heat risks permanent molecular degradation. Achieving the right thermal equilibrium ensures the final product achieves design targets and maintains durability over its intended lifespan.