How much glue is best for plywood?
Guide: Plywood adhesive refers to the adhesive used for splicing wood products such as laminated wood, and is suitable for plywood bonding of non structural materials and structural materials such as laminated wood.
Plywood glue is a kind of adhesive used for splicing between boards. It will be popularized today. When boards are used for plywood, the amount of glue applied will have the best bonding effect. The cross section of plywood with different glue amount is as follows: large glue amount leads to excessive glue overflow. (Abnormal) The amount of glue is uneven, and there is no glue overflow on one side. (Abnormal) The amount of glue coating is seriously insufficient, and there is no glue overflow. (Abnormal) The glue amount is normal, the glue overflow is reasonable, and the plywood effect is the best! (Normal) Too much or too little gluing on the board is likely to cause cracking of the plywood. Therefore, it is necessary to pay attention to the uniformity of the adhesive coating surface, without leakage, and the amount of double-sided adhesive coating is generally controlled at 200-250g/m ² (Single side 120-150g/m ²）。
Brief Analysis of the Usage and Precautions of Plywood Glue
Guide: Plywood glue refers to the adhesive used for splicing wood products such as laminated wood, mainly used for hardwood species, such as hard maple, ash, red oak, teak, etc.
Usage of plywood adhesive
- The moisture content of wood is 8-12%;
- Ratio: plywood adhesive: curing agent=10:0.8~1 (weight ratio).
- When using, add the curing agent into the glue and stir it evenly. It is best to use it within 1-2 hours. It is normal to find bubbles in use. If there are too many bubbles, you need to stir them several times until the bubbles settle naturally before use.
- Pressure removal: It needs to be pressurized for a long time. Small area plates can be removed 1.5 hours after pressurization, but must be removed 3 hours before moving to the next process.
Eight Precautions for Using Plywood Glue
I Wood control 1. Control of moisture content: below 14%; 2. Keep the splicing surface flat and free of wavy surface or curved or twisted surface. For the wood that is easy to deform (such as oak, ash, etc.), the wood that is planed on the same day must be spliced on the same day, and the wood that is planed overnight must be planed again; 3. The wood dust on the wood surface shall be removed before splicing.
II Mixing method 1. When mixing the curing agent, determine the amount of glue according to the size of the glue container. Only one third of the volume can be used in the glue container, otherwise the glue will react and bubble and overflow. 2. It is better to use a flat bottom round plastic bucket for mixing, which is easy to mix the curing agent evenly. 3. Do not add water or other substances to the glue, otherwise it will cause solidification or sharp drop in strength. 4. The plywood adhesive with curing agent is generally required to be used up within 12 hours (the effect of reuse is more significant after the bubble is raised). 5. The unused curing agent must be strictly sealed and stored, and no water can be mixed in, so as to avoid hardening and scrapping. 6. Once the amount of curing agent is confirmed, it cannot be changed arbitrarily, otherwise it will seriously affect the key functions such as bonding strength and water resistance.
III The control of gelatinizing amount The user shall determine the gelatinizing amount according to the space temperature and humidity at that time of the day. When the space temperature is low, the humidity is high (below 80%), and the wood is hard, the amount of glue should be less; When the space temperature is high, the humidity is low (below 60%), and the wood is soft, more glue should be applied.
IV Due to the large viscosity (consistency) of the glue, it is better to use a manual glue applicator, a pig brush or a rubber scraper to evenly apply the glue, and the size is generally controlled between 150g-250g/m (120g-150g/m for hard miscellaneous wood and 120g-250g/m for soft wood). The workpieces shall be spliced as soon as possible after being coated with glue to prevent the formation of film on the colloid surface, so as to avoid false splicing and easy opening of glue. V No matter what kind of pressurization method and time is used, the multiple points at a pressure point of 30-50cm shall be uniformly pressurized. The time of pressurization shall be controlled according to the temperature and air humidity at the work site. Except that the pressurization time of the disc plywood machine is 30-40 minutes, other pressurization methods are normally defined as 2-4 hours (at 25 ℃, the humidity is below 60%). Under the condition of high temperature and low humidity, the pressing time can be shortened to about one hour; Otherwise, it will take 4 hours or more.
VI During pressurization, check and pressurize to prevent the wooden strip from being drawn out (uneven and small ends are most likely to occur). If it is drawn out, loosen and reset it, and do not forcibly reset it under pressure; Check whether there is glue overflow in the abutted joint. If there is no glue overflow, it means that the amount of glue is not enough or the pressing time is too long after the glue is applied. Correct this phenomenon immediately. The pressurization inspection process cannot be ignored.
VII The curing period after pressure relief is in the process of solid wood plywood or tooth jointing. In order to prevent glue opening, the spliced workpieces shall be stacked for curing after pressure relief. According to the different climate conditions of different woods, a curing time period should be set to ensure the normal use of the next process. We suggest that the best time for yard curing should be 3-5 days when the temperature is low, the humidity is high, and the wood is hard. The best time for stacking curing should be 1-2 days when the temperature is high, the humidity is low, and the wood is soft.
VIII The remaining glue that can not be used up should be sealed for temporary storage until the next time (it should not be exposed to the air for a long time to prevent dry skin), which will not affect the splicing quality.
