Selection Guide for PTFE High-Temperature Tape for Demolding & Anti-Stick Applications of Injection Molding Machines

Jiangsu Aokai New Materials, a professional manufacturer of PTFE and fluoroplastic products, shares the selection criteria of PTFE high-temperature tape for demolding and anti-stick scenarios on injection molding equipment.

I. Temperature-Based Selection: Focus on Heat Resistance of Adhesive Layer and Substrate

PTFE tape consists of two parts: substrate (generally fiberglass fabric coated with PTFE) and backing adhesive. The adhesive layer is usually the performance bottleneck.

1. Continuous operating temperature ≤ 260°C (General plastics & partial engineering plastics)

Applicable materials: PE, PP, PS, ABS, soft PVC, EVA, as well as PA, PBT and other materials processed at lower temperature ranges. Recommended selection: Standard fiberglass-reinforced PTFE tape with silicone pressure-sensitive adhesive (PSA). Suggested thickness: 0.13 mm or 0.18 mm, balancing conformability and service durability. Key notes: This is the optimal working range for PTFE tape, featuring excellent chemical stability and release performance.

2. Continuous operating temperature 260°C ~ 300°C (High-temperature engineering plastics)

Applicable materials: PC, PA66, POM, PET, high-temperature PPA, modified PPO and other high-temperature injection molds. Recommended selection: Fiberglass PTFE tape formulated with high-temperature resistant silicone adhesive. Ordinary silicone adhesive will rapidly age, lose tackiness and leave residues under this temperature range. Suggested thickness: 0.18 mm or 0.25 mm. Thicker adhesive and substrate layers deliver better thermal buffering and wear resistance. Critical confirmation: Specify adhesive systems with long-term temperature resistance above 280°C to suppliers, and verify whether the adhesive will contaminate molds under high heat.

3. Instant peak temperature 300°C ~ 400°C (Special high-temperature plastics or local hot spots)

Applicable materials: PEEK, LCP, PPS, PEI, mainly found near hot runner nozzles and partial extrusion die heads. Selection warning: No reliable pressure-sensitive adhesive can withstand this temperature range. Any adhesive-backed PTFE tape will instantly fail, carbonize and contaminate finished products. Alternative solutions:

1. Adhesive-free PTFE fiberglass fabric, mechanically fixed via mold clamping frames, strips or high-temperature structural adhesives (non-pressure-sensitive adhesives such as silicone sealants).

2. Fusible fully fluorinated PFA film tape, attached to mold surfaces via hot air welding. It withstands continuous 260°C and short-term 300°C exposure, yet cannot be replaced flexibly like self-adhesive tape. Optimized alternative proposal: For such high-temperature conditions, mold PTFE coating or nano ceramic high-temperature resistant coating is more recommended.

II. Material Property-Based Selection: Match Wear Resistance, Corrosion Resistance and Release Requirements

Physical and chemical properties of molten plastic determine the required surface functionality and structural strength of the tape.

1. Highly tacky / mold-prone materials

Representative materials: EVA, hot melt adhesive, TPE, TPU, certain modified PP grades. Selection key points: Choose high-release tape with high PTFE content and dense coating. Prioritize pure PTFE film tape (without fiberglass reinforcement, low tensile strength, only suitable for low-stress areas) or premium fully-impregnated fiberglass PTFE tape. Surfaces closer to pure PTFE deliver superior anti-stick performance.

2. Glass fiber / mineral filled reinforced materials

Representative materials: Glass fiber reinforced PA, PP, PBT, calcium carbonate filled PP. Wear mechanism: Flowing melt acts like liquid sandpaper, rapidly abrading ordinary PTFE coatings; exposed fiberglass substrate will cause adhesion defects. Selection key points:

1. Thickness priority: Select heavy-duty wear-resistant tape of 0.25 mm or thicker.

2. Structural reinforcement: Choose products with multi-layer PTFE coating or surface hardening treatment instead of single thin coating.

3. Replacement strategy: Treat tape as a regular consumable for such working conditions, and set up periodic inspection and replacement cycles instead of pursuing permanent service life.

3. Materials with corrosive or precipitating additives

Representative materials: Hard PVC (releases HCl), flame retardant compounds (brominated, phosphorus-based flame retardant precipitation), fluorinated processing aids. Failure mode: Precipitates erode the adhesive layer or penetrate the substrate, resulting in tape blistering and delamination.

1. Chemical resistance of adhesive: Confirm silicone adhesive has sufficient inertness against weak acids, plasticizers and other precipitates.

2. Dense substrate: Select tape with tightly woven fiberglass and fully sealed PTFE impregnation to prevent gas/liquid penetration that damages the backing adhesive.

3. Venting optimization: Combine mold vacuum extraction or additional vent grooves if necessary to reduce accumulation of precipitates at the tape interface from the source.

4. Static-sensitive materials

Typical scenarios: Electronic component injection molding, high-flow PP film extrusion. Recommended selection: Anti-static PTFE tape (black PTFE tape coated with conductive carbon black or special anti-static layer) to avoid dust adsorption and electrostatic discharge risks.

III. Adaptation Based on Equipment and Application Scenarios

1. Injection mold demolding

Cavities, sliders and lifters: Tape is commonly applied to mold-adhesive areas. Thin 0.13 mm tape with good extensibility is required to fit complex curved surfaces. Avoid ejector pins and vent slots; exercise caution for precision parts as tape thickness will alter product dimensional tolerances. Hot runner plates and nozzle tips: Extremely high temperatures apply here; only mechanically fixed adhesive-free PTFE cloth can be used to prevent flash adhesion. Self-adhesive tape is strictly prohibited.

2. Extruders and downstream equipment

Extrusion die lips / outlets: Prevent melt accumulation and stringing at the discharge port. Select ultra-thin (0.08 mm–0.13 mm) high-release tape to avoid altering die orifice dimensions. Wrap the tape from the front to the end face of the outlet to reduce melt penetration into lap joints. Pelletizer template: Directly exposed to high-temperature melt and glass fiber abrasion. Heavy-duty tape of 0.25 mm or above is mandatory, and managed as a regular consumable. Cast film rolls / traction press rolls: Anti-stick and easy to clean. Silicone-backed PTFE tape can be wrapped around rollers, or adhesive-free PTFE fiberglass sleeves can be adopted. Verify the tape’s temperature resistance matches roller surface temperature if heating is involved.

The above technical content is provided by Jiangsu Aokai New Materials Technology Co., Ltd.

If you wish to obtain detailed specifications, application scenarios and customized solutions for our full product portfolio including PTFE high-temperature cloth, PTFE high-temperature adhesive tape, PTFE high-temperature mesh belt, seamless heat press belt, single-sided PTFE fabric, high-temperature resistant conveyor belt and heat-resistant fiberglass cloth, please contact us via the information below:

· Service Hotline: Mr. Guo +86 18944819998

· Service Hotline: Mr. Liu +86 13705266308

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