Flood and Scrape Molding: Complete Guide for Commercial Gummy Production

What Is Flood and Scrape Molding?

Flood and scrape is a high-efficiency depositing method used in commercial gummy, candy, and chocolate production. Instead of filling individual cavities one at a time, the entire mold tray is "flooded" with product material, and a scraper blade passes across the surface to remove excess and level all cavities simultaneously.

This method is the industry standard for high-volume gummy production because it offers:

• Speed: Fill 48-144 cavities in a single pour
• Consistency: All cavities fill at the same time, reducing weight variation
• Efficiency: Minimal operator involvement, ideal for automated production lines
• Waste reduction: Excess material can be collected and reused

How Flood and Scrape Works

The Process Step by Step

1. Position the mold on the depositor conveyor 2. Deposit the product — The depositor nozzles flood the tray with gummy mass, filling all cavities simultaneously 3. Scrape the surface — A blade passes across the tray, removing excess material and leveling all cavities 4. Transport to cooling — The filled tray moves to the cooling chamber 5. Demold the product — Once set, gummies are removed from the cavities

Key Equipment Components

Mold Design Requirements for Flood and Scrape

1. Surface Flatness

The top surface of the mold tray must be perfectly flat. This is critical because:

• The scraper blade rides on this surface to level product across all cavities
• Any warp, bow, or unevenness causes inconsistent product weight
• Surface irregularities create material waste and production delays

Specification: Surface flatness tolerance of ≤0.5mm across the entire tray surface.

2. Cavity Depth Consistency

Every cavity in the tray must have identical depth. Variation in cavity depth directly translates to variation in product weight:

Specification: Cavity depth tolerance of CAD-locked cavity dimensions across all cavities.

3. Structural Rigidity

During the scraping phase, the blade applies downward pressure across the entire tray surface. The tray must resist flexing under this pressure:

• Insufficient rigidity: Tray flexes, causing uneven scraping and variable cavity fill
• Adequate rigidity: Tray remains flat, scraper makes consistent contact, all cavities fill uniformly

Design features for rigidity:

• Structural ribbing between cavity rows
• Reinforced border frames (minimum 25mm width)
• Strategic rib placement that doesn't interfere with depositor nozzles
• Optimal tray thickness (typically 15-25mm depending on tray size)

4. Nozzle Clearance

The cavity layout must provide adequate clearance for your depositor's nozzle array:

• Minimum clearance: 10mm between cavity edge and tray edge
• Nozzle spacing: Layout must match your depositor's nozzle row and column spacing
• Scraper path: No cavities should be positioned where the scraper blade would cause obstruction

5. Pour Gate Design

For optimal fill performance, pour gates should be designed to:

• Distribute material evenly across all cavities
• Minimize air entrapment
• Allow excess material to flow to overflow channels
• Be positioned for easy access by the depositor nozzles

Compatible Depositor Systems

Our flood-and-scrape molds are engineered for compatibility with all major depositor brands:

Mold Architecture for Flood and Scrape

One-Piece (Open) Molds — Recommended

For flood-and-scrape applications, one-piece (open) molds are the standard choice because:

• Cavities are open to the top, allowing direct flooding
• No parting line to interfere with scraper contact
• Higher cavity density possible (up to 144 cavities per tray)
• Simpler design, faster production, lower cost

Two-Piece (Split) Molds — Special Cases

Two-piece molds can be used for flood-and-scrape applications when:

• The product requires 3D detail on all surfaces
• The design includes undercuts
• Regulatory symbols require full encapsulation

Considerations for two-piece flood-and-scrape:

• Parting line must be perfectly flush to maintain scraper contact
• Registration pins must maintain alignment under depositor pressure
• Tray rigidity is even more critical with two-piece construction

Production Optimization

Maximizing Throughput

Reducing Waste

• Overflow channel design — Captures excess material for reuse
• Uniform fill — Prevents partial fills and underweight products
• Consistent scraping — Minimizes material left on tray surface
• Proper durometer — Reduces product damage during demolding

Troubleshooting Flood and Scrape Issues

Issue 1: Inconsistent Product Weight

Issue 2: Partial Cavity Fills

Issue 3: Excess Material Waste

FAQ

Q: Can I use my existing molds with a new depositor? A: Possibly, but we recommend verifying compatibility. Depositor nozzle patterns, scraper width, and tray dimension requirements vary by brand and model.

Q: How do I know if my current molds are suitable for flood and scrape? A: Check if your molds have a flat top surface, consistent cavity depth, and adequate structural rigidity. If you're experiencing weight variation or scraper issues, your molds may need redesign.

Q: What tray size do I need for my depositor? A: This depends on your depositor's specifications. Contact us with your depositor brand, model, and nozzle pattern, and we'll recommend the optimal tray configuration.

Q: Can flood-and-scrape molds be used for hand pouring? A: Yes. While designed for automatic deposition, flood-and-scrape molds work equally well for manual filling. The open cavity design allows easy manual pouring.

*Published: 2026-08-12 | Category: Production Engineering | Read Time: 10 minutes*